Respiratory System

Question 1

What structures make up the respiratory system in mammals?

Answer 1

nasal chambers
larynx
trachea
bronchi
bronchioles
alveoli
lungs
diaphragm

Question 2

What are the nasal chambers?

Answer 2

the interior of the nose

Question 3

What is the larynx?

Answer 3

also known as the voice box

responsible for the production of sounds

Question 4

What is the trachea?

Answer 4

also known as the windpipe

carries air into the lower respiratory system

Question 5

What are the bronchi?

Answer 5

the two main passageways that carry air into the lungs

one for each lung

Question 6

What are the bronchioles?

Answer 6

branches that form from the bronchi

Question 7

What are the alveoli?

Answer 7

located at the end of each bronchiole

are microscopic sacs that are in contact with blood capillaries

allow oxygen and carbon dioxide to pass through (gas exchange)

Question 8

What are the lungs?

Answer 8

organs where gas exchange take place

Question 9

What is the diaphragm?

Answer 9

a muscle which is responsible for breathing

Question 10

What happens during gas exchange?

Answer 10

contraction of diaphragm and intercostal muscles enlarges chest cavity

this increases volume of lungs but decreases pressure within lungs

this causes air rich in oxygen to be drawn into mouth and through respiratory system

air reaches alveoli

oxygen molecules pass from alveoli an into blood capillaries at the same time molecules of carbon dioxide pass from blood capillaries and into alveoli

oxygenated blood travels through capillaries to the pulmonary vein and on to the heart

relaxation of diaphragm and intercostal muscles decreases the lung volume but increases the pressure in lungs

increased pressure forces mix of oxygen-depleted air and carbon dioxide out of lungs to be breathed out of mouth

exhaled air and carbon dioxide is released into the atmosphere

Question 11

Why does the surface area of the alveoli need to be large?

Answer 11

necessary to allow enough oxygen to be absorbed and sent around the body so that the animal can carry out it’s normal activities

Question 12

What adaptations do bats have?

Answer 12

relatively larger lungs than other mammals

alveoli are relatively smaller than other mammals which increases surface area for gas exchange

alveoli more densely packed with blood vessels

Question 13

What do the adaptations in a bat allow for?

Answer 13

allow a bat to extract more oxygen from the air than other mammals

Question 14

What adaptations do cetaceans have?

Answer 14

breathe through blowholes on top of their head

blowholes connect to the trachea

trachea does not connect to the mouth

do not breathe through their mouths

Question 15

What adaptations do diving mammals have?

Answer 15

lung is fully collapsible

use blood as a store of oxygen

Question 16

What is the benefit of a collapsible lung in diving mammals?

Answer 16

reduces buoyancy - if the lung was filled with air, the animal would find it hard to dive

Question 17

Why do diving mammals need to store oxygen in their blood?

Answer 17

the lungs cannot store oxygen if they collapse therefore oxygen needs to be stored somewhere else

Question 18

How can diving mammals store oxygen in their blood?

Answer 18

they have relatively more blood than other mammals
they have a higher percentage of oxygen carrying red blood cells

Question 19

How do amphibians breathe?

Answer 19

they are born larvae and breathe through gills

when they become adults they lose their gills and develop lungs

respire through their skin to be able to take oxygen from water

Question 20

How can amphibians respire through their skin?

Answer 20

amphibian lungs are more primitive than in mammals and cannot be relied on to supply all of the animal’s oxygen requirements
amphibians must always keep their skin wet or damp

Question 21

Where does gas exchange take place in amphibians?

Answer 21

skin

Question 22

How do fish breathe?

Answer 22

when a fish opens it’s mouth it draws water into and through the gills

special cells in the gills absorb oxygen and pass it into the bloodstream and remove carbon dioxide and pass it into the water

Question 23

How are gills efficient in extracting enough oxygen?

Answer 23

fish open and close their mouth and gills in sequence to ensure that water only flows one way through the gills

blood flows through the gills in the opposite direction meaning oxygen is continually entering the bloodstream

gills also have a very large surface area

Question 24

Why do birds have a higher oxygen demand?

Answer 24

the exertion of flying

Question 25

What differences do birds have in their respiratory system than mammals?

Answer 25

do not have a diaphragm

have additional organs called air sacs which draw air in and push air out

lungs don’t inflate or deflate

air only moves through the lungs in one direction to allow gas exchange to continually take place

it takes two inhalation-exhalation cycles for air to make it’s way through the system and back out

Question 26

What happens during inhalation in birds?

Answer 26

air sacs expand and draw in air from the mouth, which passes into the posterior and abdominal air sacs

at the same time, air that was already in the lungs passes into the anterior air sacs

Question 27

What happens during exhalation in birds?

Answer 27

when the air sacs contract air is forced from the posterior and abdominal air sacs into the lungs

gas exchange occurs in the lungs but instead of alveoli birds have parabronchi which opens at both ends which allows for the unidirectional flow of air in the lungs

at the same time, air in the anterior air sac is forced out into the trachea and through the mouth

Question 28

What is the expansion and contraction of the air sacs caused by?

Answer 28

the movement of muscles in the chest

Question 29

Describe the respiratory system in invertebrates.

Answer 29

do not have lungs

do not have a circulatory system

have a system of tubes called trachea which transport air directly to cells around the body

trachea connected to spiracles (external openings on the surface of the animal’s body)

Question 30

Describe the book lung.

Answer 30

consists of a series of plate-like structures arranged closely together

air surrounds the plates which are filled with haemolymph

gas exchange occurs across the surface

located within the abdomen

air enters through the spiracles