Homeostasis - Chapter 11 Flashcards

1
Q

What is homeostasis?

A

The maintenance of constant internal conditions.
This is important as the enzymes in our body work best in these conditions.

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

What are receptors?

A

They detect stimuli in internal and external environments

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

What is a stimulus?

A

A change in the environment

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

What is the coordination centre?

A

Areas that receive and process the information then send out signals and coordinate body response.
This includes brain, spinal cord, and some organs like pancreas.

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

What is an effector

A

A muscle or a gland that produces responses to restore internal conditions.

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

What happens in the nervous system?

A
  1. Receptor detects stimuli - information is sent to the CNS via the sensory neuron
  2. Electrical impulse travels to the CNS to the relay neuron where it coordinates a response
  3. CNS passes this information using impulses via the motor neurons which go to the effector
  4. The effector - muscle or gland - responds by contracting (muscle), or secreting a hormone (glands)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the flow chart for what happens in the nervous system?

A

Receptor –> sensory neurone –> CNS (relay neurone) –> motor neurone –> effector

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

2 ways reaction time can be measured?

A
  1. use ruler drop test
  2. Investigate different factors that affect reaction time such as talking on the phone, listening to music, drinking cola.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are reflexes?

A

Automatic, unconscious responses.
Reflexes bypass the conscious part of the CNS.

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

Reflex Arc Flowchart

A

Receptor –> sensory –> CNS –> relay (in the spinal cord) –> motor –> effector

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

You realise you have had a reflex after it happens. How?

A

An impulse travels up the spinal cord to the conscious part of the brain so you know the reflex has occurred, but only after it’s happened.

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

What is the 2 things that protect the brain?

A
  1. The skull
  2. It is encased in protective membranes called the meninges
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What disease occurs when the meninges get infected?

A

Meningitis

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

4 different parts of the brain.

A

Cerebral Cortex
Cerebellum
Medulla
Hypothalamus

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

What does the cerebral cortex control?

A

Consciousness, intelligence, memory and language.

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

What does the cerebellum do?

A

Coordinates muscular activity and balance (think of Trisha tiptoeing to ring the koyil bell)

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

What does the medulla do?

A

Unconscious activities –> breathing, heartbeat, movements of the gut

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

What does hypothalamus do?

A

Controls body temperature, and has the pituitary gland which produces many hormones

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

How do we learn about the brain?

A
  1. MRI Scans (magnetic resonance imaging)
  2. Comparing a injured person’s brain to a normal brain to see the differences and their possible effects.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Go label an nerve cell

A

Well done

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

What is an eye?

A

A sense organ, which contains many receptors that are sensitive to light intensity and colour.

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

9 structures of eye.

A
  1. Lens
  2. Cornea
  3. Pupil
  4. Iris
  5. Suspensory ligament
  6. Ciliary muscles
  7. Retina
  8. Sclera
  9. Optic Nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the sclera?

A
  • The white outer layer of the eye
  • Relatively tough and strong, to avoid damage to the eye
  • Sclera=Safety
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the cornea?

A
  • Transparent area at the front of eyeball.
  • Allows light into the eye.
  • Has curved surface, which is important for changing the direction of light rays coming into the eye.
  • It makes sure that light rays which enter the eye are focused on the retina.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the iris?

A
  • Controls the size of the pupil
  • Made up of muscles that contract or relax to change the size of the pupil.
  • Control the amount of light reaching the retina.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the pupil?

A

The pupil is the opening at the centre of the iris through which light passes.

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

What happens in bright light?

A
  • Pupil constricts ( gets smaller)
  • Circular muscles contract
  • Radial muscles relax

BRIGHT LIGHT =PC CC RR

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

What happens in dim light?

A
  • Pupils dilate ( get bigger)
  • Circle muscles relax
  • Radial muscles contract

DIM LIGHT = PD CR RC

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

What happens in the lens?

A
  • Changes the direction of light rays to produce a clear image
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the lens held in place by?

A
  • Suspensory ligament
  • Ciliary muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What happens when light rays hit the retina?

A
  • Light sensitive cells are stimulated.
  • They send impulses to the brain, along the sensory neurones in the optic nerve.
  • When the brain receives these messages, it interprets them as a visual image.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens if light is focused behind or in front of the retina?

A

The image becomes blurry.

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

How does light get focused?

A
  • Light is focused by refractions, where it changes directions are it passes through the eye.
  • The cornea changes the direction of the light rays onto the retina.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the process of accommodation?

A
  • The process of changing the shape of the lens of the eye, to focus on near/distant objects.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How can you focus on close object?

