B9. 3 Respiratory System Flashcards
Describe the passage of air down the respiratory system
Nasal passage Pharynx Larynx Trachea Bronchus Bronchiole Cluster of alveoli (INTO OVERALL LUNG)
How does air enter into the nose
Air enters through nostrils, which lead into two nasal passages lined with a moist mucus membrane.
How does the nose provide a level of protecting
Dust and foreign particles are trapped by hair and mucus.
how is the trachea kept open
Supported by C-shaped rings of cartilage which keeps the lumen of the trachea open
what does the trachea contain for protection and where
epithelium of trachea contains gland cells and ciliated cells
what are the two types of protective cells in the trachea
gland cells: secrete mucus to trap dust particles and bacteria
ciliated cells: sweep dust-trapped mucus up the bronchi and trachea
what do the gland cells of the trachea do to protect from bacteria
secrete mucus to trap dust particles and bacteria
what do the ciliated cells of the trachea do to protect from bacteria
sweep dust-trapped mucus up the bronchi and trachea
how does the trachea divide up
The trachea divides into two tubes (bronchi)
how does bronchus further divide
Each bronchus carries air into the lung and branches repeatedly, giving rise to numerous bronchioles.
Each bronchiole ends in a cluster of air sacs (alveoli)
what are the alveoli
a cluster of air sacs (alveoli)
where does gas exchange take place
Gas exchange takes place through the walls of the alveoli
what do the numerous alveoli in the lungs do
provide a large surface area to volume ratio for efficient gaseous exchange
what does the walls of alveoli do to make gas exchange efficient
wall of the alveolus is only one cell thick. This provides a short diffusion distance for gases, ensuring faster rate of diffusion.
what does the blood supply of the alveoli do to make gas exchange efficient
The walls of the alveoli are richly supplied with blood capillaries. The flow of blood maintains the concentration gradient for diffusion of:
o oxygen from alveoli to blood capillaries
o carbon dioxide from blood capillaries to alveoli
what is the gradient of diffusion within the alveoli between
concentration gradient for diffusion of:
o oxygen from alveoli to blood capillaries
o carbon dioxide from blood capillaries to alveoli
what is the chest wall supported by
chest wall is supported by the ribs
how are ribs attached to help support the chest wall and what does this facilitate
attached dorsally to the vertebral column such that they can move up and down.
how many ribs do humans have
Humans have 12 pairs of ribs.
what are the ribs of a human attached to
The first 10 pairs are attached ventrally to the sternum.
what are the muscles in between the ribs
Two sets of muscles:
o external intercostal muscles
o internal intercostal muscles
how does the muscles in between the ribs interact
two sets of ribs:
o external intercostal muscles
o internal intercostal muscles
antagonistic muscles: when one relaxes the other muscle contracts
how is the thorax separated from the abdomen
Thorax is separated from abdomen by the diaphragm (a dome-shaped sheet)
describe how the respiratory system interacts during inhalation
- Diaphragm muscle contracts and diaphragm flattens.
- External intercostal muscles contract, internal intercostal muscles relax.
- Ribs move upwards and outwards. Sternum moves up and forwards.
- Volume of thoracic cavity increases.
- Lungs expand and air pressure inside decreases.
- Atmospheric pressure is higher than pressure in lungs, which forces air into lungs.
