Human Respiratory System Flashcards
Trachea and bronchi function
To connect the lungs + the mouth
Trachea and bronchi structure
- many c-shaped cartilage rings to provide support + flexibility
- smooth muscle allows them to constrict to reduce air flow
- walls lined with ciliated epithelial cell containing goblet cells
What do goblet cells do?
Secrete mucus that traps dirt + pathogens
What does the ciliated epithelium do?
Wafts mucus up & out of the airways
Bronchioles structure + function
- lead from the 2 bronchi to the alveoli
- consist mainly of smooth muscle and epithelial cells
- larger ones may have cartilage but most do not
Alveoli structure
- consist of squamous epithelial tissue + elastic fibres
- surrounded by a network of capillaries to remove exchanged gases + therefore maintain a concentration gradient
What are some adaptations alveoli have for efficient gas exchange?
- large surface area + good blood supply
- short diffusion distance for gases to travel (2 cells thick)
What is gaseous exchange?
Diffusion of oxygen from the air in the alveoli into the blood + of CO2 from the blood into the air in the alveoli
What happens when external intercostal muscles are contracted?
Leads to inspiration
What happens when internal intercostal muscles are contracted?
Leads to expiration
What are the 6 parts of inspiration?
- external intercostal muscles contract
- internal intercostal muscles relax
- diaphragm contracts/flattens
- air pressure in lungs initially drops then rises above atmosphere
- lung volume increases to decrease pressure
- air moves into the lungs
What are the 6 parts of expiration?
- external intercostal muscles relax
- internal intercostal muscles contract
- diaphragm relaxes into a dome shape
- air pressure initially great than atmosphere then drops
- lung volume decreases
- air moves out of lungs