A
  • Ciliary muscles contract.
  • Suspensory ligaments loosen.
  • Lens becomes thicker.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What happens to focus on distant objects?

A
  • Ciliary muscles relax
  • Suspensory ligament contract
  • Lens become thinner.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a myopia?

A
  • Short sightedness
  • Distant objects look blurred.
  • Caused because light is focused in
    front of the retina.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is hyperopia?

A
  • Long sightedness
  • Close-by objects are blurry
  • Caused because light is focused
    behind the retina.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What can myopia be treated with?

A

Concave lens glasses

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

What can hyperopia glasses be treated with?

A

Convex glasses

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

What other ways are there to treat eye defects?

A
  • Glasses
  • Hard and Soft contact lenses
  • Laser surgery
  • Replacement lenses in the eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Go label an eye

A

Well done

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

What is the endocrine system?

A

The hormone system

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

What are hormones?

A

chemical messengers (they are also a protein)

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

What is the endocrine system made up of?

A

glands that secrete hormones directly into the bloodstream

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

What does the blood do to the hormones?

A

The blood takes the hormones to their target organs/cells where it binds to receptors to produce a response

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

Difference between nervous system responses and hormonal responses?

A

Hormones can act rapidly, but are a lot slower compared to the nervous system. However hormones have a longer lasting effect

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

What are examples of rapid hormones?

A

Insulin and adrenaline

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

Examples of slow hormones?

A

Growth hormones and sex hormones

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

What are all endocrine glands controlled by?

A

the pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is TSH?

A

Thyroid stimulating hormone –> this hormone stimulates the thyroid gland to release thyroxine, a hormone that is involved in metabloic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is glucose?

A

a sugar used in respiration

53
Q

what is glycogen?

A

the storage form of excess glucose - can be found in the liver and muscle

54
Q

what is glucagon?

A

(glucose is gone, glucagon) a hormone that stimulates the conversion of glycogen into glucose

55
Q

where are hormones insulin and glucagon produced?

A

in the pancreas

56
Q

what does the pancreas do?

A

The pancreas continuous monitors and controls blood glucose concentration using negative feedback

57
Q

what happens when blood glucose levels get too high?

A
  1. Insulin is secreted –>
  2. Insulin allows glucose to move from the blood into cells, where:
  3. either, it is used in respiration OR –>
  4. insulin stimulates the conversion of excess glucose into glycogen
    - When the glycogen stores in our body are full, glucose is converted to and stored as lipids
58
Q

What is Type 1 Diabetes?

A

when the pancreas doesn’t produce enough/any insulin and blood glucose concentration is not controlled. It has a genetic element, and it usually starts in children and teens.

59
Q

what is type 2 diabetes?

A

when your body cells stop responding properly to insulin
- This disease is linked heavily with obesity and lack of exercise

60
Q

Not having insulin is a problem because

A
  1. glucose cannot get into your cells –> so you lack energy and feel tired
  2. Your body breaks down fats and proteins for respiration instead, so you lose weight
61
Q

How is type 1 diabetes treated?

A

Insulin is injected

Pancreas transplants can cure type one diabetes, however there are not enough pancreas donors, and patients will just be exchanging one medicine for another - after an organ transplant patients take immunosuppressants so that the body does not reject and attack the new organ

62
Q

Why is insulin an injection and not oral?

A

Insulin is a protein, so if taken orally, the enzymes in the stomach might break this down

63
Q

For type 2 diabetes, many people can restore their glucose balance by:

A
  1. eating a balanced diet with a healthy amount of carbohydrates
  2. losing weight
  3. doing exercise
    Alternatively there are drugs that:
  4. help insulin work better on the body cells
  5. help the panceras make more insulin
  6. reduce the amount of glucose you absorb from your gut
    - A last resort for type 2 diabetics is insulin injections
64
Q

Who does type 2 diabetes tend to affect?

A

older people more, but younger are starting to get it due to being overweight.

65
Q

What is negative feedback?

A

They maintain a steady state
The response in a negative feedback system normally causes the opposite of the initial change

66
Q

where is the thyroid gland found?

A

neck

67
Q

what does the thyroid gland use from our diet and what does it produce?

A

The thyroid gland in the neck uses iodide from our diet to produce the hormone thyroxine

68
Q

What does thyroxine control?

A

The basal metabolic rate–> how quickly substances are broken down/built up, how much oxygen tissues use, how the brain of a growing child develops

69
Q

How does the thyroxine levels remain stable in adults?

A

due to negative feedback control of the pituitary gland producing TSH (Thyroid Stimulating Hormone)

70
Q

what occurs when we are stressed/angry/excited/frightened?

