Coordination Flashcards
1
Q
Homeostasis
A
Homeostasis is the control or regulation of the internal conditions of a cell or organism
2
Q
2 types a communication systems
A
The nervous system
The endocrine system
3
Q
things homeostasis controls
A
temperature
pH
blood pressure
glucose conc.
water
4
Q
where is body temperature controlled
A
thermoregulatory centre
5
Q
A
6
Q
how does skin controls temperature
A
contains temperature receptors
7
Q
stimulus
A
change in environment
8
Q
receptor
A
what detects a stimuli
9
Q
coodination centre
A
brain, spinal cord, pancrease
receives and processes information from receptors
10
Q
effector
A
what brings a response to bring back to optimum levels
11
Q
2 things plants need to respond to
A
light and response to gravity
12
Q
tropisms
A
directional growth responses made by plants in response to light and gravity
13
Q
positive tropism
A
if it grows towards stimuli
14
Q
2 trophisms in plants
A
phototropism and geotropism
15
Q
what are plant growth regulators called
A
auxin
16
Q
where is auxin produced
A
tip ofo the shoot and roots
17
Q
auxin in shoots
A
promotes cell elongation
18
Q
auxin in roots
A
inhibits cell elongation
19
Q
what is distribuition of auxin affected by in shoots
A
light and gravity
20
Q
what is distribuition of auxin affected by in roots
A
gravity
21
Q
what happens if a shoot is placed on its side
A
auxin accumulates along the lower side
lower side grows faster than upper side
22
Q
how does auxin distribute down the shoot
A
diffusion
23
Q
what happens if light shines evenly around the tip
A
auxin is distributed evenly
24
Q
what happens when auxin shines on one side
A
auxin concentrates on the shaded side so it grows faster on the shaded side
25
the nervous systems
info sent through as electrical impulses. they pass along nerve cells as neurones
26
what does nervous systems allow
rapid responses to stimuli
27
CNS
Brain and spinal cord
28
endocrine system
info is sent through as chemical substances known as hormones
29
how are hormones carried through the body
blood
30
where are hormones produced
endocrine glands
31
what does the endocrine system target
target cells in specific tissues
32
what does human nervous system consist of
PNS - periphiral nervous system
ALL NERVES IN BODY
CNS- brain and spinal
33
neurones
nerve cells in which electrical signals pass through
34
nerve
bundle of neurones
35
what do neurones consist of
cell body
cytoplasmic extensions (axons and dendrites)
36
axon
main long fibre of neurone
37
why do humans have one long neurone instead of multiple short ones
less time is wasted transferring electrical impulses from one cell to another
38
what is an axon insulated by
fatty myelin sheath
39
what are uninsulated sections of axon called
nodes
40
how do electrical impulses travel to axon
jumps from one node to the next
41
how are axons and dendrites helpful
neurones can connect to many other neurones forming a network
42
types of neurones
sensory
relay
motor
43
sensory neurones
carries impulses from sense organs to the CNS
44
Relay neurones
found inside CNS
connects sensory and motor neurones
45
motor neurones
carries impulses from CNS to effectors
46
how to identify sensory neurones
long and have a cell body branching off the middle of the axon
47
how to identify relay neurones
short and have small cell body at one end with many dendrites branching off it
48
how to identify motor neurones
long and have a large cell body at one end with long dendrites branching off it
49
pathway of nervous system
stimulus
sensory neurone
relay neurone
motor neurone
effector
response
50
what happens when a receptor is stimulated
it produces electrical impulse
51
synapse
when dendrites of 2 neurons meet
52
what is the small gap in between neurones called
synaptic cleft
53
what happens at the synaptic cleft
electrical signals are briefly converted to a chemical signal to cross the gap.
54
neurotransmitters
chemical signalling molecules used to transfer the signal between neurones
55
how are impulses sent across a synapse
1) electrical impulse travels along the first axon which triggers the end of the presynaptic neurone to release chemical messengers
2) these fuse with presynaptic membrane which releases contents to the cleft
3) neurotransmitters diffuse across the synaptic cleft and bind with the receptor molecules on the membrane of the postsynaptic membrane which stimulates second neurone to generate impulse
4) neurotransmitters are destroyed to prevent continued stimulation
56
what do synapses ensure
that impulses travel in one direction only
57
what is a reflex action
an involuntary response which is automatic and rapid which does not involve the concious part of the brain as the coordinator.
