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210 Cards in this Set
- Front
- Back
Cerebral Cortex |
the outer layer of gray matter of the cerebrum |
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Cerebrum |
-controls intelligence & conscious thought, reasoning, judgment -interprets senses -controls complex muscle pattern -each hemisphere connects to the contralateral side of the body -memory storage/retrieval |
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Functional Areas of the Cerebrum |
-motor areas -sensory areas -association areas |
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Motor Areas |
-control voluntary movement -includes: two cortexes, Broca's area, frontal eye field |
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Primary Motor Cortex |
allows conscious control of precise, skilled, voluntary movements |
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Premotor Cortex |
controls learned, repetitious, or patterned motor skills; movements that depend on sensory feedback |
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Broca's Area |
a motor speech area that is in charge of speech control |
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Sensory Areas |
-conscious awareness of sensation -includes: primary somatosensory cortex, somatosensory association cortex, visual cortex, auditory cortex, olfactory cortex, gustatory cortex, visceral sensory area, vestibular cortex |
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Primary Somatosensory Cortex |
receives sensory information from the skin, skeletal muscles and joints |
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Somatosensory Association Cortex |
integrates sensory input from another cortex regarding size, texture, and relationship of objects |
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Vestibular Cortex |
responsible for conscious awareness of balance (position of the head in space) |
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Association Areas |
integrate diverse information |
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Diencephalon |
posterior part of the forebrain, containing the thalamus, hypothalamus, and the epithalamus |
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Thalamus |
relay and processing centers for sensory information |
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Hypothalamus |
centers controlling: -emotion -autonomic functions -hormone production |
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Epithalamus |
represented mainly by the pineal gland, which synthesizes melatonin and enzymes sensitive to daylight |
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Brain Stem |
-consists of the medulla oblongata, pons, and midbrain -houses many of the control centers for vital body functions, such as consciousness, breathing, and heart rate -all of the cranial nerves, except those associated with olfaction and vision, are located here |
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Mid-Brain |
-maintains alertness
-contains visual and auditory reflex centers to protect the head |
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Pons |
regulates respiration rate (maintains rhythm of breathing and transition between inhalation and exhalation)
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Medulla Oblongata |
-regulates breathing rhythm, heart rate and blood flow -autonomic reflex centers: vomiting, sneezing, hiccuping, and swallowing -connects brain to spinal cord |
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Cerebellum |
-coordinates subconscious skeletal muscle--maintains balance and posture (ex: moving an object) posture balance coordination of movement |
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Frontal Lobe |
-decision making -problem solving -deliberate movements -consciousness -emotions (behavior, personality, mood) |
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Parietal Lobe |
-processing sensory information -body orientation -attention |
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Occipital Lobe |
-visual processing
-object recognition |
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Temporal Lobe |
-hearing
-language comprehension -speech |
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Insula Lobe |
-emotion
-body's homeostasis |
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Functional Brain Systems |
networks of neurons that work together but span relatively large distances in the brain, so they cannot be localized to specific regions
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Limbic System |
-in parts of the cerebrum, hypothalamus, and brain stem
-emotion centers, memories, links conscious thoughts to unconscious functions
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Main Functions of the Meninges |
-protecting the brain and spinal cord from mechanical injury
-providing blood supply to the skull and to the hemispheres -providing a space for the flow of cerebrospinal fluid |
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Dura Mater |
-outermost and toughest layer
-covers the brain and the spinal cord -responsible for keeping in the cerebrospinal fluid |
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Arachnoid Mater |
-thin, web-like membrane
-protective layer to the brain |
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Pia Mater |
-composed of fibrous tissue -protects central nervous system by containing the cerebrospinal fluid |
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Cerebrospinal Fluid |
-protects the brain from shock and injury -transports nutrients and waste to and from the cells |
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How does the cerebrospinal fluid move through the brain and spinal cord? |
