Circulatory System Flashcards
Movement of Blood through Circulatory system (start at Vena cava)
Vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta, body, vena cava.
Function of circulatory system
Transports nutrients and gases around the body
Erythrocytes
- Red blood cells
- Produced in bone marrow
- Haemoglobin carries O2 molecule
Thrombocytes
- Platelets
- responsible for clotting blood
Coagulation
When a blood vessel is injured, the tissues release a chemical that makes the platelets stick to the opening.
When the injury to the blood vessel is larger, platelets begin the process of forming a blood clot.
Haemostasis
Clot formation process:
- Blood vessel contracts, causing reduced blood loss at the wound
- platelets are chemically attracted to the wounded epithelium and stick together
- Fibrin filaments from the blood are activated and attach to the wound causing a net/mesh-like structure
Simpler terms:
- Vascular spasm
- formation of platelet plug
- Coagulation
Abnormal clots (Thrombus
if a thrombus dislodges and floats through the blood it is called an embolus.
Can be dangerous as they restrict blood flow.
e.g. stroke, heart attack, death may occur
Blood types
Determined by presence of ANTIGENS on red blood cells. Antigens stimulate the blood to agglutinate (clump) when they encounter a different type of blood cell.
A, Ab, B, O
3 proteins in Plasma
- albumin - Regulates osmosis between blood and tissue
- Globulins - Transport substances and fight infection
- Fibrinogen - Used in blood clotting
RH factor
The Rh system is determined by the presence or absence of an RH antigen on their red blood cells.
Rh- people form anti-RH antibodies when they come into contact with RH+ blood.
RH factors and pregnancy
If mother is RH- and the baby is RH+, and blood is leaked it causes mother’s blood to form anti-RH antibodies.
If mother the has another RH+ baby, her body will treat fetes as a foreign substance and destroy baby’s blood cells.
Leukocytes
Granulocytes - have lobe shaped nuclei and visible granules:
- Basophil
- Eosinophil
- Neutrophil
Granulocytes - have spherical/kidney shaped nuclei, no visible granules
- Lymphocyte
- Monocyte
Whole blood transfusion
Has a chemical added to prevent clotting, transfused mainly in severe cases of blood loss
Red cell concentrates (transfusion)
Most widely used component of blood, made by centrifuging whole blood to seperate cells from plasma
Platelet Concentrates (transfusion)
Given to patients with abnormal platelets or a reduced number of platelets
Plasmatransfusion
Liquid part of blood; may be given to patients needing extra clotting factors or have liver disease
Cryoprecipitate (transfusion)
Obtained by freezing the plasma and thawing slowly. The cryoprecipitate which contains many of the substances needed for clotting, remain solid.
Immunoglobulin transfusion
A group of proteins that act as antibodies; extracted from plasma of suitable donors.
Pulmonary circuit
Carries blood from heart to lungs and back
Picks up O2 and releases CO2
Systematic circuit
Carries blood from heart to body tissues and back
Picks up CO2 and releases O2
Heart muscle is composed of what 3 layers
Epicardium - outer layer
Myocardium - middle layer
Endocardium - Inner layer
List valves in heart ❤️
Between atria and ventricles: Right - Tricuspid Left - Bicuspid / mitrial Between ventricles and blood vessels Right - Pulmonary valve Left - Aortic valve
Sinoatrial node
Begins impulse which causes contraction of the atria
Atrioventricular node
Impulse pauses to let atria empty into ventricles, then causes ventricles to contract, pushing blood out of heart.
Systole
Pumping phase of cycle, when heart contracts
Diastole
Filling phase of cycle, when heart relaxes
Cardiac output equation
Cardiac output = stroke volume (mL) x Heart Rate (beats/min)
Cardiac output
Amount of blood leaving ventricles per minute
Stroke volume
Volume of blood leaving ventricles each contraction
Heart rate
Heart beats per minute
Pericardial fluid
Reduces friction within the pericardium by lubricating the epicardial surface.
