Block D Lecture 1: CNS Functional Anatomy

Question 1

What are the 4 main functions of the CNS?

Answer 1

Keep the body in homeostasis
Perception (sight, taste, smell, hearing)
Movement and co-ordination
Intellect and emotions
(Lecture 1, Slide 2)

Question 2

What is the central nervous system (CNS) composed of?

Answer 2

The brain and spinal cord
(Lecture 1, Slide 5)

Question 3

What are the 3 cellular components of the CNS?

Answer 3

Neurons
Glia
Blood supply
(Lecture 1, Slide 5)

Question 4

In the PNS (peripheral nervous system), clusters of neurons are called ganglions (ganglia plural). What are they called in the CNS?

Answer 4

Nucleus (plural nuclei)
(Lecture 1, Slide 6)

Question 5

What are glial cells?

Answer 5

They are cells in the CNS which help support and maintain neurons
(Lecture 1, Slide 7)

Question 6

What are 4 types of glial cells?

Answer 6

Astrocytes
Ependymal cells
Microglia
Oligodendrocytes
(Lecture 1, Slide 7)

Question 7

What do astrocytes do?

Answer 7

They connect with neurons and blood vessels
(Lecture 1, Slide 7)

Question 8

What do ependymal cells do?

Answer 8

They line ventricles and the spinal canal and their cilia aid CSF flow
(Lecture 1, Slides 7 and 30)

Question 9

What do microglia do?

Answer 9

They are resident immune cells and they clear cellular debris, pathogens and damaged cells
(Lecture 1, Slide 7)

Question 10

What do oligodendrocytes do?

Answer 10

They are responsible for producing and maintaining the myelin sheath
(Lecture 1, Slide 7)

Question 11

What is the myelin sheath?

Answer 11

It is a layer wrapped round the axon of a neuron
(Lecture 1, Slide 8)

Question 12

What 2 things does the myelin sheath provide?

Answer 12

Electrical insulation and it ups the speed of action potential conduction
(Lecture 1, Slide 8)

Question 13

What 2 things require oligodendrocytes?

Answer 13

Learning new motor skills and cognitive processing
(Lecture 1, Slide 9)

Question 14

What are the 3 major subdivisions of the brain?

Answer 14

Forebrain
Midbrain
Hindbrain
(Lecture 1, Slide 10)

Question 15

What are the 2 regions of the forebrain?

Answer 15

Outer and inner
(Lecture 1, Slide 10)

Question 16

What 3 parts of the brain are in the outer forebrain?

Answer 16

Cerebrum
Corpus striatum
Hippocampus
(Lecture 1, Slide 10)

Question 17

What are the 2 parts of the brain in the inner forebrain?

Answer 17

Thalamus
Hypothalamus
(Lecture 1, Slide 10)

Question 18

What is contained in the midbrain part of the brain?

Answer 18

Basal ganglia including substantia nigra
(Lecture 1, Slide 10)

Question 19

What 4 parts of the brain are in the hindbrain region?

Answer 19

Cerebellum
Medulla oblongata
Pons
Reticular formation
(Lecture 1, Slide 10)

Question 20

How many lobes are contained in the outer forebrain and how arranged?

Answer 20

4, 1 on each side
(Lecture 1, Slide 12)

Question 21

What 3 things does the outer forebrain control?

Answer 21

Cognition, sensory and motor functions
(Lecture 1, Slide 12)

Question 22

How is the surface area of the outer forebrain increased?

Answer 22

By ridges and grooves
(Lecture 1, Slide 12)

Question 23

What 2 things is the outer forebrain comprised of?

Answer 23

Nerve cells and myelin
(Lecture 1, Slide 13)

Question 24

What is the basal ganglia?

Answer 24

A group of nuclei (nerve clusters) located deep inside the brain
(Lecture 1, Slide 14)

Question 25

What 3 things are contained in the basal ganglia?

Answer 25

The striatum, substantia nigra and the globus pallidus (Lecture 1, Slides 14 and 17)

Question 26

What does the basal ganglia link to?

Answer 26

The thalamus (Lecture 1, Slide 14)

Question 27

What system is the hippocampus a part of and what does this system control?

Answer 27

The limbic system - which controls emotions, pleasure, hostility, anger and instincts (Lecture 1, Slide 15)

Question 28

What is the thalamus?

Answer 28

It is a relay centre for information on it's way to the cerebrum, relaying cerebrum motor output to other areas (Lecture 1, Slide 16)

Question 29

What 2 systems does the hypothalamus regulate?

Answer 29

Autonomic and endocrine systems (hunger, thirst, osmotic balance, body temp, metabolic rate) (Lecture 1, Slide 16)

Question 30

What is the function of the substantia nigra?

Answer 30

It co-ordinates body movements (Lecture 1, Slide 17)

Question 31

What does the cerebellum control?