absorbed through blood vessels over the surface of the brain back into the bloodstream |
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Blood Brain Barrier |
highly selective permeability barrier that separates the circulating blood from the brain's extracellular fluid in the central nervous system |
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White Matter |
-myelinated fibers and their tracts -responsible for communication |
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Dorsal Median Sulcus |
-located on a groove in the dorsal side of spinal cord -divides spinal cord in half |
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Gray Matter |
consists of nerve cell bodies, dendrites, and axons called the nucleus |
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Gray Commissure |
-located on the middle portion of gray matter -communicates between left and right side of body |
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Dorsal Horn |
-located on the dorsal part of gray matter -interneurons that receive somatic and visceral sensory input |
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Ventral Horn |
-located on the part of gray matter, contains somatic motor nuclei -transmission of neural signals -somatic motor neurons whose axons exit the cord via ventral roots |
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Lateral Horn |
-located on the lateral side of gray matter on spinal cord -transmission of neural signals -only in thoracic and lumbar regions -sympathetic neurons |
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Ventral Median Fissure |
-located on the more open ventral fissure of white matter in spinal cord -divides spinal cord in half |
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Dorsal Root Ganglion |
-located on an enlarged area of the dorsal root -contains cell bodies of neurons |
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Dorsal Root |
contain sensory (afferent) fibers from sensory neurons in the dorsal root ganglia |
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Ventral Root |
contain motor (efferent) fibers from the ventral horn motor neurons |
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Ascending Tracts |
carry sensory information up the spinal cord |
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Descending Tracts |
carry motor information down the spinal cord
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Transverse Tracts |
-commissural fibers -cross from one side to the other |
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First-order Neurons |
conducts impulses from cutaneous receptors and proprioceptors to spinal cord |
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Second-order Neurons |
-interneurons -axons extend to thalamus or cerebellum |
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Third-order Neurons |
axon extends to somatosensory cortex from the thalamus |
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Left Hemisphere Controls... |
-language -math -liner thinking process |
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Right Hemisphere Controls... |
-visual-spatial skills -parallel thinking processes |
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Declarative Memory |
-factual knowledge -explicit information, stored in long-term memory with context in which it was learned |
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Non-declarative Memory |
-less conscious or unconscious -acquired through experience and repetition -includes procedural memory, motor memory, and emotional memory |
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Choroid Plexus |
-produces cerebrospinal fluid -forms the blood-cerebrospinal fluid barrier -network of blood vessels in each ventricle of the brain -part of the epithalamus |
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Basal Nuclei |
-grey matter lying deep in the cerebral hemispheres -influenced by muscular control and attention & cognition |
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Absence Seizures |
mild seizures in which the expression goes blank |
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Tonic-Clonic Seizures |
victim loses consciousness and may break bones, experience loss of bowel & bladder control, and severe biting of the tongue |
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Alzheimer's Disease |
a progressive degenerative disease of the brain that results in dementia |
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Parkinson's Disease |
loss of the dopamine-releasing neurons of the substantia nigra of the midbrain |
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Huntington's Disease |
a fatal hereditary disorder caused by accumulation of the protein huntingin that leads to degeneration of the basal nuclei and the cerebral cortex |
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Parasthesia |
sensory loss |
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Flaccid Paralysis |
impulses do not reach muscles; there is no voluntary or involuntary control of muscles |
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Spastic Paralysis |
spinal neurons remain intact, muscles are stimulated by reflex activity |
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Poliomyelitis |
-destruction of the ventral horn motor neurons by the poliovirus -muscles atrophy -death may occur to paralysis of respiratory muscles or cardiac arrest |
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Amyotrophic Lateral Sclerosis (ALS) |
-Lou Gehrig's disease -involves progressive destruction of ventral horn motor neurons -symptoms: loss of the ability to speak, swallow, and breathe |
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Sensation |
