Heart, Blood and Immunity Flashcards
What is blood?
A free-flowing liquid, composed of plasma and other substances.
What are the two main types of leucocytes (white blood cells)?
phagocytes and lymphocytes
What are platelets, and what is their role?
tiny cell fragments that help in blood clotting
What is the shape of a red blood cell and why is it that shape?
biconcave disc for increased surface area, helping in efficient exchange of oxygen in and out of the red blood cell
What is the concentration of plasma in the blood?
55%
What is the concentration of red blood cells in the blood?
44%
What is the concentration of lymphocytes in the blood?
0.3%
What is the concentration of phagocytes in the blood?
0.5%
What is the concentration of platelets in the blood?
0.2%
Describe the functions of the plasma.
circulation of dissolved nutrients (eg glucose and amino acids), mineral ions and waterremoval of waste products (eg lactic acid and carbon dioxide)transportation of hormones (glands to target cells)keeps body temperature regulated
What is plasma?
a liquid medium making it possible for blood cells to float and molecules to dissolve
What is the function of the red blood cell?
carries and transports oxygen in the form of oxyhaemoglobin, and it has no nucleus in order to have more space
What is the function of a lymphocyte? How is it adapted to its function?
produces antibodies to combat antigens, contains a large nucleus to produce antibodies effectively
What is the function of a phagocyte? How is it adapted to its function?
carries out phagocytosisirregular and multi-lobed nucleus cytoplasm that contains digestive enzymes that can be released during phagocytosis
Describe the blood clotting process.
wounds, like cuts, could potentially allow the entry of pathogens in the bodyplatelets release clotting factorsthe clotting factors lead to fibrinogen (soluble protein in plasma) to become fibrin (insoluble protein in plasma)fibrin forms a mesh of fibres that capture both platelets and blood cellsthis forms a clot over the wound, which dries to become a scab
Describe the process of phagocytosis.
phagocytes are attracted to the area in which there are pathogens invading the bodyphagocytes engulf the pathogenenzymes in the phagocyte’s cytoplasm digest the pathogenthese enzymes break the pathogen down into molecules called antigensantigens are either absorbed, exposed at the cell surface or expelled from the cell
What type of organ is the heart?
myogenic
What is phagocytosis?
process in which phagocytes extend their cell membranes to engulf and digest pathogens
What are the blood vessels that carry blood towards the heart?
veins
What are the blood vessels that carry blood away from the heart?
arteries
What is the function of the vena cava, and where is it located?
it brings blood from the rest of the body to the heartit is on the right side of the heart
What is the function of the aorta and where is it located?
sends blood from the heart to the rest of the bodyit is on the left side of the heart
What is the function of the valves?
control direction of blood flow by closing when blood fills up the ventricle
Which structure of the heart is found at the top on both its sides?
the atriums
Which structure of the heart is found at the bottom on both its sides?
the ventricles
What are coronary arteries?
arteries that provide blood to the heart and can cause heart attacks when blocked with too much fat deposits
Which vessels carry oxygenated blood?
aorta, pulmonary vein
Which vessels carry deoxygenated blood?
vena cava, pulmonary artery
Name four differences between a single and a double circulatory system.
double: two complete body circuits (passes through heart 2x before reaching other organs)double has four chambers instead of twodouble pumps deoxygenated and oxygenated blood, not only deoxygenateddouble has a very high pressure of oxygenated blood, unlike in a single
What is the main function of the right side of the heart?
pump deoxygenated blood to the lungs
What is the main function of the left side of the heart?
pump oxygenated blood to whole body except lungs
What are factors that increase the risk of coronary heart disease?
stress, bad diet, low exercise, smoking, diabetes, age, family smoking history…
What type of blood do arteries carry? What is an exception?
they carry oxygenated bloodpulmonary artery is an exception
What type of blood do veins carry? What is an exception?
they carry deoxygenated bloodpulmonary vein is an exception
Which blood vessel contains valves?
vein
Which has the highest blood pressure, capillary, vein or artery?
artery - high pressurevein - low pressurecapillary - very low pressure
Where do capillaries transport blood?
through organs
How is the structure of the artery?
small lumen, thin endothelial layer, thick muscle and elastic layers
How is the structure of the vein?
large lumen, thin endothelial layer, thin muscle and elastic layer
How is the structure of the vein?
large lumen, thin endothelial layer
What is immunity?
the defence system of the body against pathogens
What are some examples of the responses of the first line of defence?
skin, avoiding entry of pathogensstomach acid, kills pathogenslacrimal gland, eliminates pathogens in the eyehair in the nose and skin, trapping pathogensciliated cells in trachea, sweep away pathogens in mucus away from lungs
When does the second line of defence start working?
