Topic 5 - Homeostasis And Response Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is the brain responsible for?

A

Complex behaviours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Whoa is the Brian made up of?

A

Billions on interconnected neurones and has different regions that carry out different functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the cerebral cortex?

A

Outer wrinkly bit - responsible for consciousness, intelligence, memory and language

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the medulla?

A

Attached to spinal cord - controls unconscious activities (like breathing and your heartbeat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the cerebellum?

A

At the back of your brain at the bottom - responsible for muscle coordination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do scientists study the brain and work out which bits do what?

A

Studying patients with brain damage
Electrically stimulating the brain
MRI scans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What makes investigating the brain difficult?

A

It is complex and delicate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is homeostasis?

A

The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does homeostasis do?

A

Maintains optimal conditions for enzyme action all functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does homoeostasis control in the human?

A

Blood glucose concentration
Body temperature
Water levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Give two examples of automatic control systems?

A

Nervous responses chemical responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do all control systems include?

A

Receptors
Coordination centres
Effectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a receptor?

A

Cells which detect stimuli (changes in environment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are coordination centres?

A

They receive and process information from the receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give examples of coordination centres?

A

Brain
Spinal cord
Pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an effector?

A

Muscles or glands which bring about responses which restore optimum levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do automatic control systems keep your internal environment stable?

A

Using a mechanism called negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does the nervous system enable humans to do?

A

React to their surroundings and coordinate their behaviour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Give examples of receptors

A

Taste receptors on tongue

Sound receptors in ears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do muscles and glands respond to information?

A

Muscles contract

Glands secrete hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens to information from receptors?

A

It passes along cells called neurones as electrical impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where are the electrical impulses from receptors sent?

A

The central nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the central nervous system?

A
  • In vertebrates this consists of the brain and spinal cord

- In mammals it is connected to the body by sensory and motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the central nervous system do?

A

Coordinates the response of effectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the order in which a nervous impulse travels?

A

1) stimulus
2) receptor
3) coordinator
4) effector
5) response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are reflex actions?

A

Automatic and rapid actions that do not involve the conscious part of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is a synapse?

A

The connection between two neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How is the nerve signals transferred through the synapse?

A

It is transferred by chemicals which diffuse (move) across the gap and the chemicals set off a new electrical signal in the next neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is stage one of the reflex arc?

A

A stimulus (a bees sting) is detected by receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is stage two of the reflex arc?

A

Impulses are sent along a sensory neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is stage three of the reflex arc?

A

The impulses reach a synapse between the sensory neurone and the relay neurone and trigger chemicals to be released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is stage four of the reflex arc?

A

The impulses pass along the relay neurone in the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is stage five of the reflex arc?

A

The impulse reaches a synapse between the relay neurone and a motor neurone and chemicals are released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is stage six of the reflex arc?

A

The impulses travel along the motor neurone to the effector which contracts as a response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Why is the reflex arc quicker than normal responses?

A

You don’t have to think about the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

how can you measure reaction time?

A

Ruler drop test

Computer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How do you test reaction time using a computer?

A

The person being tested has to click the mouse as soon as they see a stimulus on the screen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the benefits of using computers to test reaction time

A
  • Give more precise readings as they remove the possibility of human error
  • Record time in milliseconds so it is more accurate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the Sclera?

A

Tough supporting wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the cornea

A

Transparent outer layer found it front of eye that refracts light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the iris?

A

Contains muscles that allow it to control diameter of the pupil and therefore how much light enters the eye
(Cover edges of lens just in-front)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the pupil?

A

The hole in the middle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the lens?

A

Focuses light onto the retina

Behind the pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the retina?

A

Contains receptors cells sensitive to light intensity and colour
(At back of eye)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What do the ciliary muscles and suspensory ligaments do?

A

Control the shape of the lens

Top (suspensory) and bottom (ciliary) of lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the optic nerve?

A

Carries impulses from the receptors on the retina to the brain
(Back and bottom of eye ball)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the eye?

A

Sense organ containing receptors sensitive to light intensity and colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are the functions of the eye the relate to it’s structure?

A

Accommodation to focus on near or distant objects

Adaptation to dim light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is accommodation in the eye?

A

The process of changing the shape of the lens to focus on near or distant objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

How does the eye focus on a near object?

A
  • The ciliary muscles contract
  • The suspensory ligament loosen
  • The lens is then thicker and refracts light rays strongly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How does the eye focus on a distant object?

A
  • The ciliary muscles relax
  • The suspensory ligament are pulled tight
  • The lens is then pulled thin and only slightly refracts light rays
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are two common defects of eyes?

A

Myopia (short sightedness)

Hyperopia (long sightedness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Why do the defects of eyes happen?