the awareness of changes in the internal and external environment |
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Perception |
the conscious interpretation of the meaning of the stimuli |
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Endoneurium |
loose connective tissue that encloses axons and their myelin sheaths |
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Perineurium |
coarse connective tissue that bundles fibers into fascicles |
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Epineurium |
tough fibrous sheath around the nerve |
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Ganglia |
contain neuron cell bodies associated with nerves -dorsal root ganglia (sensory, somatic) -autonomic ganglia (motor, visceral) |
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I Olfactory Nerve |
type: sensory -smell |
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II Optic Nerve |
type: sensory -vision |
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III Oculomotor Nerve |
type: motor -eye movement -pupil constriction |
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IV Trochlear Nerve |
type: motor -eye movement |
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V Trigeminal Nerve |
type: both sensory and motor -somatosensory information (touch, pain) from the face and head -muscles for chewing |
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VI Abducens Nerve |
type: motor -moves (abducts) eye |
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VII Facial Nerve |
type: both sensory and motor -controls muscles used in facial expression -somatosensory information from ear -taste (anterior 2/3 of tongue) |
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VIII Vestibulocchlear Nerve |
type: both sensory and motor, but heavily sensory -hearing -balance -equilibrium |
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IX Glossopharyngeal Nerve |
type: both sensory and motor -taste (posterior 1/3 of tongue) -gag reflex |
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X Vagus Nerve |
type: both sensory and motor -gag reflex -parasympathetic innervation -autonomic functions of viscera (glands, digestion, heart rate) |
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XI Accessory Nerve |
type: both sensory and motor -shoulder shrug -controls muscles used in head movement |
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XII Hypoglossal Nerve |
type: both sensory and motor -swallowing -speech |
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Cervical Plexus |
-formed by ventral rami of C1-C4 -innervates skin and muscles of the neck, ear, back of head, and shoulders |
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Phrenic Nerve |
origin: C1-C5 plexus: cervical function: motor nerve to diaphragm |
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Musculocutaneous Nerve |
origin: C5-C7 plexus: brachial function: flexion of the arm at the elbow and supination of the forearm |
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Median Nerve |
origin: C5-C8 and T1 plexus: Brachial function: muscles involving fine precision and pinch function of hand |
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Ulnar Nerve |
origin: C8 and T1 plexus: brachial function: muscles involving grasping function |
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Radial Nerve |
origin: C5-C8 and T1 plexus: brachial function: extension of wrist, fingers, and thumb against resistance |
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Axillary Nerve |
origin: C5 and C6 plexus: brachial function: abduction of arm at shoulder beyond the first 15 degrees |
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Lumbar Plexus |
-arises from L1-L4 -innervates the thigh, abdominal wall, and psoas muscle |
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Femoral Nerve |
origin: L2-L4 plexus: lumbar function: leg flexion at the hip, leg extension at the knee |
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Obturator Nerve |
origin: L2-L4 plexus: lumbar function: adduction of the thigh |
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Sacral Plexus |
-arises from L4-S4 -serves the buttock, lower limb, pelvic structures, and perineum |
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Sciatic Nerve |
origin: L4-S4 plexus: sacral function: supplies sensation to the skin of the foot, as well as the entire lower leg (except for its inner side) |
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Dermatome |
area of the skin innervated by the cutaneous branches of a single spinal nerve |
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Spinal Reflex |
a reflexive action mediated by cells in the spinal cord, by passing the brain altogether |
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Sensory Receptor |
a sensory nerve ending that responds to a stimulus in the internal or external environment of an organism |
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Sensory Neuron |
nerves that transmit sensory information (sight, sound, feeling, etc.) |
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Interneuron |
a neuron that transmits impulses between other neurons, especially as part of a reflex arc |
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Motor Neuron |
a nerve cell (neuron) whose cell body is located in the spinal cord and whose fiber (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands |
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Stretch Reflex |
-maintain muscle tone in large postural muscles -cause muscle contraction in response to increased muscle length--protect against over stretching |
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Stretch Reflexes Components |
