The Circulatory System Flashcards
Biconcave
1 mark
Surface that curves inwards on both sides.
Blood plasma
7 marks
Liquid part of the blood containing useful things like -
- Glucose
- Amino acids
- Minerals
- Vitamins (nutrients)
- Hormones
as well as waste materials such as urea.
Cardiac output
Amount of blood pumped by the heart in one minute.
Heart Rate x Stroke Volume = Cardiac Output.
Deoxygenated
3 marks
Blood that is -
Low in oxygen (as cells have used it)
+ High in CO2 (as cells have produced it).
Lumen
2 marks
Central cavity of a hollow structure in an organism or cell.
Oxygenated
(1 mark)
Blood
- high in O2
- and low in CO2.
Urea
3 marks
A nitrogenous waste product resulting from the breakdown of proteins.
It is excreted in urine.
Valve
1 mark
Structure in veins that prevents the backflow of blood.
The circulatory system has three main components:
3 marks
Blood
Blood vessels
The heart
2 Main Functions of Circulatory System
2 marks
Transportation of substances
Protection against disease
Function of Red Blood Cells
1 mark
Carry oxygen.
Function of White Blood Cells
1 mark
Defend the body against disease.
Function of Platelets
2 marks
Convert fibrinogen to fibrin - to clot blood/form a scab.
Fibrin
3 marks
Forms a mesh that traps blood - important in blood clotting + scab formation.
Function of Plasma
5 marks
Transports;
Blood Cells, Digested food molecules, CO2, Urea \+ Hormones.
Example of digested food Molecules
1 mark
Glucose
Red Blood Cells Structure
6 marks
Contain haemoglobin (rich in iron) to carry O2.
Biconcave shape - provides large surface area for diffusion of O2.
No nucleus - provide more space for haemoglobin.
Haemoglobin
2 marks
Rich in iron - required to carry O2 in RBC’s.
White Blood Cells Structure
3 marks
Large cells that contain a nucleus.
2 types - Lymphocytes + Phagocytes
Lymphocytes
1 mark
Make antibodies.
Phagocytes
2 marks
Engulf + digest microorganisms.
Platelets Structure
1 mark
Cell fragments (very small).
Plasma Structure
1 mark
Straw coloured liquid.
Cell Lysis in RBC’s
6 marks
RBC’s placed in a high conc. of water -
osmosis will cause water to move into cell + without a cell wall = they lyse (burst).
Salts + other chemicals are present in the blood plasma - keep its conc. similar to conc. of blood cells.
Present in the blood plasma - keep its concentration similar to the concentration of blood cells.
(2 marks)
Salts + other chemicals
Main Vessels
3 marks
Artery
Vein
Capillary
Artery direction of blood flow
1 mark
Away from the heart.
Vein direction of blood flow
1 mark
Towards the heart.
Capillary direction of blood flow
1 mark
From artery to vein.
Lumen diameter in artery
1 mark
Small
Lumen diameter in vein
2 marks
Large - reduces friction as the blood moves through.
Lumen diameter in capillaries
1 mark
Small
Wall thickness in artery
3 marks
Thick - with muscle + elastic fibres
to withstand high pressure.
Wall thickness in Vein
2 marks
Thin - because Blood travels at a low pressure.
Wall thickness in capillaries
2 marks
1 cell thick to provide a thin, permeable surface for diffusion.
Blood Pressure in artery
1 mark
High
Blood pressure in vein
1 mark
Low
Blood pressure in capillaries
1 mark
Low
Are valves present in arteries?
1 mark
No
Are valves present in veins?
2 marks
Yes - present to prevent the backflow of blood.
Are valves present in capillaries?
1 mark
No
Arteries
2 marks
Usually carries oxygenated blood from heart to rest of the body.
Why are there muscle + elastic fibres within the walls of arteries?
(2 marks)
To allow the artery to expand + recoil with each surge of blood.
Pulmonary artery is the exception as it
2 marks
Carries deoxygenated blood from heart to lungs.
Veins
2 marks
Usually carry deoxygenated blood from the body back to heart.
Pulmonary vein
2 marks
Carries oxygenated blood from the lungs to the heart.
Why are very few muscle + elastic fibres present in the veins?
(1 mark)
Blood does not surge through veins.
Capillaries
3 marks
Allow the diffusion of substances (e.g. O2, CO2, dissolved food + urea) between the blood + body’s cells or vice versa.
The Heart
9 marks
A unidirectional pump with Valves to prevent the backflow of blood.
