L01 Cardiovascular system Flashcards
Why are erythrocytes red?
Haemoglobin
What are the 3 types of leucocytes (WBC)?
Lymphocytes, neutrophils and monocytes
What are lymphocytes?
Part of the immune system
B-cells and T-cells
B-cells develop in the bone marrow
produce antibodies to destroy antigens
T-cells develop in the thymus gland
destroy the body’s own cells that have been taken over by viruses or have become cancerous
What are neutrophils?
Small and fast, they are one of the first cell types to travel to the site of infection
What are monocytes?
Largest of the WBC
Adaptions of erythrocytes
Do not have a nucleus
Bi-concave shape
flattened
Small
Flexible
Function of platelets
Form blood clots by clumping together, to stop bleeding.
Function of plasma
Provides a mean of transport for glucose, lipids, amino acids, hormones, carbon dioxide and oxygen
Carries proteins such as fibrinogen, which helps with blood clotting
Helps with temperature regulation
What are the 4 major blood vessels?
Aorta
Pulmonary Vein
Vena Cava
Pulmonary Artery
Where does the aorta transport blood to and from?
Oxygenated blood from the left ventricle to the body
Where does the pulmonary vein transport blood to and from?
Oxygenated blood from the lungs to the left atrium
Where does the vena cava transport blood to and from?
Deoxygenated from the body to the right atrium
Where does the pulmonary artery transport blood to and from?
Deoxygenated blood from the right ventricle to the lungs
4 valves in the heart are:
Tricuspid, Bicuspid, Pulmonary and Aortic
Which side of the heart is the tricuspid valve?
Right
What is pulmonary circulation?
Right side of the heart receives deoxygenated blood from the body and pumps it to the lungs
What is systemic circulation?
Left side of the heart receives oxygenated blood from the lungs and pumps it to the body
Healthy heart rate range is?
60-80bpm
Atrial systole
Contraction of the atria
Where is the sino atrial node?
right atrium
Where is the atrioventricular node?
Bottom of the right atrium
What is the atrioventricular node responsible for?
delaying electrical impulses it receives from the sinoatrial node
Pathway of electrical activity in the heart:
sinoatrial node
Atrioventricular node
bundle of His
Purkyne fibres
On an ECG what does the P wave show?
atrial systole
On an ECG what does the QRS complex show?
Ventricular systole
On an ECG what does the T wave show?
Diastole
State the order at which blood runs from the heart through the vessels and back to the heart
Heart - Arteries - Capillaries - Veins - Heart
Why do veins have a larger diameter
To carry large volumes of blood at a low pressure
Why do veins have valves?
To prevent the backflow of blood
Name the components of the lymphatic system
lymph
lymph vessels
lymph nodes
lymph organs
bone marrow
The role of the lymphatic system
- Removes waste from body tissue and returns it back to the blood
- removes access fluid from body tissue
- absorbs fatty acids, transports to blood stream so that the small intestine absorbs it
- Contains lymphocytes so plays a role in immune response
Role of hydrostatic pressure
Pressure from heart contractions
forces water and dissolved substances in the blood plasma out through capillary walls into surrounding tissues - forming tissue fluid
Properties of blood plasma
Straw coloured, clear
Contains plasma proteins
Properties of tissue fluid
fluid between body cells
carries nutrients and oxygen to tissue cells
does not contain plasma proteins
Properties of lymph
Formed from plasma
contains white blood cells
involved in the removal of wastes and infectious organisms from tissues
What are the main plasma proteins
Albumins
What do albumins do to plasma
Contribute to the thickness/viscosity and to osmostic pressure - higher it
What is the function of globulins
essential for immune responses
Role of fibrinogen
blood coagulation and clotting
Normal blood pressure range
90/60mmHg and 120/80mmHg
High blood pressure (hypertension)
140/90mmHg
What does the systolic pressure represent?
high number
Pressure against arteries during contraction
What does the diastolic pressure represent?
