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Flashcards in CNS Deck (72)
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What colour are myelinated cells?

white

1

What is the key learning point for neurons?

Neurons do not regenerate - lack of oxygen leads to permanent cellular death. There is no ability to store O2 in the CNS tissues, and the central neurons do not undergo mitosis.

2

What are the types of neuroglial cells?

astrocytes
oligodentroglia
ependyma
microglia
Schwann cells

3

What are the basic characteristics of astrocytes?

-part of the blood brain barrier, nutrition
-support brain framework (neurons and capillaries)
-largest and most numerous
-synaptic conductivity

4

What are the basic characteristics of oligodendroglia?

helps form myelin sheath in the CNS

5

What are the basic characteristics of the ependyma?

-forms choroid plexus
-secretes cerebrospinal fluid
-lines the ventricles and spinal cord

6

What are the basic functions of the microglia?

eliminates waste by phagocytosis

7

Describe the polarity of the neuron at rest.

inside cell membrane negative (K+ in cell)
outside cell membrane positive (Na)

8

What is the minimum threshold to achieve action potential?

-60mV

9

What are the steps of impulse transmission?

slow influx of sodium (RMP changes from -70mC to -35mV), rapid sodium influx (sodium channels open, RMP +70 to +90mV), depolarization: K+ channels open (K+ efflux promotes onset of repolarization), repolarization: sodium-potassium pump: re-establish RMP

10

What is the target for acetylcholine?

motor nerves to muscles

11

What does a lack of dopamine in the brain lead to?

parkinsons

12

What does norepinephrine do?

increase heart rate, and stimulates fight or flight

13

What are the characteristics of the cranium?

-inside is jagged
-eight flat irregular shaped bones fused together during childhood
-solid, non-expanding
-function to protect the brain

14

What is the foramen magnum?

opening at the base to allow brainstem to project and connect to the spinal cord

15

What are the layers of the meninges and where are they located?

Dura mater - outermost, tough, adhered to the skull, covers brain and spinal cord to S2
Arachnoid - delicate, fragile, vascular, spiderweb, spongy, connects dura to pia, acts as a cushion
Pia mater - adheres directly to brain tissue

16

Describe the characteristics of the neural ventricals.

lateral ventricles - foramen of monroe
third ventricle - aqueduct of sylvius
fourth ventricle - foramen of lushka, foramen of magendie

17

Describe the pathway of CSF

lateral ventricles - foramen of monroe - third ventricle - cerebral aqueduct - fourth ventricle - central canal or subarachnoid via foramen of lushka and mangendie - reabsorbed by arachnoid villi into venous system

18

What are the basic functions of the frontal lobe?

logical thinking, short term memory, personality and judgement

19

What are the functions of the parietal lobes?

sensory receiving and interpreting, speech, grammar, and hand skills

20

What are the functions of the temporal lobe?

auditory receiving and interpretation, emotion, personality, behaviour, memory storage

21

What is the function of the Wernicke area?

understanding spoken and written word

22

What is the function of the occipital lobe?

visual receiving and interpretation

23

What are the functions of the thalamus?

consciousness, pain, attention span, damage can mean permanent coma, sorts information that goes to cerebral cortex (auditory, visual, taste, touch)

24

What are the functions of the hypothalamus?

thermostat, internal homeostatsis, controls autonomic nervous system, afferent impulses, uses pituitary for communication.

25

What are the characteristics of the pituitary gland?

attached to the hypothalamus at the base of the brain, the master gland, secretes 9 hormones, controls/influences all other endocrine glands, growth, metabolic rate, sexuality

26

What are the characteristics of the cerebellum?

surrounds the brainstem
helps provide smooth, coordinated body movement,
motor planning
muscle memory
fine movement
balance through feedback loops
no initiation of movement - send/receive impulses for muscle activity

27

Your patient has an injured Cerebellum. What physical findings would you see in ataxia?

preservation of motor strength, lack of coordination, staggering gait, lack of ocntrol, injury, parkinsons, alzheimers

28

What are the characteristics of the midbrain?

located below the cerebrum and above the pons, contains cranial nerve 3 and 4 and the visual reflex, functions to relay stimuli involved in voluntary movement.

29

What are the characteristics of the pons?

a bridge - connects midbrain with the medulla
contains respiratory centres - pneumotaxic control (breathing patterns)
Regulates consciousness
cranial nerves 5, 6, 7,8