Functions and structure of respiratory system

Question 1

Structure of the trachea

Answer 1

Main airway path carrying air from the nose to the chest.
the tube is wide and supported by incomplete rings of cartilage which stop the trachea from collapsing
Lined with ciliated epithelium cells+ goblet cells

Question 2

Function of the trachea

Answer 2

Carry warm, clean, moist air to the chest
Cartilage rings are incomplete to allow food to move down the oesophagus
Goblet cells secret mucus to trap dust and microorganisms
The cilia beat and move the mucus+dirt to the mouth

Question 3

Structure of the bronchus

Answer 3

In the chest cavity the trachea divides to form the left bronchus, leading into the left lung, and the right bronchus,leading into the right lung.

Question 4

Structure of the bronchioles

Answer 4

In the lungs the bronchi divide to form smaller bronchioles that have no cartilage rings but contain smooth muscle.
Bronchioles are lined with a thin layer of flattered ciliated epithelium to make gaseous exchange effective

Question 5

Function of the bronchioles

Answer 5

When he smooth muscle contracts bronchioles constrict decreasing air flow.
When the smooth muscle relaxes the bronchioles dilate increasing air flow
Bronchioles are lined with a thin layer of flattered epithelium making some gaseous exchange possible

Question 6

Structure of the nasal cavity

Answer 6

Large surface area with good blood supply
Hairy lining which secretes mucus
Moist surface

Question 7

Function of the nasal cavity

Answer 7

Warm the air

Trap any bacteria or dirt to stop it from reaching the trachea

Question 8

Structure of the alveoli

Answer 8

Tiny air sacs which are the main gas exchange surfaces of the body
Each alveolus consists of a layer of thin epithelial cell, collagen and elastic fibres

Question 9

Function of alveoli

Answer 9

Elastic tissue allows the alveoli to stretch as air is drawn in
When they return to resting size they squeeze the air out
This is elastic recoil

Question 10

What is the function of smooth muscle

Answer 10

When the smooth muscle contracts the bronchioles constrict
When they relax the bronchioles dilate
This changes the amount of air reaching the lungs

Question 11

Functions of goblet cells

Answer 11

Secrete mucus onto the lining of the trachea to trap dust and microorganisms

Question 12

Functions of ciliated epithelium

Answer 12

Cilia on the surface

Waft dust and microorganisms trapped in mucus towards mouth

Question 13

Cartilage

Answer 13

Incomplete rings
Stops trachea from collapsing under changes of volume and pressure
Rings are incomplete so food can move down the oesophagus behind.

Question 14

Features of the lungs that make it effective

Answer 14

Good blood supply - keeps concentration gradients
Squamous epithelium- short diffusion distance
Lots of alveoli providing a large SA