Exchange surfaces and breathing Flashcards
Module 3 (3.1 - 3.1.4)
Where are the LUNGS located?
IN the chest cavity in front of the heart and behind the ribs.
What surrounds the lungs?
Rib cage
What produces a lubricating substance around the lungs during breathing?
Lungs
What muscles are found in the lungs?
Internal and external intercostal muscles
How do lungs work? (Mechanism simplified) (air flow)
Air enters:
1) through nose -> trachea -> bronchi -> bronchioles
2) trachea/bronchi/bronchioles enable flow of air in/out lungs
3) airway held open with INCOMPLETE rings of cartilage in trachea.
What happens to the external intercostal muscles during inspiration?
They contract
What happens to the internal intercostal muscles during inspiration?
They relax
What happens to the ribs during inspiration?
They raise up
What happens to the diaphragm during inspiration?
It contracts and flattens
What is the effect of inspiration on thoracic volume?
It increases
What is the effect of inspiration on pressure in the thorax?
It lowers
What does the lowering of pressure during inspiration cause?
It creates a gradient for airflow into the lungs
What happens to the internal intercostal muscles during expiration?
They CONTRACT
What happens to the external intercostal muscles during expiration?
They RELAX
What happens to the ribs during expiration?
What happens to the ribs during expiration?
What happens to the diaphragm during expiration?
It relaxes and raises up
What occurs to the thorax volume during expiration?
It decreases
What happens to the pressure in the thorax during expiration?
It increases
What is the result of the increased pressure in the thorax during expiration?
Forces air OUT of the lungs
Cartilage
Supports trachea/bronchi, prevents lung collapse during exhalation
Ciliated epithelium
Moves mucus in airways to prevent lung infections Cells with hair-like structures that help move mucus and trap particles
Goblet cells
Secrete mucus to trap bacteria/dust, reduce infection risk Cells that secrete mucus to protect and lubricate the respiratory tract
Smooth muscle
Contracts to control airway diameter and airflow to alveoli
Elastic fibres
Stretch/recoil to control airflow in lungs
Short diffusion distance in alveoli
Gases exchange quickly due to thin alveolar walls
Oxygen and carbon dioxide exchange
Occurs between alveoli and lung capillaries through simple diffusion
Alveoli surface area
480-500 million alveoli provide 40-75 m2 for gas exchange
Extensive capillary network
Maintains concentration gradient for efficient gas exchange
Gas exchange
Process of exchanging gases, like oxygen and carbon dioxide, in the body
Thorax
Collection of organs and tissues in the chest cavity
Tissues of gas exchange system
Various tissue types adapted for specific functions in the respiratory system
Tracheal rings
Rings of cartilage along the trachea that support and maintain its shape
Trachea
Airway channel that carries air to the lungs
Bronchi
Airway tubes branching off the trachea, leading to the lungs
Bronchioles
Small airway tubes in the lungs that lack cartilage support
Alveoli
Tiny air sacs at the end of bronchioles where gas exchange occurs
Vital capacity
Maximum air volume in/out in one breath
Tidal volume
Volume of air in/out during normal breathing
Breathing rate
Number of breaths per minute
Oxygen uptake
Volume of oxygen used in a given time
Spirometers
Apparatus for measuring breathing
Carbon dioxide absorption
Removal of CO2 from exhaled air to prevent high concentrations
Trace on rotating drum
Record of breathing patterns drawn during spirometry
Residual volume
Small amount of air always retained in the lungs
Digital graph
Visual representation of breathing patterns on a computer