Low number
Pressure against arteries during relaxation (Between beats)
Risk factors of hypertension
Age
Family history
High salt intake
Lack of exercise
Overweight
Smoking
Drinking large amount of alcohol
Health conditions that cause hypertension
Kidney disease
Diabetes
Hormone problems such as an overactive thyroid
How to treat hypertension (Lifestyle changes)
Balanced diet with low fat and salt
regular exercise
reduce alcohol intake
stop smoking
get enough sleep
reduce stress
How to treat hypertension (medication)
ACE inhibitors - lower the bp
beta blocks - slow heart rate
Impacts of hypertension
increased chance of coronary heart disease
strokes
kidney disease
Symptoms and effects of coronary heart disease
angina and heart attack
Symptoms of angina
breathlessness, nausea, dizziness, chest pain, tightness in the chest
Symptoms of heart attack (myocardial infarction)
light headedness, feeling weak, sweating, shortness of breath, chest pain that radiates to jaw neck and arms
Biological explanation to coronary heart disease
coronary arteries become blocked with fatty deposits through a process called atherosclerosis
when they are fully blocked it can cause heart attack which can permanently damage the heart muscle
Causes of coronary heart disease
Build up of fatty deposits due to smoking, lack of exercise, obesity, high cholesterol, hypertension, diabetes
age. genes and gender
Testing for coronary heart disease
blood tests - levels of certain fats, cholesterol, sugar and proteins
ECG - measure electrical activity and show damage to heart muscle
Medication for coronary heart disease
Nitrates - relax coronary arteries, allowing more blood to reach the heart
Statins - reduce cholesterol
Aspirin or clopidogrel - antiplatelets, makes the blood less likely to clot
ACE inhibitors - lower bp
Surgery for coronary heart disease
Angioplasty:
1. tiny, deflated balloon into narrow artery
2. inflate balloon - arteries open - stent or mesh tube inserted
Coronary artery bypass graft
How do platelets work?
They get trapped by fibrin and form scabs
What is another name for platelets?
Thrombocytes
What happens when body temperature is too high?
Vasodilation
Heat is lost to the environment
Sweat glands release fluid
Fluid evaporates
What happens when body temperature is too low?
Vasoconstriction
Sweat glands do no release fluid
Shivering generates heat
What is blood pressure?
The force of blood against artery walls per contraction
Do lymph vessels have valves?
Yes
Describe how blood plasma becomes lymph. (4)
Blood plasma is forced out of “leaky capillaries”
by hydrostatic pressure
Fluid carries nutrients like oxygen and glucose to cells of tissues
Fluid must return to the circulatory system of oedema will occur
Excess fluid enters the lymphatic system
rejoins blood stream at the top of the body
Outline 2 roles of blood proteins in the formation of tissue fluid
Increases osmotic pressure of blood
Lower water potential of blood
opposite force to hydrostatic pressure
affects viscosity of the blood
Outline 2 roles of hydrostatic pressure in the formation of tissue fluid
Caused by the heart contracting
Higher in arteriole end
Forces blood plasma out of capillary pores
4 functions of the heart
Primary muscle
Beats continuously
Provides tissues & cells with oxygen and nutrients
Controls two separate circulatory systems
Function of the pericardium.
Protects the heart from overexpansion
Function of the pericardial fluid.
Aids movement of the heart and reduces friction
What’s unique about the muscle in the heart and what is it called?
Myocardium never tired but cannot tolerate a lack of oxygen
What is the pericardium?
The thick outside tissue of the heart
What is myocardium?
The thick muscular wall of the heart
What is the endocardium?
The inner layer of cells that line the ventricles
Why is the muscular wall of the left ventricle thicker than the right ventricle?
Has to produce bigger contractions since the blood has to go further distances
Why is there valves in the heart?
To prevent the backflow of blood
Reasons for a blocked artery (6)
Cholesterol deposits
Atheromas
plaques
plaques breaking down
blood clots
atheroscelorsis hardens
Role of blood proteins (4)
Increase osmotic potential of blood
Lower water potential of blood
Opposite force to hydrostatic pressure
Affects viscosity of blood
