Topic 9 Flashcards
How does blood circulate
Blood flows in arteries away from the heart to different organs. Blood flows back to the heart in veins. The smaller vessels are capillaries. The circulatory system allows a one way flow of blood around the body
What are semi lunar valves
To make sure blood does not flow backwards away from the heart
What is double circulation
Blood flows through the heart twice during one complete circuit around the body
Blood circulation 2 functions
Right side - deoxygenated blood to the lungs and back to the heart again
Left side - the heart pumps oxygenated blood to the rest of the body and back to the heart again
What is the atria
Upper chambers of the heart
Heart structure
Atria to ventricles
Right ventricle to pulmonary artery
Left ventricle to the rest of the body
Between atrium and ventricle is a one way valve
Deoxygenated blood - returns to the right atrium in the vena cava
Oxygenated blood - returns to the left atrium in the pulmonary veins
Bringing blood to each organ
To heart - vena cava to right atrium, pulmonary vein to left atrium
Lungs - pulmonary artery
Kidneys - renal artery
Liver - hepatic artery
Risk factors for Chd
Genes
Age
Sex
Smoking
Coronary arteries
Heart muscle needs glucose and oxygen to keep it contracting and these are transported to the heart
Two groups of white blood cells
Phagocytes
Lymphocytes
Phagocytosis
White blood cells that ingest Pathogens such as bacteria. surround the pathogens, ingest them and take them into vacuoles. Then they digest them by using enzymes and this kills them
Lymphocytes
When bacterium enters the body they recognize them as foreign and They make proteins called antibodies
What are antibodies
Proteins that have different shaped enzymes so they can bind and combine with one type of pathogen
How Antibodies attack the pathogens in a number of ways
They can make them stick together
They can dissolve their cell membranes
They can neutralize the toxins that some pathogens such as some bacteria produce
How does blood clotting work
The skin is cut and blood starts leaking out of the body. However there is a protein in the blood called fibrinogen when platelets come in contact with air they turn them into threads of fibrin.
Red blood cells get caught in the net and make a blood clot and create a scab
