Back to 课程

Biology AS CIE

0% Complete
0/0 Steps
  1. 1-cell-structure
    10 主题
  2. 2-biological-molecules
    19 主题
  3. 3-enzymes
    13 主题
  4. 4-cell-membranes-and-transport
    16 主题
  5. 5-the-mitotic-cell-cycle
    8 主题
  6. 6-nucleic-acids-and-protein-synthesis
    9 主题
  7. 7-transport-in-plants
    11 主题
  8. 8-transport-in-mammals
    16 主题
  9. 9-gas-exchange
    6 主题
  10. 10-infectious-diseases
    6 主题
  11. 11-immunity
    10 主题
课 9, 主题 2
In Progress

9-1-the-gas-exchange-system AS structures-and-functions-of-the-gas-exchange-system

课 Progress
0% Complete

Exam code:9700

The gas exchange system: structure and functions

  • Ciliated epithelial cells, goblet cells and mucous glands play vital roles in maintaining the health of the gas exchange system

  • Cartilage, smooth muscle, elastic fibres and squamous epithelial tissue all play important structural roles in the gas exchange system

Structure

Function

Ciliated epithelial cells

These cells line the trachea to the bronchi

Each cell has tiny projections called cilia, which sweep mucus, dust, bacteria and other microorganisms up and away from the lungs to the mouth, where they are swallowed and digested by stomach acid

Goblet cells

Goblet cells are embedded throughout the ciliated epithelium and are mucus-producing cells

The mucus they produce traps dust, bacteria and microorganisms as mentioned above

Mucous glands

The mucous glands work with goblet cells in the trachea and bronchi to produce mucus

Cartilage

Rings of cartilage line the trachea, or windpipe

Cartilage is a strong but flexible tissue and is essential for keeping the trachea open

Because of its flexibility, the cartilage can move and flex as we breathe

Smooth muscle

Smooth muscle is muscle not under conscious control and is found in the walls of the trachea, bronchi and bronchioles

It helps to regulate the flow of air into and out of the lungs by dilating and widening when more air is needed

Elastic fibres

Elastic fibres are found in the squamous epithelium of the alveolar walls

Elastic fibres are a critical component of alveoli because they allow the tiny alveoli to stretch as they fill with air and recoil to help force air out

It is the elastic abilities of alveoli which enable them to have such a large surface area

Squamous epithelium

The squamous epithelium is made up of flattened cells that line the alveoli

This layer is thin and permeable for the easy diffusion of gases

Examiner Tips and Tricks

Make sure that you don’t confuse the cilia in the respiratory system for microvilli in the small intestine. At first glance they appear similar, but they have very different functions! Cilia are for sweeping mucus while microvilli are for the absorption of nutrients.

Responses

您的邮箱地址不会被公开。 必填项已用 * 标注