Unit 2: Book 2 Flashcards
(135 cards)
1
Q
What is the heart? 💚
A
A muscular pump
2
Q
What is blood?💚
A
Fluid connective tissue
3
Q
What are the blood vessels ?💚
A
Arteries, veins and capillaries
4
Q
Where does blood flow away from the heart in?💚
A
The arteries
5
Q
Where does the blood flow back to the heart in?💚
A
The veins
6
Q
What happens when the blood travels away from the heart💚
A
There is a decrease in blood pressure
7
Q
What supplies oxygenated blood to all parts of the body💚
A
Arterial branches of the aorta
8
Q
Where does deoxygenated blood leave the organs💚
A
Through the veins
9
Q
What returns the blood to the heart💚
A
The vena cava
10
Q
What provides the heart with oxygenated blood💚
A
The coronary artery
11
Q
What returns deoxygenated blood to the circulation💚
A
The coronary vein
12
Q
What is different about the pulmonary system💚
A
The pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood
13
Q
What does the hepatic portal vein do🧡
A
Carries blood from the capillary bed of the intestine to the capillary bed of the liver
14
Q
What is the lumen❤️
A
The central cavity of a blood vessel
15
Q
What is the lumen lined with💚
A
The endothelium
16
Q
What are thicker, veins or arteries💚
A
Arteries have a thick middle layer with more elastic fibres
17
Q
What do elastic fibres do💚
A
Enable the artery to pulsate , stretch and recoil, thereby accommodating the surge of blood after each contraction of the heart
18
Q
What causes vasodilation🧡
A
The contraction or relaxation of the smooth muscle
19
Q
What is vasodilation🧡
A
The circular muscle in the arteriole wall is relaxed and the lumen is wider
20
Q
What is vasoconstriction🧡
A
The circular muscles are contracted and the lumen is narrower
21
Q
Where do veins carry blood❤️
A
Back into the heart
22
Q
Are veins thinner than arteries, and why💚
A
Yes, as the outer muscular layer of the connecting tissue containing layers of elastic fibres in the vein are thinner than those in artery because blood flows along a vein at low pressure
23
Q
What lumen is wider, vein or artery💚
A
Vein
24
Q
Why are valves present in veins💚
A
To prevent the back flow or blood
25
How is blood transported from the arterioles to venules💚
The capillaries
26
What takes places through the capillary walls❤️
All exchange of substances between blood and living tissue
27
What are capillary walls composed of💚
Endothelium
28
What is plasma💚
A watery yellow fluid containing dissolved substances such as glucose, amino acids, blood cells, platelets and plasma proteins
29
Is blood arriving at the arteriole end of a capillary bed at a higher or lower pressure than blood in the capillaries💚
Higher
30
What is pressure filtration🧡
As blood is forced into the narrow capillaries, it undergoes pressure filtration
31
What does tissue fluid contain🧡
A high concentration of dissolved food, oxygen and other useful substances
32
Where does much of the tissue fluid return to❤️
In the capillaries at the venule end of the capillary bed
33
What does tissue fluid lack❤️
Plasma proteins, which are too large to be filtered through the capillary walls, so it has a higher water concentration then the blood plasma
34
Where are some of the tissue fluid absorbed by🧡
Thin walled lymphatic vessels
35
What is lymph💚
When the tissue fluid is in the lymphatic vessel it is called lymph
36
What is flow of lymph brought
| about by💚
The vessels being compressed when muscles contract during breathing or body movement
37
What do larger lymph vessels have💚
Valves to prevent back flow
38
how do lymph vessels return their contents to the blood🧡
Via two lymphatic ducts
39
What is the heart divided into and what are they called💚
4 chambers, two atria and two ventricles
40
What does the right atrium receive and where does it come from🧡
Deoxygenated blood from all parts of the body via the Vena cava
41
What passes into the right ventricle💚
Deoxygenated blood passes into the right ventricle before pressing the heart the pulmonary artery
42
What do valves do💚
Prevent the backflow of blood
43
What valves are present at the origins of the pulmonary artery and the aorta💚
Semi lunar
44
What is cardiac output🧡
The volume of blood out of a ventricle per minute
45
What is heart rate💚
This is the number of heart contracts per minute which correspond to the pulse rate
46
What is stroke volume🧡
This is the volume expenses by each ventricle on contraction
47
How do you calculate the cardiac output💚
CO= HR (heart rate) x SV (stroke volume)
48
If a person is fit will the quantity of cardiac muscle present in their heart wall be greater or smaller💚
Greater
49
Is a fit persons stroke volume greater or smaller💚
Greater
50
What is the cardiac cycle💚
The pattern of contraction and relaxation during one complete heart beat
51
What is systole❤️
Contraction
52
What is diastole💚
