Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
53 Cards in this Set
- Front
- Back
CNS consists of the |
brain and spinal cord
|
|
Peripheral nervous system (PNS) consists of |
nerve fibres that carry information between the CNS and peripheral parts of the body |
|
What is afferent division? |
carries information/instructions from peripheral body parts to CNS |
|
What is efferent division? |
carries information AWAY from CNS to effector organs (muscles and glands) |
|
Efferent division is divided into: |
1. somatic nervous system: consists of fibres of motor neurons that supply skeletal muscles 2. autonomic nervous system: consists of fibres that innervate smooth muscle, cardiac muscle and glands |
|
The autonomic nervous system has two divisions |
1. Sympathetic NS 2. Parasympathetic NS |
|
Sympathetic NS |
prepares body for stressful, emergency or energetic activities such as fight or flight
|
|
Parasympathetic NS |
dominates during times of "rest and repose" - directs maintenance activities |
|
Afferent neurons |
inform CNS about conditions in both external and internal environment |
|
Efferent neurons |
carry instructions from CNS to effector organs - muscles and glands |
|
Interneurons |
found entirely within CNS and responsible for: - integrating afferent information and formulating an efferent response - higher mental functions associated with the mind |
|
Glial cells form most of |
the brain tissue
|
|
4 types of glial cells, briefly describe each |
1. astrocytes: help form the blood-brain barrier 2. Oligodendrites: form sheaths around axons in CNS 3. Microglia: act like white blood cells to clear the brain of microbes/antigens 4. Ependymal cells: help form choroid plexes of ventricles for the formation of cerebrospinal fluid (CSF) |
|
4 major feature that protect the CNS from injuries, briefly describe each: |
1. Meninges: wrap, protect and nourish the membranes 2. cerebrospinal fluid (CSF): floating and cushioning fluid of the brian 3. Blood-brain barrier (BBB): access limiting barrier to blood born material to the brain 4. Cranium: Bony case that encloses the brain and spinal cord |
|
3 parts of the meninges: |
1. dura matter 2. arachnoid matter 3. pia matter |
|
Location and function of dura matter |
outermost, double, tough, inelastic membrane that forms dura and venous sinuses |
|
Location and function of arachnoid matter: |
middle, vascularized, - CSF is reabsorbed across the surfaces of these villi into blood circulating within the sinuses |
|
Location and function of pia matter: |
innermost, fragile membrane, highly vascularized - is closely attached to the surface of the brain and spinal cord |
|
Cerebrospinal fluid (CSF) function (2) |
- surround, protect and cushion the brian and spinal cord - serve as "shock absorbing fluid" |
|
Composition of CSF (3) |
- produced by choroid plexus (CP consists of vascularized masses called ependymal cells) - selective transport mechanisms across the membranes of the choroid plexuses forms the CSF - composed of lower K+ ions than plasma |
|
After circulating through the upper region of the brain, CSF reabsorbed into the ______ ________ through ________ ________ |
venous blood, through arachnoid villi |
|
Defects in CSF formation, circulation and reabsorption leads to |
hydrocephalus - increase in CSF pressure and can lead to brain damage and mental retardation |
|
Flow of CSF |
formed in (lateral) first, second and third ventricles -> circulates around brain and spinal cord -> exits at 4th ventricle at base of brain -> flows in subarachnoid space -> reabsorbed into venous blood at arachnoid vili |
|
BBB (2) |
- carefully regulates exchanges b/w the blood and brain - protect the brain from chemical fluctuation in the blood and prevent harmful blood-borne substances from entering brain |
|
Brain capilaries are equipped with |
tight junction |
|
What can be easily transported across the brain capillaries? (4) |
- Oxygen - Carbon dioxide - alcohol - steroids |
|
What molecules are transported by selective transport mechanisms in the brain? (3) |
glucose, amino acids, ions |
|
Disadvantages of the BBB(2) |
1. BBB limits the use of drugs for treatment of brain and spinal cord disorders 2. prevents certain neurotransmitters from reaching brain |
|
Cerebrum |
- largest portion of the brain, divided in two halves (right and left cerebral hemispheres) |
|
What separates the two hemispheres of the cerebrum? what is its function? |
