Coordination And Response

Question 1

Synapse

Answer 1

Junction between two neurones including a neurotransmitter with vesicles the synaptic cleft and neurotransmitter receptor molecules

Question 2

Sequence as an impulse passes across a synapse

Answer 2

Impulse triggers release of neurotransmitters from the vesicles into the synaptic gap
Neurotransmitters diffuse across to bind with receptor molecules causing the impulse to continue this system ensures that impulses can only travel in one direction

Question 3

Sense organs

Answer 3

Groups of receptor cells that respond to specific stimuli including light sound touch temperature and chemicals

Question 4

Pupil reflex action

Answer 4

High light intensity- pupil reduces its diameter by contracting circular muscles and relaxing radial muscles
Low light intensity-pupil increases its diameter radial muscles contract and circular muscles relax

Question 5

Accommodation

Answer 5

Distant vision the lens needs to refract light less so the suspending ligaments are taught the ciliary muscles are relaxed and the lens is flat
Near vision the lens must refract light more so the ciliary muscles contract the suspensory ligaments are slack and the lens bulges out

Question 6

Distribution of rods and cones

Answer 6

Both types of photoreceptors are found in the retina however the most concentrated area of photo receptors is the fovea

Question 7

Function of rods

Answer 7

Sensitive at sensing light so good for low light levels however they don’t detect colour as well

Question 8

Function of cones

Answer 8

3 different types
Red blue or green
Detect colour and provide better resolution

Question 9

Hormone

Answer 9

Chemical substance produced in a gland and carried j t he blood which alters the activity of one or more target organs

Question 10

Glands and their secretions

Adrenal gland
Pancreas
Testes
Ovaries

Answer 10

Adrenaline
Insulin and glucagon
Testosterone
Oestrogen and progesterone

Question 11

Homeostasis

Answer 11

Control of internal conditions within set limits by negative feedback

Question 12

Control of glucose concentration

Answer 12

Insulin is secreted if the blood glucose concentration had become too high from the pancreas it causes the liver to turn glucose into glycogen
Glucagon is also secreted from the pancreas but when blood glucose concentrations are too low it causes the liver to turn glycogen into glucose

Question 13

Symptoms of type 1 diabetes

Answer 13

Symptoms of type 1 diabetes include feeling faint and lack of energy

Question 14

Methods of maintaining a constant body temperature

Answer 14

Insulation sweating shivering vasodilation vasoconstriction and hairs standing bin end to reduce conduction