Transport in humans Flashcards
What are the components in the blood and their percentage
- Plasma: 55%
- Red blood cells: 45%
- White blood cells and platelets: <1%
What is plasma
A straw-coloured liquid which transports substances in the blood
It has the following functions:
- Transports CO2
- Transports digested foods and minerals
- Transport heat to cold areas in our body
- Transports urea to kidneys
- Transports hormones
What are red blood cells
Biconcave discs which increases surface area. Specialised cells which carry oxygen to respiring cells
No nucleus to pack more haemoglobin
What are platelets
Fragments of cells which help with blood clotting
If skin gets damaged, platelets rush to the wound. Reactions take place in the plasma
Platelets release chemicals that trap red blood cells at the wound, creating a scab which prevents bacteria from getting in which may cause infections
Blood clotting helps minimise blood loss and prevent microorganisms from entering the wound which may cause infections
What are white blood cells
White blood cells are part of our immune system
There are 2 types: Phagocytes and Lymphocytes
Phagocytes:
- Carry out phagocytosis (engulf and digest pathogens)
- They have multi-lobed nucleus and granulated cytoplasm
Lymphocytes:
- They have a large, circular nucleus which takes up most of the cell
- They release antibodies (Y-shaped proteins) which are complimentary to the shape of the antigen
- The antibodies cause chemicals to be released which signal the pathogens for destruction
- They also prevent pathogens from moving easily
- They release antitoxins which neutralise the toxins released by the pathogens
Name the chambers of the heart
- right atrium
- right ventricle
- left atrium
- left ventricle
Which side of the heart is oxygenated blood carried in
the left side
which side of the heart is deoxygenated blood carried in
the right side
why does the left ventricle have thicker walls than the right ventricle
The thicker walls of the left ventricle help pump the blood at a higher pressure
What is the coronary artery
The artery which supplies oxygenated blood to the cardiac muscle tissues
what is the functions of the valves
they prevent blood backflow
In order, what is the pathway of blood in the heart
- Deoxygenated blood from the body enters the heart through the vena cava
- The deoxygenated blood in the right atrium is pushed through the tricuspid valve into the right ventricle
- The right ventricle contracts and pumps the blood to the lungs through the pulmonary arteries where it passes through its capillaries and passes by the alveoli where gas exchange takes place
- The oxygenated blood enters the heart through the pulmonary vein into the left atrium
- The left atrium contracts and pushes the blood through the bicuspid valve into the left ventricle
- The left ventricle contracts and pumps the blood to the rest of the body through the aorta
What is heart rate measured in
bpm
What controls the resting heart rate
Pacemakers. Cells in the right atrium. They send out electrical impulses which forces the heart to contract
What may cause heart rate to increase
When exercising, our cells respire more therefore require more oxygen and glucose therefore more blood needs to be pumped
So our heart rate increases as well as the volume of blood pumped
after exercising, we will maintain our quick heart rate for a while to pay off oxygen debt
the time it takes for our heart rate to go back to normal is called the recovery time
What are the different types of blood vessels
- Arteries
- Veins
- Capillaries
Describe function and adaptations of arteries
- They carry oxygenated blood from the heart to the rest of the body
- They have thick, muscular walls with elastic fibres to withstand and maintain a high blood pressure
- Narrow lumen helps maintain high blood pressure
- Blood flow is fast
Describe functions and adaptations of veins
- Thin walls
- Carry deoxygenated blood to the heart
- Large lumen to maintain low blood pressure
- Blood flow is slow
- Contain valves to prevent blood backflow
Describe the functions and adaptations of capillaries
- Carry oxygenated and deoxygenated blood within out tissues
- Walls are one-cell thick to reduce diffusion distance
- Blood flow is slow
- Has leaky walls
What are the lymphatic cells
Lymphatic vessels carry excess tissue fluid that leaked out the capillaries back to the circulatory system
Name all the lymphatic vessels and their function
- Aorta, carries oxygenated blood from the heart to the rest of the body
- Hepatic artery, carries oxygenated blood to the liver
- Mesenteric artery, carries oxygenated blood to the gut
- Renal artery, carries oxygenated blood to the kidneys
- Renal vein, carries deoxygenated blood from kidney back to the heart
- Hepatic portal vein, carries deoxygenated blood from the gut to the liver
- Hepatic vein, carries deoxygenated blood from the liver to the heart
- Carries deoxygenated blood from the body to the heart
- Pulmonary artery, carries deoxygenated blood from the heart to the lungs
- Pulmonary vein, carries oxygenated blood from the lungs to the heart
What is coronary heart disease
The build up of fatty plaques in the coronary arteries, reducing blood flow to the coronary heart muscles and therefore their oxygen supply
The build up of fatty plaques makes the coronary artery lose its elasticity so cannot stretch when blood is pumped
Partial blockage can lead to angina
Complete blockage can lead to heart attack
Explain the risk factors of coronary heart disease
Obesity
- Added weight puts strain on the heart
- Can lead to diabetes which further damages blood vessels
High blood pressure
- Increases the force of blood against the artery walls which may damage them
High cholesterol
- Speeds up the build up of fatty plaque in coronary arteries
Smoking
- Smoke contains chemicals which speed up the build up of fatty plaques in coronary arteries and increases blood pressure
- Carbon monoxide also reduces the oxygen carrying capacity of the red blood cells
