The Respiratory System

Question 1

What is the need for exchange surfaces?

Answer 1

Multicellular organisms have a lower SA:V ratio so diffusion isn’t efficient enough to meet their needs. As multicellular organisms increase in size their volume increases and their SA doesn’t increase as fast as the volume and.

Question 2

How can the effectiveness of an exchange surface in plants and animals increased?

Answer 2

.Large SA
. short diffusion distacne

Question 3

What are example of adaptions that allow for a large SA in an exchange surface?

Answer 3

.Flattened shape of structures e.g. leaf
.alveoli
.villi & micro-villi

Question 4

What are example of adaptions that allow for a short diffusion distance in an exchange surface?

Answer 4

.membranes of cells
.flattened shape of structures e.g. leaf
.1 cell thick capillary wall
.epithelia of alveoli and villi are 1 cell thick
.

Question 5

What is another name for breathing?

Answer 5

Ventilation

Question 6

What is the gas exchange system made up of?

Answer 6

.Trachea
.intercostal muscles
.Bronchi
.Bronchioles
.alveoli
.diaphragm

Question 7

What is the Trachea?

Answer 7

the windpipe

Question 8

What is the pleural membrane?

Answer 8

The pleural membrane is a thin, moist, and slippery lining that covers the lungs and the inside of the chest cavity.

Question 9

What is the rib cage?

Answer 9

The rib cage is the bony structure that forms the walls of the chest cavity. The pleural membrane is actually located inside the rib cage, lining the inside surface of the chest wall and surrounding the lungs. The ribcage protects the heart and lungs

Question 10

What do the intercostal muscles do?

Answer 10

Contract and relax to ventilate lungs

Question 11

Bronchi

Answer 11

split from windpipe

Question 12

Bronchioloes

Answer 12

Bronchi split into bronchioloes

Question 13

Alveoli

Answer 13

Bronchioles lead to air sacs called alveoli where gaseous exchange occurs

Question 14

Diaphragm

Answer 14

separates lungs from digestive organs, moves down causing inhalation

Question 15

What’s the most important muscle when we inhale?

Answer 15

diaphragm

Question 16

What’s the 2nd most important muscle when we inhale?

Answer 16

external intercostal muscles

Question 17

What is breathing a result if?

Answer 17

It’s a passive process resulting from pressure changes in the lungs

Question 18

Breathing in

Question 19

A

Answer 19

External intercostal muscles contract pulling the rib-cage up and out

Question 20

B

Answer 20

The diaphragm contracts and flattens

Question 21

C

Answer 21

This increases the volume and decreases the pressure of the thorax - there’s a lower air pressure inside the lungs than outside the body

Question 22

D

Answer 22

Air is therefore drawn into the body (when we inhale forcibly, other muscles are used)

Question 23

Breathing out

Answer 23

the opposite happens when exhaling

Question 24

1

Answer 24

External intercostal muscles relax pulling the ribcage down and in

Question 25

2

Answer 25

the diaphragm relaxes and moves upwards

Question 26

3

Answer 26

This decreases the volume and increases the pressure of the thorax --> there's a higher air pressure inside the lungs than outside the body

Question 27

4

Answer 27

Air is therefore expelled from the body

Question 28

What is the thorax?

Answer 28

top part of the body separated from bottom by diaphragm

Question 29

How does air get to our lungs?

Question 30

step 1

Answer 30

we breathe in thru the mouth and nose - the air travels down the trachea that has rings of cartilage in its walls that keep it open as air is drawn in

Question 31

Step 2

Answer 31

The trachea splits into 2 bronchi (one bronchus for each lung)

Question 32

Step 3

Answer 32

The bronchi split into bronchioles --> each bronchiole ends in a cluster of microscopic air sacs called alveoli (which are the exchange surfaces for gases in and out of the body)