respiratory system Flashcards
how does the respiratory system and circulatory system work together?
the circulatory and respiratory Systems work together to ensure that all cells have a constant supply of oxygen, and that carbon dioxide is continually move from the cells. The amount of oxygen carbon dioxide are kept constant between the tissues during this.
organs of respiratory system (in order of inhalation)
nose, through which the air is taken in; the trachea, or windpipe, which branches into two tubes; the bronchi; and the two lungs.
nose/nasal cavity: structure and function
structure: lined with mucus membranes, goblet cells which secrete mucus which traps dirt
function: air is cleaned, warmed and moistured in nasal cavity
pharynx
The pharynx is the region from the nasal cavity to the top of the trachea and oesophagus.
purpose of epiglottis in respiratory system
air travels through the pharynx before being diverted into the trachea by the epiglottis which is made out of cartilage.
larynx
The larynx is made out of cartilage, which joins the pharynx and trachea, and contains the vocal chords.
trachea
The trachea is known as a windpipe as it carries air into and out of the lung and is made up of cartilage rings that hold the structure open. It traps, dust and debris.
bronchi types + structure
bronchi: primary (2), secondary(3/4), tertiary(many)
bronchi contain cartilage
bronchioles
tertiary bronchi divide into smaller airways called bronchioles and continue to split until they form millions of terminal bronchioles.
bronchioles don’t contain cartilage
lobes of the lung
lungs divided into lobes, left: two, right:three
membrane of the lung
pleural membranes/pleura
- visceral pleura (outer)
- parietal pleura (inner)
- pleural fluid between these pleura, membranes
alveoli
bronchioles open into clusters of tiny air sacs called alveoli (functional units of the lungs), site of gas exchange
capillary network around alveolus for gaseous exchange
air flow (ventilation)
ventilation is the process by which air moves into and out of the lungs
airflows from places of high-pressure to places of lower pressure,
for the efficient exchange of gases between blood in the air in the alveoli, the air in the lungs must continually change
gases travel from high pressure to low pressure
pressure (not during inspiration/expiration)
atmospheric pressure and intrapulmonary pressure = balanced
intrapleural pressure → in pleural cavity
what occurs during inspiration
- volume inside the lungs increases due to constriction of two muscles
- diaphragm contracts and moves down causing intrapulmonary volume to increase → intrapulmonary pressure drops
- air flow into the lungs down its pressure gradient
- external intercostals contract leading diaphragm to descend, rib cage ascends
- thoracic cavity volume increases
what is inspiration
the process of taking air into the lungs (inhalation)
what is expiration
breathing out (exhalation)
what occurs during expiration
- diaphragm rises and goes back to usual state
- intrapulmonary volume drops leading intrapulmonary pressure rises as air flow out from the lungs down its pressure gradient
- external intercostals relax leading to diaphragm to ascend, ribcage descends
- thoracic cavity volume decreases
oxygen and carbon dioxide concentrations in inspired and expired air
oxygen:
inspired air: 20.95%
expired air: 15.8%
carbon dioxide:
inspired air: 0.04%
expired air: 4.3%
characteristics of alveoli that make it easy for diffusion of gases
- The wall of the alveolus is just one cell thick and the wall of the capillary is one cell thick
- large surface area due to shape, very thin →short diffusion passage
- the inside of the alveolus is lined with a film of moisture.
gaseous exchange
air flows into and out of the alveoli as we breathe
The blood in the capillaries surrounding the alveoli is brought to the lungs by the pulmonary arteries (good blood supply)
oxygen diffuses from the high concentration in the air in the alveolus to the lower concentration in the blood
carbon dioxide diffuses from higher concentration, the blood to the lower concentration, the air in the alveolus
oxygenated blood leaves the capillaries of the alveoli and it’s taken to the heart in the veins from the lungs
The artery to the lungs brings deoxygenated blood to the capillaries
emphysema
emphysema is a disease usually caused by long-term exposure to irritating particles in the air taken into the lungs, air sacs damaged
asthma
asthma is a medical condition that causes difficulty breathing due to the narrowing of airways
pneumonia
Pneumonia is an infection in the lungs caused by bacteria or viruses, fungi another organisms
tuberculosis
tuberculosis is an infection, usually have the lung by bacteria
