Unit 1 (Body Systems): Respiratory System Flashcards
Define nasal cavity
The nose.
Entry point of air - 70% of the air inhaled is through this way.
What does the mucous in the nasal cavity do?
The mucous membrane and cilia in your nose warms, filters and moistens the air to prepare it for entry into the lungs.
Define pharynx
Lies at the back of the throat
Where your mouth, nasal cavity and throat join together.
Define epiglottis
Cartilaginous structure that forms a flap at the back of the throat to cover the oesophagus when you are breathing so air doesn’t enter into the stomach and food cannot enter the lungs and choke you.
Define larynx
Voice box
Where speech is created .
Air moves over the vocal cords where they are moved and adjusted by the muscles to create sounds and words.
Define trachea
Tube that connects the pharynx to the larynx.
Structure of C shaped cartilage that runs down the front of the trachea. keeping it open.
Define bronchi
Bronchi branch out from the left and and right of the trachea and lead into the lungs.
Define bronchioles
Branch off bronchi into the lobes of the lungs. Become increasingly smaller into 5-6 alveoli sacks.
Define alveoli
Small, grape like structures in the lungs covered in a bed of capillaries.
Approximately 700 million alveoli in the lungs.
Place of gaseous exchange.
Define sternocleidomastoid
Muscle that pulls the collar bone higher to increase the size of the thoracic cavity.
Define pectoralis major
This is the muscle that helps to reduce the size of the thoracic cavity by squeezing the ribs in.
What muscles contract in order to inspire?
External intercostal muscles
When the external intercostal muscles contract what happens?
Increases the volume of the lungs by stretching them, decreasing the pressure of the lungs.
What additional muscles work during breathing during physical activity and what do these muscles do?
Sternocleidomastoid
Scalene
Pectoralis major
Help to pull the clavicle upwards and outwards
What are the differences between internal and external intercostal muscles?
The internal intercostals bring the ribs down during forced expiration. The external intercostals elevate the ribs in inspiration.
Describe what happens during inspiration
Sternocleidomastoid contracts to lift the sternum outwards
Diaphragm contracts
Rib cage moves up and out
Thoracic cavity increases
Pressure decreases
Describe what happens during inspiration
Sternocleidomastoid contracts to lift the sternum outwards
Diaphragm contracts
Rib cage moves up and out
Thoracic cavity increases
Pressure decreases
Describe what happens during expiration
Pectoralis major contracts
Diaphragm relaxes
Rib cage moves in and down
Thoracic cavity decreases
Pressure increases
Describe tidal volume
The volume of air inspired or expired per breath
What is the average tidal volume
500ml
Define frequency
Rate, the number of breaths taken in one minute.
What is the average breathing frequency?
12-15 breaths
Define minute ventilation
The volume of air inspired or expired in one minute.
What is the average minute ventilation?
5-7L/min
Minute ventilation equation:
MV = TV x F
What happens to tidal volume during exercise?
Increases up to around 3-4L
What happens to breathing frequency during exercise?
Increases to 40-60
Define inspiratory reserve volume
The volume of air available that could be inspired after tidal br.
Define expiratory reserve volume
The volume of air available that could be expired after tidal volume.
Define residual volume
The volume of air that is left in the lungs after total forced expiration
Define vital capacity
The total volume of air that can be inspired or expired
Define total lung capacity
The total volume of lungs at maximum inflation, calculated by TLC = Residual volume + Vital capacity
What are the short term effects of exercise on the respiratory system?
Increased volume of air inspired per breath.
Increased frequency of breaths per min.
More O2 in
More CO2 out
Increased breathing rate
What are the long term effects of exercise on the respiratory system?
Hypertrophy of capillaries around alveoli.
Diaphragm and intercostal muscles stronger allowing ribcage to go higher allowing more air into the lungs.
Role of the rectus abdomius in breathing
Increase volume of air expired
Pulls down the sternum and rib cage
Decreasing volume of the thoracic cavity
