The Cardiovascular System Flashcards
What 3 things does the cardiovascular system consist of?
The heart
The blood vessels
The blood
What’s the function of the heart?
It is made up of cardiac muscle and pumps blood around the body
What is the 4 things blood is made up of?
White blood cells
Platelets
Red blood cells
Plasma
What is the function of blood vessels?
Responsible for transporting blood around the body
What does white blood cells do?
Fight disease
What do platelets help do?
They help blood clot
What does red blood cells Carry?
Oxygen
What does the plasma carry?
Ions and nutrients
What direction does arteries carry blood?
Away from the heart
What do arteries subdivide into?
They subdivide into arterioles which eventually divide into capillaries
In what part of the vessel does blood flow?
In the lumen
What direction does the blood flow go in veins?
Return blood to the heart
What does veins subdivide into?
Venules Which then divide into capillaries
What does valves do?
Prevent back flow (in veins)
Why is capillaries involved in diffusion?
They have a short diffusion pathway, wall is only one cell thick
What gets diffused in capillaries?
Oxygen and nutrients and also waste products such as urea (excess protein) and carbon dioxide
Order of the blood vessel network
Heart Artery Arteriole Capillary Venule Vein Heart
Explain the structure of an artery
Thick wall with fibrous tissue Thick middle layer with muscle and elastic fibre Has a narrow lumen and endothelium Round shape Have a high blood pressure in pulses
Structure of a vein
Thin wall outer layer of fibrous tissue Thin middle layer with some muscle and very elastic tissue Inner endothelium layer Large lumen Valves at intervals Low blood pressure Less regular shape
Structure of a cappilary
Miscroscopic vessels
One cell thick walls
Reduction in pressure across the network
Why do we need a circulatory system?
To transport materials to and from the respiring tissue
What is a double circulatory system?
The blood goes through the heart twice for every full circuit of the body
What are the two systems blood gets pumped around?
The pulmonary system
The systemic system
Where does the pulmonary system pump blood from and to?
From the right side of the heart and to the lungs.. pumped at a low pressure so it travels through the heart slow to allow more diffusion time
Where does the systemic system pump blood to and from?
From the left side and to the rest of the body.. pumped at a high pressure as it goes all around the body, the thick cardiac muscle allows this to happen
Why do red blood cells have a biconcave shape?
To increase surface area/volume ratio for diffusion
Why do red blood cells have no nucleus?
This allows them to carry more haemolglobin (the molecule that carries oxygen)
What is the plasma?
The liquid part of the blood that transports blood cells
What substances does the plasma carry?
Blood cells, glucose, amino acids, carbon dioxide, urea, heat, hormones and molecules involved in blood clotting
What size are white blood cells in comparison to red blood cells?
They are larger than red blood cells but less numerous
Do white blood cells have a nucleus?
Yes
What are the two main types of white blood cells?
Lymphocytes
Phagocytes
What do lymphocytes do?
The produce antibodies to combat infection by microbes
What do phagocytes do?
They engulf and digest bacteria and other foreign material in the blood and tissue by phagocytosis
What are platelets?
Cell fragments
What are the two sides of the heart separated by?
A thick muscular wall called the septum
What is the thin layer in the lumen lining that all 3 vessels have?
Squamous endothelial cells
What are the atria and where does the blood come from and go to?
The upper chambers of the heart, they receive blood from the lungs (left atrium) or the body (right atrium) they then pump the blood into the ventricles
What are the ventricles and where does the blood come from/go to?
The lower chambers of the heart and have much thicker walls.. they pump blood to the lungs (right ventricle) it around the body (left ventricle)
What ventricle has more muscle?
The left ventricle as it pumps blood around the whole body
Where are the atrioventricular valves at?
Between the atria and ventricles and prevent backflow of blood into the atria
What is the atrioventricular valve called on the left side of the heart?
The bicuspid valve
What is the atrioventricular valve called on the right side of the heart?
The tricuspid valve
What are the atrioventricular valves anchored by?
Papillary muscle that are embedded in the ventricle wall
What links the muscle and the valves?
Chordae tendinae… these anchor the valves and prevent them from turning inside out
When do the semi lunar valves shut?
When the pressure in the arteries exceeds that in the ventricles
What are the 4 major blood vessels?
The aorta
The pulmonary artery
The venae cavae
The pulmonary vein
What sort of blood comes from the aorta and where does the aorta come out of?
Oxygenated blood and it comes from the left ventricle
What sort of blood does the pulmonary artery carry and where from?
Deoxygenated blood and from the right ventricle to the lungs
What sort of blood does the vena cava carry and where does it carry it from/to?
Brings deoxygenated blood back from the body and returns it to the right atrium
Where does the pulmonary vein carry blood to and what sort of blood is it?
Transports oxygenated blood from the lungs and to the left atrium
