D1 - Structure of the Cardiovascular system Flashcards
What does the cardiovascular system consist of?
- heart
- vessels
- blood
What do the blood vessels provide?
- a circulatory network
Where is the heart located in the body?
- underneath the sternum
What is the function of the heart?
- to drive blood through the vessels in order to deliver it to the tissues and working muscles
What is the heart surrounded by?
- a twin layered sac called the pericardium
What does the cavity between the two outer layers of the heart contain?
- pericardial fluid
- prevents friction as the heart beats
What are the four parts that make up the cell wall?
- septum (separating left and right sides of the heart)
- endocardium (on the inside of the heart walls)
- epidcardium (outer layer)
- myocardium (thick muscle)
Order of blood flow through the heart …
- superior & inferior vena cava
- right atrium
- tricuspid valve
- right ventricle
- pulmonary semi lunar valve
- left & right pulmonary arteries
- left & right pulmonary veins
- left atrium
- bicuspid valve
- left ventricle
- aortic semi lunar valve
- aorta
Heart …
- two separate pumps
- 1 pump = 2 chambers on the right
- 2 pump = 2 chambers on the left
- chambers on the right supply low pressured blood to the lungs via pulmonary veins
- low pressured to the lungs (right)
- high pressured to the body (left)
Pulmonary circuit …
- between heart and lungs
Systematic circuit …
- between heart and rest of the body
- muscles tissues and organs
Coronary arteries …
- supply the heart with blood so it is able to pump
- on the heart itself
Atria …
- upper chambers of the heart
- right receives deoxygenated
- left receives oxygenated
- they receive blood from other parts of the body
Ventricles …
- pumping chambers
- thicker walls
- right pumps to pulmonary
Bicuspid valve …
- it allows blood flow in one direction only
- between left atrium and ventricle
Tricuspid valve …
- it allows blood flow in one direction only
- between right atrium and right ventricle
Semi-lunar valve …
- entrance to the pulmonary artery and aorta
- they allow blood flow in one direction only
Aorta …
- main artery
- under the most pressure as oxygenated blood is pumped through this to the rest of the body
Superior Vena Cava …
- a vein that receives deoxygenated blood from the upper body into the right atrium
Inferior vena cava …
- a vein that receives deoxygenated blood from the lower body into the right atrium
Pulmonary vein …
- carries oxygenated blood from the lungs into the heart (left atrium)
Pulmonary artery …
- carries deoxygenated blood from the heart to the lungs
- its the only artery in the body that carries deoxygenated blood
What are the five type of blood vessel that create a network?
- arteries
- arterioles
- capillaries
- veins
- venules
Arteries …
- carry blood away from the heart
- carry oxygenated blood (except pulmonary artery0
- have thick muscular walls to carry blood at high speed under high pressure
- expand when blood is forced through them
- do not require valves as they have high pressure
- deep under skin, if close to skin they can be forced as pulses
Two main properties of arteries …
- elasticity
- contract ability = smooth muscle within the vessels allow for this = size of the arteries can be changed
What is the relationship between contract ability and blood pressure?
- contracting increases blood pressure
- relaxing decreases blood pressure
Arterioles …
- thinner walls than arteries
- how oxygen is redistributed during exercise
- they contract (vasoconstriction) to reduce blood flow or relax (vasodilate) to increase blood flow to muscles
- responsible for altering the amounts of blood flow to certain parts of the body, and how much blood gets to the capillaries
Capillaries …
- smallest vessel (narrow and thin)
- connect circulatory system = link between veins and arteries
- number at a muscle is influenced by physical activity completed
- essential as they allow for diffusion of oxygen/ nutrients to body tissues
- ensure muscles get oxygen/ remove waste products
- walls of capillaries are only cell thick = diffusion is efficient
Veins …
- veins facilitate to the rest of the body, venous return deoxygenated blood back to the heart
- thinner walls than arteries as they do not have high pressured blood
- muscles in the veins that push thin walls of the veins inwards, squeezing blood back towards the heart
- pocket valves within veins (& venules) = contract veins to increase pressure so blood flows up the vein
- contractions within the veins are not constant, valves close, stopping back flow of blood
- veins are close to the surface and can be seen under skin
- branch into smaller vessels called venules
Venules …
- small vessels that connect the capillaries to veins
- take blood from the capillaries and transport deoxygenated blood under low pressure to the veins, which in turn go the heart
What are the three components of the blood?
- red/ white blood cells
- platletes
- plasma
Red blood cells …
- function to transport oxygen to tissues in the body
- contain haemoglobin (makes them red) and mixed with oxygen creates oxyhaemoglobin
- have large surface area (dimple)
- drop of blood contains millions of red blood cells
White blood cells …
- protect body from infection
- identify, locate and destroy foreign bodies in the blood
- remove bacteria and viruses from the body
- formed in bone marrow and stored in blood
Platelets …
- primary function is clotting to prevent blood loss
- if there is a cut, platelets rush to the area to close the wound (stopping bacteria from entering and blood loss)
- produced in the blood marrow
Plasma …
- yellow liquid in which all blood cells are carried
- made of 90% water as well as electrolytes such as sodium, potassium and proteins
- purpose is to allow the movement of other cells within the blood