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237 Cards in this Set
- Front
- Back
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2 Cavities of Eye
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Anterior cavity and posterior cavity
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2 Divisions of Autonomic Nervous System
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sympathetic and parasympathetic division
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2 Types of Photoreceptors
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rods and cones
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3 Layers of Eye
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Outer layer, middle layer and inner layer
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3 Parts of the Inner Ear
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semicircular canals, vestibule and cochlea
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4 Parts of Brain
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cerebrum, cerebellum, diencephalon and brain stem
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5 Components of Reflex Arc
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receptor, sensory neuron, interneuron, motor neuron and effector (RSIME)
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ACTH (Adrenocorticotropic Hormone)
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controls the secretions of adrenal cortex
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Action Potentials are all or nothing
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if the neuron is stimulated to threshold then an action potiential begins; if the neuron is not stimulated to threshold then there is no action potential; it occurs maximally or not at all
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Action Potentials are Chain Reactions
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they are self propagating; once begun they go all the way to the synaptic end bulb
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Action Potentials are sterotypical
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all action potentials have exactly the same magnitude; if action potentials have the same magnitude how does the nervous system distinguish between strong stimuli and weak stimuli?; strong stimuli result in greater frequency of the nerve impulse and weak stimuli result in lesser frequency of nerve impulse
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ADH (Antidiuretic Hormone)
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Reduces volume of water excreted by kidney; conserves water for the body; decreases urine volume; increases blood volume therefore increases BP
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Adrenal Cortex
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Edge of adrenal gland
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Adrenal Glands
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triangular glands superior to kidney; divided into adrenal cortex and adrenal medulla
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Adrenal Medulla
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middle of adrenal gland
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Aldosterone
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Secretes aldosterone= minerlacorticoid; stimulates kidney to reabsorb Na+ into the blood secrete K+ into the urine; increases blood plasma levels of Na+; decreases blood plasma levels of K+; when Na+ is reabsorbed in blood so is CT and other negatively charged ions; this creates an osmotic gradient and water follows salt into the blood stream; secondary affect of aldosterone as it increases BV and BP
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All Action Potentials are stereotypical
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different responses where the action potential ends up (does it end up at a muscle or gland? Does it end up on the cerebral cortex? What lobe of the cerebral cortex? Does it end in the medulla oblongata
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Amino Acids
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glycine, glutamic acid, aspartic acid and GABA
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Anterior Cavity
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Contains aqueous humor
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Anterior Pituitary Gland
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stimulated by releasing hormones from hypothalamus; secretes GH, PRL, LH, FSH, TSH and ACTH
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Antiduretics
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chemicals that decrease urine production
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Aqueous Humor
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Clear, watery fluid that functions to nourish the cornea and lens
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Arachnoid Mater
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middle layer that forms a web-like structure of fibers that is between the dura mater and the Pia mater; forms a space called subarachnoid space which is filled with CSF
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Ascending Tracts
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carry sensory information to the brain
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Astrocytes
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star shaped; attaches neurons to blood vessels
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Auditory Ossicles
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malleus, incus, stapes; transmit vibrations to the oval window of the inner ear
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Auditory Tube (Eustachian Tube)
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connects middle ear to nasopharynx (throat) and maintains equal air pressure on both sides of the eardrum
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Autonomic Division of Motor
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motor neurons carry information to smooth muscle, cardiac muscle and glands and they contract or secrete; under unconscious, involuntary control; effectors: heart muscle, smooth muscle and glands
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Autonomic Division of Sensory
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sensations are unconsciously perceived, such as heart rate, respiratory rate and blood pressure
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Autonomic Nervous System
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functions independently & continuously without conscious thought; sensations are not sconsciously perceived; controls visceral functions by regulating smooth muscle, cardiac muscle and glands; regulates HR, BP, RR, body temperature; carries out these functions without instructions or interferance from the conscious mind (cerebral cortex); ANS called involuntary nervous system; consist of 2 motor neurons called preganglionic fibers and postganglionic fiber that synapses at ganglion outside CNS
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Autonomic Reflexes
