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Flashcards in Physiology and Health Deck (161)
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1
Q

What do the testes produce?

A

Sperm and testosterone

2
Q

Where is sperm made?

A

In the seminiferous tubules

3
Q

Where is testosterone made?

A

In the interstitial cells

4
Q

What does the prostate gland and seminal vesicles do?

A

Secrete fluids which maintain the mobility and viability of sperm

5
Q

Where are immature ova contained?

A

In the ovaries

6
Q

What are ova surrounded by?

A

A follicle

7
Q

What does the follicle do?

A

Protects the developing ovum and secrets hormones

8
Q

What happens when an ova is mature?

A

It is released into the oviduct and then either discarded during menstruation or fertilised

9
Q

What does the hypothalamus do?

A

Secretes a releaser hormone whose target is the pituitary gland

10
Q

What does the pituitary gland release?

A

FSH
ICSH
LH

11
Q

What does ICSH do?

A

Stimulates testosterone production

12
Q

What does FSH do?

A

In females - stimulates follicle development

In males - stimulates sperm production

13
Q

What does LH do?

A

Stimulates ovulation

Brings the development of the corpus luteum

14
Q

What triggers puberty?

A

ICSH
FSH
LH

15
Q

What does testosterone do?

A

Stimulates sperm production

Activates the prostate gland and seminal vesicles

16
Q

How does negative feedback control testosterone levels?

A

Testosterone builds up in the bloodstream and reaches a level where it inhibits the secretion of FSH and ICSH
Testosterone decreases
Inhibition lowers
Pituitary gland is stimulated
A steady secretion of sperm is maintained

17
Q

How long does the menstrual cycle last?

A

28 days

18
Q

What is the first day of menstruation regarded as?

A

Day one of the cycle

19
Q

What happens during the follicular phase of the menstrual cycle?

A
  • FSH stimulates the development of a follicle
  • Follicle produces oestrogen
  • Oestrogen stimulates proliferation of the endometrium and thins the cervical mucus
  • High levels of oestrogen cause a surge in LH
  • Surge in LH = direct cause of ovulation
20
Q

What happens during the luteal phase of the menstrual cycle?

A
  • Follicle develops into corpus luteum
  • Corpus luteum produces progesterone
  • Progesterone stimulates further vascularisation of the endometrium
  • High levels of ovarian hormones trigger negative feedback on pituitary
  • LH levels drop
  • Corpus luteum can’t be maintained
  • Progesterone levels drop
  • Endometrium can’t be maintained
  • Menstruation occurs
21
Q

What is a males fertility described as?

A

Continuous

22
Q

What is a females fertility described as?

A

Cyclical (lasts 1-2 days)

23
Q

How can a females fertile period be calculated?

A

Temperature (rises around 0.5°C day after ovulation)

Cervical mucus (becomes thin and watery to allow sperm to travel through)

24
Q

How can ovulation be stimulated?

A

Drugs that mimic FSH and LH

Drugs that prevent negative feedback of oestrogen on FSH

25
Q

What is a flaw of stimulating ovulation?

A

Super ovulation can occur

26
Q

What is artificial insemination and when is it useful?

A

Semen samples are collected over a period of time and inserted into female reproductive tract

Useful for low sperm count

27
Q

What is ICSI and when is it useful?

A

Sperm drawn into a needle and injected into egg

Useful if low or defective sperm

28
Q

What is IVF?

A

Eggs are surgically removed and mixed with sperm

The zygotes are incubated and implanted into the uterus

29
Q

What is PGD (pre-implantation genetic diagnosis)?

A

It is used during IVF to identify single gene disorders and chromosomal abnormalities

30
Q

What is a barrier method?

A

A plastic or rubber barrier which blocks passage of sperm through the vagina

31
Q

What is IUD and how does it work?

A

Birth control device
Inserted through the cervix and into the womb
Releases copper which thickens cervical mucus

32
Q

What is male and female sterilisation?

A

Male - vasectomy
Cuts/seals the tube that carries the sperm

Female - cutting of the Fallopian tube

33
Q

What does the morning after pill do?

A

Prevents ovulation

34
Q

What does the combined pill do?

A

Prevents ovulation

Thickens the cervical mucus

35
Q

What does the mini pill do?

A

Thickens cervical mucus

Can stop ovulation

36
Q

What is antenatal screening benefitial for?

A

Identifying the risk of a disorder

37
Q

When is a dating scan carried out and what does it determine?

A

Carried out between 8-14 weeks

Determines pregnancy stage and due date

38
Q

When is an anomaly scan and what does it detect?

A

Carried out Between 18-20 weeks

It detects serious physical abnormalities

39
Q

What do blood and urine tests check for?

