Pack 3 – The Heart and Circulatory System & The Lungs and Respiratory System Flashcards
(107 cards)
1
Q
Aerobic respiration equation:
A
Glucose + oxygen -> ATP energy + carbon dioxide + water
2
Q
What does double circulatory system mean?
A
Blood flows twice through the heart for each complete circuit of the body
3
Q
Pulmonary circulation
A
Carries deoxygenated blood from the heart to the lungs to receive oxygen and remove carbon dioxide, then carries the blood back to the heart
4
Q
Systemic circulation
A
Carries oxygenated blood to the body to
oxygenate tissues and collect waste carbon dioxide, then carries the
blood back to the heart
5
Q
Platelets function:
A
Clots blood to prevent continuous bleeding from wounds
6
Q
White blood cells function:
A
Protection against infection (macrophages, antibodies)
7
Q
Red blood cells function:
A
Transport oxygen to the cells and carbon dioxide to be exhaled out of the body
8
Q
Plasma function:
A
The fluid which transports the other components. Also involved in regulating temperature, Ph and water content
9
Q
Coronary arteries
A
Left and right coronary arteries supply the entire heart muscle with blood for its cells
10
Q
Coronary veins
A
Carry the deoxygenated blood away from the heart muscle
11
Q
How is the heart divided into two halves?
A
By the septum
12
Q
How does deoxygenated blood enter the heart?
A
Enters the right atrium through the vena cava
13
Q
How does oxygenated blood enter the heart?
A
From the Lungs enters the left atrium through the pulmonary vein at the same time
14
Q
Artrial systole
A
The atria contract together and force the blood down into the Ventricles through the open atrioventricular valves
15
Q
Ventricular systole
A
When the ventricles have filled with blood they contract
- The Semilunar valves open
- The right ventricle forces deoxygenated blood to the lungs through the pulmonary artery
- The left ventricle pumps oxygenated blood out of the heart and around the body through the Aorta
- The atrioventricular valves close to stop the Backflow of blood into the atria
16
Q
Cardiac diastole
A
The atria and ventricles relax
- The atria fill with blood and blood begins to move into the ventricles - - The semilunar valves close to prevent the backflow of blood from the arteries into the Ventricles
17
Q
Why do atria have thinner walls (less muscle mass) than ventricles
A
- Atria only pump blood to ventricles which are a shorter distance from them so do not need to generate as high blood pressure
- Ventricles have to pump blood a greater distance to reach lungs (RV) or the rest of the body (LV) so need to generate a higher blood pressure
18
Q
How does the heart beat?
A
- Electrical impulses from the SAN spread across the atrial walls, causing contraction
- Impulses pass to the ventricles via a patch of conducting fibres, AVN
- Impulses pass down the Bundle of His to the heart apex
- Impulses spread through ventricle walls causing contraction from the bottom upwards. Blood is squeezed into the arteries
19
Q
How is heart rate controlled?
A
By the cardiovascular control centre (CCC)
20
Q
Where is the CCC located?
A
Medulla oblongata of the brain
21
Q
What 2 nerves control the CCC?
A
- Sympathetic nerve
- Vagus nerve
22
Q
Sympathetic nerve function:
A
This sends impulses to stimulate the SAN to increase heart rate
23
Q
Vagus nerve function:
A
- This send impulses to the SAN to decrease heart rate
- The cardiovascular centre continuously monitors changes in the body in order to fine tune heart rate
24
Q
How do hormones control heart rate?
A
- Adrenaline is released into the bloodstream from the adrenal glands located above the kidneys
- Adrenaline directly stimulates the SAN, increasing the heart rate to prepare the body for physical demands
25
4 similarities between the structure of arteries and veins:
1. Both have an outer wall containing collagen fibres
2. Both contain elastic fibres
3. Both contain smooth muscle cells
4. Both have an endothelial cell layer
26
4 differences between the structure of arteries and veins:
1. Arteries have a narrow lumen whereas veins have a wide lumen
2. Arteries have a thicker wall than veins
3. Arteries have more smooth muscle cells and elastic fibres than veins
4. Arteries do not have valves whereas veins do
27
What blood do arteries carry?
- High pressure blood away from the heart
- The blood is oxygenated (except in pulmonary arteries)
- Arterioles are small branches off the arteries
28
Blood flow through arteries during systole:
Blood is forced through artery and the narrow lumen expands to accommodate blood
29
Blood flow through the arteries during diastole:
- The artery recoils behind moving blood flow and the lumen returns to its original diameter
- This elastic recoil helps push blood flow forward
30
Blood flow in capillaries:
- There is a steady blood flow – no pulse
- The narrow lumen (1 RBC diameter) slows blood flow
- There is a network of capillaries to touch every cell in body
31
Blood flow in veins:
From the capillaries, blood flows into venules and then into veins
- Almost all veins carry deoxygenated blood (except pulmonary vein). - They carry low pressure blood back to the heart
32
What 2 mechanisms achieve blood flow in veins?