A

the adrenal glands (on top of kidneys) secrets lots of adrenaline which affects lots of organs

71
Q

what does adrenaline cause?

A

Adrenaline causes:
1. heart rate and breathing rate to increase
2. glycogen in the liver is converted to glucose for respiration
3. the pupils of your eyes dilate to let in more light
4. your mental awareness to increase
5. blood to be directed away from digestive system and towards big muscles of the limbs.

72
Q

B 11.5 - Human Reproduction

A

New Topic

73
Q

What are primary sexual characteristics?

A

Sexual characteristics you are born with.
Boys - testes
Girls - ovaries

74
Q

What is oestrogen?

A
  • The main female reproductive hormone
  • Produced in the ovaries
  • Rising oestrogen levels trigger the development of secondary sexual characteristics.
75
Q

Main changes caused by puberty

A

Female -
- growth spurt
- pubic hair
- development of breast
- fat deposited on hips and thighs
- menstruation begins
- uterus grows
- brain changes and matures.

Male-
- growth spurt
- pubic hair
- deepening of voice
- facial hair grows
- shoulders and chest broadens

76
Q

How long is the menstruation cycle?

A

28 days

77
Q

What is ovulation?

A

The releasing of an egg

78
Q

Give a small overview on the menstrual cycle.

A
  1. egg begins to mature and uterus produces a thickened lining ready for a pregnancy
  2. on the 14th day, an egg is released, to be fertilised.
  3. If the egg is not fertilised in the next 14 days, the lining of uterus begins to break down and the girl gets her period.
79
Q

What are the four hormones involved in the menstrual cycle?

A

FSH
LH
Oestrogen
Progesterone

80
Q

What does FSH do?

A
  • Follicles stimulating hormone
  • Causes the eggs in ovaries to mature
  • Stimulates production of oestrogen
  • Secreted by the pituitary gland
81
Q

What does LH do?

A
  • Luteinising hormone
  • Stimulates the release of the egg at ovulation
  • Secreted in the pituitary gland
82
Q

What does oestrogen do?

A
  • Builds up and thickens the lining of your uterus to prepare for a pregnancy.
  • Inhibits production of FSH
  • Stimulates release of LH
  • Secreted in the pituitary glands.
83
Q

What does progesterone do?

A
  • Maintains the lining of the uterus
  • Inhibits production of FSH and LH
84
Q

Draw the graphs, which show the changing levels of the female hormones at different stages of the menstrual cycle

A

Well done !!

85
Q

Problem with woman having a child close to menopause?

A
  • The woman is less fertile
  • The child has a higher risk of having genetic problems.
86
Q

What is the main male reproductive hormone?

A

Testosterone

87
Q

Function of the lining of the uterus

A
  • Provides protection and food for the developing embryo
88
Q

What are oral contraceptives (contraceptive pills) used for?

A

To prevent pregnancy

89
Q

What does the contraceptive pill contain?

A

Low doses of oestrogen, and some progesterone.
- This will inhibit the production + releasing of FSH ( in the pituitary glands).
- This results in no eggs maturing, and no pregnancy.
- The pill also stops the uterus line developing.
- It also makes the mucus thick in the cervix, to prevent sperm from entering.

90
Q

Side effects/Disadvantages of contraceptive pill?

A
  • Raised blood pressure
  • Breast cancer
  • Thrombosis
91
Q

What do some contraceptive pills only contain?

A

Progesterone

92
Q

Advantages of taking progesterone- only contraceptive pills?

A
  • Fewer side effects
93
Q

Disadvantages of taking progesterone-only contraceptive pills?

A
  • The pill will have to be taken everyday. If not, the artificial hormone will drop in level in the body and cannot try to stop the release of an egg. So, this can still result in an unexpected pregnancy.
94
Q

What are other ways to deliver hormones into the body to prevent pregnancy? ( Hormone-based contraception)

A
  • A contraceptive implant ( lasts 3 years)
  • Contraceptive injection ( lasts 12 weeks)
  • Contraceptive patch ( lasts 7 days)
95
Q

What are the chemical methods to prevent a pregnancy?

A
  • Spermicide - kill/disable the sperms ( not very effective at preventing pregnancy.)
96
Q

What are barrier methods to prevent a pregnancy?

A
  • A condom - prevents egg and sperm from meeting
    No side effects. Can easily be damaged and still cause a pregnancy.
97
Q

What are intrauterine devices?

A
  • small structures inserted into the uterus and last for 3-5 years
98
Q

What is abstinence?

A

Avoiding having sex to avoid becoming pregnant.

