2j Flashcards
1
Q
Stimulus
A
- Change in an organism’s surroundings that produces a response
2
Q
Receptor
A
- Cell / Organ that detects a stimulus
3
Q
Effector
A
- Organ that brings about a response
4
Q
Nervous system characteristics
A
- Works by nerve impulses transmitted through nerve cells
- Nerve impulses travel fast and usually have an ‘instant’ effect
- Response is usually short-lived
- Impulses act on individual cells such as muscle fibres, so they have a very localised effect
5
Q
Endocrine system characteristics
A
- Works by hormones transmitted through the bloodstream
- Hormones travel slower and generally take longer to act
- Response is usually longer lasting
- Hormones can have widespread effects on different organs but they only act on organs whose cells have the correct receptors for that hormone
6
Q
CNS
A
- Central Nervous System (CNS)
- Linked to organs by nerves
Consists of:
- Brain
- Spinal cord
7
Q
Impulse
A
- Electrical signal that carries information through nerve cells
8
Q
Synapse
A
- The gap between two neurons
- Messages cross the synapse with chemicals called neurotransmitters
9
Q
Reflex & Reflex arc
A
- Automatic reaction
- Stimulus – (sensory neuron) –> Relay neuron – (motor neuron) – (Effector) –> Response
10
Q
Skin temperature regulation
A
- Cool down: sweating, vasodilation
- Keep warm: vasoconstriction
11
Q
FSH
A
Gland: pituitary
Function: Stimulates egg development and oestrogen secretion / sperm production
12
Q
LH
A
Gland: pituitary
Function: Stimulates egg release / testosterone production
13
Q
ADH
A
Gland: pituitary
Function: Controls water content of the blood (osmoregulation)
14
Q
Insulin
A
- Gland: pancreas
- Function: lower blood glucose
15
Q
Glucagon
A
- Gland: pancreas
- Function: raise blood glucose
16
Q
Adrenaline
A
- Gland: adrenals
- Function: prepare body for physical activity
17
Q
Testosterone
A
- Gland: Testes
- Function: Controls male secondary sexual characteristics
18
Q
Oestrogen
A
- Gland: ovaries
- Function: Controls female secondary sexual characteristics & repairs uterus lining
19
Q
Progesterone
A
- Gland: ovaries
- Function: Completes the thickening of the uterus lining and stops other hormones from causing ovulation.
20
Q
Exocrine gland
A
- Secretes products through a tube (duct)
21
Q
Endocrine gland
A
- Secretes products (hormones) into blood vessels
22
Q
Accommodation
A
- Changes taking place in the eye to allow one to focus on objects at different distances
23
Q
Eye in bright light
A
- Circular muscles contract and radial muscles relax
- Make pupils smaller
24
Q
Eye in dim light
A
- Circular muscles relax and radial muscles contract
- Make pupils larger (dilate pupils)
25
Q
Focus on nearby objects
A
- Convex (rounded) lens
- Ciliary muscles contract and suspensory ligaments slack
26
Q
Focus on distant objects
A
- Concave (flatter) lens
- Ciliary muscles relax and suspensory ligaments tight
27
Q
Eye structure
A
- The eye is surrounded by the sclera, a tough white layer
- The front of the eye (cornea) is transparent, it lets light into the eye and helps refract the light
- The iris is coloured, surrounds the pupil, and is made up of two sets of muscles that control pupil diameter
- Behind the pupil, the lens helps focus light on the retina
- The inside of the eye has the choroid, a black layer and the retina that contains rods and cones which connect to the optic nerve
