LO1 cardiovascular system Flashcards
what are the 5 main functions of blood?
1) transportation of elements needed for life
2) temperature regulation
3) exchange of materials in body tissue
4) preventing infection
5) blood clotting
what are the 4 components of blood and outline the rough percentage that is made up of blood and outline it’s general function
Plasma - 55% transports dissolved substances. exchanges glucose and adrenaline
red blood cells (erythrocytes) 45% - carry oxygen and some carbon dioxide
white blood cells (leukocytes) helps destroy bacteria
platelets (thrombocytes) triggers blood clotting
What is glucose?
nutrient needed for energy
what are antibodies?
proteins made by the immune system
what is urea?
poisonous waste product from protein
what are nutrients?
Glucose for energy, amino acids to make protein, and vitamins and minerals needed for essential processes
what is plasma?
90% water
transport of lots of dissolved substances
what are amino acids?
nutrient needed to make proteins
what are vitamins and minerals?
micro-nutrients needed for essential processes
what is albumin?
blood protein needed to maintain fluid levels
what is fibrinogen
blood protein needed for clotting
what is lipoproteins
proteins that carry fats/cholesterol
what is carbon dioxide?
poisonous waste gas
what are electrolytes?
eg sodium, needed to maintain blood concentration
what are the 3 white blood cell components?
neutrophils
lymphocytes
monocytes
what is neutrophils?
B-type cells produce antibodies
lymphocytes
T-type cells destroy viruses and cancer cells
what is monocytes?
remove dead cells and bacteria
describe the transportation of elements needed for life
-blood transports materials in either red blood cells or plasma
-erythrocytes (rbc) —> have iron - containing protein called haemoglobin
-example 1: O2 + haemoglobin = oxyhemoglobin —> tissues
-example 2: many substances dissolve in watery plasma —> glucose, amino acids and hormones
describe temperature regulation
-as mammals we generate and regulate our own temperature (process of homeostasis.)
-millions of chemicals reactions in body —> regulated by enzymes —> produce heart (eg muscle tissues)
-core temperature must be regulated 37C —> enzymes breakdown (denature) at high temperature and slow down at low temperature
example:
too hot —> skin blood vessels widen (vasodilate) —> lose heat
too cold —> skin blood vessels narrow (vasoconstrict) —> save heat
describe the exchange of materials in body tissue
-using our cardiovascular system we can exchange materials in body tissues
-capillaries - only blood vessels thin enough for gases (O2 and CO2) and nutrients (eg glucose) to pass into tissues
-materials exchange between blood and tissues by diffusion (random movements of particles from high to low concentration until equilibrium is attained)
describe preventing infection
-our cardiovascular system helps to to prevent infection
-WBC (leukocytes) —> our immune response to pathogens —> disease - causing organisms (bacteria, parasites or viruses)
example: bacteria and parasites —> neutrophils and lymphocytes recognised threats —> forms protein antibodies —> they look on and immobilise them —> monocytes then kill and break them up
describe blood clotting
-our cardiovascular system is important in blood clotting
-we have about 5 litres of blood. losing 2 litres can lead to death
-broken skin can lead to pathogen access and blood poisoning
-platelets —> convert soluble fibrinogen —> insoluble fibrin —> process called coagulation (‘turning liquid into gel’)
example: coagulation forms a net like structure —> traps platelets (cell fragments) and erythrocytes (RBCs) —> forms clot and broken skin
what are coronary arteries
supply oxygen and nutrients to the heart muscle
what 2 things do coronary arteries supply?
oxygen and nutrients
what can build up in the coronary arteries?
Plaque
Fatty deposit
Atheroma
Atherosclerosis
what is the effect of coronary arteries building up
less / reduced blood flow, less oxygen, less nutrients
-angina can lead to a heart attack
-stroke
explain what is meant by the heart being a double pump
The heart sends blood onto two different circuits. Each time your heart beats, blood goes out on one circuit to the lungs and back, and other circuit goes all around the body at the same time.
1 heart beat = blood going onto circuits —> pulmonary circuit lungs and back. systemic circuit body head and back. Two circuits at the same time
cardiac cycle
DIASTOLE
-The atria and ventricles relax and expand - blood fills the atria
-pressure in the atria increases opening the AV values (bicuspid & tricuspid valve)
-blood passively fills the ventricles. SL valves are closed to prevent blood leaving the heart
cardiac style
ATRIAL SYSTOLE
the atria contract forcing the remaining blood down into the ventricles
cardiac cycle
VENTRICLE SYSTOLE
-the ventricles contract whilst AV valves close preventing back flow into the atria
-the SL valves are forced open and blood is ejected from the ventricles into the aorta and pulmonary artery
diastole and systole
diastole - filling phase
systole - emptying phase
explain how the conduction system controls the cardiac system
-the SA node causes atrial systole
-purkinje fibres trigger ventricular systole
FILL FILL IMPULSE EMPTY IMPULSE IMPULSE IMPULSE EMPTY
-ATRIA DIASTOLE - the atria fill the blood
-VENTRICULAR DIASTOLE - ventricles passively fill with blood due to the pressure of blood filling the atrium
- SA NOSE - initiates an electrical impulse which causes the atrium walls to contract
-this causes ATRIA SYSTOLE where the blood empties from the atrium into the ventricles
-the AV NOSE receives and delays the impulse from the sa node to allow the atria to finish contracting
-the BUNDLE OF HIS located in the septum then receives the impulse.
