Section 6 - Coordination & Response Flashcards
1
Q
What do receptors do?
A
Detect external stimuli
(eyes, nose, tongue)
2
Q
What are effectors?
A
Bring a response to the stimuli
(muscle cells + cells found in glands)
3
Q
Receptors and effectors
A
- They comunicate via the nervouse system or the hormonal system, sometimes both
- The route taken of this information is called reflex arc.
4
Q
What is the CNS?
A
- Consits of the brain and spinal cord
- It coordinates the response to stimuli
5
Q
Neurones
A
- Three main type: sensory, relay and motor.
- Transmit information using high speed electrical impulses
6
Q
Synapses
A
- connection between two neurones
- Nerve signals transferred by neurotransmiters which diffuse.
7
Q
Relfex arc
A
- When stimulus is detected by receptors a sensory neuroneis sent to the CNS
- In the CNS the sensory neurone passes the message along to the relay neurone
- Relay neurons relay the message to motor neurone
- Motor neurone then travels to the effector
8
Q
Simplified relfex arc
A
- Stimulus
- Receptor
- Sensory neurone
- CNS
- Relay neurone
- Motor neurone
- Effector
- Response
9
Q
Parts of the eye
A
- Sclera
- Cornea
- Iris
- Lens
- Optic nerves
- Fovea
- Pupil
- Conjunctiva
- Ciliary muscle
- Suspensory ligaments
10
Q
sclera
A
tough layer that protects the eye
11
Q
iris
A
control diameter of pupil
11
Q
cornea
A
refracts light into the eye
12
Q
lens
A
focus light into the retina
13
Q
Optic nerves
A
carries impulses to brain
14
Q
accommodation def
A
eye focuses light on the retina by changing the shape of lens
15
Q
Look distance
A
- Ciliary muscles relax allows suspensory ligaments to pull tight
- Makes lens go thin
- Refracts light by smaller amount
16
Q
Look near
A
- Ciliary muslce contract, allows suspensory ligaments slacken
- Lens become fat
- Increases the amount by which refracts light
17
Q
Hormones
A
- Adrenaline
- Insulin
- Testosterone
- Progesterone
- Oestrogen
18
Q
Adrenaline
A
- Source: Adrenal glands
- Role: Prepares body for action
- Effect: Increases heart rate, blood flow + blood sugar level
19
Q
Insulin
A
- Source: Pancreas
- Role: Helps control blood sugar level
- Effect: Stimulates liver to convert glucose into glycogen
20
Q
Testosterone
A
- Source: Testes
- Role: Main male sex hormone
- Effect: Promotes male secondary sexual characteristics
21
Q
Progesterone
A
- Source: Ovaries
- Role: Supports pregnancy
- Effect: Maintains lining of the uterus
22
Q
Oestrogen
A
- Source: Ovaries
- Role: Main female sex hormone
- Effect: Controls menstrual cycle + promotes female secondary sexual characteristics
23
Q
Homeostasis def
A
balancing body functions to maintain a ‘constant internal enviroment’
24
What happens when its cold?
- little sweat is produced
- Blood vessels near the surface of the skin constrict (vasocontriction). Less blood flows near surface
- Shivering increases rate of respiration which transfers more energy
- Hair stand up to create a insulating layer of air
25
What happens when your hot?
- Sweat produced that when evaporated transfers energy to enviroment cooling you down
- Blood vessels close to the surface of skin dilate (vasodilation). Transfers more energy into surroundings
- Hair lie's flat
