5-21 Respiratory system Flashcards
5 functions:
Brings air from outside to lungs, Transfers oxygen into blood, removes carbon diaoxide from blood
The respiratory system:
The respiratory system consists of the lungs and associated structures responsible for gas exchange to the body, bringing air into the body and removing waste products.
Lungs consist of:
Conducting system, Pleura, Diaphragm
Nasal Cavity Function
The nose is the initial pathway for air. Here, air is warmed and moistened. Cilia filter foreign particles from the air
Nasal Cavity Structure:
Layers of tissue called Septa covered with cilia
Pharynx Structure:
section of the throat is where the backs of the mouth and the nose combine.
Pharynx Function：
The pharynx connects the back of the mouth and nose. It branches off so that food is channelled to the stomach, while the air moves into the larynx.
Larynx Structure
The larynx contains the vocal cords. This structure is more evident in males with their ‘Adam’s apple’.
Larynx Function:
The larynx houses vocal cords that create the voice as air passes through them.
Trachea Structure:
The trachea consists of rings of hyaline cartilage enclosed by other cartilage and tissue.
Trachea Function:
Often referred to as the windpipe, the trachea provides a well-protected medium for the passage of air into the lungs.
Bronchi Structure
The trachea divides into two bronchi. Each bronchus feeds one of the lungs.
Bronchi Function
The bronchi maintain the air passage to the lungs.
Bronchioles Structure:
Each bronchus subdivides into a series of further subdividing bronchioles, similar to the branches of a tree.
Bronchioles Function:
The bronchioles deliver air to be diffused by the alveoli
Alveoli Structure:
These ‘leaves’ of the lungs are microscopic, cup-shaped sacs at the ends of the smallest bronchiole. exchanges oxygen for carbon dioxide and water.
Alveoli Function:
The alveoli are the site where the gas exchange of oxygen and carbon dioxide takes place.
Pleura
Covers each lung
Gap between the membrane and each lung is filled with fluid that allows lung to expand & contract with each breath
Diaphragm
Involuntary smooth muscle, contracts & relaxes to aid breathing
The respiratory system functions to remove carbon dioxide from the blood. Happens by…
CO2 production, CO2 diffuses into the bloodstream, CO2 enters the lungs
What is ventilation
Ventilation (V) is the amount of air that is inspired and expired during 1 minute.
How is ventilation calculated?
V (L/Min) = Tidal Volume (L/Breath) * Respiratory rate (breaths/min)
Inspiration:
movement of air from the external environment into the lungs (breathing in) diaphragm pulls down on rib cage when it contracts, and expanding the volume of the chest cavity. Intercostal muscles between ribs contract to help pull rib cage outwards, increasing size of chest cavity
Expiration:
movement of air out of the lungs into external environment (breathing out) When the diaphragm & intercostal muscles relax (diaphragm pushes up & creates dome shape)
Relaxation & natural elasticity of thorax (chest area) is enough to squeeze the air within the chest cavity
Inspiration: Air, Pressure inside lungs, Ribcage
Drawn into lungs, low, Expands up and out
Expiration: Air, Pressure inside lungs, Ribcage
Forced out of lungs, High, Moves down and in
Total lung capacity
is volume of air that can be held in lungs after maximum inspiration (approx. 6L for males, 4.2L for females
Tidal volume
is the amount of air inspired & expired with each breath (approx. 500 millilitres at rest)
Residual volume
is the amount of air left in the lungs at the end of a conscious, maximal expiration (same at rest and max. exertion)
Inspiratory and expiratory reserve capacity
is the maximal amount of air that can be inspired after a normal inspiration
Vital capacity
is the maximum amount of air that can be expired after maximum inspiration
VO2 max
is the maximum amount of oxygen per minute that can be taken in, transported to, and used by the working muscles to produce ATP
The respiratory and the cardiovascular systems work together to…
transfer and transport gas molecules (in particular, oxygen and carbon dioxide) around the body
Diffusion
involves the movement of a molecule from a higher concentration to a lower concentration across a thin membrane.
Gas exchange at the capillary
Oxygen-rich blood is transported to the muscles, low levels of oxygen within the muscles attract the higher concentration oxygen, In reverse, the carbon dioxide produced as a by-product from energy production from the muscle is pushed into the capillary to be transported to the alveoli and expired.