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are visceral reflexes that control smooth muscle, cardiac muscle, and glands to include heart rate, respiratory rate, blood pressure and digestion
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Axon
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a nerve fiber for conducting the impulse away from the cell body to other cells (neurons, muscles or glands); one axon per neuron
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Axon Collateral
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side branch of axon
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Axon Terminals
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branched end portions of an axon
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Bipolar
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2 processes emerge from cell body; found in ear, eye and olfactory mucosa
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Brain
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composed of billions of interneurons
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Broca's Area
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regulates muscles of respiration, tongue, cheeks, lips and jaws to say words (motor area)
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Calcitonin
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decreases blood plasma levels of calcium, stimulates osteoblast which draw Ca out of blood and store Ca in the bone
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Cell Body
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contains nucleus and cytoplasm with mitochondria, ribosomes, lysosomes, Golgi complex and chromatopilic substance in RER also called Nissl bodies; cell membrane receptive to stimulate from other neurons
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Cerebellum
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second largest part of the brain, located below the occipital lobe, has 2 hemispheres with gray matter and white matter; functions below conscious thought
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Cerebellum Receives and Transmits Information
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recevies information on position of limbs and joints; receives information from the cerebral cortex on what limbs and joint are supposed to be doing and the cerebellum integrates and analyzes this information; transmits corrective information to the midbrain that is incorporated with motor commands sent from the cerebral cortex; this smoothes out muscle activity; cerebellum mediates myuscle tone and posture; maintains balance (information sent from inner ear)
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Cerebral Cortex
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thin layer of gray matter on outermost part of cerebrum; contains 75% of all neuron cell bodies in the nervous system
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Cerebral Spinal Fluid
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circulates within the subarachnoid space and the central canal; lumbar puncture or spinal tap occurs below the 4th lumbar vertebra to prevent injury to the spinal cord
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Cerebrum
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largest part of the brain; made up of 2 hemispheres (left and right)
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Characteristics of Action Potentials
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action potentials are all or nothing; actions potentials are stereotypical; all action potentials are stereotypical; action potentials are chain reactions; action potentials travel in only one direction down the axon; action potentials travel from pre-synaptic to post-synaptic neuron
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Characteristics of Endocrine System
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both nervous and endocrine systems coordinate and regulate body activities; nervous system does it with nerve impulses (instantaneous)
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Chemoreceptors
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respond to changes in chemical concentration
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Choroid Coat
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loosely joined to sclera; contains BV that nourish sclera and retina; contains melanocytes that produce melanin so this membrane is black and absorbs excess light
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Ciliary Body
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Secretes aqueous humor into the anterior cavity; extends forward from choroids coat and forms a ring around the front of eye; contains ciliary muscles that control the shape of the lens and suspensory ligaments that attach ciliary body to the lens (functions to focus)
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Cochlea
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contains organ of Corti = organ for hearing; transmits impulses via cochlear branch of vestibulocochlear nerve to temporal lobe for sensation of hearing
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Cones
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stimulated in bright light, see sharp edges; color
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Conjunctiva
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Mucous membrane that lines inner surface of eyelid and part of the eyeball except cornea
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Convolutions or Gyri
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ridges
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Cornea
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Transparent, avascular (no BV); window of eye; focuses entering light rays
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Corpus Callosum
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area where axons connect the 2 hemisphere
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Cortisol (Hydrocortisone)
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secretes cortisol = a glucocorticoid; increases blood plasma levels of glucose three ways; inhibits protein synthesis, promotes FA release from adipose tissue, stimulates conversion of glycogen to glucose
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Cranial Reflexes
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integration occurs in the brain (doesn't include cerebral cortex)
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Dendrites
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a nerve fiber (Dendron: tree or branches); can be highly branched; conducts impulse to cell body; sensory organs for receiving the stimuli from the environment or other neurons
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Depolarization
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Na+ channels open; Na+ rushes into the cell driven by concentrating gradient and attraction of negative ions; depolarization of the membrane occurs; now Na+ and K+ inside the neuron and positive charge on inside of neuron and negative on outside of neuron; charges have reversed