Answer 31

Fine, co-ordinated body movements (Lecture 1, Slide 18)

Question 32

What is the medulla oblongata comprised of?

Answer 32

Ascending/descending nerves to/form the forebrain (Lecture 1, Slide 18)

Question 33

What does the medulla oblongata control?

Answer 33

Visceral reflexes such as heart rate, digestion and breathing (Lecture 1, Slide 18)

Question 34

What does the brain stem reticular formation modulate?

Answer 34

Level of wakefulness/sleep (Lecture 1, Slide 18)

Question 35

What is contained in the centre of the spinal cord?

Answer 35

Neuronal cell bodies (Lecture 1, Slide 20)

Question 36

What is the spinal cord surrounded by?

Answer 36

Ascending and descending nerve tracts (Lecture 1, Slide 20)

Question 37

What is the ventral root of the spinal cord?

Answer 37

Motor/efferent nerves leaving the spinal cord and they innervate effectors (Lecture 1, Slide 20)

Question 38

What is the dorsal root of the spinal cord?

Answer 38

Sensory / afferent nerves entering the spinal cord (Lecture 1, Slide 20)

Question 39

What is the dorsal root ganglion in the spinal cord?

Answer 39

Sensory nerve cell bodies (Lecture 1, Slide 20)

Question 40

What is the blood-brain-barrier?

Answer 40

A impermeable barrier between blood and the interstitial fluid (ISF) of the brain (Lecture 1, Slides 21 and 22)

Question 41

What is the blood-CSF-barrier?

Answer 41

An impermeable barrier between the blood and the cerebrospinal fluid of the brain (Lecture 1, Slides 21 and 22)

Question 42

What is the CSF-ISF-interface?

Answer 42

A permeable barrier between the cerebrospinal fluid (CSF) and the interstitial fluid (ISF) of the brain (Lecture 1, Slides 21 and 22)

Question 43

What are the 4 functions of the ISF and CSF?

Answer 43

Supplies metabolites Physically protects the brain Provides appropriate chemical environment for neuronal function Removes wastes (Lecture 1, Slide 24)

Question 44

What is the consequence of the brain having no glycogen stores?

Answer 44

It has to rely on blood glucose and O2 being supplied to it (Lecture 1, Slide 25)

Question 45

What percent of blood pumped by the heart does the brain receive?

Answer 45

15% (Lecture 1, Slide 25)

Question 46

What percent of the bodies oxygen does the brain use?

Answer 46

20% (Lecture 1, Slide 25)

Question 47

What are 2 differences between arterioles in the peripheral nervous system and arterioles in the central nervous system?

Answer 47

Arterioles in the CNS have smaller gaps between endothelial cells and have astrocytes surrounding them - acting as a 2nd barrier (Lecture 1, Slide 26)

Question 48

What does the blood-brain-barrier do?

Answer 48

It restricts access from the blood to the CNS (Lecture 1, Slide 27)

Question 49

What 2 things are allowed to pass through the blood brain barrier?

Answer 49

Small, non-ionised lipid-soluble compounds (e.g O2 or CO2) Substrates for specific transporters (e.g glucose, amino acids, ions) (Lecture 1, Slide 27)

Question 50

What are 4 things are not allowed to pass through the blood-brain-barrier?

Answer 50

Answers Include: Proteins Substrates bound to plasma proteins Toxins Pathogens Most drugs (Lecture 1, Slide 27)

Question 51

What can injury or inflammation in relation to the blood-brain-barrier result in?

Answer 51

The blood-brain-barrier breaking down, exposing the CNS to harmful surfaces (Lecture 1, Slide 27)

Question 52

How many chambers does the CSF fill and what are they?

Answer 52

2x lateral, 3rd and 4th ventricles (Lecture 1, Slide 28)

Question 53

How does the CSF flow?

Answer 53

It flows from ventricles to surround the brain and spinal cord + spinal canal, and exits via one-way valves to the vein (Lecture 1, Slide 29)

Question 54

What do ependymal glial cells actively secrete into ventricles?

Answer 54

Na+ ions (Lecture 1, Slide 31)

Question 55

What flows passively into ventricles?

Answer 55

Cl- ions (Lecture 1, Slide 31)

Question 56

What does ependymal cells secreting Na+ into ventirlces and Cl- flowing into ventricles do?

Answer 56

It increases osmotic pressure, which drives water into the ventricle (Lecture 1, Slide 31)

Question 57

What percentage of the brain's glucose supply comes from the CSF?

Answer 57

66% (Lecture 1, Slide 31)

Question 58

What does interferon cytokine do to choroid plexus activity and what is it associated with in old age?

Answer 58

decrease it and is associated with decreased cognitive function in old age (Lecture 1, Slide 32)

Question 59

What does genetically blocking interferon cytokine in old animals do?

Answer 59

Increase choroid plexus activity and cognitive function (Lecture 1, Slide 32)