unit 7 - respiratory system Flashcards
primary functions of the respiratory system
- exchange gases
- produce vocal sounds
- sense of smell
- regulate blood PH
Breathing/ventilation
involves inhalation and exhalation
inpiration/inhalation
moves air from the external environment to the lungs inside the body
expiration/exhalation
moves air from the lungs back to the external environment
2 types of respiration
- external respiration - involves the exchange of oxygen and carbon dioxide between the air and the cells of the lungs
- internal respiration - involves the exchange of oxygen and carbon dioxide between the blood and tissue fluids
The upper respiratory track
Nasal Passage - warm moistens and clean incoming air
Paranasal sinuses - spaces between the bones
Pharynx - space not a structure, behind the oral cavity (back of the throat)
Larynx - houses vocal folds
Glottis - the part of the larynx consisting of the vocal chords and the opening between them
Epiglottis - closes during swallowing to prevent food from going down the airway
Trachea - windpipe, flexible cylinder with cartilage to hold it up and keep it open
what is cilia’s role
protect and filter out dust and other particles
The lower respiratory track
Bronchi - are two tubes that branch off from the trachea and carry the air to the left and right lungs
Bronchioles - smaller branches off the bronchi that become progressively smaller until they reach alveoli
Alveoli - are the sites of gas exchange
5 important things about alveoli and its function
- large surface area
- very thin
- moist lining
- good supply of blood
- good ventilation
pleural membranes
Thin membranes surrounding the outer surface of the lungs. They are filled with fluid to reduce friction between the lungs and the chest cavity during inhalation.
Two muscles that control the air pressure within the lungs
Diaphragm - a large sheet of muscle that separates the organs of the thoracic cavity(upper) and the abdominal cavity(lower)
- when the muscle contracts it flattens decreasing air pressure inside the chest cavity drawing air inside the lungs
- when it is relaxed it is dome-shaped
Intercostal muscles - found between the ribs
- as they contract the ribs are pulled upward and outward, increasing the chest volume
a difference between the atmospheres and the chest cavity’s __ ________ determines the movement of gases into and out of the lungs
air pressure
gases move from ___ concentration to ___ concentration
high to low
mechanics summary for inhalation (4 steps)
- a message is sent to the brain to inhale
- the intercostal muscles contract and the rib cage is lifted up and out
- at the same time, the diaphragm contracts (pulls downward)
- air moves in and the lungs expand
mechanics summary for exhalation
- a message sent from the brain to exhale
- the intercostal muscles relax, the ribcage returns to its normal position
- at the same time, the diaphragm moves upward (back to dome shape)
- air moves out and the lungs contract
what is pneumothorax
a collapsed lung (a hole in the plural cavity can cause the lung to collapse or deflate)
Respiratory volumes - tidal volume
volume of air being inhaled and exhaled during normal breathing
Respiratory volumes - inspiratory reserve
max amount of air that is inhaled above tidal volume
Respiratory volumes - expiratory reserve
amount of air that can be exhaled after normal exhalation
Respiratory volumes - residual volume
volume of air that always stays in the lungs
Respiratory volumes - vital capacity
total volume of air that the lungs can inhale and exhale
how do ventilators work?
- uses negative pressure similar to your lungs to assist your breathing
what is an ECMO
- a life support machine, people who use is have life threatening diseases
- instead of giving oxygen to the lungs the oxygen goes straight into their blood stream
breathing movements are controlled by
info about the O2 and CO2 is directed by the chemoreceptors which send a message to the the medulla oblongata in the brain
what happens when oxygen levels are low
- oxygen chemoreceptors called the carotid and aortic bodies detect when levels are low
- send a message to the brain
- this increases breathing movements
what happens when carbon dioxide levels increase
- chemoreceptors sense the increase
- message is sent to the brain
- increases breathing movements, therefore increasing the amount of CO2 being exhaled
what is a hematocrit
a simple red blood test done to measure the # of RBC in the blood
oxygen transport
- O2 in the alveoli diffuses into the fluid around the cells surrounding the capillary bed
- O2 then diffuses through the capillary walls and into the blood plasma and oxygen binds on the hemoglobin
carbon dioxide transport
23% is carried on hemoglobin
7% is carried in plasma
70% enters the RBC’s combining with water to create carbonic acid
blood buffering
in order for blood PH to stay at 7.4, carbonic acid goes through many series of chemical reactions before the CO2 is released from the lungs
hypoxia
a disease where there is a lack of oxygen in the body’s tissue
- can lead to cell death
