Cardiovascular system Flashcards
What are the 3 layers of the heart?
- Epicardium (outer)
- Myocardium (middle)
- Endocardium (inner)
What do white blood cells do?
- Fights infection
- Identify, destroy and remove pathogens
- Originate in bone marrow
Capillaries
- Connects arteries and venules
- One cell thick
- Where gas exchange takes place
Thermoregulation
- Helps maintain thermal balance
- Occurs in vasodilation and constriction
How are waste products removed?
1) Lactic acid carried from the tissues to the kidneys and liver
2) CO2 is carried from tissue to the lungs
Functions of the cardiovascular system
- Delivering oxygen and nutrients
- Removes waste products
- Thermoregulation
Platelets
- Clots blood to prevent blood loss
- Disc shaped
- Made in the bone marrow
Tricuspid valve
Between the right atrium and right ventricle
Veins
- Return blood to the heart
- Thin walls due to low pressure
- Large diameter
Pulmonary semi-lunar valve
Between right ventricle and pulmonary artery
Arteries
- Carry blood away from the heart
- Thick walls due to high pressure
- Small diameter
- Have elasticity
Aortic semi-lunar valve
Between left ventricle and aorta
Bicuspid valve
Between left atrium and left ventricle
Plasma
- Transports nutrients like CO2, hormones and protein
- Maintains blood pressure and homeostasis
- Maintains blood volume
Under what bone is the heart located?
The sternum
What surrounds the outside of the heart?
The pericardium - a twin layered sac
What is in between the pericardium and the heart?
Pericardial fluid
What is pericardial fluid important to prevent?
Friction
Right atrium
Supplies deoxygenated blood at low pressure to move the blood down to the right ventricle
Right ventricle
Supplies deoxygenated blood at low pressure to move the blood to the lungs
Left atrium
Supplies oxygenated blood at high pressure and moves blood to the left ventricle
Left ventricle
Supplies oxygenated blood at high pressure and moves blood to the body
How many layers do arteries and veins have?
3
What are the 3 layers of arteries and veins?
- Tunica Externa
- Tunica Media
- Tunica Intima
What is the Tunica externa?
The outermost layer of arteries and veins that are made of connective tissue
What is the Tunica media?
The middle layer of arteries and veins and is made of elastic fibres
What is the Tunica intima?
The innermost layer of arteries and veins and are made of a single layer of endothelium
Definition of elasticity
Being able to stretch and then go back to the original position
Definition of contractility
A measure of cardiac pump performance
What are arterioles?
Smaller versions of arteries
What are venules?
Smaller versions of veins
What do arterioles do?
- Control blood distribution
- Enable blood to pass to the capillary
What protein do red blood cells contain?
Haemoglobin - gives the blood its colour
What happens when 4 oxygens combine with haemoglobin?
It forms oxyhaemoglobin
What are the 5 main functions of the CV system?
- Delivering oxygen and nutrients
- Removing waste products
- Thermoregulation
- Fighting infection
- Clotting blood
What is thermoregulation?
The distribution of heat allowing us to maintain thermal balance
Explain the function - Delivering oxygen and nutrients
- During exercise we need more oxygen and nutrients
- When the CV system can’t meet needs we will fatigue
Explain the function - Removal of waste products
- Lactic acid is carried to the kidneys and liver
- Carbon dioxide is carried to the lungs
- If these aren’t removed then fatigue will occr
Explain the function - Thermoregulation
- Distribution and redistribution of heat
- Help us to maintain thermal balance
- Occurs in vasoconstriction and vasodilation
Explain the function - Fighting infection
- The WBC are stored in the bone marrow and transported through the blood
- Destroy pathogens and produce antibodies
Where are the ‘bundle of his’ located?
In the septum that separates the ventricles
Where are the purkinje fibres located?
In the walls of the ventricles
What do purkinje fibres do?
Carry the impulse to ventricle walls, causing them to contract
