Lecture 13 CNS Flashcards Preview

Physiology > Lecture 13 CNS > Flashcards

Flashcards in Lecture 13 CNS Deck (39):
1

Development of the CNS

CNS develops from neural tube of embryo starting around 3 weeks
anterior neural tube first differentiates into forebrain, midbrain, and hindbrain (4weeks)
forebrain greatly enlarges to form cerebral hemispheres

2

Supporting structures of the CNS

meninges
brain ventricles and cerebrospinal fluid (CSF)
Glial cells

3

Meninges

Dura mater - outer layer
Arachnoid mater - middle
Pia mater - inner layer

4

Brain ventricles and CSF

CSF is produced by the choroid plexuses of the brain ventricles
CSF circulates through ventricles and into subarachnoid space
CSF composition is regualted; low protein concentration compared to plasma

5

Glial cells

supporting cells of the NS
astrocytes
microglia
oligodendrocytes
ependymal cells

6

Astrocytes

provide physical and metabolic support to neurons
blood-brain barrier- tight junction between capillary endothelial cells
regulates passage of substances from blood to CNS interstitial fluid

7

microglia

phagocytes, protective functions

8

oligodendrocytes

myelinate axons in CNS

9

ependymal cells

produce CSF

10

Spinal Cord
Gray matter

nuclei, contain cell bodies, dendrites, axon terminals integration areas of CNS
dorsal (posterior) horn
ventral (anterior) horn

11

Spinal Cord
White matter

tracts (bundles of axons in the CNS)
contains myelinated areas
conduct APs over long distances
ascending tracts & descending tracts

12

Ascending tracts

sensory information
carries info to the brain in the dorsal white columns

13

Descending tracts

motor information
down to appropriate level of the spinal cord and then out to the appropriate body part
in lateral anterior parts of white matter

14

Ganglia

clusters of cell bodies in the PNS

15

Spinal nerves
Dorsal Root

incoming axons of sensory neurons
cell bodies in dorsal root ganglia

16

Spinal nerves
Ventral Root

outgoing axons of motor neurons
cell bodies in ventral horn

17

How many pairs of spinal nerves

31 pairs
C1-8, T1-12, L1-5, S1-5 Co1

18

Spinal Reflexes
Parts of the reflex arc

sensory receptor
sensory neuron
integration center
motor neuron
effector (muscle)

19

2 spinal reflexes

monosynaptic reflex (e.g. muscle spindle stretch reflex)
polysynaptic reflex (e.g withdrawal reflex and crossed extensor reflex

20

Brain stem

medulla ,pons, and midbrain
transition from spinal cord to higher brain regions
sensory motor tracts pass through
origins of cranial nerves

21

reticular formation

network of neurons involved in arousal of cerebral cortex (sleep/wake)

22

Medulla Oblongata

ascending (somatosensory) tracts convey sensory information to higher brain areas
descending (corticospinal) tracts carry motor signals, cross over in pyramids of the medulla
respiratory and cardiovascular control centers
other involuntary control centers (swallowing, vomiting)

23

Pons

connections between cerebellum and other CNS areas
respiratory centers coordinate with medulla to control breathing

24

Midbrain

visual and auditory reflexes
role in unconscious motor control (red nucleus, substantia nigra)

25

Cerebellum

major role in coordination of movement
cortex (gray matter)
arbor vitae (white matter)

26

Parts of the diencephalon

thalamus
hypothalamus
pineal gland

27

thalamus

sensory "relay station" from lower CNS centers to the cerebral cortex

28

hypothalamus

major center for homeostasis
regulates appetite, thirst, body temp
regulate endocrine function via control of the pituitary gland
activates sympathetic division of ANS
mediates physiological responses of emotional states (via autonomic NS)

29

Pineal gland

endocrine gland
secretes melatonin

30

Cerebrum

higher brain functions, sensory perception, voluntary control of movement
lobes: frontal, parietal, temporal, occipital

31

Cerebral gray matter

cerebral cortex
basal ganglia
limbic system

32

Cerebral white matter

association fibers
commissural fibers (corpus callosum) - connect 2 hemispheres
projection fibers - ascending and descending tracts

33

Basal ganglia

deep gray matter areas, involved in subconscious control of movement
part of cerebrum

34

Limbic system

emotional brain
amygdala - control center of strong emotions (fear, anger) role in memory processing
hippocampus - major role in consolidation of long term memory

35

Cerebral cortex

highest level processing and integration area
what makes you, you
gyri and sulci increase surface area
6 distinct cell layers of cortex
functional areas of the brain
cerebral lateralization (left brain- right brain)

36

Frontal love

primary motor area
speech (Broca's) area
prefrontal cortex - higher level thinking, plannin, judgement, personality

37

Parietal lobe

primary somatosensory area
sensory association areas

38

Occipital lobe

visual cortex

39

temporal lobe

auditory cortex
language association (Wernicke's) area