Circulatory system

Question 1

what is the circulatory system?

Answer 1

The body’s transport system that consist of lungs, heart, blood vessels and blood.
- provides oxygen/nutrients via oxygenated blood and removes waste products/CO2 via deoxygenated blood

Question 2

Components of blood? (5)

Answer 2

Plasma - 55%
Red Blood Cells - 46%
White blood cells - 19%
Platelets
Haemoglobin

Question 3

Function of plasma/ consists of ? (3)

Answer 3

FUNCTION - transport nutrients, hormones/ proteins around the body
CONSISTS OF - mainly water to allow substances to dissolve/ be transported easily

Question 4

Function of RBCs / consists of ? (3)

Answer 4

FUNCTION - transport oxygen/CO2 around the body
CONTAINS - haemoglobin (binds to oxygen so OXYHAEMOGLOBIN)

Question 5

Adaptations of red blood cells? (3)

Answer 5

• biconcave - larger surface area for oxygen
• packed with haemoglobin
• no nucleus, so more space for haemoglobin/oxygen

Question 6

Function of WBCs ? (2)

Answer 6

• help fight infections
• help defend body against pathogens

Question 7

Function/Consist of of platelets ?(2)

Answer 7

FUNCTION - clot blood to prevent blood loss
CONSIST OF - contains enzyme which cause blood to clot

Question 8

Function of the 3 blood vessels. (3)

Answer 8

Artery - carry blood AWAY from heart to the organs at HIGH PRESSURE
Veins - carry blood TO heart from the organs AT LOW PRESSURE
Capillaries - form a huge network of tiny vessels linking arteries and veins

Question 9

Describe the 3 blood vessels/adapations (3)

Answer 9

ARTERIES - muscular elastic tubes
THICK WALL
NARROW LUMEN
VEINS - THIN WALL
WIDER LUMEN
has valves to prevent backflow

CAPPILARIES - ONE CELL THICK WALL - thin to allow diffusion of gases/nutrients

Question 10

what does the pulmonary circuit and the systemic circuit do?

Answer 10

PULMONARY CIRCUIT ( right side) - pumps blood TO LUNGS back to HEART
SYSTEMIC CIRCUIT (left side) - pumps blood TO BODY back to the HEART

Question 11

What is double circulation?

Answer 11

• this circulation sees blood pass through the heart twice in each circuit at HIGH pressure

Question 12

pathway of blood through the heart? (6)

Answer 12

Deoxygenated blood from the body enters the heart via the VENA CAVA into the RIGHT ATRIUM.

ATRIUM contracts and pushes blood past the valve into the RIGHT VENTRICLE

RIGHT VENTRICLE contacts forcing blood through the PULMONARY ARTERY to the LUNGS (collect oxygen)

OXYGENATED BLOOD enter the heart via the PULMONARY VEIN into the LEFT ATRIUM

LEFT ATRIUM contacts forcing blood into LEFT VENTRICLE

LEFT VENTRICLE contacts forcing blood through the AORTA into the BODY

Question 13

What is heart rate ?

Answer 13

measure the heart beats per minute when ventricles were contracting
RESTING BPM (teen) - 50-90
RESTING BPM (adult) - 60-80

Question 14

What is stroke volume ?

Answer 14

The volume of blood pumped out of the heart by EACH ventricle in ONE beat.
average fitness - 70ml athlete - 90ml

Question 15

how do people develop a higher stroke volume ?(3)

Answer 15

Regular excercise -> increase size in heart (hypertrophy) -> more blood pumped in/out -> higher stroke volume

Question 16

what is cardiac output? formula?

Answer 16

The amount of blood expelled from the heart in each minute .
Cardiac output = stroke volume x heart rate

IN LITRES PER MIN (so remember to convert stroke volume to LITRES)

Question 17

How do people develop higher cardiac output?

Answer 17

fitter you are -> higher stroke volume -> more blood pumped -> more oxygen delivered -> higher cardiac output