Respiratory System Flashcards
Role of the nasal cavity
It’s where the air enters the body and it warms and moisten the air
Role of the epiglottis
Flap of cartilage that stops food entering the lungs and instead allows air to enter the lungs
Role of the alveoli
It’s where gaseous exchange takes place and they are tiny air sacs
Role of the trachea
Allows passage of air to the lungs and consists of rings of cartilage
Role of the bronchus/bronchi
Branch off from the trachea to the left and right lung
Role of the larynx
Known as the voice box , has rigid walls of cartilage and connects the pharynx to the trachea
Role of the pharynx
Known as the throat and connects the nasal cavity to the larynx
Role of the bronchioles
Connects the bronchi to the alveoli and are small airways that extend from the bronchi
What additional respiratory muscles are used during exercise?
- Internal intercostals
- Pectoralis minor
- Scalene
- Sternocleidomastoid
- Rectus abdominus
- Diaphragm
Facts about the scalene
Found in the neck and helps pull ribs up and out
Facts about the internal intercostals
They lie inside the rib cage and help draw ribs down and in for expiration
Facts about the pectoralis minor
They help raise the ribs and expand the thoracic cavity
Facts about the sternocleidomastoid
- It contracts to increase the amount of air into the lungs by lifting up rib cage , increasing volume of the thoracic cavity more and reducing pressure in the lungs more.
- It relaxes to increase the amount of air expired by pulling down the rib cage , decreasing volume of the thoracic cavity more and increasing pressure in the lungs more.
Facts about the diaphragm
Inspiration
- Contracts to increase volume of thoracic cavity and decrease pressure in the lungs
Expiration
- Relaxes to decrease volume of thoracic cavity and increase pressure in the lungs
During exercise
- Contracts harder to achieve increases in tidal volume
Expiration process during exercise
Becomes active
- Additional muscles contract to force expiration
- Rib cage moves in and down more by the internal intercostal muscles and the rectus abdominus which helps to force the diaphragm upwards
- So bigger decrease in volume of thoracic cavity
- So bigger increase in pressure in the lungs
- As a result more air is forced out faster so a faster breathing frequency
Inspiration process during exercise
There is an increase in depth and rate of breathing
- External intercostal and diaphragm contract more strongly
- Sternocleidomastoid, scalene and the pectoralis major help to pull the clavicle which is the bone that the internal intercostal muscles pull against upwards and outwards
- So larger volume of thoracic cavity
- So Bigger decrease in pressure in the lungs
- As a result more air is drawn into the lungs
Role of the external intercostal muscles
Inspiration - they contract
- Helping pull rib cage up and out , increasing volume of thoracic cavity and reducing pressure in the lungs
Expiration - they relax
- Causing the rib cage to move down and in , decreasing volume of thoracic cavity and increasing pressure in the lungs
Mechanics of breathing during Inspiration
Diaphragm and external intercostal muscles contract
Rib cage moves up and out
Volume of thoracic cavity increases
Pressure in the lungs decreases
Air is drawn into the lungs
Mechanics of breathing during Expiration
Diaphragm and external intercostal muscles relax and internal intercostal muscles contract
Rib cage moves down and in
Volume of thoracic cavity decreases
pressure in the lungs increases
Air is drawn out of the lungs
What occurs at the alveoli?
Gasesous exchange
- In capillaries the PP of oxygen is low and the PP of carbon dioxide is high
- In the alveoli the PP of oxygen is high and the PP of carbon dioxide is low
- This difference in partial pressure allows diffusion to take place