Anatomy of Lungs and Airways Flashcards
What are the functions of the respiratory system?
Gas Exchange, Acid Base balance, Protection from infection and Communication Via Speech
What is Gas Exchange?
Oxygen added to the blood from the air, Carbon dioxide removed from the blood into the air.
Why is Oxygen needed in the body?
To produce energy to fuel cells so they can carry out their functions.
To fuel aerobic respiration.
The brain to retain consciousness.
Where is the only location of Gas exchange?
Alveoli
What are the two types of Circulation?
Pulmonary Circulation and Systemic circulation
What is systemic circulation?
Delivers oxygen to tissues and picks up carbon dioxide.
What is pulmonary Circulation?
More localised. Blood from lungs to heart and heart to lungs. Delivers Carbon dioxide to lungs and picks up oxygen.
What is an artery?
Carries blood away from the heart. Generally carries oxygenated blood to peripheral tissues.
What is a vein?
Carry blood towards the heart. Generally deoxygenated.
What does the Pulmonary Artery carry?
Deoxygenated away from the heart to the lungs.
What is the Pulmonary Vein?
Oxygenated blood from the lungs to the heart.
What is the relationship between the cardiovascular and respiratory systems.
Energy demand increased by working muscles - Rate and depth of breathing increases - Substrate O2 acquisition - waste disposal CO2 (TOXIC).
Heart rate & Force of contraction speeds up - substrate delivery to muscle via blood - waste removal via blood.
What occurs at the systemic Capillaries?
O2 moves from blood to cells, CO2 moves from cells to blood.
What are systemic Capillaries
Arteries that have branched. They have very thin walls. Only site of gas exchange.
In the steady state, what is the net volume of oxygen exchanged in the lungs per unit time equal to?
And what does it prevent?
The net volume exchanged in the tissues.
Same applies for CO2.
Prevents the build up of gas in circulation.
What are the average volumes of gas exchanged per minute?
250ml O2 consumed.
200ml CO2 produced
What is the breathing rate at rest?
10-20 breaths/min
What is the breathing rate at Maximum exercise?
40-45 breaths/min
Describe the role of the nose?
Air enters. Cilia and mucus trap particles and warm and moisten the air. (Air must be in solution for gas exchange)
What is the Pharynx also known as?
Throat
Role of the Epiglottis?
Small flap of tissue folds over and stops food from entering it when you swallow
Role of Larynx (vocal chords)?
Vibrate to produce sound
Role of bronchus?
Air moves from trachea into right and left bronchi, which lead inside the lungs.
What to Bronchi divide to produce?
Open ended sacks called Alveoli
What makes up the Upper Respiratory Tract?
Nasal cavity, Pharynx, Larynx, Epiglottis
What makes up the Lower Respiratory Tract?
Trachea, both lungs, Left and right bronchus, diaphragm.
Anything in the thoracic cavity
How Many lobes is the right lung split into and what are they called?
- The SUPERIOR lobe - separated by horizontal fissure to the - MIDDLE lobe - separated by oblique fissure to the - INFERIOR
How many Lobes does the Left lung have?
2 (in most cases).
SUPERIOR and INFERIOR separated by oblique fissure.
What covers the heart?
Fibrous layer of Pericardium
What is the space that sites between the lungs and ribcage called? and its Function?
Pleural Cavity.
Fundamental in expanding the lungs. Normally held against the ribcage.
What are the names of the divided trachea branches?
Trachea bifurcates to give primary bronchi that split into 3 secondary bronchi on the right side (lobes).
Secondary bronchi split again to broncho pulmonary segments (unique tertiary bronchi or Bronchiole)
How are the right and left primary bronchi arranged?
Right is more upright - almost vertical trajectory = common to find foreign bodies in this side.
How is the patency of airways maintained?
Semi-rigid tubes held open by C-shaped rings of cartilage.
Where does the c-shaped cartilage rings stop? what what hold them open?
Not found in Tertiary bronchi (Bronchiole), which are held by physical forces in thorax
Where is the most resistance found in airways and why?
Most resistance in the upper airways as the diameter isn’t increased proportionate with the amount of air passing through it.
THINK about driving from country into city - Bottleneck
What does contraction cause?
Decreased diameter or airway = increased resistance
What does Relaxation cause?
Increased diameter = decreased resistance
What changes the diameter of Bronchioles?
Smooth muscle
Explain the structure of where gas exchange occurs?
Capillary beds found directly over Alveoli - both must have walls thin for gas exchange.
What carries O2 from the Alveoli to the heart?
The pulmonary vein
What is the role of elastic fibres?
Allow expansion and release elastic energy to push air out during expiration.
Is expiration passive or active?
Passive. Energy has already been invested in the elastic fibres which is released.
What are the 2 cell types found in Alveoli?
Type 1 cells - Gas exchange
Type 2 - specialist cells that produce Surfactant. Too thick for gas exchange.
What is Anatomical dead space?
Area of no gas exchange as the walls are too thick.
What is the function of mucus?
Moistens air, Traps particles, provides large surface area for cilia to act on, Goblet cells, Subepithelial glands.