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Descending Tracts
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carry motor information from the brain
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Diuresis
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to urinate
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Diuretics
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Chemicals that increase urine production
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Division of Nervous System
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central (CNS) and peripheral (PNS) nervous systems
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Divisions of Peripheral Nervous System (PNS)
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sensory and motor division
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Dura Mater
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tough, white, outermost membrane that is fibrous CT that contains many blood vessels and nerves; inside cranial cavity and replaces periosteum; in the vertebral canal it surrounds spinal cord next to epidural space
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Dural Sinus
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is a blood vessel formed when dura mater splits open and where CSF reenter the blood stream
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Effector
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muscle contracts or gland secretes thus causing the response that is called the reflex (behavior)
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Ependymal Cells
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epithelial cells with cilia that line the ventricles of the brain and central canal of the spinal cord; cilia beat rhythmically to aid in circulation of CSF
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Epidural Space
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lies between vertebra and dura mater; contains loose connective tissue and adipose tissue and blood vessels and acts as a protective pad around spinal cord
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Equilibrium
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Ears
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Excitatory Neurotransmitter
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bring the postsynaptic neuron closer to threshold; may trigger a nerve impulse
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Eyelid
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Contains skin, muscles, CT and congunctiva
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Fissures
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deep grooves
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Four Lobes of Cerebrum
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frontal, parietal, temporal and occipital
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Free Nerve Ending
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Extend into the epidermis
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Frontal Lobe
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behind the frontal bone; primary motor area (cortex) controls voluntary skeletal muscles; association areas for carrying out higher intellectual processes such as problem solving, concentration, memory, thinking in the abstract, judgment, creativity, this is your personality
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FSH (Follicle-Stimulating Hormone)
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gonadotropin because exerts effect on gonads; in males: stimulates spermatogenesis; in females: stimulates follicular cells around the egg to divide and then produce estrogen
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Function of Cerebrum
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provides "higher" brain functions; conscious thought and intellectual function; stores information as memory; retrieves stored memory as information in reasoning; seat of intelligence, creativity, and personality; receives somatic sensory information; processes sensory information; sends motor commands; interprets impulses from sense organs; initiates voluntary muscular movement
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Functions of Cerebellum
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integrates sensory information concerning positions of body parts; coordinates skeletal muscle activity; maintains posture
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Functions of Nervous System
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sensory, integrative, motor
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Functions of Spinal Cord
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conducting nerve impulses and serving as a center for spinal reflexes (reflex arc)
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Ganglia
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group of cell bodies of sensory neurons in PNS
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GH (Growth Hormone)
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Stimulates cells to increase in size and divide
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Glucagon
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increases blood plasma levels of glucose, stimulates liver to breakdown glycogen and release glucose into the blood
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Hearing
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Ears
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Hormones
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steroid or nonsteriod hormones
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Hormones of Adrenal Cortex
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aldosterone and cortisol (hydrocortisone)
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Hormones of Adrenal Medulla
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Epinephrine and norepinephrine= adrenalin or noradrenalin; effects resemble sympathetic neurons stimulating effectors; increases HR, RR, BP, dilates bronchioles and BV going to muscles, constricts BV going to urinary, digestive and reproductive system; functions with sympathetic nervous system in "fight or flight"
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How Endocrine System Works
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Endocrine system does it with hormones that are secreted from endocrine glands and move into the bloodstream which carries the hormone to its target cell; may take minutes or days
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Hypothalamus
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located in nervous system; connects nervous system to endocrine system; producing releasing hormones that stimulate the anterior pituitary or inhibiting hormones that inhibit the anterior pituitary; produces ADH and OT that are stored in posterior pituitary; functions to maintain homeostasis by regulating: HR and BP, body temperature, water and electrolyte balance, controls hunger and body weight, controls movement and secretions of the GI tract, produces hormones to stimulate the pituitary gland, and sleep and wakefulness