1. receptor: muscle spindle cell 2. sensory neuron: carries information to spinal cord 3. (interneuron: present only for the antagonist) 4. motor neurons: carry directions to effectors 5. effectors: the reflex muscle and antagonist |
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Golgi Tendon Reflexes |
-important for smooth onset and termination of muscle contraction -produce muscle relaxation (lengthening) in response to tension |
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Golgi Tendon Reflexes Components |
1. receptor: golgi tendon organ 2. sensory neuron: carries information to the spinal cord 3. interneurons (2): coordinates information with action 4. motor neurons: carry directions to effectors 5. effectors: the reflex muscle and antagonist |
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Flexor (withdrawal) Reflex |
causes autonomic withdrawal of the threatened body part |
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Crossed-Extensor Reflex |
occurs with flexor reflexes in weight-bearing limbs to maintain balance |
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Flexor and Crossed-Extensor Reflexes Components |
1. receptor: nociceptor 2. sensory neuron: carries information to the spinal cord 3. interneuron (3): coordinates flexor and cross-extensor 4. motor neurons: carry directions to effectors 5. effectors: the flexors and extensors on the afferent side, extensors on opposite side |
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Plantar Reflex |
downward flexion of toes |
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Babinski's Sign |
dorsiflexion of hallux and fanning of toes; in adults, it indicates corticospinal or motor cortex damage |
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Abdominal Reflexes |
cause contraction of abdominal muscles and movement of the umbilicus |
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Somatic Effectors |
transmits signals from the CNS to skeletal muscles |
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Autonomic Effectors |
transmits signals from the CNS to smooth muscle, cardiac muscle & glands |
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Somatic Efferent Pathway |
a thick, heavily myelinated somatic motor fiber makes up each pathway from the CNS to the muscle |
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Autonomic Efferent Pathway |
a two chain neuron consisting of preganglionic and postganglionic (ganglionic) neurons |
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Preganglionic Neuron |
has a lightly myelinated axon |
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Postganglionic (ganglionic) Neuron |
has an unmyelinated axon that extends to the effector organ |
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Somatic Nervous System Neurotransmitters |
-neuron fibers release acetylcholine -effects are always stimulatory |
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Autonomic Nervous System Neurotransmitters |
-neuron fibers release norepinephrine or ACh at effectors -effect is either stimulatory or inhibitory, depending on the type of receptors |
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Sympathetic Division |
-mobilizes the body during activity -"fight or flight" system -promotes adjustment during exercise or when threatened -increases heart rate and respiratory rates -inhibits digestion and elimination -mobilizes fats for fuels |
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Sympathetic Division Anatomy |
origin of fibers: thoracolumbar region of the spinal cord length: short preganglionic and long postganglionic location: close to the spinal cord |
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Parasympathetic Division |
-promotes maintenance activities and conserves body energy -"rest and digest" system -blood pressure, heart rate, and respiratory rates are low -pupils are constricted (accommodated for close vision) |
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Parasympathetic Division Anatomy |
origin of fibers: brain and sacral spinal cord (craniosacral) length: long preganglionic and short postganglionic location: in visceral effector organs |
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Autonomic Dysreflexia |
syndrome in which there is a sudden onset of excessively high blood pressure |
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Mechanoreceptors |
respond to touch, pressure, vibration, stretch, and itch |
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Thermoreceptors |
sensitive to changes in temperature |
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Photoreceptors |
respond to light energy (e.g., retina) |
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Chemoreceptors |
respond to chemicals (e.g., smell, taste, changes in blood chemistry) |
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Nociceptors |
sensitive to pain-causing stimuli (e.g., extreme heat or cold, excessive pressure, inflammatory chemicals, capsaicin {active component in chili peppers}) |
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Exteroceptors |
respond to stimuli arising outside the body |
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Exteroceptor Examples |
stimuli detected by this sensory receptor include thermoreceptors |
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Interoceptors (Visceroceptors) |
respond to stimuli arising in internal viscera and blood vessels |
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Interoceptor Examples |
stimuli detected by this sensory receptor includes blood pressure and blood oxygen levels |
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Proprioceptors |
respond to stretch in skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles |
