PNS - CNS with spinal cord anatomy and function and introduces students to the PNS and reflexes

Question 1

Identify the location of the spinal cord within the vertebral column

Answer 1

The spinal cord is encased within the vertebral foramen of each vertebrae.

Question 2

What is the spinal cord protected by?

Answer 2

The spinal cord is protected by the vertebrae, meninges and CSF

Question 3

At which level does the spinal cord terminate?

Answer 3

Between the first and second lumbar vertebrae in an adult

Question 4

What does the structure of the PNS contain?

Answer 4

Nerves, ganglia, plexus and sensory receptors

Question 5

Describe a nerve

Answer 5

A bundle of axons, which provides a structured pathway that supports the electrochemical nerve impulse transmitted along each of the axons

Question 6

Describe a ganglia

Answer 6

A group of nuclei interconnected with the cerebral cortex, thalamus and brain stem

Question 7

Describe a plexus

Answer 7

A network of capillaries and specialised ependymal cells which is found in the cerebral ventricles

Question 8

Describe a sensory receptors

Answer 8

A structure that reacts to a physical stimulus in the environment, whether internal or external. It is a sensory nerve ending that receives info and conducts a process of generating nerve impulse to the transmitted to the brain for interpretation and perception.

Question 9

What are the divisions of the PNS

Answer 9

Somatic and autonomic

Question 10

What is the somatic system responsible for?

Answer 10

Voluntary control of skeletal muscles

Question 11

What is the autonomic system responsible for?

Answer 11

Hypothalamus regulates homeostasis by involuntary control of smooth muscles, cardiac muscles and glands

Question 12

Define a reflex

Answer 12

A fast, predictable ‘involuntary’ response to changes in the environment that helps maintain homeostasis

Question 13

Locations of reflexes?

Answer 13

Spinal reflex and cranial reflex

Question 14

What is the reason for testing reflexes?

Answer 14

To pick up on signs of nerve damage

Question 15

Types of reflexes

Answer 15

Somatic refelex = effector skeletal muscles

Autonomic reflex = effector smooth muscles, glands and cardiac muscles

Question 16

What is the function of the vagus nerve?

Answer 16

Forms part of the involuntary NS and commands unconscious body producers e.g keeping the heart rate constant and controlling food digestion

Question 17

Name the four plexus

Answer 17

Cervical, branchial, lumbar and sacral

Question 18

What is a plexus?

Answer 18

A network of converging and diverging nerve fibres

Question 19

State the location and function of the phrenic nerve

Answer 19

(C3-C5) controls movement of the diaphragm

Question 20

What is the difference between a somatic sensory tract and a somatic motor tract?

Answer 20

A somatic sensory tract ascends and the somatic motor tract descends

Question 21

How many pairs of cranial nerves are there?

Answer 21

12 pairs (in roman numerals)

Question 22

How many pairs of spinal nerves are there?

Answer 22

31 pairs

Question 23

What is the function of the phrenic nerve?

Answer 23

Supplies motor and sensory nerves to the diaphragm. Controls 75% of breathing (C3-C5)

Question 24

Explain the cervical plexus

Answer 24

Anterior and posterior branches of the spinal cord (C1-C2). Supplies parts of the head, neck, shoulders and chest

Question 25

Explain the brachial plexus

Answer 25

Supplies anterior and posterior branches of the spinal nerves (C5-T1). It provides the entire nerve supply of the upper limbs. The major peripheral nerves include

• radial nerve
• medial nerve
• ulna nerve

Question 26

Lumbosacral Plexus

Answer 26

Supplies anterior and posterior branches of spinal nerves (L1-L4 L4-L5 S1- S4). Supplies the external genital and anterior/medial thighn

Question 27

Explain the femoral nerve

Answer 27

L2-4 supplies buttocks, perineum and part of the lower limb

Question 28

Explain the sciatic nerve

Answer 28

L4-S3 supplies posterior thigh and rest of leg below the knee

Question 29

What are dermatomes

Answer 29

An area of skin which sends most of it sensory input to the CNS from a. single pair of spinal nerves

Question 30

The choroid plexuses are located in the?

Answer 30

ventricles of the brain

Question 31

Inferior to the lumbar enlargement, the spinal cord tapers to a conical portion called the

Answer 31

conus medullaris

Question 32

lists the parts of a reflex arc in the correct sequence?

Answer 32

receptor, sensory neuron, association neuron, motor neuron, effector

Question 33

Cerebrospinal fluid is produced by what?

Answer 33

produced by the choroid plexuses

Question 34

Cerebrospinal fluid is reabsorbed by arachnoid villi into the

Answer 34

superior sagittal sinus

Question 35

The basilar artery is formed by the union of the _____ arteries

Answer 35

vertebral