8 Gas Exchange and Respiration

Large surface area Thin surface area Good blood supply Good ventilation

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.

Bone structure that protects internal organs such as the lungs.

Muscles between the ribs which control their movement causing inhalation and exhalation.

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.

Windpipe that connects the mouth and nose to the lungs.

Also known as the voice box, when air passes across here we are able to make sounds.

Large tubes branching off the trachea with one bronchus for each lung.

Bronchi split to form smaller tubes called bronchioles in the lungs connected to alveoli.

Tiny air sacs where gas exchange takes place.

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.

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.

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.

Chronic obstructive pulmonary disease (COPD) Lung cancer Coronary heart disease.

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.

In inspired air: Oxygen - 21%, Carbon Dioxide - 0.04%, water - variable. In expired air: Oxygen - 16%, Carbon Dioxide - 4.5%, water - high.

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.

The chemical reactions in cells that use oxygen to break down nutrient molecules to release energy.

Glucose + Oxygen –> Carbon Dioxide + Water

C6H12O6 + 6CO2 –> 6CO2 + 6H2O

The chemical reactions in cells that break down nutrient molecules to release energy without using oxygen.

Glucose –> Lactic acid

Glucose –> Alcohol + Carbon dioxide

Carbon dioxide released forms bubbles in the dough making it light and spongy.