-corpus callosum - information superhighway of the brain (serves as communication b/w hemisphere |
|
Cerebral cortex (3) |
- thin outer shell of gray matter of each hemisphere - it is composed of a thick central white matter - also contains basal nuclei within white matter |
|
Cerebral cortex contains 4 lobes |
1. frontal 2. parietal 3. occipital 4. temporal |
|
Functions of the 4 cerebral cortex lobes: |
1. occipital: intial processing of visual info 2. temporal: contains primary auditory cortex and part of limbic association area for motivation, emotion and memory 3. parietal: receive and process sensory info 4. frontal: voluntary motor activity, speaking ability and elaboration of thought |
|
Function of basal nuclei (4) |
- inhibition of tone throughout the body - selection and maintenance of purposeful activities - help in monitoring and coordinating sustained contractions related to posture and support - produces neurotransmitter dopamine |
|
Diancephalon - thalamus (4) |
- serve as relay center and synapsing integration center for sensory inputs to cortex - routes important impulses to appropriate areas of the somatosensory cortex - has ability to direct our attention to stimuli of interest - is capable of creating awareness of various types of sensation |
|
Diancephalon - hypothalamus (4) |
- integrating center for many important homeostatic functions - serves important link between the ANS and endocrine systems - directly regulate the internal environment - extensive involvement in emotion and basic behavioural patterns |
|
The hypothalamus is the |
brain area most involved in directly regulating internal environment |
|
What is the limbic system? |
composed of separate structures that surround the brainstem and interconnected by intricate neuronal pathways |
|
Limbic system includs: |
portions of the hypothalamus and other forebrain structures that encircle the brain |
|
Limbic system is responsible for (3) |
- emotion - basic, inborn behavioural patterns related to survival and perpetuation of the species - plays important role in motivation and learning |
|
Brainstem consists of |
- consists of pons, medulla oblongata and midbrain |
|
Brainstem function (4) |
- vital link b/w spinal cord an higher brain centers - passes all incoming/outgoing fibres of peripheral and higher brain centers - centers in brainstemcontrol heart, blood vessels, respiration and digest activities - modulate the sense of pain |
|
Pons: |
- located on inferior surface of the brain (b/w midbrain and M.O) |
|
Several nuclei of the pons is associated with nerves such as (3) briefly describe |
1. trigeminal nerve (V) - impulses for chewing ad sensory sensation from head 2. abducens nerve (VI) - transmit impulses for facial movements and taste buds 3. facial nerve (VII) - control movement of the eyeball and maintains equilibrium |
|
Medulla oblongata: (2) |
- is inferior portion of brainstem - nuclei and white matter forms the descending/ascending tracts communicating b/w spinal cord and various parts |
|
3 major functions of the medulla oblongata |
1. Cardiac center: bot inhibitory and accelerating impulses travel through vagus nerve to elevate heart rate 2. Vasomotor center: nuclei of this center send the impulses to the smooth muscle of the arterial wall to constrict and elevate the blood pressure 3. Respiratory center: control rate/depth of breathing - work together with respiratory nuclei of the Pons |
|
Cerebellum |
- is attached to the back of the upper portion of the brainstem and lies underneath of occipital lobe |
|
Functions (3) of cerebellum? |
1. maintenance of balance 2. enhancement of muscle tone 3. coordinating and planning of skilled voluntary muscle activities |
|
3 parts of the cerebellums |
1. vestibulocerebellum - maintain balance and crontrol eye movements 2. spinocerebellum - enhances muscle tone, coordinated skilled and voluntary movements 3. cerebrocerebellum - plays role in planning & initiating of voluntary activity by providing input to the cortical motor areas |
|
Reticular formation |
- widespread network of interconnected neurons that spread throughout the entire brainstem and into thalamus - |
|
Reticular formation consists of |
ascending and descending fibres that carry signals upward to arouse and activate cerebral cortex |
|
Reticular Activating System (RAS) |
controls the overall degree of cortical alertness and direct the attention |
|
Centers with RAS as responsible for? |
Sleep |