Glial Cells, Diencephalon, brainstem

Question 1

What do glial cells do.

Answer 1

• Support the function of neurons
• Isolate nerve fibres from each other
• Divide throughout life unlike neurons

Question 2

Describe oligodendrocytes.

Answer 2

Glial cells of the CNS that hold nerve fibres together and produce the fatty (phospholipid) myelin sheaths around axons.

Question 3

Describe Schwann cells.

Answer 3

Glial cells of the PNS that surround axons and form fatty (phospholipid) myelin sheaths around axons.

Question 4

Describe satellite cells.

Answer 4

Glial cells of the PNS. A type of Schwann cells that surround neuron cell bodies within ganglia, giving them structural support and protection

Question 5

Describe astrocytes.

Answer 5

Glial cells of the CNS that attach to neurons and ‘feed’ them with lactic acid from glucose.

astronaut food?

Question 6

Where is the Diencephalon located?

Answer 6

Between the cerebrum and midbrain.

Question 7

What is the thalamus made of?

Answer 7

Grey matter

Question 8

What are 3 functions of the thalamus?

Answer 8

• Central relay station for incoming sensory impulses before they travel to the cerebral cortex
• Regulates sleep: damage->coma
• Helps produce sensations & associations to these

Question 9

What is the hypothalamus?

Answer 9

The survival and pleasure ‘centre’

Question 10

What are 3 functions of the hypothalamus?

Answer 10

• Connects the nervous and endocrine systems
• Regulator and coordinator of autonomic activities (blood pressure, heart rate, digestion, respiratory rate)
• Regulates homeostasis

Question 11

What happens if the hypothalamus is damaged?

Answer 11

Major problems with homeostatic regulation-> larger issues

Question 12

What are 7 homeostatic mechanisms controlled by the hypothalamus?

Answer 12

• Thermoregulation
• Appetite
• CO2 levels
• Growth hormone secretion
• Waking state
• Water balance
• Thyroid activity

Question 13

What/where is the epithalamus?

Answer 13

Small structures outside the thalamus and hypothalamus

Question 14

What is an important structure of the epithalamus and what does it do?

Answer 14

The pineal gland, an endocrine gland which regulates the body’s biological clock and produces melatonin.

Question 15

What cross over in the epithalamus?

Answer 15

At the optic chiasma optic nerves cross and exchange fibres before entering the brain. This allows vision from both eyes to be appreciated by the occipital cortex of the opposite side

Question 16

What is formed in the epithalamus?

Answer 16

Cerebrospinal fluid is formed here in the choroid plexuses.

Question 17

What is a sub-organ of the epithalamus and what does it control?

Answer 17

The pretectum, controls the pupillary light reflex (dilation)

Question 18

What are the three divisions of the brainstem?

Answer 18

• Medulla oblongata
• Pons
• Midbrain

Question 19

Describe the medulla oblongata. (3 points)

Answer 19

• Most vital part of the brain: injury or disease causes death
• Contains ‘vital’ centres: cardiac, vasomotor, respiratory control centres
• Contains non-essential centres: coughing, sneezing, hiccuping

Question 20

Where is the medulla oblongata located?

Answer 20

The base of the brainstem

Question 21

Where is the pons located?

Answer 21

Between the midbrain and the medulla oblongata.

Question 22

Describe the pons (2 points)

Answer 22

• Contains reflex centres for cranial nerves V,VI,VII,VIII
• Origin of many nerves

Question 23

Where is the midbrain located?

Answer 23

In the literal middle of the brain: Above the pons and below the cerebrum

Question 24

Describe the midbrain (2 points)

Answer 24

• Contains auditory and visual centres and clusters of neurons involved in muscular control
• Contains centres for pupillary reflexes and eye movements.

Question 25

What are the meninges?

Answer 25

The inner protective covering for the brain and spinal cord.

Question 26

What are the three layers of the meninges?

Answer 26

• The dura mater
• The arachnoid mater
• The pia mater

Question 27

Describe the dura mater.

Answer 27

The outer layer of the meninges and the inner periosteum of the cranial bones.

Question 28

Describe the arachnoid mater.

Answer 28

The delicate cobweb-like middle layer of the meninges

Question 29

Describe the pia mater.

Answer 29

The innermost transparent layer of the meninges directly covering the brain and spinal cord.