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Inhibitory Neurotransmitter
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makes the postsynaptic neuron less likely to reach threshold; may trigger a nerve impulse
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Inner (Internal) Ear
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complex system of connecting tubes and chambers called a labyrinth; fluid filled
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Inner Layer
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nervous layer = retina; contains retina, rods, cones, macula Lutea and optic disc
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Inside Macula Lutea
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Fovea Centralis= Contains only cones for sharpest, color vision
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Insulin
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decreases blood plasma levels of glucose, stimulates liver to absorb glucose and convert glucose into glycogen for energy storage, stimulates muscle cells to absorb glucose and convert glucose into glycogen for energy storage; insulin is antagonistic to glucagon
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Integrative Functions
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carried out by interneurons; located in brain and spinal cord and gather and put the information together to store in memory, produce thoughts, create sensations of the detected change; we make conscious or subconscious decision and use motor neurons to act on them
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Interneurons
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carry impulses from 1 interneuron to another interneuron within the CNS or forms links between sensory and motor neurons; are multipolar and located in CNS
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Iris
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colored part of eye that dilates and constrict to regulate amount of light coming into eye
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Knee Jerk Reflex
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somatic reflex; 2 neurons required (sensory and motor); effector = skeletal muscle; functions to maintain upright posture
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Labyrinth
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complex system of connecting tubes and chambers
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Lacrimal Apparatus
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Lacrimal gland and ducts; lacrimal gland secretes tears through ducts to nasal cavity
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Layers of Meninges
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dura mater, arachnoid mater, and Pia mater
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Lens
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separates eyeball into the anterior and posterior cavities
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LH (Luteinizing Hormone)
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In male called interstitial cell stimulating hormone = ICSH; gonadotropin because exerts effect on gonads; in males; stimulates interstitial cells to secrete testosterone; in females; stimulates follicular cells around the eggs to divide and then produce estrogen
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Limbic System
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located within diencephalon; emotional or feelings brain; allows a person to recognize emotions in others; communication between cerebral cortex and limbia system explains why sometimes emotions override logic or conversely why reason can stop us from expressing our emotions inappropriately
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Macula Lutea
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Yellow spot on retina
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Major Endocrine Glands
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Pituitary gland, pineal gland, thyroid gland, parathyroid glands, thymus gland, adrenal glands, pancreas, ovaries/testes
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Mechanoreceptors
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respond to changes in pressure or movement
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Medulla Oblongata
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blends into the spinal cord at the foramen magnum; about 3 inches long and about the size of a thumb; all ascending and descending tracts pass through here between the brain and spinal cord; where crossing over occurs which results with the right cerebral hemispheres controlling the voluntary movements of the left side of the body and vise-versa
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Meissner's Corpuscles
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Sensory dendrites located in small, oval, flattened CT that respond to light touch
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Membranous Labyrinth
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tube lies inside osseous labyrinth and contains endolymph
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Microglial Cells
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brain macrophages (WBCs); move around in CNS and engulf cell debris, waste products, and pathogens
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Midbrain
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contains visual and auditory reflex centers (known as startle reflex) where you turn your head and trunk to the direction of the visual of auditory stimuli. Protective reflex
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Middle Ear (Tympanic Cavity)
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air filled space in temporal bone that contains auditory ossicles
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Middle Layer
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Vascular Layer; contains choroid coat, ciliary body, iris and pupil
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Monoamines
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norepinephrine (NE) or epinephrine (E), (adrenaline or noradrenaline), dopamine, serotonin
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Motor Division of PNS
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motor neurons carry out commands to interneurons to stimulate muscles and glands
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Motor Functions
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carried out by motor neurons; carry nervous impulses from brain/spinal cord to effectors
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Motor Neurons
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carry outgoing impulses from CNS to effectors (muscles or glands); are multipolar and located in PNS
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Multipolar
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many processes emerge from the cell body; all motor neurons and most interneurons
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Na/K Ion Pump