A

Rays of light do not focus on the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How are the defects of eyes treated?

A

Spectacle lenses which refract the light rays so that they focus on the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the new technologies to treat eye defects?

A
  • Hard and soft contact lenses
  • Laser surgery to change the shape of the cornea
  • Replacement lens in the eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the iris reflex?

A

Adjusting the eye for bright light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How does the iris reflex work in bright light?

A

A reflex is triggered that makes the pupil smaller
The circular muscles in the iris contract and the radial muscles relax to reduce the amount of light that can enter the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How does the iris reflex work in dim light?

A

The radial muscles contract and the circular muscles relax making the pupil wider

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

When does long sightedness occur?

A

When the lens is the wrong shape and doesn’t refract the light enough or when the eyeball is too short

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What happens to the light rays in long sighted eyes?

A

The images of new objects are brought into focus behind the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How can you correct long sightedness?

A

Using glasses with a convex lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

When does short sightedness occur?

A

When the lens is the wrong shape and refracts light too much or when the eyeball is too long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What happens to the light rays in short sighted eyes?

A

The images of distant objects are brought into focus in front of the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How can you correct shortsightedness?

A

Using glasses with a concave lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What are the advantages of contact lenses?

A

Convenient, light weight and almost invisible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are the two types of contact lenses and which is better?

A

Hard lenses and soft lenses

Soft lenses are more comfortable but carry a higher risk of eyes infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is laser eye surgery?

A

Laser is used to vaporise tissue, changing the shape of the cornea - slimming it down makes it less powerful and can improve short sight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are the advantages of laser eye surgery?

A

The surgeon can precisely control how much tissue the laser takes off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are the disadvantages of laser eye surgery?

A

There is a risk of complications such as infection or the eye reacting to make your vision worse than before

70
Q

What is replacement lens surgery?

A

The natural lens of the eye is removed and an artificial lens, made of clear plastic, is inserted in its place

71
Q

What are the disadvantages of replacement lens surgery?

A

Carries higher risk than laser eye surgery as it involves work inside the eye including possible damage to the retina and blindness

72
Q

How is body temperature monitored and controlled?

A

By the thermoregulatory centre in the brain

73
Q

What does the thermoregulatory centre contain?

A

Receptors sensitive to temperature of the blood

74
Q

How does the thermoregulatory centre receive information?

A

The skin contains temperature receptors and sends nervous impulses to the thermoregulatory centre

75
Q

What happens if the body temperature is too high?

A

Blood vessels dilate (vasodilation) and sweat is produced from the sweat glands - transferring energy from the skin to the environment

76
Q

What happens if the body temperature is too low?

A

Blood vessels constrict (Vasoconstriction),sweating stops, hairs snags up to trap an insulating layer of air and skeletal muscles contract (shiver)

77
Q

What is the endocrine system?

A

Composed of glands which secrete chemicals called hormones directly into the bloodstream

78
Q

What are hormones?

A

Chemical molecules released directly into the blood

79
Q

How are hormones transported around the body?

A

The blood carries the hormone to the target organ where it produces an effect

80
Q

What do hormones do?

A

Control things in organs and cells that need constant adjustment

81
Q

Where are hormones produced?

A

Various glands called endocrine glands

82
Q

Compare hormones and nerves?

A
  • Nerves are very fast but act for a short time in a precise area
  • hormones have slower actions but act for a long time in a more general way
83
Q

What is the pituitary gland?

A

The master gland in the brain which secretes several hormones that regulate body conditions, these hormones act on other glands and direct them to release hormones that bring about change

84
Q

Where is the pancreas and what does it do?

A
  • Produces insulin which is used to regulate the blood glucose level
  • in front of kidneys
85
Q

Where is the thyroid and what does it do?

A
  • In the throat

- produces thyroxine which is involved in regulating things like the rate of metabolism, heart rate and temperature

86
Q

Where is the adrenal gland and what does it do?

A
  • Above/on top of the kidneys

- produces adrenaline which is used by the body for flight or fight response

87
Q

Where are the ovaries and what do they do?

A
  • in the lower abdomen connected to the uterus

- produce oestrogen, which is involved in menstrual cycle

88
Q

Where are the testes and what do they do?

A
  • The male ball sack

- produce testosterone which controls puberty and sperm production

89
Q

What does the pancreas monitor and control?

A

Blood glucose concentration

90
Q

How does the pancreas react if the blood glucose concentration is too high?

A

The pancreas produces the hormone insulin that causes glucose to move from the blood into the cells

91
Q

How do the liver and muscles aid the pancreas for blood glucose concentration?

A

Excess glucose is converted to glycogen storage

92
Q

How does glucose get into the blood?

