the CNS

Question 1

what does gray matter consist mostly of?

Answer 1

unmyelinated axons, with somas and dendrites

Question 2

what does white matter consist of?

Answer 2

mostly myelinated axons, no somas or dendrites

Question 3

where is cerebral spinal fluid contained?

Answer 3

in the space between the arachnoid membrane and pia mater (the subarachnoid space)

Question 4

what are the meninges and what do they do?

Answer 4

three layers that protect the brain and spinal cord–pia mater, arachnoid membrane, dura mater

Question 5

the spinal cord is the major pathway for information flowing back and forth between the brain, skin, muscles, and joints of the body

Answer 5

ya

Question 6

how many cervical segments are there?

Answer 6

8

Question 7

how many thoracic segments are there?

Answer 7

12

Question 8

how many lumbar segments are there?

Answer 8

5

Question 9

how many sacral segments are there?

Answer 9

5

Question 10

how many coccygeal segments are there?

Answer 10

1

Question 11

what is the role of the dorsal root?

Answer 11

carries afferent info from the periphery, through spinal cord, up to brain

Question 12

what is the role of the ventral root?

Answer 12

carries efferent info from brain, down spinal cord, to periphery

Question 13

white matter contains tracts of axons carrying info to and from the brain

Answer 13

ya

Question 14

what is a spinal reflex?

Answer 14

a response created by the spine without input from the brain–particularly important in body movement

Question 15

brainstem contains 11 of 12 cranial nerves (except the olfactory one) as it leads straight into the thalamus–where olfactory nerve just goes to olfactory cortex

Answer 15

ya

Question 16

what are the processes with which the brainstem is involved?

Answer 16

sleep and arousal, muscle tone and stretch reflexes, coordination of breathing, blood pressure and modulation of pain

Question 17

white matter of the medulla contains all of the ascending somatosensory tracts and descending corticospinal tracts

Answer 17

ya

Question 18

90% of all corticospinal tracts decussate/crossover at the pyramids

Answer 18

ya

Question 19

nuclei in the medulla contain the cardio centre and medulla resp centre–linked together–>changes in blood flow means you need changes in resp

Answer 19

ya

Question 20

what centres does the medulla contain?

Answer 20

cardio and medulla resp centre; vomiting centre; sneezing/coughing/hicupping centre; swallowing or deglutition centre

Question 21

what does the pons contain?

Answer 21

nuclei and tracts

Question 22

what is the purpose of the pons?

Answer 22

relay info between the cerebrum and cerebellum and to assist the medulla in the coordination of breathing

Question 23

function of the midbrain

Answer 23

control of eye movement, relays auditory and visual reflexes (movement of body in response to these stimuli) and contains the substantia nigra which plays a role in reward (dopaminergic) and movement

Question 24

midbrain is the junction bw the lower brainstem and the diencephalon (nuclei and tracts)

Answer 24

ya

Question 25

what is reticular formation?

Answer 25

extends throughout the brainstem–small neuronal cell bodies interspersed among tracts (ascending and descending)

Question 26

what is reticular formation important in?

Answer 26

conciousness, arousal, attention, alertness; involved in the reticular activating system (RAS)?

Question 27

what is the purpose of ras?

Answer 27

sends sensory info to cortex and filters info so you’re not overloaded; RAS inactivated during sleep–>damage to RAS can lead to coma; regulates muscle tone, assists in vital functions

Question 28

what is the purpose of the cerebellum?

Answer 28

processes sensory info and coordinates the execution of movement; alters movement as it occurs; regulates posture and balance; sends feedback signals to motor areas of the cerebral cortex, via its connections to the thalamus helping to correct any errors and smooth the movements

Question 29

what is the diencephalon composed of?

Answer 29

two primary structures: thalamus and hypothalamus; and two endocrine structure: pineal gland and pituitary gland

Question 30

what is the role of the thalamus?

Answer 30

relay centre–recieves sensory info from the optic tracts, ears, spinal cord, and motor info from cereellum and projects info to cerebrum for processing

Question 31

what is the role of the pineal gland?

Answer 31

cyclically releases melatonin and is involved in the sleep/wake cycle

Question 32

functions of the hypothalamus?

Answer 32

centre for homeostasis-influences autonomic and endocrine function;

1. activates symp NS: controls catecholamine release from adrenal medulla (important for flight or fight rxn); maintains BGL via endocrine pancreas;
2. maintains body temp–stimulates shivering and sweating
3. controls body osmolarity–motivates thirst and drinking; stimulates secretion of vasopressin
4. controls repro functions–directs secreton of oxytocin (not homeostatic)–for milk production and uterine contractions; directs tropic hormone control of ant pit hormones–FSH and LH
5. controls food intake–stimualtes satiety centre and feeding centre
6. interacts with limbic system to influence behaviour and emotion
7. influences cardi cntrol centre in medulla oblongata
8. secretes tropic hormones that control release of hormones from ant pit

Question 33

Function of pit gland?

Answer 33

output for hypothalamus

Question 34

describe the structure of the pit gland

Answer 34

connected to the hypothalamus by a long stalk called the infundibulum; the post pit is an extension of neural tissue while the ant pit is an endocrine gland; protected by the sphenoid bone

Question 35

types of neurons in neurohypophysis

Answer 35

one contains oxytocin which stilumates milk production and urinary contraction; the other contains vasopressin which stimulates water reabsoprtion from kidneys

Question 36

describe release of hormones in ant pit

Answer 36

neurons from hypothal release trophic hormones which are carried by capillary beds (hypothalamic-hypophyseal portal system) to the ant pit where they stimulate the release of peptide hormones

Question 37

what does the gray matter in the cerebrum contain?

Answer 37

cerebral cortex, basal ganglia, limbic system

Question 38

cerebrum is the area of higher processing–separated into 2 distinct lobes connected by the corpus callosum

Answer 38

ya

Question 39

what is the basal ganglia/nuclei and what is its role?

Answer 39

three nuclei collectively termed basal ganglia–globus pallidus, putamen, caudate nucleus; receives input from cerebral cortex and provides output to motor portions of the cortex; major job is to regulate and coordinate the initiation and termination of movement

Question 40

limbic system role

Answer 40

primary role in emotions including pain, pleasrure, docility, affection, and anger; may play a major role in learning and memory

Question 41

major components of limbic system and their roles

Answer 41

cingulate gyrus–produces emotion; amygdala–emotion, some learning and memory; hippocampus–has a major role in learning and memory by creating new neurons

Question 42

cerebral cortex is the outermost layer of the cerebrum and is the integrating centre for the CNS

Answer 42

ya

Question 43

what are sulci and gyri?

Answer 43

sulci–indentations in the brain tissue; gyri–protrustions created by two indentations

Question 44

specializations of the cerebral cortex

Answer 44

1. sensory areas–translate sensory input into perceptions
2. motor areas–direct skeletal muscle movement
3. association areas–integrate into from sensory nd motor areas and helps direct voluntary behaviours

Question 45

cerebral cortex can undergo plasticity–if you lose your hand, that part responsible for your hand will move to another part of the body (e.g. leg)

Answer 45

ya

Question 46

what are receptor/generator potentials?

Answer 46

graded potentials in sensory neurons