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after many action potentials Na/K pumps moves Na+ to the outside of the neuron and K+ to the inside of the neuron and membrane is back to original resting membrane potential
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Negative Feedback
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As a result to negative feedback; hormone concentrations remain stable even through they may fluctuate slightly above or below average concentrations; as the substance (product) the hormones controls increases, then the accumulation of product inhibits the hormone being produced; endocrine gland turks off; as the substance (product) the hormone controls decrease, the lack of product removes the inhibition of the hormone being produced and the endocrine gland turns back on
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Nerve
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cord-like bundle of axons in PNS
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Nerve Pathway
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routes that nerve impulses travel in the nervous system
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Nerve Tracts
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two-way conduction paths to and from the brain
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Nervous System
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functions to coordinate and regulate all body activities to maintain homeostasis with the endocrine systems
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Neurilemma
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portion of Schwann Cell that contains nucleus and cytoplasm; may allow regeneration of axon in PNS
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Neuroglia Cells found in PNS
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Schwann Cells
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Neuroglial Cells Found in the CNS
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Oligodendrocytes, Astrocytes, Microglial Cells, Ependymal Cells
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Neurons
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nerve cells that transmit nerve impulse; basic structual and functional unit; has 3 parts: cell body, dendrites and axons
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Neuropeptides
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endorphins
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Neurotransmitters
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Acetylcholine (Ach), Monoamines, Amino Acids, and Neuropeptides
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Nodes of Ranvier
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spaces between two adjacent Schwann Cells
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Nonsteroid Hormones
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synthesized from amino acids; bind to receptors on target cell's membrane and cause a change to occur in the target cell's cytoplasm to carry out specific effects associated with the hormone
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Nuclei
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groups of cell bodies of interneurons in CNS
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Occipital Lobe
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behind the occipital bone; sensory area for vision; association area for visual recognition of objects and faces
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Oligodendrocytes
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forms myelin around axon; can myelinate up to 15 axons (octopus style); does not contain a neurilemma; none or little regeneration of axons in the CNS
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Optic Disc
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Blind spot; no rods and cones located here because it is the beginning of optic nerve; nervous impulse down optic nerve to occipital lobe
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Osseous Labyrinth
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carved out of the temporal bone and contains perilymph
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OT (Oxytocin)
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stimulates contraction of smooth muscle in uterus during childbirth and orgasm; stimulates milk ejection or milk letdown
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Outer Ear
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Funnel-like structure called auricle; contains external acoustic meatus that leads to tympanic membrane
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Outer Layer
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Fibrous layer contains the cornea and sclera
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Pacinian Corpuscles
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dendrites located in larger, oval structures in dermis, subcutaneous layer, tendons and ligaments; respond to heavy pressure
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Pain Receptors
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repsond to tissue damage
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Pancreas
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Located posterior to stomach and medial to spleen, both and endocrine and exocrine gland, hormones secreted from pancreatic Islets, pancreatic Islets= Islets and Langerhans, secretes glucagons and insulin
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Parasympathetic Division
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called craniosacral division because preganglionic fibers exit from cranial nerves (cranium) and sacrum; called "resting and digesting", "rest and restore", "feed and breed" because it restores the body and is concerned with normal digestion and elimination; returns body to normal by: lowering HR, RR, BP, return to normal glucose levels in blood, restores glycogen to liver and muscle cells, bronchioles and BV return to normal diameter, digestive, urinary and reproductive systems return to normal functions
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Parathyroid Glands
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4 small glands on the posterior thyroid gland; secretes PTH (parathyroid hormone); increases blood plasma levels of calcium three ways: Stimulates osteoclast which demineralize bone and release Ca into blood plasma, stimulates kidney to reabsorb Ca into the blood; stimulates intestines to absorb Ca into the blood; calcitonin and parathyroid hormone are antagonistic hormones
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Parietal Lobe
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behind the parietal bone; primary sensory area (cortex) for all incoming; sensory info from skin; sensory area for taste; association area for understanding speech and choosing words to express thoughts and feelings
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Parts of Brain Stem
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midbrain, pons, and medulla oblongata
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Parts of Diencephalon
