Circulatory System Flashcards
What’s the function of the circulatory system?
It provides oxygen, nutrients and hormones to muscles and tissues throughout the body and also removed waste from cells and organs so the body can dispose of it
Main parts of the circulatory system
Blood, the heart, veins, arteries, capillaries
What is blood made out of in vertebrates?
Erythrocytes (red blood cells), leukocytes (white blood cells), thrombocytes (platelets), plasma
Structure of / information on erythrocytes
Disc-shaped, think and sunken centre, thick around outside, can survive around 120 days, can bend fold and squeeze through small spaces
Functions of erythrocytes
To pick up oxygen from the lungs and take it to the tissues and to pick up carbon dioxide from the tissues and take it to the lungs
Structure of / information on leukocytes
Appear granulated, live for 3-4 days, found in blood and lymphatic system, formed in bone marrow
What are the 5 types of leukocytes and what do they do?
Neutrophils - ingest and destroy pathogens
Eosinophils - attack pathogens, cause allergic reactions
Basophils - also plays a role in allergies
Monocytes - clean up dead cells , identifies invaders for lymphocytes
Lymphocytes - part of adaptive immune system, creat antibodies
Functions of leukocytes
Help destroy bacteria, help disable pathogens, destroy allergens and inflammatory chemicals
Structure of / information on thrombocytes
Very small fragments of bone marrow, no nucleus - they aren’t cells, irregularly-shaped
Functions of thrombocytes
Form temporary platelet plugs to stop bleeding, promote and then dissolve blood clots, digest and destroy bacteria, maintain linings of blood vessels
Structure of / information on plasma
Largest component in blood - 55%, clear extracellular fluid, a liquid in which erythrocytes / leukocytes / thrombocytes are suspended
Blood plasma of a mixture of …?
Water - 91%, proteins - 77%, nutrients - 2%, hormones - <1%, electrolytes - <1%
Functions of plasma
Carries proteins, transports nutrients, waste materials, water, enzymes and hormones around the body and regulates bleeding
What is hemoglobin?
it is a protein found in erythrocytes that loads and transports oxygen. it contains iron which binds the oxygen to the erythrocyte. it has a high affinity for oxygen - can carry 4 oxygen molecules. animals that live in areas of low oxygen content have an increased amount of hemoglobin in their blood. hemoglobin will also take up oxygen at a lower concentration due to the change in amino acids which dictate how the protein folds
Function of arteries
to deliver oxygenated blood away from the heart and to the rest of the body - one exception is the pulmonary artery which takes deoxygenated blood to the lungs
Structure of arteries
thick walls made of elastic fibers and smooth muscle - allows them to stretch so they don’t burst/rupture. have a small/narrow lumen
Arterioles
large artery splits into smaller vessels called arterioles. they branch further into capillaries when it reaches the tissue cells. they slow down blood flow which causes a drop in blood pressure so that the capillaries dont get damaged
Function of veins
carry deoxygenated blood back to the heart - exception is pulmonary vein which takes oxygenates blood from the lungs to the heart
Structure of veins
thin walls that are less elastic and less muscular than arteries, wide/large lumen, have valves to keep blood flowing in the same direction and prevent blood flowing backwards
Venules
smaller blood vessels that pass to larger veins , are porous - fluid/waste substances can filter back into the bloodstream
Structure of capillaries
a network of tiny blood vessels that sit between veins and arteries, wall is one cell thick
Function of capillaries
supply tissues and organs of the body with components of the blood such as oxygen, remove waste from surrounding cells
what is diffusion
the movement of molecules from a high concentration to a low concentration
What’s an closed circulatory system
internal organs aren,t in direct contact with the blood, blood flow can be regulated and blood is enclosed within the heart and blood vessels
Whats an open circulatory system
the body cavity is filled with blood and blood flow cannot be regulated, organs and tissues are bathed in a fluid called haemolymph, the heart pumps the haemolymph so it can reach the rest of the body, haemolympoh transports the necessary nutrients to the cells of the body
whats a single circulatory system
blood passes through the heart once and the heart has two chambers (one atrium and one ventricle), blood receives oxygen after being pumped from the heart, the heart only receives oxygenated blood, blood pressure is lower than double circulatory system.