Right side - pumps Deoxygenated Blood to the Lungs.
Left side - pumps Oxygenated Blood to the body’s Organs.
The Heart Job - Right side
2 marks
Pumps Deoxygenated Blood to the Lungs.
The Hearts Job - Left side
2 marks
Pumps Oxygenated Blood to the body’s Organs.
The Circulatory System - Journey of the Blood
20 marks
- Deoxygenated Blood enters Right Atrium from Vena Cava.
- Blood moves into right ventricle.
- Blood is pumped into pulmonary artery.
- Pulmonary Artery carries Deoxygenated Blood to Lungs.
- Blood becomes Oxygenated in Lungs.
- Oxygenated Blood leaves the Lung via Pulmonary Vein.
- Blood enters the Left Atrium.
- Blood moves into Left Ventricle.
- Blood is pumped into the Aorta, which carries Oxygenated Blood around the body.
Where does the Deoxygenated Blood move to from the Vena Cava?
(1 mark)
The Deoxygenated Blood enters the Right Atrium from the Vena Cava.
From the Right Atrium where does the Deoxygenated Blood move to?
(1 mark)
Into the Right Ventricle.
Where is Blood pumped into from the Right Ventricle?
1 mark
Pulmonary artery.
Where does the Pulmonary Artery carry Deoxygenated Blood to?
1 mark
The Lungs.
What type of blood does the Pulmonary artery carry to the Lungs?
(1 mark)
Deoxygenated Blood.
What happens to Deoxygenated Blood when carried to the Lungs?
(1 mark)
Becomes Oxygenated.
Where does Oxygenated Blood leave the Lungs?
1 mark
Via the Pulmonary Vein.
Where does the Pulmonary Vein carry Blood to?
1 mark
The Left Atrium.
From the Left Atrium where is Oxygenated Blood carried to?
1 mark
The Left Ventricle.
From the Left Ventricle where is Oxygenated Blood pumped to?
2 marks
The Aorta - which carries Oxygenated Blood around the body.
Where does the Journey of Blood in the Circulatory System start from? - And what kind of Blood?
(2 marks)
Deoxygenated Blood starts its journey from the Vena Cava to the Right Atrium.
What does the Unidirectional flow of blood through the heart show?
(2 marks)
It’s shows that Mammals have a Double Circulatory System.
Kind of animal that has a Double Circulatory System
1 mark
Mammal
Double Circulatory System:
Meaning
(2 marks)
Blood travels through the heart twice in 1 circulation of the body.
Vena Cava:
Function
(2 marks)
Carries deoxygenated blood from the body back to the heart.
Pulmonary Artery:
Function
(2 marks)
Carries deoxygenated blood from the heart to the lungs.
Pulmonary Vein:
Function
(2 marks)
Carries oxygenated blood from the lungs to the heart.
Aorta:
Function
(2 marks)
Carries oxygenated blood from the heart around the body.
Hepatic Artery:
Function
(2 marks)
Carries oxygenated blood to the liver.
Hepatic Vein:
Functions
(4 marks)
- Carries deoxygenated blood back to the heart.
2. Carries digested food (glucose + amino acids) from the liver around the body.
Hepatic Portal Vein:
Function
(2 marks)
Carries digested food from the small intestine to the liver.
Renal Artery:
Function
(3 marks)
Carries oxygenated blood (rich in urea) to the kidneys for excretion.
Renal Vein:
Function
(4 marks)
Carries deoxygenated blood (low in urea as it has been purified in the kidney) back to the heart
The O2 + glucose carried in Oxygenated Blood
2 marks
Used for respiration in the body’s cells.
Coronary arteries
6 marks
Small Blood Vessels that branch off the aorta + can be seen on external surface of heart.
- Provide the heart muscle with glucose + O2 needed for respiration.
Exercise causes
1 mark
An increase in pulse rate (heart rate).
When exercising
3 marks
Muscles contract more often + require more energy - which is made during the process of respiration.
As more glucose + O2 is needed
4 marks
Cardiac output (blood pumped per minute) + blood flow to the muscles increases
- causing an increase in heart rate + blood pressure
Causes an increase in heart rate and blood pressure
4 marks
When more glucose + O2 used -
Cardiac output (blood pumped per minute) + blood flow to the muscles increase.
Regular exercise is beneficial as
4 marks
- It strengthens heart muscle - leading to an increased cardiac output even when at rest.
- Reduces the recovery rate (time taken for heart rate to return to normal after exercise).