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thalamus and hypothalamus
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Parts of Neurons
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cell body, dendrites and axons
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Pathway of Tears
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Lacrimal gland- superior and inferior canaliculi. Lacrimal sac- nasolacrimal duct- nasal cavity
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Peripheral Nervous System (PNS)
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consist of cranial nerves and spinal nerves that branch out of CNS to muscle and glands; broken down into 2 parts: somatic and autonomic nervous systems
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Photoreceptors
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respond to changes in light
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Pia Mater
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innermost membrane; thin layer of loose connective tissue that is transparent and extends into every fold and curve of brain and spinal cord; it contains many blood vessels that nourish brain and spinal cord
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Pineal Gland
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located in posterior part of brain, secretes hormone melatonin in response to light, in dark melatonin secretions increase which induces sleep, melatonin controls sleep/wake cycles or circadian rhythms
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Pituitary Gland
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Small gland about the size of a grape; located in sella turcica of sphenoid bone; divided into 2 major portions called the anterior pituitary gland and posterior pituitary gland
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Pons
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means bridge; contains tracts that course in 2 directions from the cerebrum, cerebellum and brain stem; part of respiratory center is located here
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Posterior Cavity
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Contains vitreous humor
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Posterior Pituitary Gland
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Stores and secretes ADH and OT; ADH and OT are produced in the cell body of the neurons located in the hypothalamus; move down axons to the posterior pituitary gland, are stored in synaptic end blubs in the posterior pituitary glands; a nervous impulse from hypothalamus stimulates the posterior pituitary gland to secrete ADH or OT
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Postganglionic Fibers of Parasympathetic Division
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called cholinergic fibers because they secrete ACh at the visceral organ
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Postganglionic Fibers of Sympathetic Division
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called adrenergic fibers because they secrete norepinephrine (nonadrenalin) at the visceral organ
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Postsynaptic Cell
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receives the message from the presynaptic cell by way of the neurotransmitter; can be either a neuron of an effector (muscle or gland)
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Preganglionic Fibers of Parasympathetic Division
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called cholinergic fibers because they secrete ACh at the synapse at the ganglion
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Preganglionic Fibers of Sympathetic Division
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called cholinergic fibers because they secrete ACh at the synapse in the ganglion
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Presynaptic Cell
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neuron with synaptic knobs & secretes neurotransmitters
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PRL (Prolactin)
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stimulates and sustains milk production
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Projection
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at the same time the cerebral cortex forms the sensation it causes the feeling to seem to come from the stimulated receptors; it projects the sensation to its apparent source
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Pupil
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Circular opening in iris
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Receptor
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detects stimulus and sends impulse to sensory neuron
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Receptors for Somatic Senses
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touch, pressure, temperature, pain are widely scattered throughout skin
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Receptors for Special Senses
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smell, taste, hearing, equilibrium and vision
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Referred Pain
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Visceral pain may feed as if it is coming from some part of the body other than the part being stimulated
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Reflex
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rapid, automatic, unconscious responses to stimulus; unlearned, involuntary, "built in"; stereotypical behavior = show little variability in response
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Reflex Arc
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simplest of a nerve pathway (few neurons); may involve only two neurons: sensory and motor; may involve only three neurons: sensory, interneuron, and motor
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Repolarization
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Na+ channels close and K+ channels open; Na+ stays in the neuron and K+ rushes out of the cell driven by concentration gradient and attraction to negative ions; repolarization begins with K+ and positive charges on the outside of neuron and Na+ and negative charges on the inside of the neuron
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Reticular Formation
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located in brainstem; also called reticular activating system (RAS) when sensory impulses reach RAS it activates the cerebral cortex to wakefulness; decreased activity of RAS = sleep; it RAS is injured, person is unconscious = comatose state "knocked out"
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Retina
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Contains visual receptors called photoreceptors
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Rods
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Stimulated in dim light; sees shapes; black and white
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Schwann Cells
