Core Terminology 5: Nervous system

Question 1

Stimulus

Answer 1

any change in the external or internal environment to which an organism responds

Question 2

Impulse

Answer 2

information carried along the nervous system

Question 3

Receptors

Answer 3

specialised cells that detect stimuli and convert them to nerve impulses; concentration of receptors with the same function forms an sense organ.

Question 4

Hypothalamus

Answer 4

homeostatic control centre of the brain

Question 5

Effectors

Answer 5

muscles or glands that respond to a nerve impulse

Question 6

Neurons

Answer 6

nerve cells; structural unit of the nervous system

Question 7

Motor neurons

Answer 7

efferent neurons; conduct impulses from CNS to the effectors

Question 8

Sensory neurons

Answer 8

afferent neurons; conduct impulses from receptors to CNS.

Question 9

Interneurons

Answer 9

connector neurons; connect sensory neurons to motor neurons in the spinal cord.

Question 10

Dendrites

Answer 10

short outgrowths of a neuron; conducts impulses to the cell body

Question 11

Axons

Answer 11

longer outgrowths; conducts nerve impulses away from cell body to effectors

Question 12

Myelin sheath

Answer 12

thin waxy membrane that surrounds the neuron; provides electrical insulation

Question 13

Synapse

Answer 13

microscopic gap between two neurons

Question 14

CNS

Answer 14

central nervous system; consist of brain + spinal cord

Question 15

Peripheral nervous system

Answer 15

consist of 12 pairs of cranial + 31 pairs of spinal nerves

Question 16

Autonomic nervous system

Answer 16

made up of sympathetic + parasympathetic systems; work antagonistic; controls the involuntary actions of the nervous system

Question 17

Meninges(3)

Answer 17

Collective name for the membranes that protect the brain and spinal cord

Question 18

Cerebrospinal fluid

Answer 18

fluid surrounding the brain + spinal cord

Question 19

Corpus callosum

Answer 19

The structure that connects the left and right hemispheres of the brain, allowing communication between them

Question 20

Cerebrum

Answer 20

largest part of brain

Question 21

Cerebellum

Answer 21

situated below cerebrum

Question 22

Medulla oblongata

Answer 22

extension of spinal cord; transmits impulses between spinal cord and brain; controls breathing and heart beat

Question 23

Reflex action

Answer 23

a quick; automatic action by an effector in response to a stimulus received by a receptor

Question 24

Reflex arc

Answer 24

functional unit of the nervous system; pathway along which nerve impulses are carried from receptor to an effector to bring about a reflex action.

Question 25

Alzheimer’s disease

Answer 25

• an irreversible brain disease that gradually worsens
• resulting in memory loss
• and decreased intellectual abilities.

Question 26

Multiple sclerosis (MS)

Answer 26

a disorder of the nervous system that is characterised by the breakdown of the myelin sheath of neurons.