Coordination And Control Flashcards
1
Q
What is the nervous system
A
Uses nerve impulses (electrical impulses) to react quickly to a stimulus
2
Q
What is the hormonal system
A
Uses hormones to react slowly to a stimulus
3
Q
What are the components of the nervous system
A
Brain
Spinal chord
Nerves (neurones)
4
Q
What is the thing we respond to
A
Stimulus
5
Q
What does each stimulus affect in the body
A
A receptor
6
Q
What are receptors often grouped in
A
Complex sense organs
7
Q
When a receptor is stimulated what happens
A
Cause an effector (muscle or gland) to produce a response
8
Q
What are receptors and effectors linked by
A
Coordinator
9
Q
What can the coordinator be
A
The brain or sometimes the spinal chord
10
Q
What are the Brian and spinal chord known as together
A
The central nervous system (CNS)
11
Q
What connects the receptors and effectors to the coordinator
A
Neurones which carry information in small electrical nerve impulses.
12
Q
List the response of the nervous system in order
A
Stimulus
Receptor
Coordinator
Effector
Response
13
Q
What are receptors
A
Specialised cells, found in your sense organs, that detect stimuli. Change from one energy into electrical impulses
14
Q
What are effectors
A
Usually a muscle or gland that produces a response to the stimuli
15
Q
What is a neurone
A
Specialised cell that carries electrical impulses around the body
16
Q
What is a nerve impulse
A
Small electrical charge that carries information along a neurone
17
Q
What is a synapse
A
A gap between the neurones
18
Q
What does it mean if a body part is really sensitive
A
It has a lot of small neurones in a small area
19
Q
What does it mean if a body part isn’t sensitive
A
It only has a few large neurones and they are more spreads out
20
Q
What are voluntary actions
A
Actions that we deliberately choose to do and they inclue conscious thought
21
Q
What is a reflex action
A
A action that does not involve conscious thought. They happen automatically and always occur in the same way
22
Q
3 characteristics of reflex’s
A
Occur rapidly
Do not involve conscious control
Happen automatically and in the same way
23
Q
Why is the nerve pathway so short
A
So it uses a minimum number of neurones to transfer the electrical impulses
24
Q
Why is there very few gaps (synapses)
A
To make sure the reflex action is as fast as possible as in synapses electrical impulses slow down
25
3 types of receptor
Sensory
Associations
Motor
26
Why is it good that the axon is a long extension of the cytoplasm
It can vary in length- up to 1m this means a message can be sent long distances from the spinal chord to the foot
27
Why does the axon have branched ends
Allows it to transmit impulses over a greater area and to make connections with other neurones
28
Why do axons have a insulating myelin sheath
A fatty layer that surrounds the axon and helps transmit the impulses at a faster rate
29
What is a synapse
A junction between two neurones
30
Transmission across synapses is caused by
Diffusion of transmitter chemicals (neurotransmitters) across the junction
31
What is the neurotransmitter produced by
End of neurone
32
How does the neurotransmitter diffuse
Quickly between a High concentration to a low concentration across the synapse
33
While synapses may slow transmission, they allow a
Greater degree of control at these junction points
34
Where does the sensory neurone carry impulses
From receptor to the CNS
35
Where does the association neurone carry information
From the sensory neurone and motor neurone
36
Where does the motor neurone carry information
From the CNS to the effector
37
What is the conjunctiva function
Thin transparent protective outer layer and keep cornea moist
38
Cornea function
Transparent part of the eye to let light enter. Causes,some refraction
39
Iris function
Controls how much light enters the eye by changing its diameter
40
Pupil function
Space in iris that allows light to enter the eye
41
Lens function
Refracts light towards the retina
42
Ciliary muscle function
Circular ring of muscle that surrounds lens and changes the shape of the lens
43
Suspensory ligaments function
Attach the lens to the ciliary muscle and changes shape of lens
44
Retina function
Inner coat of eye where light sensitive receptor cells are found
45
Optic nerve function
Contains neurones that carry information from light sensitive receptor cells of the retina to the brain
46
Aqueous humour function
Watery fluid between the cornea and the lens. Keeps pressure correct, helps maintain shape of the eye and lens and allows light to pass through
47
Vitreous humour function
Jelly like fluid between lens and retina. Keeps eye spherical and allows light to pass through
48
What is accommodation
Refers to how the shape of the eye lens is changed to focus light rays on the retina
49
How do light rays arrive when focusing on a distant object
Parallel
50
What does the cornea do go light rays when focusing on a distant object
Refracts rays
51
What happens to the lens when focusing on a distant object
It is thin as little additional refraction is needed to focus light on the retina
52
What happens to light rays when focusing on a near object
Diverge
53
What does the cornea do to rays when focusing on a near object
Refracts rays
54
What is the lens like when focusing on a near object
Thicker as more refraction is needed to focus light on the retina
55
What happens if the ciliary muscle relaxes
It springs out to give a bigger diameter. When this happens suspensory ligaments pull lens and it becomes thinner
56
What happens when the ciliary muscle contracts
Forms a tighter circle with a smaller diameter. The suspensory ligaments then relax and with less pressure on the lens, it’s able to spring back to its original thick shape
57
2 muscles the iris contains
Radial and circular
58
What is the reflex called when ur pupil changes size
Pupillary reflex
59
What happens to the circular muscles in bright light
Contract
60
