Respiratory system Flashcards
What are the two main functions of the respiratory system?
- pulmonary ventilation: inspiration and expiration
- gaseous exchange (external and internal)
What is external respiration?
movement of oxygen into the blood system and carbon dioxide into the lungs
What is internal respiration?
the release of oxygen to respiring cells for energy production and collection of waste products
Explain the path of air through the body?
- air is drawn into nasal cavity through the nose and travels down pharynx, larynx and trachea.
- trachea divides into left and right bronchi as they enter lung cavity
- bronchi sub divide into smaller bronchioles and end in alveolar ducts
- air moves into alveoli by diffusion
In what two ways can oxygen be transported
- carried with heamoglobin in red blood cless
- carried within blood plasma
What is carbon dioxide a waste product of?
aerobic energy production
What three ways can carbon dioxide be transported>
- dissolved in water and carried as carbonic acid
- carried with haemoglobin
- dissolved in blood plasma
What is breathing rate?
- number of inspirations per minute
What is tidal volume?
volume of air inspired or expired per breath
What is minute ventilation?
-volume of air inspired or expired per minute
How do you calculate minute ventilation?
tidal volume x breathing rate
Explain minute ventilation response to increasing exercise intensity?
- initial anticipatory rise in VE prior to excersie due to release of adrenaline
- rapid increase in VE at start of excersise due to increased f and TV in order to increase oxygen delivery and waster removal
- steady state VE throughout the sustained intensity exercise as oxygen supply meets demand
- initially rapid and then more gradual decrease in VE to resting levels as recovary is entered and the demand for oxygen reduces
Where are the lungs located and what are they encased in?
- located in thoracic cavity and encased in pleural sacs
What reduces friction between inspiration and expiration?
pleural fluid between lung and pleural membrane
Which two muscles are responsible for inspiration at rest?
- external intercostals (contract lifting rib cage and sternum up and out)
- diaphragm (seperates the thoracic and abdominal cavity, contracts and flattens)
Explain the pressure differance in the lungs at rest?
- volume inside thoracic cavity and space inside lungs lungs increases. lowers the pressure below the atmosphere outside body. gases move from high to low pressure, so air rushes into the lungs
during excersise which muscles are are recruited to give a larger force of contraction?
- sternocleidomastoid
- pectoralis minor
During expiration during exersise, what muslces are recruited to give a larger force of contraction?
- internal intercostals
- rectus abdominis
What is the respiratory control centre?
a control centre in the medulla oblongata responsible for respiratory regulation
What are the two centres within the RCC?
- inspiratory center (stimulates inspiratory muscles to contract at rest and during exercise)
- expiratory centre (inactive at rest, but will stimulate additional expiratory muslces to contract during exercise)
At rest what is the IC responsible for?
rhythmic cycle of breathing
nerve impulses are generated and stimulate the inspiratory muscles causing them to contract
Which nerves cause the inspiratory muscles to contract?
- intercostal nerve to the external intercostals
- phrenic nerve to the diaphragm
What picks up an increase in blood acidity and CO2 concentration?
- chemoreceptors located in the aorta and carotid arteries
What are the three neural stimuli which feed information to the RCC?
- thermorecpetors (blood temperature
- proprioceptors (motor activity)
- baroreceptors (state of lung inflation)
What is partial pressure?
the pressure exerted by an individual gas held in a mixture of gases
WHat is gaseous exchange?
movement of gases across a membrane
What is a diffusion gradient?
- the differance in areas of pressure from one side of the membrane to another
What is external respiration?
the exchange of gases at the lungs between the deoxygenated blood that arrives in the capillaries with the oxygen-rich atmospheric air held in the alveoli
Explain oxygen during gas exchange?
- oxygeb moves from alveoli into low partial pressure capillary blood. haemoglobin combines with oxygen
What is internal respiration?
exchange of gases at the muscle cells between the oxygenated blood that arrives in the capillaries with the carbon dioxide producing muscle cells
What is heamoglobin?
a protein able to carry four oxygen molecule
What is association?
- the combining of oxygen with heamoglobin to form oxyheamoglobin What
What is association?
- the combining of oxygen with heamoglobin to form oxyheamoglobin What
What is association?
- the combining of oxygen with heamoglobin to form oxyheamoglobin What
What is dissociation?
- release of oxygen with heamoglobin for gaseous exchange
As pO2 decreases what happens to the heamoglobin?
more readily dissociates with oxygen, releasing it to the respiring tissues
WHat is the oxyheamoglobin dissociation curve?
a graph showing the relationship between pO2 and percentage saturation of haemoglobin
What are the three other effects of exercise which increase the dissociation of oxygen, the muscle tissue?
- increases in temperature
- increases production of C)2
- increases production of lactic acid and carbonic acid
What is the bohr shift?
a move in the oxyhaemoglobin dissociation curve to the right caused by increased acidity in the blood stream
In recovary what happens to the oxyhaemoglobin curve?
shifts back to the left
