Circulatory system Flashcards
What are the functions of blood?
-transport O2 and nutrients to cells
-remove CO2 and wastes from cells
-transport chemical messages to cells (like hormones)
-maintain the pH of body fluids
-distribute heat and maintain body temperature
-maintain water content and ion concentration in fluids
-protect against microbes that cause disease
What membrane covers the heart?
Pericardium
-holds heart in place
allows movement (beats)
What are the chambers of the heart and their functions?
-Right atrium:
-receives blood from the body and passes it to the right ventricle
-through the tricuspid valve which stops it from flowing back into the right atrium
-Right ventricle:
-pumps blood to the lungs
-through pulmonary artery where the pulmonary valve stops blood flow back into the ventricle
-Left atrium:
-receives blood from the lung
-passes to the left ventricle through the mitral valve
-stops the backflow of blood into left atrium
-Left ventricle:
-pumps blood out of the heart
-to the rest of the body through the aorta, which house the aortic valve
-who’s function is to stop the blood from flowing back into the left ventricle
Why is the left wall of the heart thicker?
It needs to be stronger and have that extra muscle to pump blood through the blood vessels to supply the oxygenated blood to the whole of the body.
The Valves and their flaps?
Semilunar:
Valve preventing back flow of blood into the ventricles
E.g. pulmonary (3) and aortic
Atrioventricular:
Ensure blood flows though the heart in one direction only
E.g. tricuspid (3) and mitral (2)
What is circulation?
The movement of blood through the heart and blood vessels.
Phases of the cardiac cycle:
Pumping phase: (systole)
-heart contracts
Filling phase: (Diastole)
-heart relaxes
What is the cardiac output equation?
cardiac output (mL/minute)=stroke volume (mL) x heart rate (beats/minute)
What occurs in diastole?
-Heart relaxes
-For a short, both the atria and ventricles are in this phase
-Atria fill with blood and the ventricles receive blood as the valves between them open
What occurs in atrial systole?
-the contraction of the atria following diastole
-blood is forced to flow in the ventricles
-atria then relax and refill
What occur in ventricular systole?
-ventricles received blood forced out form atria
-contract
-force blood into the arteries
What are the components of blood?
Plasma (55%)
Non formed element (45%)
e.g. erythrocytes, leukocytes, thrombocytes
What is plasma’s function?
Transport components of blood, including cells, wastes, nutrients, hormones, proteins and antibodies, throughout the body
What are erythrocytes and their function?
-red blood cells
-Transport oxygen from the lungs to the cells throughout the body
What are thrombocytes and their function?
-platelets
-adhere to lining of damaged blood vessels and forms a scaffold for coagulation
What are leukocytes and their function?
-White blood cells
-Protect the body from infection
Have five different types:
.neutrophils
.basophils
.monocytes
.eosinophils
.lymphocytes
What are eosinophils?
Inflammatory response to protect against parasites
What are monocytes?
Form other cells
e.g. macrophages that kill pathogens
What are basophils?
Responsible for allergic reactions
What are lymphocytes?
Involved in immune responses
What is haematocrit?
Ratio of red blood cells to total volume of blood
Why are red blood cells suited to their function?
-contain haemoglobin (combines with oxygen)
-no nucleus which allows for extra room for haemoglobin and can fit in vessels
-biconcave disk which increase SA of oxygen exchange and more space in edges for haemoglobin molecules
What is haemoglobin?
-Pigment in RBC’s
-involved in the t5ransport of oxygen
-and carbon dioxide out of cell
What is oxyhaemoglobin?
-formed from combo of oxygen and haemoglobin
-bright red in colour
What is carbaminohaemoglobin?
-combo of carbon dioxide and haemoglobin
What are the capillaries?
-link between veins and arteries
-suited to function due to one layer cells walls
-allow substances to pass through easily
What are veins?
-carry blood to the heart
-constant low blood pressure
-thin, inelastic, little muscle walls
-will often have valves
What are arteries?
-carry blood from heart to the body
-higher blood pressure as ventricles contract, lower if relaxed
-thick, elastic, muscular walls
-no valves
What is the aorta?
Main artery that takes blood to all parts of the body (except lungs)
What are the ways that carbon dioxide is carried in the blood?
-7-8% in the plasma
-20% combines w/ globin of haemoglobin which forms carbaminohaemoglobin
-70% carried in plasma as bicarbonate
How are most nutrients and wastes transported in the body?
Dissolved and transported in the plasma
Best way that oxygen is transported in the body?
Oxyhaemoglobin