A

Marker chemicals in the mother

40
Q

What does diagnostic testing do?

A

Diagnoses a range of conditions

41
Q

What is a karyotype?

A

Shows chromosomes arranged as homologous pairs

42
Q

When is amniocentesis carried out and what does it consist of?

A

Carried out at 14-16 weeks

Sample of amniotic fluid taken

43
Q

When is chorionic villus sampling (CVS) carried out and what does it consist of?

A

Carried out as early as 8 weeks

Sample of placental cells taken

44
Q

Which has a lower chance of miscarriage - amniocentesis or CVS?

A

Amniocentesis

45
Q

What are the traits of autosomal recessive?

A

Expressed rarely

Skips generations

46
Q

What are the traits of autosomal dominant?

A

Expressed in every generation
Every sufferer has an affected parent
When it fails to appear in a generation it dies out

47
Q

What are the traits of autosomal incomplete dominance?

A

Fully expressed form is rare
Partially expressed is more common
Fully expressed sufferer has two partially expressed parents

48
Q

What are the traits of sex linked?

A

More common in males
Passed from mother to son
Y does not carry the gene

49
Q

How is PKU tested for?

A

Heel prick test

50
Q

What is PKU?

A

Substitution mutation which causes the enzyme which converts phenylaline to tyrosine to be non-functional

51
Q

What happens to sufferers of PKU?

A

They are placed on a restricted diet

52
Q

Where does the left side of the heart pump blood to?

A

The body

53
Q

Does the left side of the heart take in oxygenated or deoxygenated blood?

A

Oxygenated

54
Q

Where does the right side of the heart pump blood to?

A

The lungs

55
Q

Does the ride side of the heart take in oxygenated or deoxygenated blood?

A

Deoxygenated

56
Q

What is cardiac output?

A

The volume of blood pumped through the ventricle per minute

57
Q

What is the stroke volume?

A

Volume of blood expelled by each ventricle on contraction

58
Q

What is the heart rate?

A

Number of beats that occur per minute

59
Q

What happens during systole?

A

The cardiac muscle contracts and the heart pumps blood

60
Q

What happens during diastole?

A

The cardiac muscle relaxes and the chambers fill with blood

61
Q

What is the definition of the cardiac cycle?

A

One complete sequence of filling and pumping blood

62
Q

What happens during atrial systole?

A

The remainder of blood is transferred through the AV valves to the ventricles

63
Q

What happens during ventricular systole?

A

AV valves are closed

Blood is pumped out through the SL valves to the aorta and pulmonary artery

64
Q

What is responsible for the sound of the heart?

A

The opening and closing of the AV and SL valves

65
Q

What is used to hear the sound of a heart?

A

Stethoscope

66
Q

What happens during the cardiac cycle?

A
  • diastole - atrium fills with blood and flows into ventricle through AV valves
  • SAN sends electrical impulse across atria to AVN
  • atrial systole - blood forced from atria into ventricles
  • ventricles fill and AV valves close
  • AVN sends impulse down conducting fibres in centre and up ventricle walls
  • ventricular systole - blood forced from ventricles into arteries through SL valves
  • arteries fill with blood, SL valves close
  • diastole
67
Q

What does the SAN do?

A

Sets the rate of cardiac contraction by autorhythmic cells

68
Q

Where is the SAN located?

A

The wall of the right atrium

69
Q

Where is the AVN located?

A

At the base of atria

70
Q

What is the job of the AVN?

A

Sends impulses down conducting fibres between ventricles causing ventricular systole

71
Q

What does the SAN do to cause atrial systole?

A

Sends electrical impulses across atria to AVN

72
Q

What can currents in the heart be detected by?

A

An electrocardiogram

73
Q

What role does the medulla play in connection to the heart?

A

Regulates rate of SAN through antagonistic action of the autonomic nervous system

74
Q

What do sympathetic nerves do?

A

Release nor-adrenaline to increase heart rate

75
Q

What do parasympathetic nerves do?

A

Release acetylcholine to decrease heart rate

76
Q

What happens at point P of a PQRST wave?

A

Atrial systole

77
Q

What happens between QRS of a PQRST wave?

A

Ventricular systole

78
Q

What happens at point T of a PQRST wave?

A

Recovery

79
Q

What happens at point T-P of a PQRST wave?

A

Diastole

80
Q

What happens to blood pressure during ventricular systole?

A

Increases

81
Q

What happens to blood pressure during diastole?

A

Decreases

82
Q

What is used to measure blood pressure?

A

Sphygmomanometer

83
Q

What is a typical blood pressure reading?

A

120/80 mmHg

84
Q

What is the systolic blood pressure?

