Transport in Humans Flashcards
what is the heart?
- muscular pump
- drives blood around the body
types of blood vessels
- arteries
- capillaries
- veins
what is the blood made off?
- 55% plasma
- red blood cells
- white blood cells
- platelets
what is a double circulatory system?
a system where blood flows through the heart twice in one circuit
what is the advantage of a double circulatory system?
- pumps blood at low pressure to lungs to be properly oxygenated
- pumps blood at high pressure to the rest of the body
- no mixing of oxygenated and deoxygenated blood
what is pulmonary circulation?
- oxygenated blood from lungs to heart
- deoxygenated blood from heart to lungs
what is systemic circulation?
- oxygenated blood from heart to the rest of the body except lungs
- deoxygenated blood from the rest of the body to the lheart
blood vessels at the liver are called?
hepatic blood vessels + hepatic portal vein
blood vessels at the kidneys are called?
renal blood vessels
what are the main functions of blood?
- to transport food substances, waste substances, oxygen and hormones and heat
- to protect the body by fighting off infections and foreign bodies
what are the adaptations of red blood cells and their functions?
- contains haemoglobin - to bind reversibly with oxygen to carry oxygen
- circular and biconcave - to increase surface area to volume ratio for quicker diffusion of oxygen
- no nucleus - to store more haemoglobin in cytoplasm to carry more oxygen
- flexible and elastic cell surface membrane - to change shapes and easily squeeze through capillaries
what are the functions of platelets?
- to prevent further blood loss
- to prevent any pathogens from entering the body through the wound
steps to blood clotting
- damaged tissue and platelets from thrombokinase
- thrombokinase and calcium ions activate prothrombin to form thrombin
- thrombin catalyzes fibrinogen to fibrin threads
- fibrin threads trap red blood cells
what is agglutination?
the clumping of red blood cells which is fatal
what are antigens?
a protein marker found on the cell surface membrane
what are antibodies?
a y-shaped protein that is complementary to the shape of a specific antigen and binds to it
what are the three layers of artery and vein walls?
- inner: endothelium
- middle: elastic fibres and smooth muscle tissues
- outer: connective tissues
special features of arteries and their functions
- thick elastic and muscular walls to withstand high blood pressure
- thick elastic walls to stretch and recoil, pushing the blood along in spurts, maintaining a high pressure
special features of veins and their functions
- semilunar valves to prevent the backflow of blood
- muscles contract to push along the vein to the heart
features of capillaries and their functions
- one cell thick partially permeable wall wall faster diffusion of certain substances
- branches repeatedly for a greater surface area to volume ratio for quick exchange of substances
what does tissue fluid contain?
- glucose
- amino acids
- urea
- hydrogencarbonate ions
which sides of the heart receives oxygenated and or deoxygenated blood?
left side: oxygenated
right side: deoxygenated
function of the septum
separates the left and right side of the heart to prevent oxygenated and deoxygenated blood from mixing
function of heart valves
to ensure blood flows in the undirectionally and not backflow
what happens in atrial systole?
- Atrial pressure is higher than ventricular pressure.
- Bicuspid valve is open to allow blood to flow.
- Blood therefore flows from left atrium to left ventricle, down its pressure gradient.
- Aortic pressure higher than ventricular pressure.
- Semi-lunar valves close to prevent backflow of blood from aorta into left ventricle
what happens in ventricular systole?
(+ atrium diastole)
- Ventricular pressure rises such that it is higher than aortic pressure.
- Semi-lunar valves open to allow blood to flow through.
- Blood flows from left ventricle into the aorta
- Meanwhile, atrium undergoes diastole and begins to be filled with blood.
- Bicuspid valve closes to prevent backflow of blood from ventricle to atrium.
what happens in ventricular diastole?
- Ventricular pressure decreases until it is lower than aortic pressure.
- Semi-lunar valves close to prevent backflow of blood from aorta into left ventricle.
- Ventricular pressure decreases further until it is lower than atrial pressure.
- Bicuspid valve opens to allow blood to flow.
- Blood therefore flows from left atrium to left ventricle, down its pressure gradient.
- The cycle repeats.
function of coronary arteries
supply nutrients and oxygen to the heart
process of heart attack
- build up of fatty deposits and cholesterol
- coronary artery narrowed and blocked
- no blood, nutrients and oxygen supplied to heart
- heart cannot respire and dies
causes of coronary heart disease
- stress
- smoking
- poor diet
- lack of exercise
preventive measures against coronary heart disease
- regular exercise
- reduce smoking
- manage stress
- healthier diet (less cholesterol and animal fats intake)
