Respiratory System Flashcards
What happens when breathing in at rest?
External intercostal muscles contract to lift rib cage up and out.
Diaphragm contracts and flattens
Volume increases
Pressure decreases
AUR comes rushing in
What happens when breathing out at rest?
External intercostal muscles relax and ribs drop down and in
Diaphragm relaxes and returns to its dome like shape
Volume decreases
Pressure increases
Air gets forced out
What process is expiration at rest known as?
A passive process
What happens when breathing in during exercise?
Sternocleidomastoid, pectorals and scalenes help to lift ribcage and sternum even further
Volume further increases
Pressure further decrease
Air rushes in
What happens when breathing out during exercise?
Internal intercostals and abdominals contract pulling ribs down even quicker
Volume further decreases
Pressure further increases
Air rushes out
What is the base of gas exchange?
Oxygen comes rushing into capillaries through airways and exchanges into capillaries where carbon dioxide exchanges out of capillaries and breathed out by airways
How is oxygen carried around the body?
97% combines with haemoglobin and 3% dissolves in blood plasma
Ocygaemoglobin
How is carbon dioxide carried round the body?
7% transported by being dissolved in plasma
Within red blood cells, 23% chemically combines with haemoglobin and carried as carbominhaemoglobin
70% converted to bicarbonate ions
What does partial pressure mean?
Pressure of a gas exerts in a mixture of gases
PO2 and pCO2 = partial pressures
|. |
PO2 40mm. PCO2 104mm
What does diffusion mean?
Movement of gases from an area of high to low partial pressure
What is the diffusion gradient?
Difference between high to low pressure of gases. The bigger the gradient the faster the diffusion
What is the dissociation curve known as?
Bohr shift
Explain Bohr shift?
When leaving lungs haemoglobin is nearly completely saturated with o2 as there is high partial pressure of o2 in lungs.
At rest 30% of o2 us released into muscle tissues.
During exercise co2 body temp and lactic acid increase. All these conditions cause a reduction in affinity of haemoglobin with o2. Therefore more o2 is released into muscle site (harder you exercise the more o2 is released)
What happens during exercise in Bohr shift?
Body temp co2 lactic acid increase and the o2 disassociates from the haemoglobin and attaches itself to myoglobin
What is myoglobin?
Substance similar to haemoglobin that attracts and bunds to o2. It has a greater affinity to o2 than haemoglobin and is located in muscle cells.