A

The first reading - taken when the blood starts to flow again

85
Q

What is the diastolic blood pressure?

A

The second reading - taken when the blood begins to flow freely again

86
Q

What is hypertension?

A

Chronic high blood pressure

87
Q

What is hypertension a major risk factor for?

A

Diseases including CVD

88
Q

Where do arteries carry blood?

A

Away from the heart

89
Q

Describe the structure of arteries. (4)

A

Connective tissue containing elastic fibres

Smooth muscle wall (thick) containing elastic fibres

Inner endothelium layer

Narrow lumen

90
Q

What do elastic fibres do?

A

Allow arteries to stretch and recoil to accommodate surge of blood after each heartbeat

91
Q

What does the smooth muscle do?

A

Contract and dilate to control blood flow to where it is most needed

92
Q

What is vasoconstriction?

A

The contraction of arterioles

93
Q

What is vasodilation?

A

The dilation of arterioles

94
Q

Where do veins carry blood?

A

Back to the heart

95
Q

Describe the structure of veins. (4)

A

Connective tissue containing elastic fibres

Smooth muscle wall (thin)

Inner endothelium lining

Wide lumen

96
Q

Why do veins have low friction?

A

Due to their wide lumen

97
Q

Why are veins thin walled?

A

Due to blood being carried back to heart at low pressure

98
Q

What are capillaries job?

A

Exchange vessels

99
Q

How thick is the wall of a capillary?

A

One cell thick

100
Q

What is the order of blood flow?

A

Heart > arteries > capillaries > veins > heart

101
Q

What happens to blood pressure as blood moves away from the heart?

A

Blood pressure decreases

102
Q

What happens to the plasma in the capillaries after it arrives at high pressure from arteries?

A

Much of it is forced out

103
Q

After leaving the capillaries, where does the plasma go?

A

Passes into tissue fluid

104
Q

What is the difference between tissue fluid and blood plasma?

A

Tissue fluid contains no proteins

105
Q

What does tissue fluid contain?

A

A high concentration of soluble food, oxygen and useful ions

106
Q

During exchange of materials, by what movement do things in tissue fluid such as soluble food, oxygen and useful ions move into cells?

A

Diffusion

107
Q

What substances diffuse out from cells into tissue fluid?

A

Carbon dioxide and urea

108
Q

By what movement does the tissue fluid return to the capillaries during exchange of materials?

A

Osmosis

109
Q

What happens to the tissue fluid that does not return to the blood?

A

It is absorbed into thin walled lymphatic vessels and then known as lymph.
The lymphatic system then returns lymph to the circulatory system

110
Q

What is atherosclerosis?

A

The accumulation of fatty material (mainly cholesterol, fibrous material and calcium) forming an atheroma beneath the endothelium

111
Q

What does atherosclerosis cause the artery to do?

A

Thicken and lose it’s elasticity
The diameter of the lumen and blood flow decreases
This results in increased blood pressure

112
Q

What can atherosclerosis lead to?

A

The development of various CVDs such as heart attack, angina, stroke and PVD

113
Q

What is the purpose of blood clotting?

A

To prevent blood loss of damaged cells

114
Q

What happens when an atheroma ruptures?

A

It damages the endothelium and causes the release of clotting factors

115
Q

How is fibrin produced in thrombosis?

A

Prothrombin (inactive enzyme) is turned into thrombin (active enzyme), when clotting factors are released
Thrombin turns fibrinogen into insoluble fibrin

116
Q

What is the job of fibrin in thrombosis?

A

Threads of fibrin from a meshwork which clots the blood, seals the wound and provides a scaffold for the formation of scar tissue

117
Q

What is thrombosis?

A

The formation of a thrombus/blood clot in a blood vessel usually caused by an atheroma rupturing the endothelium

118
Q

What happens if a thrombus breaks loose?

A

It is known as an embolus which is carried along by blood until it blocks a narrow vessel

119
Q

What can thrombosis in a coronary artery cause?

A

A myocardial infarction

120
Q

What is a myocardial infarction?

A

A heart attack

121
Q

What can thrombosis in a coronary artery leading to the brain cause?

A

A stroke

122
Q

How does thrombosis cause health problems in terms of cells?

A

Cells are deprived of oxygen leading to the death of tissues

123
Q

When is an embolus known as an embolism?

A

When it blocks a vessel

124
Q

What are peripheral arteries?

A

Those other than aorta, coronary arteries or carotid arteries

125
Q

What happens when peripheral arteries are affected by atherosclerosis?

A

Leads to PVD

Most commonly affecting the legs due to a limited supply of oxygen

126
Q

What is deep vein thrombosis?

A

A formation of a thrombus in a deep vein, usually the calf

127
Q

What happens if a thrombus breaks free in a vein?