99
Q

What are the surgical methods to avoid becoming pregnant?

A
  • Sterilisation - where in men, sperm duct is cut and tied and in women, oviduct is cut and tied
100
Q

What causes infertility?

A
  • Lack of female and/or male hormones
  • Damaged oviducts
101
Q

Common non-hormonal related reasons for infertility?

A
  • Obesity
  • Eating disorders, such as anorexia
  • Age
102
Q

What is a lack of ovulation?

A

When the woman doesn’t produce enough FSH to stimulate the maturing of eggs.

103
Q

How is lack of ovulation treated?

A

Using artificial FSH, as a fertility drug.

104
Q

What is IVF?

A
  • In vitro fertilisation
  • a form of fertility treatment, if 1. oviduct has been damaged or blocked, 2. donor has to be used 3. if there is no obvious cause of long-term infertility.
105
Q

How does IVF work?

A
  1. Mother is given synthetic FSH, to stimulate maturing of some eggs. Then, she is given LH, to bring the eggs to ovulation.
  2. They collect the eggs from the ovary and fertilise with sperm, in a lab.
  3. The fertilised eggs are kept in a special solution, to develop into tiny embryos.
  4. 1 or 2 of the embryos are inserted back into the uterus, and in this way they bypass the faulty tubes.
106
Q

Advantages of fertility treatments

A
  1. Allows couples to have children of their own, if struggling with infertility.
  2. The mature eggs produced by the woman, using fertility drugs, can be collected and stored, until she wants to be pregnant later.
107
Q

Disadvantages of fertility treatments?

A
  1. Expensive
  2. It is not always successful
  3. The use of fertility drugs can have some health risks for the mother
  4. The process of IVF is very emotionally + physically stressful, because it may not be successful on the first cycle.
  5. Increases the chance of a multiple pregnancy ( such as twins and triplets) - this could increase risk for both mother and babies. Multiple births are more likely to lead to stillbirths and premature births.
108
Q

What is phototropism?

A

A plant’s response to light

109
Q

What is gravitropism/ geotropism?

A

A plant’s response to gravity

110
Q

What causes these tropisms?

A

The hormone auxin

111
Q

Effect of auxins on a plant?

A

Sunlight hits one side of the plant. So auxin is secreted on the shaded side of the plant. The auxin causes the cells on the shaded side to elongate causing the plant to bend towards the sunlight. once light falls evenly on both sides of the plant, the auxin will be equal on both sides, so it grows straight again

112
Q

What are gibberellins?

A
  • Plant hormones that important in initiating seed germination
  • At the start they trigger the breakdown of food stores and stimulate the growth of plant stems
113
Q

What is ethene?

A

Important in controlling cell division and important in fruit ripening

114
Q

What is auxin useful for?

A

Auxin is also an effective weedkiller –> when sprayed, it’s absorbed, sending the plant into rapid uncontrolled growth, killing it

115
Q

Ways of using gibberellins?

A
  1. brewing industry - speeds up germination of barley seeds (used to make malt)
  2. Promote flowering throughout the year, especially in pot plants
  3. Increase the size of fruit
116
Q

Describe mitosis?

A
  1. Sub-cellular organelles and DNA duplicates, so that it has 200% of the organelles.
  2. Chromosomes in the cells line up along the equator.
  3. The chromosome splits into two
  4. The cell membrane forms down the middle of the cells and splits, forming two cells
117
Q

What are gametes, in terms of cell types?

A

Haploid cells

118
Q

What are all other body cells, except gametes, in terms of cell types?

A

Diploid cells

119
Q

Describe the characteristics of meiosis?

A
  1. 2 cell divisions
  2. Form 4 cells
120
Q

Describe the similarities between mitosis and meiosis?

A

Both involve DNA replication

121
Q

Describe the differences between mitosis and meiosis?

A
  1. Mitosis only consists of one cell cycle. But meiosis consists of two cell cycles.
  2. Mitosis produces 2 genetically identical cells. Meiosis produces 4 genetically varying cells.
  3. Mitosis produces all other body cells, except gametes. Meiosis only produces gametes.
122
Q

What is negative feedback?

A

The idea of counteracting a stimuli in the body, through hormones and the endocrine system.

123
Q

What are hormones [2]

A

Chemical messengers in the blood

124
Q

What is osmoregulation?

A

Regulating water

125
Q

Where does osmoregulation take place??

A

In the kidneys

126
Q

What is ADH?

A

Antidiuretic hormones

127
Q

How is water levels monitored and controlled by the body?

A

The water level is monitored by the hypothalamus.

It is controlled by the hormone ADH

128
Q
A

l