coordianation and response- key terms

Question 1

Define central nervous system (CNS)

Answer 1

consists of the brain and spinal cord, which are the areas of coordination.

Question 2

Define peripheral nervous system (PNS)

Answer 2

comprises nerves and neurones, which coordinate and regulate body functions.

Question 3

types of neurones: define nerve impulse

Answer 3

an electrical signal that passes along the nerve cells called neurones

Question 4

types of neurones: define axons

Answer 4

Ensure less time is wasted when the impulse is transferred from one neurone to another

Question 5

types of neurones: define dendrities

Answer 5

Extensions which form a network for easy communication.

Question 6

types of neurones: define motor neurone

Answer 6

Carry impulses from the CNS to effectors (muscles or the glands)

Question 7

types of neurones: define sensory neurone

Answer 7

Carry impulses from the sense organs (sensory receptors) to the CNS.

Question 8

types of neurones: define relay neurone (Interneurone)

Answer 8

The middleman inside the CNS connects sensory to motor neurones.

Question 9

Define reflex action

Answer 9

automatically and rapidly integrates and coordinates the stimuli with the responses of effectors (muscles and glands).

Question 10

Define synapse

Answer 10

a junction between two neurones, consisting of a gap across which impulses pass by diffusion of a neurotransmitter

Question 11

Define sense organ

Answer 11

groups of receptor cells responding to specific stimuli: light, sound, touch, temperature, and chemicals

Question 12

Define cornea

Answer 12

refracts light

Question 13

Define Iris

Answer 13

controls how much light enters the pupil

Question 14

Define lens

Answer 14

focuses light onto the retina

Question 15

Define retina

Answer 15

contains light receptors, some sensitive to light of different colours (Rods and cones)

Question 16

Define optic nerve

Answer 16

carry impulses to the brain

Question 17

Define pupil

Answer 17

A hole which allows light to enter

Question 18

Define hormones

Answer 18

A chemical substance produced by a gland and carried by the blood, altering the activity of one or more specific target organs.

Question 19

Define the hormone and function of Adrenal gland

Answer 19

horomone: Adrenaline
function: Prepares the body for vigorous action

Question 20

Define the hormone and function of Pancreas

Answer 20

hormone: Insulin
function: Reduces the concentration of glucose in the blood

Question 20

Define the hormone and function of Testes

Answer 20

hormone: Testosterone
function: Causes the development of male sexual characteristics

Question 20

Define the hormone and function of Ovary

Answer 20

hormone: Oestrogen
function: Causes the development of female sexual characteristics

Question 21

Define the hormone and function of Pancreas

Answer 21

hormone: Glucagon
function: Increases concentration of glucose in the blood

Question 22

Define homeostasis

Answer 22

The maintenance of a constant internal environment.

Question 23

Define negative feedback

Answer 23

controls the production of hormones and regulates their own production

Question 24

Define type one diabetes

Answer 24

caused by the death of the cells that secrete insulin.

Question 25

Define auxin

Answer 25

Plant hormones or growth substances Controls tropisms It is produced by cells at the tip of the roots and shoots of plants

Question 26

Define gravitropism

Answer 26

a response in which a plant grows towards (positive) or away (negative) from gravity.

Question 27

Define phototropism

Answer 27

a response in which a plant grows towards (positive) or away (negative) from the direction light is coming.

Question 28

Define insulation

Answer 28

provided by fatty tissue retains heat. Hairs become erect to trap warm air by contracting erector muscles and vice versa.

Question 29

Define vasodilation

Answer 29

when it is hot, arterioles, which supply blood to the skin-surface capillaries, dilate (become wider) to allow more blood near the skin surface to increase heat loss (face redder)

Question 30

Define vasoconstriction

Answer 30

when it is cold, arterioles, which supply blood to the skin-surface capillaries, constrict (become smaller) to allow less blood near the skin surface to decrease heat loss

Question 31

Define sweating

Answer 31

the water evaporates, giving a cooling effect

Question 32

Define skin receptors

Answer 32

sense heat, and sensory neurons send impulses to the hypothalamus

Question 33

Define shivering

Answer 33

muscular activity generates heat

Question 34

Define sweat glands

Answer 34

Producing sweat to regulate heat.

Question 35

Define thermoregulatory centre

Answer 35

the hypothalamus controls corrective mechanisms (e.g. sweating and shivering).