Post on 06-May-2015
description
Structure and Function of the Lungs
Lloyd Dean
Cardio - respiratory System
Aims Describe the structure of the lungs
Identify the function of the lungs
Recall how lungs perform their function
RecapConcave Discs
Artery
Arterioles
Plasma
Lumen
Venule
Platelets
Capillary
CO2
Tunica Media (Smooth Muscle)
TIME TO DO SOME COLOURING IN! (1 Pack per study buddy)
Rule 1. Have funRule 2. If you find a term that you do not
know then research it on your mobile deviceRule 3. Make as many notes on the sheets
as possible to help with your video!
Component Structure Function
Epiglottis•Small flap of cartilage Prevents food entering the
trachea
Trachea
•Tube which carriers air•Covered in hairs (Cilia)•Surrounded by C-shaped cartilage rings (Protect)
Also known as the wind pipe; passage for oxygen to travel through
Bronchus
•Cartilage rings•Smooth muscle
Splits trachea into two tube to allow oxygen in right and left lungs
Bronchioles
•Further division of bronchi•Very narrow tubes•Lead to alveoli
Allows oxygen to filter into alveoli
Alveoli
•Air sacs•Thin walls
Site for exchange of gasses
Diaphragm
•Muscle that sits underneath lungs•Attached to the ribs and sternum•Base of thoracic cavity
Enables thoracic cavity to be increased and decreased
Intercostal muscles
•Muscles that sit between the ribs•Internal and external
Enables thoracic cavity to be increased and decreased
Respiratory Volumes
• Tidal Volume Amount of air moved in and out of the lungs in once breath
Residual Volume Amount of air left in the lungs after exhalation
Vital Capacity Maximum amount of air that can be inhaled and exhaled in
one breath
Gaseous Exchange
InspirationDiaphragm flattens and stretches lungs downward
Intercostals pull the ribcage up and out causing the lungs to stretch
Expansion of air causes a drop in air pressure in the lungs
Air in the lungs is at a lower pressure than the air outside, so air enters the lungs
ExpirationDiaphragm relaxes
Intercostals relax
Lungs recoil
Volume of air in the lungs decreases causing an increase in the air pressure
Air flows from higher to lower pressure so the air flows out of the lungs
Intercostal and Diaphragm Muscles
DiaphragmDome shaped muscleSeparates thoracic
cavity from abdominals
Intercostal MusclesChanges the shape rib cage
during breathing External intercostals contract to
breathe in Internal intercostals contract
during forced breathing out
(Author Unknown, Date Unknown)
(Dugdale, 2009)
Inspiration and Expiration During Exercise
Inhalation and Exhalation
External Respiration
(WebMD, 2009)
•Exchange of Oxygen and Carbon dioxide between the lungs and blood stream
•Occurs at Alveoli
DiffusionOxygen (02) is required in tissues
Carbon dioxide (CO2) has to be removedExchange occurs through Diffusion
Movement of particles from a high concentration area, to a low concentration area
Rule = Diffusion only occurs down a concentration gradient
Concentration (pressure ) oxygen in lungs must be higher than concentration (pressure) in capillaries
Partial Pressure
INHALED % GAS EXHALED %
79.04 Nitrogen 79
20.93 Oxygen 17
0.03 Carbon Dioxide 4
•Individual pressure of a particular gas within a mixture of gases
•Diffusion occurs from high to low concentrations
Exchange of GasesFast rate of diffusion occurs with:Large surface areaSmall distance between areas involved
Other Factors:Capillary sizeMoist surface of alveoliSlow capillary blood flow = Complete OxygenationHaemoglobin – Magnet for oxygen
Internal RespirationExchange of gases in the bodies cellsWorks similar to external respirationCell use of oxygen to make ATP
Gas Exchange
Neural and Chemical Control of BreathingMedulla Oblongata (Respiratory centre)
Impulses
Stretch receptors
Chemoreceptors
Lactic acid