Ch 11 - (Gas Exchange in Humans) Flashcards
What are the features of gas exchange surfaces?
- Large surface area: To allow faster diffusion of gases across the surface
- Thin walls: To ensure distance diffusion is shorter
- Good ventilation with air: To maintain diffusion gradient
- Good blood supply: Maintain a high concentration gradient so diffusion occurs faster.
Description of ribs
Bone structure that protects the internal structure lungs
Description of intercoastal muscles
muscles between the ribs that control their movement causing inhalation and exhalation
Description of trachea
windpipe that connects the mouth and nose to the lungs
Description of larynx
also known as the voice box, when air passes across here we are able to make noise.
Description of bronchi
large tubes branching off the trachea with one bronchus for each lung
Description of bronchioles
split to form longer tubes that connects to the alveoli
Description of alveoli
tiny air sacs where gas exchange takes place
Description of diaphragm
sheet of connectives tissue and muscles at the bottom of the thorax that helps change the volume of thorax to allow inhalation and exhalation.
What is present when we breathe in and out?
- When we breathe out contains more water vapor.
- Temperature of exhaled air is higher
What is the composition of inspired air in the following:
a) Oxygen
b) Carbon dioxide
c) Nitrogen
a) Oxygen - 21%
b) Carbon dioxide - 0.04%
c) Nitrogen -78%
What is the composition of expired air in the following:
a) Oxygen
b) Carbon dioxide
c) Nitrogen
a) Oxygen - 16%
b) Carbon dioxide - 4%
c) Nitrogen - 78%
What is the effect of exercise on breathing?
Increases the frequency and depth of breathing.
How can the effect of physical exercise effect on breathing.
By counting breaths taken during one min at rest and measuring average chest expansion for 5 breaths
What are the 2 intercoastal muscles?
- Internal intercostal muscles (found inside the ribcage)
- External intercoastal muscles (found outside the ribcage)
What is a cartilage?
A structure that surrounds the trachea
What is the function of the cartilage?
- Supports the Airways
- Keeps them open during breathing
If not present:
- Sides could collapse inwards
- air pressure inside the tubes drops
What is a diaphragm?
A thin sheet of muscles that separates the chest cavity from the abdomen.
What is the diaphragm responsible for in breathing?
Controlling ventilation
What happens to the diaphragm when you breathe in?
- Diaphragm contracts and it flattens
- This increases the volume of chest cavity
- Decrease in air pressure
- Draws air in
What happens to the diaphragm when you breathe out?
- Diaphragm relaxes and moves upward into dome shaped
- Decreases the volume of chest cavity
- Increase in air pressure in the lungs
- Draws air out
How do the external and internal intercoastal muscles work while breathing?
Work as antagonist pairs (they work in different directions to each other)
What happens during inhalation?
- External set of intercoastal muscles contract
- pull the ribs up and out
- Increases the volume of chest cavity, that decreases air pressure.
- forces air to move in
What happens during exhalation?
- Set of internal coastal muscles relaxes,
- ribs drop down and in
-decreases the volume of chest cavity, increasing air pressure
- forces air to move out