A

Eating food containing carbohydrates puts glucose into the blood from the gut

93
Q

How can you remove glucose from the blood?

A

Normal metabolism of cells and vigourous exercise

94
Q

What is the negative feedback cycle if the blood glucose level is too high?

A

The pancreas secretes insulin so did you close it moves from blood into the liver and muscle cells so blood glucose is reduced

95
Q

What is the negative feedback cycle if the blood glucose level is too low?

A

The pancreas secrete glucagon so glucose is released into the blood by liver (as glucagon enters liver) and blood glucose is increased

96
Q

What does insulin in the liver do?

A

Turns glucose into glycogen

97
Q

What does glucagon in the liver do?

A

Turns glycogen into glucose

98
Q

What is type one diabetes?

A

A disorder in which the pancreas fails to produce sufficient insulin and uncontrolled high blood glucose

99
Q

How can type one diabetes normally be treated ?

A

Insulin injections to make sure glucose is removed from blood quickly once food has been digested

  • very effective
  • amount depends on diet and activity levels
100
Q

How can someone with type 1 diabetes help to prevent high blood glucose?

A

Limiting the intake of food which in simple carbohydrates and taking regular exercise

101
Q

What is Type II diabetes?

A

When the body cells no longer respond the insulin produced by the pancreas

102
Q

How can you treat Type II diabetes?

A

A carbohydrate controlled diet and exercise regime

103
Q

What is a risk factor for Type II diabetes?

A

Obesity

104
Q

How does water leave the body?

A

Via the lungs during exhalation

105
Q

What is lost from the skin through sweat?

A

Water, ions and urea

106
Q

Can you control water, ion or urea loss by the lungs or skin?

A

No

107
Q

How are excess water, ions and urea removed?

A

Via the kidneys in urine

108
Q

What happens if body cells lose or gain too much water by osmosis?

A

They do not function efficiently

109
Q

What does the digestions of proteins from the diet result in?

A

Excess amino acid‘s which need to be extracted safely

110
Q

What happens to amino acid in the liver?

A

They are deaminated to form ammonia which is toxic and is immediately converted to urea for safe excretion

111
Q

What is deamination?

A

A process used to break down amino acid for energy

112
Q

What do the kidneys do?

A

Produces urine by filtration of the blood and selective reabsorption of useful substances such as glucose, some ions and water

113
Q

What is water level in the body controlled by?

A

The hormone ADH which acts on the kidney tubules

114
Q

When is ADH released?

A

The pituitary gland releases it when the blood is too concentrated

115
Q

What does ADH do?

A

It causes more water to be reabsorbed back into the blood from the kidney tubules controlled by negative feedback

116
Q

How are people who suffer from kidney failure treated?

A

By organ transplant or using kidney dialysis

117
Q

How does dialysis work?

A

In a dialysis machine The person’s blood flows between partially permeable membranes (for ions and waste substances e.g. small molecules) surrounded by dialysis fluid

118
Q

How does the dialysis fluid work?

A

It has the same concentration of dissolved ions and glucose as healthy blood which means that useful dissolved ions and glucose won’t be lost only waste substances diffuse across the barrier

119
Q

What are the advantages of dialysis?

A

Don’t have to wait for a donor

120
Q

What are the disadvantages of dialysis?

A
  • Regular unpleasant sessions which are 3 to 4 hours long
  • expensive
  • May cause blood clot or infections
121
Q

What are the advantages of kidney transplants?

A

Cheaper and easier in the long run than dialysis

122
Q

What are the disadvantages of kidney transplants?

A
  • Can be rejected

- long waiting list‘s

123
Q

During puberty what do reproductive hormones cause?

A

Secondary sex characteristics to develop

124
Q

What is oestrogen?

A

The main female reproductive hormones produced in the ovaries

125
Q

What is ovulation?

A

At puberty eggs begin to mature and one is released approximately every 28 days

126
Q

What is testosterone?

A

The main male reproductive hormones produced by the testes

127
Q

What does testosterone do?

A

Stimulate sperm production

128
Q

Which hormones are involved in the menstrual cycle or a woman?

A

FSH
LH
oestrogen
Progesterone

129
Q

What is FSH?

A

Follicle stimulating hormone that causes maturation of an egg in the ovary and stimulates ovaries to produce oestrogen
Produced in pituitary gland

130
Q

What is LH?

A

Luteinising hormone that stimulates the release of the egg at day 14
Produced in pituitary gland

131
Q

What do oestrogen and progesterone do in the menstrual cycle?

A

Maintain the uterus lining (when the level of progesterone falls, the lining breaks down)
Produced in ovaries

132
Q

How do you oestrogen and progesterone effect the release of LH and FSH?