Surrounding muscle contraction and valves.
33
Arterioles
Tiny branches of arteries that lead to capillaries. They constrict and dilate, to regulate blood flow and pressure
34
Venules
- Minute vessels that drain blood from capillaries and into veins
- Many venules unite to form a vein
35
4 key structures of an artery:
1. Thick muscular wall
2. Thick smooth muscle cell layer
3. Narrow lumen
4. No valves
36
Thick muscular wall in arteries function:
To withstand the high blood pressure
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Thick smooth muscle cell layer function in arteries:
Smooth muscle contracts to constrict artery (narrowing of lumen) to maintain blood pressure
38
Narrow lumen function in arteries:
To maintain the high blood pressure
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No valves function in arteries:
Not needed - blood is always forced forward by heart contraction and by elastic recoil of the arteries
40
3 key structures of a capillary:
1. Capillary wall is one cell thick
2. Very narrow lumen
3. Have tiny holes/pores in their walls
41
Function of capillary wall is one cell thick:
Helps the exchange of dissolved substances between the blood and tissue fluid/cells by reducing the diffusion distance
42
Function of very narrow lumen in capillaries:
Walls of blood cells are in contact with the wall of the capillary, reducing the diffusion distance for exchange
43
Function of tiny holes/pores in capillary walls:
To allow the passage of materials through the wall and into tissue fluid
44
4 key structures of a vein:
1. Wider lumen and thinner walls than arteries
2. Valves
3. Thin smooth muscle layer
4. Thin elastic tissue layer
45
Function of Wider lumen and thinner walls than arteries in veins:
May make the vessel easier to squeeze between skeletal muscles during blood return to the heart
46
Function of valves in veins:
Prevent backflow of blood
47
Function of thin smooth muscle layer in veins:
Less ability for contraction to constrict blood vessel
48
Function of thin elastic tissue layer in veins:
Less elastic recoil (blood moved by skeletal muscles)
49
Why does blood pressure fluctuate, and what happens when it does?
- Blood pressure fluctuates in the arteries due to the heart beating
- Elastic fibres stretch and recoil when the heart contracts and relaxes
50
When is blood pressure lowest and highest?
Highest pressure during ventricular systole and lowest during diastole
51
Peripheral resistance
Contact between the blood and the vessel walls cause frictions which slows the flow of blood
52
3 ways blood pressure can be regulated:
- Varying heart rate - increasing heart rate increases blood pressure as more blood is pumped into the circulatory system within a set time
- Vasoconstriction and vasodilation
- Varying strength of heart muscle contraction - increasing strength of contraction increases blood pressure
53
How is blood pressure affected by water content?
- If blood volume decreases, the hypothalamus triggers the release of more ADH from the pituitary gland
- This causes the kidneys to reabsorb more water into the blood to increase the blood volume and consequently pressure
54
2 ways the body knows when it needs to vary blood pressure:
1. Baroreceptors
2. Higher brain regions
55
How do baroreceptors know when it needs to vary blood pressure?
- Baroreceptors in the aorta and carotid artery detect an increase or decrease in blood pressure and pass impulses to the hypothalamus
- Nerve impulses can then be sent to effectors, leading to the responses described above
56
How do higher brain regions know when it needs to vary blood pressure?