58
what do reflex action prevent
minmist damage and aids survival
59
what is a reflex arc
pathway of a reflex response
60
reflex arc for a pin touching finger
The pin (the stimulus) is detected by a (pain/pressure/touch) receptor in the skin on the person's foot
A sensory neurone sends electrical impulses to the spinal cord
An electrical impulse is passed to a relay neurone in the spinal cord
A relay neurone synapses with a motor neurone
A motor neurone carries an impulse to a muscle in the leg (the effector)
When stimulated by the motor neurone, the muscle will contract and pull the foot up and away from the sharp object (the response)
61
what does the retina contain
rods
cones
62
rods
receptor cells that are sensitive to light
63
cones
receptor cells which are sensitive to colour
64
cornea
transparent lens that refracts light as it enters eye
65
iris
controls how much light enters the pupil
66
lens
transparent disc that can change the shape to focus light onto the retina
67
retina
Contains light receptor cells and cones
68
optic nerve
sensory neurone that carries impulses between the eye and the brain
69
pupil
hole that allows the light to enter the eye
70
ciliary muscle
ring of muscle that contracts and relaxes to change the shape of lens
71
suspensory ligaments
ligaments that connects the cilliary muscle to lens
72
sclera
strong outer wall of the eyeball that helps keep an eye in shape and provides a place for muscles to attach
73
fovea
region in retina with highest density of cones where eyes sees good detail
74
aqeous humour
watery liquid between cornea and lens
75
vitreous humour
jelly like liquid filling eyeball
76
choroid
pigmented layer of tissue lining the inside of the scelera that prevents the reflection of light rays inside the eyeball
77
blind spot
point at which optic nerve leaves eye with no receptor cells
78
accomoodation
the way lens brings out fine focusing
79
adapatation of lens
elastic and its shape can be changed when suspensory ligaments attached to it
80
staring at a close image
- cilliary muscles contract
- suspensory ligaments loosen
- lens becomes fatter
- light is refracted more
81
staring at a faw away object
- cillary muscles relax
- suspensory ligaments tighten
- suspensory ligaments pull lens
- lens becomes thinner
- less light refracted
82
pupil reflex
reflex action carried out to protect the retina from damage
83
pupil in dim light
dilates to allow as much light into eye
84
pupil in bright light
constricts to prevent light from entering eye and damaging retina
85
cooling mechanisms in body
- vascodilation: greater volume of blood in capilarries. arterioles go near skin and dilate
- increased sweat to cool off by evaporation
- hair erector muscles relax so hair lies flat to prevent trapping heat
86
what detects change in temperature in the body
temp receptors and hypothalamus
87
hormone
chemical substance produced by a gland and carried by the blood which alters the activity of one or more specific target organs
88
hormones in body
adrenaline
insulin
testosterone
progesterone
oestrogen
89
role of adrenaline
- fight of flight
- produced when body is in danger
- prepares for movement
90
what does adrenaline do
- increases heart rate and breathing rate
- diverts blood flow to muscles
- dilation of blood vessels inside muscles
- breaking down of stored glycogen to glucose
91
what does too high glucose levels lead to
cells losing water by osmosis
92
what does low glucose levels lead too
insufficient glucose for respiration leading to death
93
what works together to control blood glucose levels
pancreas and live
94
what produces insulin
pancreas
95
what happens if blood glucose levels are high
- pancreas produces insulin
- stimulates live to take up glucose and store is a glycogen
96
what happens if glucose levels are low
- pancreas produced glucagon
- causes glucagon stored in liver to convert into glucose and to be released in blood
97
where is testosterone produced
male testes
98
testosterone
responsible for development of secondary sexual characteristics
99
where is progesterone produced
ovaries
100
progesterone
responsible in maintaining the uterine lining during pregnancy
101
where is oestrogen produces
female ovaries
102
oestrogen
responsible for development of secondary sexual characteristics and regulating the menstrual cycle
103
Advanced hormones
Antidiuretic
follicle- stimulating
luteinising
104
ADH
controls water levels
105
what happens when water content in blood falls
- blood is conc.
- pituitary glands release ADH
- causes collecting ducts to be mroe permeable
- water is reabsorbed
106
what releases ADH
Pituitary glands
107
what happens when water content is high
- blood dilute
- less ADH
- collecting duct is less permeable
- less water reabsorbed
- larger volume of urine which is less conc.
108
what releases FSH
Pituitary gland
109
role of FSH
Causes ovary to develop a mature egg cell
110
effect of FSH
Stimulates development of egg cells in ovary and the release of oestrogen
111
What releases LH
Pituitary glandd
112
role of LH
Causes ovary to release a mature egg cell
113
effect of LH
Stimulates the release of an egg cell from ovary and the release of progesterone
114
what produces progesterone
corpus luteum