Relaxation, during diastole, the god returning to the atria flows into the ventricles
53
What is the average length of one cardiac cycle
0.8 seconds
54
What happens when atrial pressure exceeds the pressure in the ventricles
The AV valves are pushed open and the blood enters the ventricles
55
What is atrial systole
during atrial systole, the two atria contract simultaneously and send the remainder of the blood into the ventricles through the AV valves to the ventricles which are still in a state of ventricular diastole
56
What is ventricular systole
This stage involves the contraction of the ventricles and the closure of the AV valve, the pressure exerted on the blood in the ventricles causes the semi lunar valves to be pushed open as blood is pushed out through the SL valves, blood is then pumped out from the heart into the aorta
57
What regulates heart rate
The medulla, it regulates the rate of the SAN (sino atrial node) through the antagonistic action of the autonomic nervous system
58
What does the cardio accelerator Center do
Sends nerve impulses via the sympathetic nerve to the heart
59
What results in an increase in heart rate
An increase in the number of nerve impulses arriving at the pacemaker via the sympathetic nerve results in an increase in heart rate
60
What does the cardio inhibitor Center do
Sends its information via a parasympathetic nerve to the heart
61
What does antagonistic mean
They have opposite effects on the same part of the body
62
What releases adrenaline
Under certain circumstances, such as stress or exercise, the sympathetic nervous system acts on the adrenal glands making them release the hormone adrenaline
63
What does adrenaline do to the pacemaker
Makes the pacemaker generate cardiac impulses at a higher rate- bringing about an increase in heart rate
64
What does the sympathetic nerve release and what does it do
Noradrenaline which increases heart rate
65
What does the parasympathetic nerve release and what does it do
Acetylcholine which decreases heart rate
66
What does ECG stand for
Electrocardiogram
67
Where does electrical activity generate in the heart
In the sino atrial node in the right atrium
68
What are the three distinct waves in an ECG
P, QRS and T
69
What does P mean on an ECG
P corresponds to the wave of electrical excitation spreading over the atria from the pacemaker
70
What does QRS mean on an ECG
QRS represents the wave of excitation through the ventricles
71
What does T mean on an ECG
T corresponds to the electrical recovery of the ventricles at the end of the ventricular systole
72
How is blood pressure generated
By the contraction of the ventricles of the heart
73
Where is blood pressure highest
In the large elastic arteries (aorta and pulmonary artery)
74
What happens to blood pressure during ventricular systole
It increases
75
What happens to blood pressure during ventricular diastole
It decreases
76
What is blood pressure
The force exerted by blood against the walls of blood
77
Where is the highest and lowest value of blood pressure
The highest value is in the aorta and lowest in the vena cava
78
What does a sphygmomanometer do
Measure blood pressure
79
What is hypertension
Hypertension is prolonged elevation of the blood pressure when at rest
80
What is the typical blood pressure reading for a young adult
120/80 mmHg
81
What is hypertension a risk for
Coronary heart disease and strokes
82
What causes hypertension
Overweight, people who don’t get enough exercise, fatty diet, too much salt, excessive alcohol, continuous stress
83
what is atherosclerosis
formation of plaques, or artheromas, beneath the inner lining in the wall of an artery
84
what are atheromes made from
cholesterol but in time they become enlarged by the addition of calcium and more cholesterol
85
what do larger atheromas lead to
- reduction in the diameter of the artery lumen
- an increase in blood pressure
- larger plaques may become hardened by calcium and this causes arterial walls to become thicker and lose their elasticity
86
what conditions can atherosclerosis lead to
coronary heart disease, strokes, heart attack, peripheral vascular disease
87
what is thrombosis
the formation of a blood clot (thrombus) in a blood vessel
88
how does prothrombin become thrombin
in the presence of damaged cells
89
what does thrombin promote
thrombin prompts the conversion of a soluble plasma protein called fibrinogen into insoluble fibrin threads- eventually becomes a blood clot
90
how does thrombosis happen
as an atheroma becomes enlarged it may burst through the inner lining of the blood vessel and this “wound” gets sealed by a blood clot, thrombosis
91
what is a thrombosis called if it breaks loose
an embolus
92
what is coronary thrombosis
the blockage of the coronary artery by a thrombosis
93
what causes a stroke