When the pathogen is in the bloodstream
What are some examples of the responses of the second line of defence?
phagocytosisblood clottinginflammation
What response occurs if the second line is not successful?
specific response
What occurs in a specific response?
antibodies are produced for the specific pathogens
What are the two types of non-specific responses?
1st and 2nd line of defence
What are the two types of immunity responses?
specific and non-specific
What is a difference between the two immunity responses?
one is defence by antibodies (specific)the other is by mechanical barriers (non-specific)
What is the circulatory system?
a system of blood vessels with a pump and valves to ensure one-way flow of blood
How can heart activity be monitored?
ECG, pulse rate, listening to sound of valves closing
What is the size of the lumen of an artery?
small
What is the size of the lumen of a vein?
large
What is the size of the lumen of a capillary?
very small
How are the muscle and elastic layers in an artery?
thick
How are the muscle and elastic layers in a vein?
thin
How thick/thin is the endothelial layer in a capillary?
one cell thin
Are endothelial layers thin or thick?
thin
What is the function of capillaries?
carry blood through organsbringing blood to every cell in the organ
In which blood vessels are valves found?
in the veins
Why do veins have thin walls and a large lumen?
because the pressure in veins is low
Why is there a high pressure in arteries?
because muscular contractions in the ventricles causes blood to flow away from the heart at a high pressure
What happens as blood flows through the arteries?
the walls of the artery expand and recoil, creating a pulse
How are capillaries adapted to their function?
it has a very thin wall so that substances can diffuse efficientlythere are many capillaries so that it comes close to every celldiffusion and molecule exchange can happen because the capillaries move slowly with very low pressurethey are permeable
blood vessels to and from the heart
vena cava, aorta, pulmonary artery and vein
blood vessels to and from the lungs
pulmonary artery and vein
blood vessels to and from the kidney
renal artery and vein
What is a circulatory system?
A system of bloodvessels with pump and valves to ensure one-way flow of blood
Describe single circulation of fish
red blood cell only passes through the heart once before returning to the capillaries (heart gills, rest of body, heart)
Describe a double circulation of a mammal
red blood cell passes through the heart twice before returning to a capillary (heart, lungs, heart, rest of body, heart)
Advantages of a double circulation
- all of the organs are supplied with a high concentration of oxygen- as blood goes through the heart twice, it is more pressurized and so is pumped quicker
function of veins
pump blood to the heart
function of artery
pump blood away from heart
how can activity of the heart be monitored
by ECG, pulse rate and listening to sounds of valves closing
effect of physical activity on heart rate
as physical activity increases, so does heart rate
what is coronary heart disease
the build up of plaque which causes the coronary artries to narrow, limiting blood flow
risk factors for coronay heart disease
- diet- old age- smoking- lack of exercise- obesity- stress- genetic factors
effect of diet and exercise on coronary heart disease
- Having a healthy weight reduces chances of high blood pressure.- Regular exercise will make your heart and blood circulatory system more efficient and lower your cholesterol level
relative thickness of the muscle wall of the left and right ventricles
- left ventricle is longer and narrower than the right ventricle- The wall of the left ventricle is three times thicker than those of right ventricle
relative thickness of muscle walls of atria compared to ventricles
The ventricles of the heart have thicker muscular walls than the atria
importance of septum
septum prevents the mixing of oxygenated and deoxygenated blood
coronary heart disease in terms of blockage of coronary arteries
If a coronary artery gets blocked, the cardiac muscles that depend on it cannot produce enough energy for contraction. As a result, this heart muscle will be damaged and may die because of the loss of blood supply.
What are the components of blood?
red blood cells, white blood cells, platelets and plasma
What is the function of red blood cells?
transporting oxygen in the form of oxyhaemoglobin
What is the function of white blood cells?
phagocytosis and antibody production
What is the function of platelets?
help in blood clotting
What is the function of plasma?
transport of blood cells, ions, nutrients, urea, hormones and carbon dioxide
What is the importance of blood clotting?
prevents blood lossprevents possible entry of pathogens into the bloodstream
What is the function of lymphocytes?
antibody production
What is the function of phagocytes?
performing phagocytosis, the process in which a phagocyte engulfs and digests a pathogen
What substances are converted in the process of clotting?
fibrinogen to fibrin, to form a mesh