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Proprioceptors Example |
stimuli detected by this sensory receptor include muscle spindles |
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Light Touch Receptors |
-unencapsulated dendritic endings -tactile (Merkel) discs -hair follicle discs |
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Meissner's (Tactile) Corpuscles |
-encapsulated dendritic endings -discriminative touch |
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Pacinian (Lamellated) Corpusles |
-encapsulated dendritic endings -deep pressure and vibration |
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Ruffini Endings |
-encapsulated dendritic endings -deep continuous pressure |
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Muscle Spindles |
-encapsulated dendritic endings -muscle stretch |
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Golgi Tendon Organs |
-encapsulated dendritic endings -stretch in tendons |
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Joint Kinesthetic Receptors |
-encapsulated dendritic endings -stretch in articular capsules |
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Layers of the Wall of the Eyeball |
-fibrous -vascular -sensory |
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Fibrous Layer |
-outermost layer -dense avascular connective tissue -made up of two regions: sclera and cornea |
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Sclera |
-opaque posterior region -anchors extrinsic eye muscles -found in the fibrous layer |
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Cornea |
-transparent anterior 1/6 of fibrous layer -bends light as it enters the eye -numerous pain receptors contribute to blinking and tearing reflexes |
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Vascular Layer (Uvea) |
-middle pigmented layer -made up of three regions: choroid region, ciliary body, and iris |
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Choroid Region |
-brown pigment that absorbs light to prevent visual confusion -found in the vascular layer |
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Ciliary Body |
-smooth muscle bundles (ciliary muscles) control lens shape -found in the vascular layer |
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Iris |
-the colored part of the eye -contains the pupil -found in the vascular layer |
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Pupil |
central opening that regulates the amount of light entering the eye |
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Sensory Layer: Retina |
delicate, two-layered membrane consisting of the pigmented layer and the neutral layer |
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Pigmented Layer |
-outer layer -absorbs light and prevents its scattering -found in the retina |
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Neutral Layer |
-made up of photoreceptors that transduce light energy -cells that transmit and process signals |
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Rods |
-operate in dim light -provide indistinct, fuzzy, non-color peripheral vision |
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Cones |
-operate in bright light -provide high-accuracy color vision |
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Lens |
-biconvex (thicker in the middle), transparent, flexible, elastic and avascular -allows for precise focusing of light on the retina -becomes denser, more convex and less elastic with age |
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Cataracts |
-clouding of lens -occurs as a consequence of aging, diabetes mellitus, heavy smoking and frequent exposure to intense sunlight |
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Refraction |
bending of a light ray due to change in speed when light passes from one transparent medium to another |
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Myopia |
-nearsightedness -focal point is in front of the retina, e.g. in a longer than normal eyeball -corrected with a concave lens |
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Hyperopia |
-farsightedness -focal point is behind the retina, e.g. in a shorter than normal eyeball -corrected with a convex lens |
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Astigmatism |
-caused by unequal curvatures in different parts of the cornea or lens -corrected with cylindrically ground lenses, corneal implants, or laser procedures |
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Glaucoma |
condition of increasing pressure inside the eye, resulting from blocked drainage of aqueous humor |
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Optic Chiasma |
-an X-shaped structure formed by the crossing of the optic nerves in the brain -nerve fibers from half of each retina cross over to the opposite side of the brain |
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Accommodation |
ability to focus for close vision (under 20 feet) |
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Convergence |
medial movement of the eyes during focusing on close objects |
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Sensory Adaptation |
the process by which brain cells become less sensitive to constant stimuli that are picked up by the senses |
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Taste - Sweet |
sugars, saccharin, alcohol, and some amino acids |
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Taste - Sour |
hydrogen ions |
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Taste - Salt |
metal ions |
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Taste - Bitter |
alkaloids such as quinine and nicotine |
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Taste - Umami |
