Unit 3: Neurobiology and Immunology: Chapter 17: Divisions of the nervous system and neural pathways

Question 1

Functions of nervous system

Answer 1

Collects & analyses sensory information from receptors in contact with external & internal environment.
Appropriate voluntary & involuntary motor responses initiated leading to muscular contractions or glandular secretions.
Some information stored for future use.

Question 2

Divisions of nervous system

Answer 2

Comprises

1. Central nervous system - brain & spinal cord
2. Peripheral nervous system
   a. Somatic - mostly voluntary movement
   b. Autonomic
   i. Sympathetic - prepares body for action. Speeds up responses.
   ii. Parasympathetic - calms body down returning to normal state.

Question 3

Sensory pathway

Answer 3

Carries nerve impulses to central nervous system (CNS) from receptors

Question 4

Receptor

Answer 4

Nerve ending which receives stimuli from external (skin/retina of eye/cochlea of ear) or internal organs (CO₂ receptors in carotid arteries/thermoreceptors in cerebellum).

Question 5

Effectors

Answer 5

End of motor pathways which receive nerve impulses to effect required response (muscular contraction/glandular response) after brain has analysed information received from receptors.

Question 6

Autonomic nervous system

Answer 6

Regulates the internal environment. Control is generally involuntary because it normally works automatically.

Question 7

Antagonistic

Answer 7

Sympathetic & parasympathetic nervous systems are said to be antagonistic i.e. in opposition to one another. They affect many of the same structures but exert opposite effects on them.

Question 8

Homeostasis

Answer 8

Stable internal environment.

Maintained by equal but opposite actions of sympathetic & parasympathetic nervous systems.

Question 9

Adrenaline

Answer 9

Hormone secreted by adrenal gland in response to stimulation of the sympathetic nervous system.
One of the exceptions to the rule of dual innervation of an effector by both sympathetic & parasympathetic nerves.

Question 10

Parasympathetic nervous system

Answer 10

So called ‘rest & digest’. Takes precedence once threat eliciting fight or flight response is past, calming body down to conserve resources and store energy.

Question 11

Negative feedback control

Answer 11

Corrective homeostatic mechanism to return body’s internal environment to within normal limits.