8 Gas Exchange and Respiration Flashcards
Feature of Gas exchange surfaces
Large surface area
Thin surface area
Good blood supply
Good ventilation
Why lungs show adaptations for rapid rate of diffusion
At the end of bronchioles there are air sacs with bulges called alveoli. They are covered in blood capillaries. This is where gases are exchanged. They are adapted for efficiency in gas exchange by diffusion:
Thin permeable walls
Moist lining
Large surface area
High concentration gradients for gases.
Describe the Ribs
Bone structure that protects internal organs such as the lungs.
Describe the Intercostal muscles
Muscles between the ribs which control their movement causing inhalation and exhalation.
Describe the Diaphragm
Sheet of connective tissue and muscle at the bottom of the thorax that helps change the volume of the thorax to allow inhalation and exhalation.
Describe the Trachea
Windpipe that connects the mouth and nose to the lungs.
Describe the Larynx
Also known as the voice box, when air passes across here we are able to make sounds.
Describe the Bronchi
Large tubes branching off the trachea with one bronchus for each lung.
Describe the Bronchioles
Bronchi split to form smaller tubes called bronchioles in the lungs connected to alveoli.
Describe the Alveoli
Tiny air sacs where gas exchange takes place.
Describe Ventilation
Breathing in and out of air to lungs, through larynx, down the trachea to the bronchi and through the bronchioles to the alveoli, where the gases are exchanged with many capillaries that lie next to the alveoli.
How does the level of activity affect breathing?
Increased level activity increases rate and depth of breathing, which removes the increased amount of carbon dioxide produced by respiration and so stops the pH of body tissues and blood falling.
Role of Goblet cells
Cells in the linings of the lungs that secrete mucus that traps pathogens and particles. Mucus is swept out of lungs by cilia which protects the lungs from damage and infection.
Diseases caused by tobacco smoking (tar)
Chronic obstructive pulmonary disease (COPD)
Lung cancer
Coronary heart disease.
Effect on the gas exchange system of tobacco smoke
Carbon monoxide takes the place of oxygen in the haemoglobin and prevents body from absorbing as much oxygen.
Nicotine is addictive and narrows blood vessels, increasing blood pressure.
Tar is a sticky substance that coats the cells of the trachea, bronchi and bronchioles, leading to cell damage and coughing. Decreases rate of gas exchange. Causes cancer.
Difference in Inspired and Expired air
In inspired air: Oxygen - 21%, Carbon Dioxide - 0.04%, water - variable.
In expired air: Oxygen - 16%, Carbon Dioxide - 4.5%, water - high.
Uses of energy in human cells
Produce contraction of muscle cells.
Produce new chemical bonds during synthesis of new protein molecules.
Produce new chemicals needed for cell division and growth of cells.
For active transport of molecules across cell membranes.
Produce the movement of nerve impulses along nerve cells.
For the maintenance of a constant core body temperature.
Define Aerobic respiration
The chemical reactions in cells that use oxygen to break down
nutrient molecules to release energy.
State the word equation for aerobic respiration
Glucose + Oxygen –> Carbon Dioxide + Water
State the balanced chemical equation for aerobic respiration
C6H12O6 + 6CO2 –> 6CO2 + 6H2O
Define Anaerobic respiration
The chemical reactions in cells that break down nutrient molecules to release energy without using oxygen.
State the word equation for anaerobic respiration in muscles during vigorous exercise
Glucose –> Lactic acid
State the word equation for anaerobic respiration in yeast
Glucose –> Alcohol + Carbon dioxide
Describe the role of anaerobic respiration in yeast during bread-making
Carbon dioxide released forms bubbles in the dough making it light and spongy.
