2.1 Flashcards Preview

AQA Science B Unit 2 > 2.1 > Flashcards

Flashcards in 2.1 Deck (29):
1

What are receptor cells

Groups of cells found in your sense organs

2

Examples of receptor cells that detect stimuli (5)

Light
Sound
Smell
Taste
Touch
Heat

3

What causes a response?

•information detected by your body is sent along neurons (bundled together in nerves) to the brain
•brain processes the info received
•brain sends impulse to effectors (muscles/glands) causing a response

4

What is a reflex action

Automatic and rapid responses to stimuli

5

Reflect actions involve what 3 neurons?

Sensory
Relay
Motor

6

Sensory

Receptor cells ---> CNS (brain/spinal chord)

7

Relay

Found in CNS
Sensory ---> motor

8

Motor

CNS ---> effectors

9

How longitudinal waves travel from vibrating objects so that we can hear sounds
(3)

•when a drum is struck,it vibrates causing air particles next to it to vibrate
•these vibrations pass energy into neighbouring particles
•this eventually causes your ear drum to vibrate so that we can hear sound

10

What is the human hearing range?

20-20,000 Hz

11

Significance or homeostasis

The body needs to maintain a constant, internal environment called a homeostasis

12

What are hormones?

Chemical substances that control many processes within the body

13

What are hormones secreted by?
Where are they transported to?

Glands
Transported to their target organs in the bloodstream

14

What do high blood glucose levels indicate?

Symptom of diabetes

15

How are type 2 diabetes controlled?

Lifestyle change
Diet/exercise

16

How are type 1 diabetes controlled?

Insulin change
(Insulin dependent diabetes)

17

How levels are monitored/controlled by the pancreas:
Too high

Pancreas releases the hormone insulin into the blood causing the liver to remove Glucose from the blood and store it as insoluble glycogen

18

How levels are monitored/controlled by the pancreas:
Too low-

Pancreas releases glucagon causing the liver to convert glycogen back to glucose and release it into the blood

19

The body maintains a constant temperature using what?

Thermoregulatory centre in the brain

20

Constant temp
Increase/decrease sweating

Cools the body down by evaporation

21

Constant temp
Dilating blood vessels in skin capillaries

Increase blood flow to/heat loss from skin

22

Constant temp
Constricting blood vessels supplying skin capillaries

Decrease blood flow/amounts of heat lost

23

What happens through negative feedback?

Changes are reversed and returned back to normal

24

implications of loud sounds

tittinus
(constant ringing in ear)

25

what must a person do to stay healthy?

the body must keep itself at the right temperature
control sugar content in the bloodstream

26

the healthy body detects external changes using what?

sense organs and the process this information in the brain
nervous system coordinates response causing body to make physiological changes

27

what is involved in a relay

•receptor detects a stimulus
•sensory neurone sends signal to relay neurone
•motor--> effector
•effector produces response

28

info- neurons to brain

Receptors respond to a stimulus and send impulses along sensory--->CNS
•CNS coordinates info and sends impulses along motor---> effectors
•which bring about a response.

29

how does the body maintain constant temp, using centre in brain

•sweating
•constricting
•dilating