Unit 3: Chapter 4 - Divisions Of The Nervous System

Question 1

Ganglia

Answer 1

Groups of cell bodies that only exist outside of the CNS

Question 2

Cranial nerves

Answer 2

12 pairs of cranial nerves arise from the brain (auditory nerve and optic nerve). Most cranial nerves are mixed nerves, they contain fibres that carry impulses to the brain as well as away. (Exist outside CNS)

Question 3

Spinal nerves

Answer 3

There are 31 pairs of spinal nerves that arise from the spinal cord. They are all mixed nerve and each is joined to the spinal cord by two roots. (Exist outside CNS)

Question 4

Sensory fibres

Answer 4

Fibres that carry impulses into the CNS

Question 5

Motor fibres

Answer 5

Fibres that carry impulses away from the CNS

Question 6

Ventral root

Answer 6

An extension of the spinal nerves. Contains the axons of motor neurons that have their cell bodies in the grey matter of the spinal cord

Question 7

Dorsal root

Answer 7

The top root extension of a spinal nerve, contains the axons of sensory neurons that have their bodies in a small swelling on the dorsal root known as the dorsal root ganglion.

Question 8

Dorsal root ganglion

Answer 8

The swelling of the sensory neuron cell bodies on the dorsal root.

Question 9

Grey matter

Answer 9

The central core of the spinal cord

Question 10

White matter

Answer 10

The outer part of the spinal cord

Question 11

Visceral sensory neurons

Answer 11

The general visceral afferent fibers (GVA) conduct sensory impulses (usually pain or reflex sensations) from the internal organs, glands, and blood vessels to the central nervous system. They are considered to be part of the autonomic nervous system.

Question 12

Somatic sensory neurons

Answer 12

The sensory-somatic nervous system is composed of cranial and spinal nerves and contains both sensory and motor neurons. Sensory neurons transmit sensory information from the skin, skeletal muscle, and sensory organs to the central nervous system (CNS).

Question 13

Afferent (sensory) division

Answer 13

The afferent or sensory division transmits impulses from peripheral organs to the CNS.

Question 14

Efferent (motor) division

Answer 14

The efferent or motor division transmits impulses from the CNS out to the peripheral organs to cause an effect or action. The somatic nervous system supplies motor impulses to the skeletal muscles.

Question 15

Autonomic division

Answer 15

Responsible for control of bodies internal environment
Acts without conscious control
Regulated by groups of nerve cells in the medulla oblongata, hypothalamus and cerebral cortex.

Question 16

Somatic (motor) division

Answer 16

The somatic nervous system (SNS or voluntary nervous system) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles. The somatic nervous system consists of afferent nerves or sensory nerves, and efferent nerves or motor nerves.

Question 17

Sympathetic division

Answer 17

Activates the “flight or fight” response and prepares the body for emergency, increases heart rate, increases blood flow, increases perspiration, decreases mobility of large intestine, increases peristalsis in the oesophagus, ect.

Question 18

Parasympathetic division

Answer 18

Generally produces responses that maintain the body in quiet conditions. Nerve endings effectors release acetylcholine.
Decrease and calm down

Question 19

Medulla oblongata

Answer 19

Forms the lower region of the brainstem, connects the brain and spinal cord.
Respiratory, cardiac and vasomotor centres are located here

Question 20

The spinal cord

Answer 20

An extension of the medulla oblongata. Is as thick as your little finger and passes through vertebral foramen (hole at the bottom of the cranium) to the level of the second lumbar vertebrae (bottom of your back just above your pelvis).