The hypothalamus signal the CVS about external stress stimuli for things like the flight or fight response – this leads to the release of adrenaline
57
3 key structures of the trachea:
1. C-shaped rings of cartilage
2. Goblet cells
3. Cilia on ciliated epithelial cells
58
Function of C-shaped rings of cartilage in the trachea:
Prevent the trachea from collapsing and provide flexibility
59
Function of goblet cells in the trachea:
Secrete mucus to trap microorganisms and particles
60
Function of cilia on ciliated epithelial cells in the trachea:
Waft mucus upwards so it can be swallowed
61
3 key structures of the bronchi:
1. Rings of cartilage
2. Goblet cells
3. Cilia on ciliated epithelial cells
62
Function of rings of cartilage in bronchi:
Prevent the bronchi from collapsing and provide flexibility
63
Function of goblet cells in bronchi:
Secrete mucus to traps microorganisms and particles
64
Function of cilia on ciliated epithelial cells in bronchi:
Waft mucus upwards so it can be swallowed
65
2 key structures of bronchioles:
1. Elastic fibres
2. Smooth muscle
66
Function of elastic fibres in bronchioles:
Prevent the bronchioles from collapsing
67
Function of smooth muscle in bronchioles:
Contract and relax, changing the diameter of the bronchioles to alter air flow
68
3 key structures of alveoli:
- Many alveoli
- Capillary network
- Elastic tissue
69
Function of many alveoli:
Large surface area for gas exchange to occur
70
Function of capillary network in alveoli:
A good supply, meaning a large surface area for gas exchange to occur
71
Function of elastic tissue in alveoli:
Stretch when filled with air during inhalation, recoil when air leaves in exhalation
72
Effects of breathing on volume and pressure:
When the volume is increased, the pressure drops, and air fills the lungs (inhalation)
73
What happens to the intercostal muscles during inhalation:
Contract
74
What happens to the way the ribs move during inhalation:
Up
75
What happens to the diaphragm muscles during inhalation:
Contract
76
What happens to the diaphragm during inhalation:
Lowers
77
What happens to the volume of the chest during inhalation:
Increases
78
What happens to the pressure in the chest during inhalation:
Decrease
79
What happens to the air pressure in the lungs compared to atmospheric pressure during inhalation:
Lower
80
Does air rush in or out during inhalation?
In
81
What happens to the intercostal muscles during exhalation:
Relax
82
What happens to the ribs movement during exhalation:
Down
83
What happens to the diaphragm muscles during exhalation:
Relax
84
What happens to the diaphragm during exhalation:
Raised
85
What happens to the volume of the chest during exhalation:
Decreases
86
What happens to the pressure in the chest during exhalation:
Increase
87
What happens to the air pressure in the lungs compared to atmospheric pressure during exhalation:
Greater
88
Does air rush in or out during exhalation?
Out
89
Ventilation process:
- The intercostal muscles contract so the ribcage moves up and out
- The diaphragm muscles contract so the diaphragm moves down
- This leads to the volume of the thoracic cavity increasing
- Therefore, the pressure decreases
- Air pressure in the lungs is lower than the atmospheric pressure
- Air moves down a pressure gradient into the lungs
90
Gas exchange process:
Oxygen moves from alveoli to blood by diffusion
- Carbon dioxide moves from blood to alveoli by diffusion
- Along a concentration gradient from high concentration to low concentration
- Gases pass through epithelium of alveoli walls and endothelium of capillary walls
91
Fick's law of diffusion:
The rate of diffusion is directly proportional to the membrane surface area and the concentration gradient and is inversely proportional to the membrane thickness
92
How does coronary heart disease occur?
Due to the gradual build-up of fatty deposits within the coronary arteries (arteries that supply the heart muscle with blood)
93
Risk factors of coronary heart disease:
Increased age, smoking, obesity, genetic predisposition, lack of exercise
94
Process of coronary heart disease:
- Over time, fatty material called atheroma can build up inside the walls of your arteries
- This hardens the walls of the vessels
- If this build up happens in the arteries that supply your heart with blood, it is called coronary heart disease
- This narrows the lumen of the artery which causes higher blood pressure
95
What are the 2 types of stroke?
1. Haemorrhagic
2. Ischemic
96
Haemorrhagic stroke
Stroke due to blood vessel rupture
97
Ischemic stroke
Stroke due to blood vessel clot
98
Chronic obstructive pulmonary disease includes:
Emphysema – damage to the air sacs in the lungs
Chronic bronchitis – long-term inflammation of the airways
99
COPD process:
- Occurs when the lungs and airways become damaged and inflamed
- It's usually associated with long-term exposure to harmful substances such as cigarette smoke, air pollution or chemical fumes
100
Symptoms of COPD:
- A persistent chesty cough with phlegm that never seems to go away
- Frequent chest infections
- Persistent wheezing
101
Hypertension
A blood pressure higher than 130 over 80 millimetres of mercury (mmHg)
102
Causes of hypertension:
- Stress
- Increased age
- Obesity
- Alcohol
- Smoking
103
Effects of hypertension:
- Cells are unable to carry out effective respiration
- High blood pressure weakens the walls of blood vessels
- High blood pressure can lead to a stroke
104
Hypotension
A blood pressure of lower than 90 (systolic) over 60 (diastolic) mmHg is classified as low blood pressure.
105
Causes of hypotension:
- Dehydration
- Pregnancy
- Heart problems
106
Symptoms of hypotension:
- Dizziness
- Fainting
- Nausea and fatigue
107
What is hypotension related to?
A systemic reduction in tissue blood flow, resulting in reduced transportation of oxygen and nutrients to body cells (failure of tissue perfusion)
