Transport System Flashcards
Atrial systole process
Contract of atira, ventricle relax
Contract forces AV valve open and blood flows out of the atria and into the ventricle
Pressure in the atria is greater than in the ventricle so blood is forced out
AV open
SL close
Ventricle systole
Pressure in the ventricle increases and the SL open and AV close to prevent back flow to the atria
Thus allowing blood to leave the left ventricle through the aorta and right ventricle through the pulmonary artery
- ventricle haev very thick muscular wall compares to teh muscular walls in the attia therefore is able to contract with a greater force generating a greater pressure
Diastole process
-atria and ventricle relax
Elastic recoil of the heart lowers the pressure insdie the heart chamebrs and blood is drawn from the arteries and vein
SL close in the aorta and pulmonary arteries preventing backflow
Erthrocytes (RBCs)
Properties and structure
Contain haemoglobin
- red pigment
- carry oxygen
- bone marrow
- immature RBC - has nucleus
Mature RNC - no nucleus
More soace for haemoblobin
Biconcave disc shape = large SA:V ratio so they can diffuse rapidly
No nucleus - more space for haemoglobin to carry oxygen
Leycocytes (WBCs)
Much larger than RBCs
Bone marrow
Can squeeze through tiny blood vessel because they can change shape
Defend against infection
Contains nucleus & colourless cytoplasm
Inflammatory respinse when in area of tissue is damaged
Platelets
Platelets are tiny fragments of large cell called “megakaryocytes”
Bone marrow
—> involved in blood clotting
Transport of oxygen
1) due to the structure of haemoglobin it is difficult for the first oxygen molecule to bind o haemoglobin
2) once the first oxygen molecule binds to the haemoglobin , the Hb undergo a conformational change making it easier for further or following O2 molecule to bind
3) Although the structure of Hb makes it easier for the 4th molecule of O2 to bind, the curve is shallow as there is only one binding site available and therefore is less possibility that the O2 molecule will bind
How does partial pressure of oxygen affect oxygen-haemoglobin binding
As partial pressure of oxygen increases, the affinity of haemoglobin for oxygen also increases, so oxygen bind tightly to haemoglobin. When partial pressure is low oxygen is released from hawmoglobin
State 3 ways that CO2 is transported in the blood
Carbaminohaemoglobin
Dissolved in plasma
As hydrogencarbonate ions (HCO3-) from the dissociation of carbonic acid
Explain the transport of CO2
CO2 dissolved in blood slowly react with water forming H2CO3 carbonic acid catalysed by the enzyme carbonic anhydrase
Carbonic acid dissociates to give hydrogen ions and hydrogencarbonate ions
Haemoglobin acts as a buffer accepting the hydrogen ions to form haemoglobinic acid to avoid changing the pH of the blood
Hydrogen carbonate ions pass put of the red blood cells by diffusion, and chloride ions move in
Explain bohr effect
As partial pressure of CO2 increases, the condition becomes acidic causing haemoglobin to change shape. The affinity of haemoglobin for oxygen therefore decreases, so oxygen is released from haemoglobin
Effect of CO2 in bohr effect
CO2 increases
Lower pH
- haemoglobin undergo conformational change
- affects the tertiary structure
Reduces affinfity for O2
O2 dissociates -binds less easily
Respiring tissue
Decrease in Co2 in bohr effect
Decrease CO2
Higher pH
Increase affinity
Readily binds with O2
-lungs
(Eg fetal haemoglobin)
Fetal haemoglobin
A fetus depends on oxygen from its mother. The blood of fetus contain fetal haemoglobin -> it has higher affnity than adult haemoglobin
Thus fetal haemoglobin can remove oxygen from maternal blood even when the proportion of oxygen is relatively low
Haemoglobin present in the fetus has higher affnity as it needs to be better at absorbing oxygen because by the time oxygen reaches the placenta the oxygen saturation of teh blood has decreased
- higher affinity as it needs to bind O2 in lower partial pressure
Define atherosclerosis
A disease caused by build up of plaque wihtin arteries which narrows them leading to ehart attck and strokes
Define cardiovascular disease
Disease of the heart and circulatory system many of which linked to atheroscelrosis
Atherosclerosis process
1) the endothelium lining of arterie is damaged for instacne by hihg cholesterol levels , smoking or high blood pressure
2) this increase the risk of blood clotting in teh artery and lead to an inflammatory response casuing white blood cells to move into the artery
Over time white blood cell, cholesterol , calcium salts and fibre build up and ahrden leadning to plaque formation
4) the build up of fibrous plaque leads to narrowing of the artyery and restrict blood flow thus increasing the blood pressure which in turn damages the endothelial lining and the process is repeated
Why does the blood need to clot
Prevent blood loss
Prevent entry of harmful bacteria
Provides a framewoek for repair
Function of serotonin
Causes the smooth muscle of the blood vessel to contract. This narrows the blood vessel, cutting off the blood flow to the damaged area
What is the vitimin K for
Important for compound needed for blood to clot
Blood clotting process
1) thromboplastin catalyze the conversion of large soluble prothrombin convert into thrombin with the presence of calcium ions
2) thrombin catalyze the conevrsion of fibronogen into a insoluble fibrin
3) fibrin forms a mesh to cover the wounds
4) mroe platelets adn red blood cells get trapped in the fibrin mesh forming a clot
5)
How can CVD lead to heart attack
Obstruction of a coronary artery due to an atheroma or blood clot
Result in loss of blood supply to an area of heart muscle
This cause death of cells and leads to a heart attack
Factors that increase the risk of cardiovascular disease
Genetics Age Gender Diet -salt , high cholesterol High blood pressure Smoking Physical inactivity Obesity
Gene affect CVD
Some allele increase the risk of CVD , these are inherited from family members
Age affect CVD
Arteries become less elastic eith age which increase blood pressure &risk of blood vessel damage
Gender affect CVD
Women have hihg HDL levels reducing risk of atheroma due to higher levels of oestrogen levels
Increase blood flow to the muscle
Execerise affect CVD
Improves blood circulation -> decrease CVD
Increase HDL levels help lower LDLs
Maintain healthy weight
Lower exercise cause heart to be inefficient as cardiac output is reduced
The heart rate increases and artery walls become less elastic
Smoking affect CVD
Nicotine - stimulate production of hormones
-increase heart rate - increase blood pressure
Reduce HDL levels
-CO increase deposition of cholesterol in atheroma formation
-content in smoke (eg free redicals) which get into blood stream can damage endothelium lining of blood vessel promoting atherosclerosis
-smoking decreases the amount of antixidant in the blood ( important for protecting the cell)
—> fewer antixiodant causes cell damage in the artery walls
—> atheroma formation
Diet HDL
-unsaturated fats, protein and cholesterol
Cholesterol transport to the liver to be broken
- reduce cholesterol blood levels
- also help to remove fatty plaque
- preventing cholesterol deposition
LDL CVD
Saturated fats , proteins and cholesterol
Circulate in blood stream Not taken up by the body cells So cholerterol level high Get deposited in artery walls leading to atheroma Thus atheroscerosis Narrow arteries Reducing blod flow
Salt affect CVD
High salt diet cause kidney to retian too much water
Higher fluid content in blood increase blood volume
—> increase blood pressure
-> risk of CVD
Alcohol
Decrase blood flow to muscle this could lead to CVD increase blood pressure by constricting arteries
Calories rich -> obesity
