Central Nervous System

Question 1

What is a pathway, tract or commissure in the CNS?

Answer 1

No nerves in the CNS –
a group of axons travelling together is called a pathway, tract or commissure

Question 2

What are nuclei in the CNS?

Answer 2

Cell bodies of neurons of similar functions often cluster together – in the CNS these clusters are called nuclei
(in the PNS they are called ganglia)

Question 3

What are the parts of the brain before we are born?

Answer 3

Question 4

What develops from the Forebrain?

Answer 4

Cerebrum, Lobes
Thalamus, Hypothalamus

Question 5

What is included in the brainstem?

Answer 5

Medulla Oblongata
Pons
Midbrain

Question 6

What develops from the Hindbrain?

Answer 6

1. Cerebellum
2. Pons
3. Medulla Oblongata

Question 8

What are the parts of The Cerebrum?

3

Answer 8

• Cerebral cortex -> superficial, grey matter, mostly cell bodies
• White matter -> deep, tracts of myelinated axons
• Subcortical nuclei -> grey matter, deep to white matter

Left and right cerebral hemispheres

Question 9

Cerebrum

What is the Corpus Callosum?

Answer 9

Massive bundle of axons that connects the left and right hemispheres allowing communication

Question 10

Cerebrum

What is The Cerebral Cortex?

4

Answer 10

• Site of complex integration of information
• Folding of the cerebral cortex increases its surface area
• Gyri/folds (s. gyrus) and sulci (s. sulcus)
• Lobes: frontal, parietal, occipital, temporal
• perception, skilled movements reasoning, learning and memory

Question 11

Cerebrum

What are Gyri?
(folds)

Answer 11

gyri allows higher order reasoning and complex decision making

Question 12

Cerebrum

What are the Lobes of the Brain?

Answer 12

frontal, parietal, occipital, temporal

Question 13

Cerebrum

What is the Subcortical Nuclei?

Answer 13

• Deep within the cerebral hemispheres
• Grey matter
• Important for controlling movement and posture and complex aspects of behaviour

Question 14

Cerebrum

What is the Limbic System? (4)
What makes it up? (4)

Answer 14

• Functional system containing both grey + white matter
• Frontal lobe + temporal lobe + thalamus + hypothalamus + the pathways that connect them
• Learning, emotional experience and behaviour
• Visceral and endocrine functioning

Question 15

What makes up The Diencephalon?

Answer 15

• Thalamus
• Hypothalamus
• Epithalamus

Question 16

The Diencephalon

What is the Thalamus?

Answer 16

• Collection of large nuclei
• Integration center for most inputs to the cortex
• Arousal, focusing attention and filtering extraneous information

Question 17

The Diencephalon

What is the Hypothalamus?

Answer 17

• Collection of nuclei
• Master command center for neural-endocrine coordination (internal homeostatic regulation)
• Connected to and regulates the pituitary gland

Question 18

The Diencephalon

What is the Epithalamus?

Answer 18

Contains the pineal gland (participates in control of circadian rhythm through release of melatonin)

Question 19

What is The Cerebellum?
What can block it?

Answer 19

• Cerebellar cortex -> superficial, grey matter
• Movement coordination and posture/balance control
• Almost exclusively functions in motor control

gets blocked when drinking alcohol, casues blance loss

Question 20

What is The Brainstem?
What is included in it?

Answer 20

• ESSENTIAL FOR LIFE (breathing, heart rate, swallowing reflexes)
• Midbrain, pons, medulla oblongata and reticular formation
• Receives input from all regions of the CNS and processes it

Question 21

Brain - Cross Section

Answer 21

Question 22

What are Meninges?

Answer 22

• Between soft neural tissue and bones (in skull and spine)
• Protect CNS, circulate and absorb cerebral spinal fluid (CSF)
• Subarachnoid space is filled with CSF

Question 23

What are the layers of the meninges?
(superficial -> deep)

Answer 23

Dura mater, arachnoid mater and pia mater (superficial -> deep)

Question 24

What is Cerebral Spinal Fluid?

Answer 24

• Provides cushioning for the CNS
• Circulates the brain through the ventricles
• Samples of CSF can provide diagnostic information about the brain

Question 25

What secretes Cerebral Spinal Fluid?

Answer 25

Produced by ependymal cells in the choroid plexus

Question 26

What forms The Blood Brain Barrier?

Answer 26

Formed by astrocytes and the cells that line the smallest blood vessels in the brain

Question 27

What is The Blood Brain Barrier?

Answer 27

Exchange of substances between the blood and extracellular fluid of CNS is highly regulated compared to other organs - Lipid-soluble solutes can easily pass the blood brain barrier - Substances that cannot diffuse across cell membranes rely on transport proteins (i.e.,

Question 28

# The Blood Brain Barrier What are Tight Junctions?

Answer 28

protein complexes that restrict the movement of polar molecules into the CNS