Respiration Flashcards
0
Q
Respiration
A
Metabolic process using glucose/O2 and creating energy/co2/wastes
1
Q
Breathing
A
- Air into/out of lungs
- aka ventilation
2
Q
Thoracic cavity
A
Sealed area contained by ribs, collar bone, shoulder blades, sternum, backbone, and diaphragm
3
Q
Intercostal muscles
A
Muscle tissue btwn ribs
4
Q
Diaphragm
A
- sheet of muscle tissue
- stretches across our bodies under rib cage
- dome shaped
- causes lungs to inflate/deflate
5
Q
Inhalation (inspiration)
A
- diaphragm muscles contract and become flatter
- ribs raise up and expand as the intercostal muscles contract
- creates a larger empty thoracic cavity -> negative pressure
- this vacuum pulls air into lungs
6
Q
Exhalation (expiration)
A
- muscles relax, ribs move down and in
- diaphragm relaxes, becoming more dome-shaped
- these movements squeeze thoracic cavity and air is pushed out
- note: lungs aren’t actively involved in breathing, they simply hold air
7
Q
Surfactant
A
- alveoli don’t fully collapse after expiration due to surfactant (lipoprotein) coating
- surfactant reduces surface tension
8
Q
Co2 levels
A
- respitory center (in medulla oblongata) responds to high co2 levels but not O2 levels
- rc sends impulse via nerves to diaphragm and intercostal muscles -> inspiration
- when alveoli are full, stretch receptors in their walls send nerve impulses back to rc
- rc stops sending out impulse -> stops inspiration
9
Q
Oxygen levels
A
- chemoreceptors in aorta and carotid artery detect decreased levels of O2
- they send signals to rc to increase breathing rates
10
Q
External respiration (lungs)
A
- inhalation brings O2 into alveoli
- amount of pressure each has exerts is called partial pressure
- O2 diffuses along its concentration gradient from alveoli to capillaries
- co2 diffuses along its concentration gradient from blood to alveoli
11
Q
Internal respiration (tissue cells)
A
- blood entering capillaries has higher Po2 and a lower PCO2 than surrounding tissue fluid & cells
- due to partial pressure differences, O2 diffuses out of capillary and into tissue and co2 leaves tissue and enters capillary
12
Q
Oxygen transport
A
- most is transported by combining with hemoglobin
O2 + HB -> HBO2 (oxyhemoglobin) - some is transported by diffusing directly into blood plasma
13
Q
Co2 transport
A
- 70% of Co2 is transported as bicarbonate ion
O2 + H20 -> h2CO3 carbonic acid -> HCO3 bicarbonate ion + h
(Requires enzyme carbonic anhydrase) - 20% transported using hemoglobin (co2 + HB -> hbco2…carbaminohemoglobin)
- 10% dissolved into blood plasma
14
Q
Maintaining ph of blood
A
- blood could become quite acidic during co2 transport, and the lower blood pressure would trigger acidosis
- to maintain ph, hemoglobin picks up excess H ions (reduced hemoglobin)
- reduced hemoglobin transports H+ to lungs where reaction is reversed