-the impulse is then received by the PURKINJE FIBRES in the ventricle walls causing the ventricles to contract
-causing VENTRICULAR SYSTOLE where the blood empties from the ventricles to the lungs and the body
what is atheroma?
when the walls of the coronary arteries become blocked with fatty deposits
what is angina
breathlessness, nasea, dizziness and chest pain and a feeling of tightness in the chest which can spread to the arms, neck and jaw.
what is a heart attack (myocardial infarction) ?
when arteries become completely blocked or can lead to a heart attack which can permanently damage the heart muscle and lead to death
what is an angiogram?
a type of x-ray where dye is injected into the blood so that narrowing or coronary arteries can be seen.
in and out quick process
what is angioplasty?
-a microscopic deflated balloon is passed into the narrowed artery and inflated
to push it open. Sometimes a microscopic mesh tube (called a stent) is inserted to keep the artery open
-takes a day to recover, you
go home the same day
why is coronary bypass?
-using a piece of artery taken from somewhere in the body to bypass or bridge a blocked region of coronary artery - allows blood to flow beyond the blockage.
-a more serious operation, takes 6-8 weeks to recover, can’t drive
list 6 care needs of CHD
-diet
-obesity
-physical activity & exercise
-smoking
-cholesterol tests
-stress
risk factors of CHD
CAN NOT CHANGE
-increasing age
-family history
CAN CHANGE
-lack of exercise
-being overweight or abuse
-high dietary salt intake
-smoking and alcohol
what is the order of flow of blood vessels leaving the heart and returning to the heart?
heart —> arteries —> capillaries —> veins —> heart
what are the differences between arteries and veins?
-veins have valves to protect back flow, arteries don’t
-middle layer is thicker in arteries compared to veins. The muscle in middle layer is thicker and elastic
-lumen is narrower in artery than in vein
DIFFERENCES BETWEEN ARTERIES AND VEINS
in arteries, blood is carried away from the heart. whereas in veins the blood is carried towards the heart
arteries usually carry oxygenated blood. veins usually carry de-oxygenated blood
in arteries blood flows quickly under high pressure. in veins blood flows slowly under low pressure
in arteries blood flows in pulses. in veins blood flows smoothly with a squeezing action
artery walls are thick and muscular and elastic. vein walls are thin with little muscular
arteries do not have valves beyond the heart. veins have valves to prevent back flow
in arteries their internal lumen diameter is narrow. in veins their lumen diameter is wider
what is hypertension?
High blood pressure
the force exerted by the blood on the inside of the vessels
what does a blood test do?
can detect LDL / HDL cholesterol and proteins in blood
what is an ECG
analyses functioning of heart from electrical signals
what is an angiogram
x-rays use dye and to pinpoint blockages to coronary arteries
what is a Bp test
readings indicate raised levels and risk of hypertension damage
Nitrates
treats angina
relaxes blocked arteries increasing blood flow
Ace inhibitors
treats blood pressure
lowers readings
statins
treats cholesterol
lowers readings
aspirin
treats clotting / heart attack
anti-platelet drug - reduces risk of clots (thrombosis)
blood pressure
healthy vs unhealthy
70-90 / 40-60 mmHg = low = possible dizziness & fainting
90-120 / 60-80 mmHg = ideal = healthy
120-140 / 80-90 mmHg= pre-high = monitor and implement lifestyle changes
140 / 90 mmHg and above = hypertension = increased risk of stroke, heart attacks and kidney damage
how is tissue fluid formed
it is formed when blood plasma is flittered through the walls of capillaries at the arteriole end due to the high hydrostatic pressure in the blood
identify the 4 methods of monitoring a heart
blood test
ECG
angiogram
blood pressure tests
identify the 3 cardiovascular malfunctions
hypertension
atherosclerosis
CHD
what do the increased surface area and thin walls of capillary beds allow exchange of?
oxygen and nutrients
what causes the formation of high pressure in the cardiovascular system?
blood going fast around the body so the heart has to pump strong
what get squeezed out of the capillaries with this high blood pressure?
plasma forces fluid out
what system collects the fluid squeezed out and returns it to the cardiovascular system?
lymphatic system
how are lymph vessels different from blood vessels
they dont form a closed loop
what is the problem with losing fluid from the blood
its unsustainable
what is the name of the fluid forced out of the vessels
lymph
what 3 things are named in the blood that are important in the formation of lymph
water, red blood cells and protein
where on the capillary wall does the fluid get squeezed out
between the cells
as blood moves towards the end of the capillary what substances have higher concentration
bigger proteins, red blood cells, cellutes
what is the difference in pressure at the start and end of the capillary
the pressure goes down
examples of 3 things in the plasma
antibodies
nutrients
pathogens
what are blood capillaries found next to
tissues
what do the cells need from the plasma to function
the nutrients from the plasma
what is the process called that nutrients get into the cell from the capillary
diffusion
when plasma flows into the cell what is its new name
tissue fluid
what happens to the fluid when it has delivered its nutrients to the cell
returns to the cardiovascular system
where does the fluid go
from the cells to the lymphatic capillary
what is the fluid called when it goes itno the lymphatic capillary
lymph
what happens to lymph before it is returned to the cardiovascular system
it gets cleaned