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forms layers of myelin around axon (myelin sheath); fat layer insulates axon and increases speed; myelin around axon = white matter; up to 500 Schwann Cells can myelinate a long axon
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Sclera
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white portion of eye; collagenous and elastic fibers of CT; protects eye
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Semicirular Canals
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contains crista ampullaris = organ for dynamic equilibrium; transmits impulses via vestibular branch of vestibulocochlear nerve to cerebellum for balance
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Sensation
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feelings that occur when brain interprets sensory impulses; all nerve impulses are stereotypical; the resulting sensation depends on which region of brain receives stimulus
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Sense of Hearing
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organ for hearing (ear) has three parts: outer ear, middle ear (tympanic cavity), inner (internal) ear
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Sense of Pain
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Free nerve endings (dendrites); widely distributed in skin, internal tissues, nervous tissue lacks pain receptors, pain receptors do not adapt
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Sense of Sight
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eye = organ that contains photoreceptors to provide vision; accessory organs = protect and assist the eye
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Sense of Smell
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Olfactory organs located on superior nasal conchae; contain olfactory receptors, are chemoreceptors, send nerve impulse to olfactory bulbs on either side of crista galli, form olfactory nerve (cranial nerve 1), impulse goes to temporal lobe and limbic system, can have emotional response to smells, olfactory receptors adapt readily
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Sense of Taste
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"taxare" Latin for estimate or judgment, taste buds organs for taste, taste buds contain taste cells= gustatory receptors, impulse goes to parietal lobe for taste sensation, gustatory receptors adapt readily
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Sensory Adaptation
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the ability to ignore unimportant stimuli; brain must prioritize the sensory inputs it receives or you would be in sensory overload; it does this by having receptors becoming unresponsive or inhibited the sensory impulse along the nervous pathway to the cerebral cortex
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Sensory Division of PNS
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respond to sensory information in the external and internal environments and delivers the sensory information to the CNS (brain and spinal cord)
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Sensory Functions
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carried out by sensory neurons; detect changes in environment; monitors changes in light, sound, heat, pain, blood pressure, heart rate, respiratory rate; sends nervous impulse toward the brain and spinal cord
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Sensory Neurons
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carry impulses from internal and external environment to CNS; most are unipolar and located in PNS
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Sight
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Eyes
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Smell
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Olfactory organs
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Somatic Division of Motor
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motor neurons carry information to skeletal muscle and they contract; under conscious, voluntary control; effector: skeletal muscle
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Somatic Division of Sensory
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sensations are consciously perceived, such as taste, smell, sight and touch
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Somatic Nervous System
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consist of cranial and spinal nerves that connect skeletal muscles; sensations are consciously perceived: touch, temperature, pressure, sight, hearing, smell, position and movement of skeletal muscles; actions carried out are conscious and voluntarily controlled; 1 motor neuron carries commands to skeletal muscles under conscious, voluntary control
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Somatic Reflexes
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provide a mechanism for involuntary contraction of skeletal muscles to include withdrawal from pain, suckling, blinking, and knee jerk (patellar reflex)
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Somatic Senses
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Associated with receptors in skin, muscles, joints and visceral pain; Senses associated with body surface such as touch, pressure, temperature and pain; senses associated with changes in muscles and tendons; senses associated with pain in the viscera
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Special Senses
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Sensory receptors are located in organ in head
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Spinal Cord
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slender nerve column within the vertebral column which begins at the foramen magnum and terminates at the second lumbar vertebrae; consist of 31 segments that give rise to 31 pairs of spinal nerves which exit through the intervertebral foramina and "connect" the body parts with the CNS; myelinated nerve fibers (axons) form major nerve pathways in the spinal cord called nerve tracts
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Spinal Reflexes
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integration occurs in the spinal cord
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Steroid Hormones
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Synthesized from cholesterol; diffuse through the target cell's membrane and moves into the nucleus of the cell; target a gene on the cell's DNA, which stimulates protein synthesis for a particular protein; proteins then carry out specific effects associated with the hormone
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Sulci
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shallow grooves
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Sympathetic Division
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called thoracolumbar division because preganglionic fibers exit from the thoracic and lumbar vertebrae; called the "emergency division", "fight or flight", or division "E" for exercise, excitement, emergency, embarrassment; prepares the body for an emergency by: increasing HR, RR, BP, glucose levels, dialates pupils, bronchioles and BV going to skeletal muscles, and constricts BV going to digestive, urinary, reproductive systems