a thrombosis that caused blockage in an artery in the brain may lead to a stroke
94
what is peripheral vascular disease
peripheral vascular disease happens when peripheral arteries (other than the heart and brain) narrow due to atherosclerosis
95
what is deep vein thrombosis
this is the formation of a thrombosis ( blood clot) in a vein, commonly in the calf muscle of the lower leg. this can result in a pulmonary embolism in the lungs
96
what is pulmonary embolism
a clot may block a small arterial branch of the pulmonary artery. this results in chest pain and breathing difficulties
97
what is cholesterol
a lipid found in cell membranes
98
where does 25% of cholesterol production happen
the liver
99
what do lipoproteins contain
lipid and protein
100
what do lipoproteins do
transport lipids around the body
101
what does a diet high in cholesterol do
increase in levels in the blood
102
what are low density lipoproteins produced by
the liver
103
what do low density lipoproteins do
transport cholesterol to body cells
104
what happens to LDL cholesterol
it becomes attached to a receptor
105
what happens when the cell has enough cholesterol for its needs
the synthesis of the new LDL receptors is inhibited by negative feedback
106
what happens when LDL deposits cholesterol in the arteries
it may form atheromas
107
where is excess cholesterol taken from and to and by what
taken from body cells to the liver by high density lipoproteins
108
does HDL-cholesterol contribute to atherosclerosis and why
no because it’s not taken into artery walls
109
what does a high ratio of HDL to LDL do
results in a decrease in blood cholesterol and reduced chance of atherosclerosis and cardiovascular disease
110
what does a lower ration of HDL to LDL do
an increase in blood cholesterol and an increased chance of atherosclerosis and cardiovascular disease
111
how may HDL levels be raised
by eating less fat and undertaking regular physical activity
112
drugs that reduce cholesterol levels in the blood
statins
113
what do statins do
they inhibit an enzyme essential for the synthesis of cholesterol by liver cells
114
what is the normal glucose concentration in blood plasma
15 millimoles per litre
115
what is the glucose concentration in blood plasma of a person suffering from untreated diabetes
30 millimoles per litre
116
what is microvascular disease
when mini cells of a small blood vessel taken in more glucose and they thicken and become weaker and haemorrhage
117
what effects can micorvascular disease have
damage the retina, damage the kidneys. affect the nerves
118
what is an example of negative feedback control
the regulation of blood glucose level
119
how much glucose is stored in the liver as glycogen
100g
120
what cells produce insulin
receptors cells in the pancreas
121
what is glucose converted into
glycogen
122
what does the high concentration of insulin do to the liver cells
make them more permeable to glucose so they absorb more
123
the glucose molecules join together to form glycogen and this does what
this brings about a decrease in blood glucose levels to normal
124
what happens when glucose concentration drops
glucagon is released and transported to the liver
125
what happens during fight or flight
the adrenal glands secrete an increase quantity of adrenaline
126
what does adrenaline to to glycogen
promotes the breakdown of glycogen to glucose
127
notes on type 1 diabetes
* first occurs in childhood or early teens
* ability of pancreatic cells to produce insulin is absent
* cells in liver have the normal number of insulin receptors on their surface
128
notes on type 2 diabetes
* adult onset, sufferer overweight or obese
* pancreatic cells able to produce insulin
* cells are less sensitive to it as a decreased number of insulin receptors, normal conversion of glucose to glycogen is prevented
* treatment included weight loss, diet control and in some cases insulin
129
what is an indicator of diabetes
glucose in urine
130
what is used to diagnose diabetes
a glucose tolerance test
131
how does a glucose tolerance test work
after fasting, a person has their blood glucose level measured, they then consume a known mass of glucose. blood glucose level is monitored and glucose tolerance curve is produced
132
how do you detect if someone has diabetes after a glucose tolerance test
a “normal” persons glucose level rises to a maximum then drops quickly well within the time period, a diabetics blood glucose concentration increases to a much higher level than non diabetics, and takes longer to return to its starting concentration
133
what is obesity
obesity is characterised by the accumulation of excess body fat
134
how to calculate BMI
body mass divided by height (squared)
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a BMI greater than what is used to indicate obesity
greater than 30