What happens to the radial muscles in bright light
Relax
61
What happens to the pupil in bright light
Smaller
62
What happens to the circular muscles in dim light
Relax
63
What happens to the radial muscles in dim light
Contract
64
What happens to the pupil in dim light
Bigger
65
What are the specialised cells in the retina that are sensitive to light r
Rod and cone cells
66
What do rod cells work in
Low light intensity and can’t distinguish between coloursm
67
What do cone cells work in
Provide colour vision and only work in bright light
68
Where are cône and rod cells placed in the retina
The cones are concentrated in the centre of the retina and the rods are more numerous at the outer edges
69
What are hormones
Chemical messengers produced by special glands which release them into the blood
70
Hormones only target certain organs what are these organ called
Target organs
71
Look at major glands
Pg 22
72
What is homeostasis
The ability of the body to maintain a constant internal environment
73
4 conditions in the body that must be controlled
Blood and glucose levels/concentration
Water content in the body
Ion content of the body
Temperature
74
Why is it important to maintain a constant internal environment
So enzymes have the correct conditions to work efficiently
Enzymes could denature in the wrong conditions which means cell activities will reduce
75
What is negative feedback
A mechanism to ensure the level of something doesn’t deviate too far from the normal value
76
Difference between nervous and hormonal systems: nature of message
Nervous : nerve impulse (electrical)
Hormonal: a hormone (chemical)
77
Difference between nervous and hormonal systems: mode of transmission
Nervous: travels along a neurone
Hormonal: travels in bloodstream
78
Difference between nervous and hormonal systems: speed of reaction
Nervous : usually rapid
Hormonal : usually slow
79
Difference between nervous and hormonal systems: duration of response
Nervous : usually short lived
Hormonal : often and long lasting
80
Difference between nervous and hormonal systems: area of response
Nervous : localised eg: contraction of a single muscle
Hormonal: wide spread
81
Difference between nervous and hormonal systems: message target
Nervous : messages carried to specific effectors
Hormonal: messages carried to target organs
82
What is insulin
A hormone that prevents concentration of glucose in blood from becoming too high
83
Why is it bad if there is too much glucose
It can damage the bodies cells due to water loss by osmosis
84
Why is it if glucose level fall below the normal Level
Respiration won’t be able to take place in cells so energy production would decrease
85
Where is insulin produced
Pancreas
86
What is the main target organs of insulin
Liver
87
What does insulin cause in the liver
Increased absorption of glucose from the blood so reduces blood glucose concentration
Conversation of excess glucose into glycogen which is stored in the liver and to a lesser extent in muscle cells
Increased respiration
88
What is glucagon
A hormone produced in pancreas when blood glucose levels are low. It acts by reversing the changes insulin brings about in the liver
89
When does type one diabetes normally develops
In childhood (before 20)
90
When does type 2 diabetes tend to develop
40+
91
What is type 1 diabetes treated by
Injection of insulin and a controlled diet where intake of carbs is closely monitored
92
What is type 1 caused by
Lack of insulin
93
How is type 2 caused
Insulin is produced but stops working effectively
94
What is type 2 associated with
Obesity, poor diet , lack of physical activity
95
Treatment to type 2
Reduce sugar intake
Exercise to achieve weight loss
Medication and insulin injections
96
Long term effects of people who have diabetes for long term (possibly undiagnosed or unknown)
Eye damage
Heart disease
Strokes
Kidney damage/failure
97
Why do people with diabetes eat something high in glucose before vigorous exercise
Will cause blood sugar to fall rapidly
Provide glucose to make sure blood glucose level doesn’t drop too quickly
Prevents a hypoglycaemic attack
98
What is osmoregulation
Ability to control amount of water in the body
99
How is water lost
Evaporation in the lungs, whilst sweating, production of urine by the kidneys and in faeces
100
What does osmoregulation ensure
The volume of water gained is equal to the amount lost
101
What is the function of the kidneys
Remove waste , carry out osmoregulation
102
Look at kidney diagram
Pg 34
103
What is the process of réabsorption of water back into the blood by the kidneys controlled by
A hormone, the anti-diuretic hormone (ADH)
104
Where is ADH produced
The part of the brain where water in the blood is monitored
105
Once ADH is produced what happens
It travels to its target organs the kidneys and in the kidney medulla ADH allows more water to pass from the urine into the blood
106
When concentration of water in the blood is too High what happens
ADH production is stopped/reduced
Less ADH allows less water to be re absorbed
107
How do plants respond to stimuli
In such a way that they receive optimum conditions to grow
108
What is phototropism
When a plant reacts to where the light source is and grows towards the light (eg: plant on a window sill will not grow straight upwards but will bend towards the light)
109
Why does phototropism occur
To ensure plant leaves receive more light and so more photosynthesis takes place allowing more growth
110
What is unilateral light
Light coming from one side only
111
How is the response of phototropism controlled
A hormone called auxin
112
Where does auxin accumulate
The side of the stem not exposed to light
113
What does the hormone cause
More rapid growth on the non illuminated side of the stem compared to the illuminated side
114
When is auxin produced
Tip of the shoot and diffuses down the shoot
115
What does the high concentration of auxin cause the cells to grow by
Elongation
