Introduction and Anatomy of Lungs, Airways and Blood Supply Flashcards
What are the functions of the respiratory system
Gas exchange
Acid base balance
Protection from infection
Communication via speech
What is the function of gas exchange in the respiratory system
Adds oxygen to blood from air
Removes carbon dioxide from blood into air
What is the function of the acid base balance in the respiratory system
Regulation of body pH
How does gas exchange produce energy
Cellular respiration
What is cellular respiration
Producing energy by ‘burning’ oxygen and releasing energy while producing CO2 as a waste product
Which two systems are required for effective gas exchage
Respiratory
Cardiovascular
What is the cardiovascular system responsible for in regards to gas exchange
Transporting oxygen to tissues
Transporting carbon dioxide away from tissues
What does the integration of the respiratory and cardiovascular system allow
External respiration
What is external respiration
The movement of gases between the air and the body’s cells
In what direction does the pulmonary artery travel
Away from the heart
In what direction does the pulmonary vein travel
Towards the heart
What does pulmonary circulation do
Deliver CO2 to the lungs
Pick up O2
What is the pulmonary circulation opposite to
Systemic circulation
How many types of exchange are there
3
What occurs in exchange 1
Exchange between the atmosphere and lung
What occurs in exchange 2
Exchange between the lung and blood
What occurs in exchange 3
Exchange between the blood and cells (cellular respiration)
Give an example of when the respiratory and cardiovascular system integrate
During the changes that occur in exercise
What types of changes occur in exercise
Increase in energy demand by working muscle leads to:
1) Increase in rate and depth of breathing which speeds up substrate (O2) acquisition and waste disposal (CO2)
2) Increase in heart rate and force of contraction which speeds up substrate delivery to muscle via blood and waste removal via blood
Where does gas exchange occur
Lungs
What occurs in the gas exchange in lungs
O2 from inspired air moved to the blood
CO2 moves from blood to air to be expired
What occurs in systemic capillaries
O2 moves from blood to cells
CO2 moves from cells to blood
What occurs in a steady state
The net volume of oxygen exchanged in the lungs per unit time is equal to the net volume exchanged in the tissues in a steady state (this is the same for CO2)
What does a steady state allow
Prevents the build up of gas in the circulation which would hinder gas exchange
Helps to ensure supply equals demands
How much O2 and CO2 is consumed and produced per minute
About
250 ml O2 is exchanged (consumed)
200 ml CO2 exchanged (produced)
What is the normal breathing rate at rest
10-20 breaths/min
What is the normal breathing rate at maximum exercise in adults
40-45 breaths/min
What are the components of the respiratory system
Nose Pharynx Trachea Bronchus Lung Epiglottis Larynx
What occurs in the nose
Air enters the body through the nose where cilia and mucus trap particles and warm and moisten air
What occurs in the pharynx
Air moves from the nose down into the pharynx or throat which is shared with the digestive system
What occurs in the trachea
Air moves from the pharynx down toward the lungs through the trachea which is made up of stiff rings of cartilage that support and protect it
What occurs in the bronchus
Air moves from the trachea into the right and left bronchi which lead inside the lungs
What are the lungs
These are the main organs of respiration
They have a soft and spongy texture due to many thousands of tiny hollow sacs that compose them
What is the epiglottis
A small flap of tissue that folds over the trachea and prevents food from entering it when you swallow
What is the larynx
Voice box that contains vocal chords which vibrate to produce sound
What can the respiratory system be split into
Upper respiratory system
Lower respiratory system
What does the upper respiratory system consist of
Mouth
Nasal cavity
Pharynx
Larynx
What does the lower respiratory system consist of
Trachea
Bronchi
Lungs
What is the lower respiratory system enclosed and bounded by
Enclosed in the thorax
Bounded by the ribs, spine and diaphragm
What does the trachea branch into
2 bronchi (one for each lung) Each bronchus will branch 22 more times before terminating in a cluster of alveoli
Describe the structure of the larynx, trachea and bronchi
Semi-rigid tubes
The ‘patency’ of the airway is maintained by the c-shaped rings of cartilage
Describe the structure of bronchioles
No cartilage
Their patency is maintained by physical forces in the thorax
What occurs in the alveoli
Only point of gas exchange
What does the conducting zone consist of
Trachea, primary and smaller bronchi
What occurs in the conducting zone
The most resistance to air flow
What does the respitaory zone consist of
Bronchioles and alveoli
How can the airway diameter and resistance to air flow be altered
By the activity of the bronchial smooth muscle
What will a contraction cause
Decrease in diameter
Increases the resistance
What will relaxation cause
Increase in diameter Decrease resistance
How is a cluster of alveoli arranged
Surrounded by elastic fibres and a network of capillaries
What are alveoli composed of
Type 1 and type 2 cells (Pneumocytes)
What do type 1 cells do
Gas exchange
What do type 2 cells do
Synthesise surfactant
What do alveolar macrophages do
Ingest foreign materials that reach the alveoli
Why can gas exchange only occur in the alveoli
They have:
Very thin walls
Large surface area
What can gas exchange not occur in the upper airways
They are too thick
Their function is purely for the conduction of air to and from the alveoli
What is the air found in the upper airways known as
Anatomical dead space as they cannot participate in gas exchange
What is the respiratory tract lined with
Epithelium (psuedo-stratified, ciliated, columnar) Glands Lymph nodes Blood vessels (nutritive) Ciliated Mucous
What changes in lining occur between the nose and alveoli
Epithelium becomes more squamous
Mucous cells are lost first
Cilia lost
What are the functions of mucous
Moistens air
Traps particles
Provides large surface area for cilia to act on
What does mucous consist of
Goblet cells and sub-epithelial glands
Describe alveoli
A very rich capillary network which has elastic fibres that can recoil
The macrophages gather residual dirt and escape to the pharynx/lymph nodes
Describe type 1 pneumocytes
Cover 97% of the alveolar surface with simple squamous epithelium
Describe type 2 pneumocytes
Consist of phospholipids and protein
They reduce surface tension at the alveolar surface
Reduce the work of breathing