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Synaptic Cleft or Gap
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space between two communicating neurons or between motor neuron and effector (muscle or gland)
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Synaptic Knob
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enlarged region at the end of the axon terminal that contains synaptic vesicles
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Synaptic Transmissions
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movement of impulse from presynaptic to postsynaptic neuron; movement of impulse from presynaptic neuron to effector
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Synaptic Vesicle
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membrane-enclosed sac filled with neurotransmitter such as acetylcholine or norepinephrine
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T3 (Triiodothyonine)
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Regulates MBR, increasing secretions increase MBR, contains 2 atoms of iodine, deficiency in iodine can cause goiter
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T4 (Thyroxine) (Tetraiodothyronine)
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regulates MBR, increasing secretions, increase MBR, contains 4 atoms of iodine, deficiency in iodine can cause goiter
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Target Cells
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contain receptors that the hormone will bind to; hormones secreted from endocrine glands that includes cells, tissues or organs
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Taste
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Taste Buds
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Temperature Senses
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2 types of free ending: Warm receptors and cold receptors, which adapt rapidly (within minutes)
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Temporal Lobe
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behind the temporal bone; sensory areas responsible for hearing and association of recognized auditory patterns such as sound, music, or noise (rhymes); association area for reading; smell
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Thalamus
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central relay station for all incoming sensory impulses on their way to the cerebral cortex; relays visual impulses to occipital lobe, and auditory impulses to temporal lobe; may suppress unimportant sensations to permit the cerebrum to concetrate on important tasks
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Thermoreceptors
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respond to changes in temperature
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Thymus Gland
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located anterior to heart and aorta, reaches its maximum size during puberty and shrinks with age, secretes thymosins that increase production of certain WBC
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Thyroid Gland
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Located inferior to larynx and anterior trachea; secretes three hormones; T3, T4 and calcitonin
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Touch and Pressure Senses
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Free nerve ending, Meissner's corpuscles, pacinian corpuscles
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Tract
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cord-like bundle of axons in CNS
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TSH (Thyroid-Stimulating Hormone)
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Controls the secretions of thyroid gland
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Tympanic Membrane
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ear drum; cone shaped, semitransparent membrane with apex of structure pointing inward; sound waves cause tympanic membrane to vibrate
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Types of Cells in Nerve Tissue
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neuron and neuroglial cells
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Types of Neuroglial Cells
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Schwann Cells, Oligodendrocytes, Astrocytes, Microglia Cells and Ependymal Cells
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Types of Neurons
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unipolar, bipolar and multipolar
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Types of Receptors
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chemoreceptors, pain receptors, thermoreceptors, mechanoreceptors, photoreceptors
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Unipolar
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only 1 process emerges from the cell body (sensory neurons)
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Ventricles
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cavities within cerebrum and brainstem that contain CSF
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Vestibule
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contains macula = organ for static equilibrium; transmits impulses via vestibular branch of vestibulocochlear nerve to cerebellum for balance
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Visceral Pain
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Only receptors in viscera whose stimulation produces a sensation
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Visual Accessory Organs
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Eyelid and Lacrimal Apparatus
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Vital Sign Center
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respiratory center: controls the rate and depth of breathing; cardiac center: adjusts force and rate of heart contractions; vasomotor center: regulates blood pressure
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Vitreous Humor
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Clear, jelly-like material that functions to keep the retina attached to the choroid coat
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What Are Sensory Receptor?
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can be free ends of dendrites, can be specialized cells, can be mulit-cellular structures that collect information; sensory receptors stimulate sensory neurons to send impulses to the brain or spinal cord; the adjustment of a sensory neuron to a continous stimulation is sensory adaption
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White Matter
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in the spinal cord consists of myelinated ascending and descending tracts
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Withdrawal Reflex
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somatic reflex; three neurons required (sensory, interneurons and motor); effector = skeletal muscle; functions to protect by limiting tissue damage
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