amino acids glutamate and aspartate |
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External Ear |
-outer ear -involved with only hearing |
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Auricle (Pinna) |
composed of the helix and ear lobe |
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External Acoustic Meatus |
-auditory canal -a short, curved tube lined with skin bearing hairs, sebaceous glands and ceruminous glands |
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Tympanic Membrane |
-transfers sound energy to the bones of the middle ear -boundary between external and middle ears -eardrum |
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Middle Ear |
-a small, air-filled, mucosa-lined cavity in the temporal bone -tympanic cavity -involved with only hearing |
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Pharyngotympanic (Auditory) Tube |
-connects the middle ear to the nasopharynx -equalizes pressure in the middle ear cavity with the external air pressure |
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Ear Ossicles |
three small bones in the tympanic cavity that transmit vibratory motion of the eardrum to the oval window |
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Internal Ear |
-consists of three parts each with bony and membranous contributions -inner ear -labyrinth functions in both hearing and equilibrium |
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Part of the Inner Ear |
-vestibule -semicircular canals -cochlea |
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Bony Labyrinth |
tortuous channels in the temporal bone, filled with perilymph |
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Membranous Labyrinth |
series of membranous sacs within the bony labyrinth, filled with a potassium-rich endolymph |
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Vestibule |
-central egg-shaped cavity of the bony labyrinth -contains two membranous sacs that house equilibrium receptor regions (maculae) -respond to gravity and changes in the position of the head |
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Semicircular Canals |
-three canals that each define two-thirds of a circle -contain membranous semicircular ducts |
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Cochlea |
-spiral, conical, bony chamber that extends from the vestibule -contains the cochlear duct, which houses the spiral organ |
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Conduction Deafness |
-blocked sound conduction to the fluids of the internal ear -can result from impacted earwax, perforated eardrum, or otosclerosis of the ossicles |
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Sensorineural Deafness |
damage to the neural structures at any point |
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Tinnitus |
-ringing or clicking sound in the ears in the absence of auditory stimuli -can be due to nerve degeneration, inflammation of the middle or internal ears, or can be due to side effects of aspirin |
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Meniere's Syndrome |
-labyrinth disorder that affects the cochlea and the semicircular canals -causes vertigo, nausea, and vomiting |
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Lacrimal Apparatus |
network of structures of the eye that secrete tears and drain them from the surface of the eyeball |
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Anterior Columns |
the front column of grey matter in the spinal cord |
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Cerebral Aqueduct |
structure within the brainstem that connects the third ventricle to the fourth |
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Ceruminous Glands |
specialized glands (sweat glands) located subcutaneously in the external auditory canal |
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Conjunctiva |
the mucous membrane that covers the front of the eye and lines the inside of the eyelids |
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Corpus Callosum |
a broad band of nerve fibers joining the two hemispheres of the brain |
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Crista Ampullaris |
-sensory organ of rotation located in the semicircular canal of the inner ear -function: to sense angular acceleration and deceleration |
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Endolymph |
the fluid contained in the membranous labyrinth of the inner ear |
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Falx Cerebri |
a small sickle shaped fold of dura mater |
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Fourth Ventricle |
characteristic diamond shape in cross-sections of the human brain |
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Macula Lutea |
an oval-shaped pigmented area near the center of the retina of the human eye |
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Oval Window |
a membrane-covered opening that leads from the middle ear to the vestibule of the inner ear |
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Perilymph |
an extracellular fluid located within the cochlea |
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Pharyngotympanic Tube |
a tube that links the nasopharynx to the middle ear |
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Romberg Test |
a test used in an exam of neurological function for balance, and also as a test for drunken driving |
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Third Ventricle |
one of four connected fluid-filled cavities comprising the ventricular system within the mammalian brain |
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Infundibulum |
a funnel-shaped extension of the hypothalamus connecting the pituitary gland to the base of the brain |