Structure and function of the nervous system

Question 1

What the nervous system divided into?

Answer 1

1. The central nervous system

2. Peripheral nervous system - somatic and autonomic

Question 2

What are the fundamental and complex processes the brain controls?

Answer 2

Basic’ fundamental life processes:
• Breathing
• Organ function
• Movement

Complex’ processes:
• Thought
• Behaviour and emotion
• Creating memories

Question 3

What are the major brain regions?

Answer 3

Forebrain
•	Telencephalon (or cerebrum)
•	Diencephalon
Brainstem
•	Midbrain
•	Pons
•	Medulla oblongata
Cerebellum

Question 4

Describe the axes of the brain

Answer 4

Anterior-posterior
•	Anterior = Front
•	Posterior = Behind
Rostral-caudal
•	Rostral = “Nose”
•	Caudal = “Tail”
Dorsal-ventral
•	Dorsal = Top
•	Ventral = Bottom
Superior-inferior
•	Superior = Above 
•	Inferior = Below

Question 5

What are the 3 planes of the brain?

Answer 5

Coronal
• Divide the brain into a front (anterior) and a back (posterior) section

Horizontal
• Divide the brain into an upper (superior) and lower (inferior) section

Sagittal
• Divide the brain into two hemispheres
• Further characterized as midsagittal (midline) or parasagittal (more lateral)

Question 6

Where is the hippocampus located?

What is the function of the hippocampus?

Answer 6

The hippocampus (derived from the Greek for “seahorse”) is a region of the cerebral cortex embedded deep within the temporal lobe.

• Learning
• Memory formation and retrieval
• Regulation of hypothalamus-pituitary-adrenal (HPA) axis

Question 7

Why are coronal, horizontal and sagital sections important?

Answer 7

Coronal sections can reveal important regions within the forebrain, including various sub-cortical structures (e.g. the hippocampus):

Horizontal sections
Horizontal sections can reveal important regions within the forebrain, including various sub-cortical structures (e.g. the hippocampus):

Sagittal sections
Sagittal sections can reveal important regions within the forebrain, including various sub-cortical structures (e.g. the hippocampus):

Question 8

What are the cranial nerves?

Answer 8

The cranial nerves describe the twelve (I-XII) pairs of nerves arising from the brainstem that perform a diverse range of functions.

Question 9

What is the function of the first 2 cranial nerves?

Answer 9

Cranial nerve I (Olfactory)
• Special sensory – sensation of smell
Cranial nerve II (Optic)
• Special sensory – sensation of vision

Question 10

What does cranial nerve 3 do (III)?

Answer 10

Cranial nerve III (Oculomotor)
• Somatic motor – eye and eyelid movement
• Visceral (autonomic) motor – parasympathetic control of pupil size

Question 11

What does cranial nerve 4 do (IV)?

Answer 11

Cranial nerve IV (Trochlear)

• Somatic motor – eye movement

Question 12

What does cranial nerve 5 do (V)?

Answer 12

• Somatic sensory – sensation of touch to the face

* Somatic motor – movement of muscles of mastication (chewing)

Question 13

What does cranial nerve 6 (VI) do?

Answer 13

• Somatic motor – eye movement

Question 14

What does cranial nerve 7 (VII) do?

Answer 14

• Somatic sensory – movement of muscles of facial expressions
• Special sensory – sensation of taste in anterior tongue

Question 15

What does cranial nerves 8 (VIII) do?

Answer 15

• Auditory-vestibular (vestibulocochlear) nerve

* Special sensory – hearing and balance

Question 16

What does cranial nerve 9 (IX) do?

Answer 16

• Special sensory – sensation of taste in posterior tongue
• Visceral sensory – detection of blood pressure changes in the aorta
• Somatic motor – movement of muscles in the throat
• Visceral motor – parasympathetic control of salivary glands

Question 17

What does cranial nerve 10 (X) do?

Answer 17

• Visceral sensory – sensation of pain associated with viscera (internal organs)
• Somatic motor – movement of muscles in the throat
• Visceral motor – parasympathetic control of heart, lungs and abdominal organs

Question 18

What does cranial nerve 11 (XI) do?

Answer 18

• Somatic motor – movement of muscles in the throat and neck

Question 19

What does cranial nerve 12 (XII) do?

Answer 19

• Somatic motor – movement of the tongue (e.g. swallowing and speech)

Question 20

What is the meninges and its function?

Answer 20

The meninges describe the three membranous layers that cover the brain (and spinal cord).
From superficial to deep, the meninges comprise:
• Dura mater
• Arachnoid mater
• Pia mater
Meninges function?
• Primary function is in the protection of the brain and spinal cord
• Passage of cerebrospinal fluid (CSF) – ventricular system
• Support of cerebral and spinal blood vessels – vasculature system

Question 21

What is the ventricular system of the brain?

What produces the cerebrospinal fluid?

What is the function of the ventricular system?

Answer 21

the ventricular system comprises a series of interconnected, cerebrospinal fluid (CSF)-filled spaces that lie at the core of forebrain and brain stem.
The ventricular system comprises:
• Lateral ventricles
• Third ventricle
• Fourth ventricle
The choroid plexus is responsible for producing the cerebrospinal fluid (CSF) that fills these ventricular spaces
Ventricular system function?

• Protection of the brain (e.g. cushion for physical shocks)
• Transport (e.g. nutrients, waste products)
• Other functions include regulation of buoyancy

Question 22

Describe the vasculature of the brain?

Answer 22

Two pairs of arteries supply blood to the brain: the internal carotid arteries and the vertebral arteries.

• Anterior circulation is derived from the internal carotid arteries – supplies the forebrain (cerebrum and diencephalon)
• Posterior circulation is derived from the vertebral arteries – supplies the brainstem, cerebellum and upper spinal cord

Question 23

Describe the positioning of both the vertebral and internal carotid arteries

Answer 23

1. Vertebral arteries
   • Vertebral arteries converge near base of pons to form the basilar artery
   • Basilar artery splits into the right and left superior cerebellar arteries and the posterior cerebral arteries at the level of the midbrain
   • Posterior cerebral arteries send branches – posterior communicating arteries – that connect to the internal carotid arteries
2. Internal carotid arteries
   • Internal carotid arteries branch to form middle cerebral arteries and the anterior cerebral arteries
   • Anterior cerebral arteries are connected by the anterior communicating artery
   • Ring of connected arteries form the circle of Willis at the base of the brain

Question 24

What is the function of the vasculature system?

Answer 24

• Delivery of oxygen (O2)
• Removal of carbon dioxide (CO2)
• Transport (e.g. nutrients, waste products)