Week 4 - Nervous System (CNS/PNS)

Question 1

What is the function of the brain stem?

Answer 1

• Connects the cerebrum and cerebellum to the spinal cord

* Controls basic body functions such as breathing, heart rate and swallowing

Question 2

What is the function of the thalamus?

Answer 2

Relays incoming sensory information to the appropriate brain area

Question 3

What is the function of the hypothalamus?

Answer 3

Is the master control centre of the autonomic nervous, helping to regulate a variety of body functions through the release of hormones by the pituitary gland (homeostasis)

Question 4

What are some of the bodily functions that the hypothalamus regulates?

Answer 4

• Body temperature
• Blood pressure
• Heart rate
• Oxytocin release

Question 5

What structure acts as an intermediate between the nervous and endocrine system?

Answer 5

Hypothalamus

Question 6

What are the 3 functions of the limbic system?

Answer 6

The limbic system is associated with:
• Memory
• Emotions
• Arousal

Question 7

What is the function of the cerebellum?

Answer 7

Helps coordinate muscle movements and is associated with balance

Question 8

Distinguish between sulcus, gyrus and fissure

Answer 8

• Gyrus - ridge
• Sulcus - groove
• Fissure - deeper groove

Question 9

What are the 12 cranial nerves and indicate whether they have sensory functions, motor functions or both.

Answer 9

• I - Olfactory (s)
• II - Optic (s)
• III - Oculomotor (m)
• IV - Trochlear (m)
• V - Trigeminal (b)
• VI - Abducens (m)
• VII - Facial (b)
• VIII - Vestibulocochlear (s)
• IX - Glossopharyngeal (b)
• X - Vagus (b)
• XI - Accessory (m)
• XII - Hypoglossal (m)

Question 10

What is the spinal cord?

Answer 10

Is a long thin tubular bundle of nerve fibers that extends from the medulla to L1-L2.

Question 11

What structure protect the spinal cord?

Answer 11

• Cerebrospinal fluid (CSF)
• Meninges
• Vertebrae

Question 12

What is white matter?

Answer 12

Bundles of myelinated axons

Question 13

What is grey matter?

Answer 13

Consists of the cell bodies of neurons

Question 14

Distinguish between the dorsal, ventral and lateral horns in terms of function

Answer 14

• Dorsal horn -contains neurons that transmit sensory information to the CNS
• Lateral horn - contains the cell bodies of neurons that innervate smooth and cardiac muscles
• Ventral horn - contain the cell bodies of neurons that innervate skeletal muscles

Question 15

Distinguish between ascending and descending pathways in terms of function

Answer 15

Ascending neural pathways transmit sensory information to the brain, whereas descending pathways transmit motor information to muscles and glands.

Question 16

Name and describe the types of senses transmitted by the 3 ascending tracts in the spinal cord

Answer 16

• Dorsal column - medial lemniscus (DCML): discriminative touch, pressure and proprioception
• Spinothalamic: Pain and temperature
• Spinocerebellar: Proprioception to the cerebellum

Question 17

Name and describe the functions of the 2 descending spinal tracts

Answer 17

• Corticospinal: Motor information to skeletal muscles
• Reticulospinal: Arise from the reticular formation of the brain stem and makes postural adjustments and aids in balance.

Question 18

Define reflex

Answer 18

Is a rapid predictable motor response to a stimulus that acts as a survival mechanism.

Question 19

Describe the 5 components of a reflex arc.

Answer 19

1) Receptor - Detects stimulus
2) Sensory neuron - sends information to the CNS
3) Integration centre - redirects signal to motor neuron
4) Motor neuron - transmits motor information to effector
5) Effector- produces the desired response (contraction or secretion)

Question 20

Describe the stretch reflex (patella tendon reflex) in basic terms

Answer 20

The stretch reflex is initiated when the stretch receptors in the quadriceps detects excessive stretch. This stretching initiates a spinal reflex which causes the quadriceps to contract to cause extension of the knee, and hamstring to receive inhibitory signals to allow the movement to occur.

Question 21

How is the stretch reflex used in everyday life?

Answer 21

It is used to help maintain balance by straightening the knee if excessive stretching of the quadriceps is detected.

Question 22

Why do doctors asses reflexes in a clinical scenario?

Answer 22

It can be used to asses spinal cord damage or peripheral nerve damage.

Question 23

What is the role of brain in reflexes?

Answer 23

The brain is not directly involved in the spinal reflex, but interprets sensory information after the reflex has occurred and can also control the extent of the reflex.

Question 24

What structures make up the diencephalon?

Answer 24

• Thalamus

* Hypothalamus

Question 25

What structures make up the brain stem?

Answer 25

• Mid brain
• Pons
• Medulla oblongata