A

It may travel through the heart and block the pulmonary artery - known as a pulmonary embolism

128
Q

What are the two functions of cholesterol?

A

Precursor for synthesis of steroids

Basic component of cell membranes

129
Q

Where is cholesterol synthesised?

A

By all cells

But 25% is produced in liver cells from saturated fats

130
Q

How is cholesterol transported around the body?

A

Attached to lipoproteins

131
Q

What do HDL do?

A

Transport excess cholesterol from body to liver cells for elimination
Which prevents a high level of cholesterol building up

132
Q

What do LDL do?

A

Transports cholesterol from liver to body cells

133
Q

What cells synthesise LDL receptors?

A

Most

134
Q

What do LDL receptors do?

A

Take LDL into the cell where it releases cholesterol

135
Q

What happens once a body cell has an adequate supply of cholesterol?

A

Negative feedback inhibits synthesis of new LDL receptors, therefore reduces amount of LDL cholesterol taken into cells - so it’s left circulating in blood where it may deposit cholesterol in the arteries forming atheroma

136
Q

Does HDL contribute to atherosclerosis?

A

No as it isn’t taken into endothelial walls

137
Q

Why is a higher ratio of HDL-LDL wanted?

A

Results in lower blood cholesterol levels and a reduced chance of atherosclerosis and CVD

138
Q

What can increase HDL levels?

A

Regular exercise and a low saturated fat diet

139
Q

How can cholesterol be reduced?

A

Statins

140
Q

What do statins do?

A

Reduce cholesterol levels by inhibiting an enzyme essential for cholesterol synthesis

141
Q

What does chronic elevation of blood glucose level lead to?

A

The endothelium cells taking in more glucose than normal damaging the blood vessels and the development of atherosclerosis

142
Q

What can happen to small blood vessels that are damaged by elevated glucose levels?

A

May result in haemorrhage of blood vessels in retina, reveal failure or peripheral nerve dysfunction

143
Q

What happens when blood glucose levels are high?

A

Detection by pancreatic receptors
Increase in insulin production
Glucose is converted to glycogen which is stored in the liver
BG levels decrease

144
Q

What happens when blood glucose levels are low?

A
Detection by pancreatic receptors
Increase in glucagon production
Glycogen is converted to glucose
Returns to blood
Increase in BG levels
145
Q

What happens with blood glucose control during exercise or fight and flight?

A

The adrenal glands secrete adrenaline into the bloodstream which overrides normal homeostatic control and inhibits secretion of insulin and promotes secretion of glucagon
This provides the body with the additional energy needed

146
Q

Describe type 1 diabetes - when it’s diagnosed, insulin production and treatment

A

Normally diagnosed in childhood
Unable to produce insulin
Treated with regular insulin injections

147
Q

Describe type 2 diabetes - when it’s diagnosed, insulin production and treatment

A

Normally diagnosed later in life
Usually attributed to obesity or unhealthy lifestyle
Cells have a decreased number of insulin receptors - meaning they’re less sensitive to insulin
Treated with lifestyle modification

148
Q

When may blood glucose concentration rise?

A

After a meal

149
Q

What is an indicator of diabetes?

A

Glucose appearing in the urine due to the kidneys removing glucose after a meal

150
Q

What happens during a glucose tolerance test?

A

It diagnoses diabetes

Blood glucose concentrations are measured after a period of fasting

A glucose solution is then consumed and changes in the patients blood glucose concentration is measured for at least 2 hours

In a diabetic, blood glucose concentration will start higher and increase to a much higher level than that of a non diabetic and takes longer to return to normal

151
Q

What is obesity a major risk factor for?

A

CVD and type 2 diabetes

152
Q

What is obesity characterised by?

A

Excess body fat in relation to lean tissue such as muscle

153
Q

What is BMI?

A

The ideal body weight for each person

154
Q

How is BMI calculated?

A

BMI = body mass/height^2

155
Q

What number of BMI is considered obese?

A

Above 30

156
Q

Why does BMI sometimes falsely classify obesity?

A

Can classify muscular individuals as obese as does not distinguish between body fat and muscle tissue

157
Q

What is obesity caused by?

A

A high fat free sugar diet and a lack of exercise

158
Q

How can you reduce high calorific value per gram?

A

Limit fats

159
Q

What does limiting free sugars do?

A

Removes the issue of having no metabolic energy expended in their digestion

160
Q

How can energy expenditure be increased and how can lean tissue be preserved?

A

By exercise

161
Q

How does exercise help to reduce risk factors for CVD?

A

By keeping weight under control
Minimising stress
Reducing hypertension
Improving HDL blood lipid profiles