The Lungs And The Circulatory System

Question 1

Where are the lungs

Answer 1

• In the thorax

Question 2

Where is the thorax

Answer 2

• the top part of your body
• it’s separated from the lower part of the body by the diaphragm

Question 3

Describe the lungs

Answer 3

• They are like big pink sponges and are protected by the rib cage
• They’re surrounded by the pleural membranes

Question 4

Where does the air you breathe go

Answer 4

• through the trachea
• This splits into 2 tubes called bronchi (each one is a bronchus), one going to each lung
• The bronchi split into progressively smaller tubes called bronchioles
• The bronchioles finally end at small bags called alveoli where the gas exchange takes place

Question 5

Answer 5

Question 6

What is the function of the alveoli

Answer 6

• carry out Gas exchange in the body

Question 7

What is the alveloli

Answer 7

• little air sacs in the lungs, surrounded by a network of blood capillaries
• this is where gas exchange happens

Question 8

How do the alveoli work

Answer 8

• blood passing next to alveoli (just returned to lungs from rest of body) contain lots of CO2 and very little oxygen
• Oxygen diffuses out of alveolus (high concentration) into the blood (low concentration)
• CO2 diffuses out of the blood (high concentration) into the alveolus (low concentration) to be breathed out

Question 9

What happens when the blood reaches body cells

Answer 9

• Oxygen diffuses from red blood cells (high conc) and diffuses into body cells (low conc)
• At the same time, CO2 diffuses out of the body cells (where there’s a high concentration) into the blood (where there’s a low concentration).
• It’s then carried back to the lungs

Question 10

How do you calculate the breathing rate

Answer 10

Breaths per minute

Question 11

What type of circulatory system do humans have

Answer 11

Double circulatory system — two circuits joined together

Question 12

What is the circulatory system made up of

Answer 12

• the heart
• blood vessels
• blood

Question 13

What does the right ventricle do

Answer 13

• pumps deoxygenated blood to the lungs to take in oxygen
• The blood then returns to the heart

Question 14

What does the left ventricle do

Answer 14

• pumps oxygenated blood around all the other organs of the body
• the blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again

Question 15

How is blood pumped around the body

Answer 15

By the heart contracting

Question 16

What are the walls of the heart made up of

Answer 16

Muscle tissue

Question 17

What is the job of the heart valves

Answer 17

• make sure that blood flows in the right direction — they prevent it flowing backwards

Question 18

How does the heart use its four chambers to pump blood around

Answer 18

1) Blood flows into the 2 atria from the vena cava and the pulmonary vein
2) The atria contract, pushing the blood into the ventricles
3) The ventricles contract, forcing the blood into the pulmonary artery and the aorta, and out of the heart
4) the blood then flows to the organs through the arteries, and returns through veins
5) The atria fill again and the whole cycle starts over

Question 19

What are the hearts 4 chambers

Answer 19

• Right atrium
• Right ventricle
• Left atrium
• Left ventricle

Question 20

What is the job of the coronary arteries

Answer 20

• they are arteries that branch off the aorta and surround the heart
• they make sure that the heart gets all the oxygenated blood it needs
• The heart needs it’s own supply of oxygenated blood

Question 21

-what is your resting heart rate controlled by

Answer 21

• a group of cells in the right atrium wall that act as a pacemaker
• These cells produce a small electrical impulse which spreads to the surrounding muscle cells, causing them to contract

Question 22

What happens if someone’s natural pacemaker cells don’t work properly (e.g. if a patient has an irregular heartbeat)

Answer 22

• An artificial pacemaker can be used
• It’s a little device that’s implanted under the skin and has a wire going to the heart
• It produces an electrical current to keep the heart beating regularly

Question 23

What are the 3 different types of blood vessel

Answer 23

1) Arteries — carry blood away from the heart
2) Capillaries — involved in the exchange of materials at the tissues
3) Veins — carry the blood to the heart

Question 24

Describe Arteries

Answer 24

• The heart pumps the blood out at high pressure so the artery walls are strong and elastic
• The walls are thick compared to the size of the hole down the middle (the “lumen”)
• They contain thick layers of muscle to make them strong and elastic fibres allow them to stretch and spring back

Question 25

Describe the Capillaries

Answer 25

• they are really small
• the arteries branch into the capillaries
• They carry the blood really close to every cell in the body to exchange substances with them
• They have permeable walls, so substances can diffuse in and out
• They supply food and oxygen, and take away waste like CO2
• Their walls are usually only 1 cell thick — This increases the rate of diffusion by decreasing the distance over which it occurs

Question 26

Describe the veins

Answer 26

• they take blood back to heart
• Capillaries join up to form veins
• The blood is at lower pressure in the veins so the walls don’t need to be as thick as artery walls
• They have a bigger lumen than arteries to help the blood flow despite the lower pressure
• They also have valves to help keep the blood flowing in the right direction

Question 27

Calc rate of blood flow

Answer 27

Rate of blood flow = volume of blood / number of mins

Question 28

What do red blood cells do

Answer 28

• carry oxygen from the lungs to all the cells in the body
• Their shape is a biconcave disc — this gives a larger SA for absorbing oxygen
• They don’t have a nucleus — this allows more room to carry oxygen
• They contain a red pigment called haemoglobin
• In the lungs, haemoglobin binds to oxygen to become oxyhemoglobin
• In body tissues, the reverse happens — oxyhemoglobin splits up into haemoglobin and oxygen, to release oxygen to the cells

Question 29

What do white blood cells do

Answer 29

• Defend against infection
• some can change shape to engulf microorganisms in a process called phagocytosis
• Others produce anti bodies to fight microorganisms, as well as antitoxins to neutralise any toxins produced by the microorganisms
• unlike red blood cells, they do have a nucleus

Question 30

What do platelets do

Answer 30

• help blood clot at a wound — to sop all your blood pouring out and to stop microorganisms getting in
• they are small fragments of cells — they have no nucleus
• lack of platelets can cause excessive bleeding and bruising

Question 31

What does plasma do

Answer 31

• a pale straw-coloured liquid which carries everything in the blood
  It carries:
• red and white blood cels and platelets
• nutrients like glucose and amino acids
• CO2 from the organs to the lungs
• urea from the liver to the kidneys
• Hormones
• Proteins
• Antibodies and antitoxins (produced by white blood cells)

Question 32

Answer 32