A

Oestrogen stimulates release of LH and inhibits release of FSH
progesterone inhibits release of LH and FSH

133
Q

What is stage one of the menstrual cycle?

A

Menstruation starts and the uterus lining breaks down for about four days

134
Q

What is stage two of the menstrual cycle?

A

uterus lining build up again from day 4 to14 into a thick spongy layer full of blood vessels ready to receive a fertilised egg

135
Q

What is stage three of the mental cycle?

A

And egg develops and is released from the ovary at day 14 (ovulation)

136
Q

What is stage four of the menstrual cycle?

A

The wall is then maintained for about 14 days until day 28, if no fertilised egg has landed on the uterus wall the spongy lining starts to break down

137
Q

How can fertility be controlled?

A

A variety of hormonal and nonhormonal methods of contraception

138
Q

What are the hormonal methods of contraception?

A
  • Oral contraceptives that contain hormones
  • injection, implant or skin patch
  • intrauterine devices
139
Q

What are the nonhormonal methods of contraception?

A
  • Barrier methods
  • spermicidal agents
  • abstaining from intercourse
  • surgical methods of sterilisation
140
Q

What are oral contraceptives?

A

Contain hormones to inhibit FSH production so that no eggs mature

141
Q

What is injection, implant or skin patch of progesterone?

A

Slow release progesterone to inhibit the maturation and release of eggs for a number of months or years

142
Q

What are barrier methods?

A

Prevent the sperm reaching an egg such as condoms and diaphragms

143
Q

What are intrauterine devices?

A

Prevent the implantation of an embryo or release of a hormone

144
Q

What do spermicidal agents do?

A

Kill or disable sperm

145
Q

When do you abstain from intercourse?

A

When an egg may be in the oviduct

146
Q

What is sterilisation?

A

Cutting or tying the fallopian tube’s in a female or cutting or tying the sperm duct in a male

147
Q

How do you do use of hormones in modern reproductive technologies treat infertility?

A

Giving FSH and LH in a fertility drug to a woman so that she can then become pregnant in the normal way

148
Q

What is IVF?

A

In vitro fertilisation treatment involves giving a mother FSH and LH to stimulate the maturation of several eggs

149
Q

What happens once the eggs have matured in IVF?

A

They are collected from the mother and fertilised by sperm from the father in the lottery so that the fertilised egg is developed into embryos

150
Q

At what stage are the embryos inserted into the mothers uterus?

A

At the stage when they are tiny balls of cells, one or two embryos are inserted

151
Q

What are the disadvantages of IVF?

A
  • Very emotionally and physically stressful
  • success rate are not high
  • can lead to multiple births
152
Q

When is adrenaline produced?

A

Produced in the adrenal grams in times of fear or stress

153
Q

What does adrenaline do?

A

Increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles preparing the body for flight or fight

154
Q

What is thyroxine?

A

A hormone produced in the thyroid gland that stimulates the basal metabolic rate and plays an important role in growth and development

155
Q

How are thyroxine levels controlled?

A

By negative feedback

156
Q

Why do plants produce hormones?

A

To coordinate and control growth and responses to light and gravity

157
Q

What is phototropism?

A

Coordinating and controlling growth and responses to light

158
Q

What is gravitropism/geotropism?

A

Coordinating and controlling responses to gravity

159
Q

What causes unequal growth rates in plant roots and shoots?

A

Unequal distribution of auxin

160
Q

What does ethene control?

A

Cell division and ripening of fruit

161
Q

What do gibberellians do?

A

They are important in initiating seed germination

162
Q

Where are plant growth hormones used?

A

Agriculture and horticulture

163
Q

What are auxins used for?

A
  • as weed killers
  • as rooting powders
  • promoting growth in tissue culture
164
Q

How do auxins work as weed killers?

A

They disrupt their normal growth patterns which soon kills them whilst leaving the grass and crops untouched

165
Q

How do auxins work as rooting powder?

A

Adding rooting powder to cuttings will produce roots rapidly and start growing as new plants enabling clones to grow very quickly

166
Q

How do auxins work in tissue culture?

A

Adding them to growth mediums to stimulate the cells to divide and form both roots and shoots

167
Q

How is ethene used in the food industry?

A

To control ripening of fruit during storage and transport

168
Q

What can gibberellins be used for?

A
  • to end seed dormancy
  • to promote flowering
  • to increase fruit size
169
Q

How do gibberellins end seed dormancy?

A

They alter the conditions to allow seeds to germinate at times of year that they wouldn’t normally and helps all seeds in one batch to germinate at the same time

170
Q

How do gibberellins induce flowering?

A

Allows plants to flower without any change in their environment and can be used to grow bigger flowers