Respiratory System Flashcards
1
Q
primary function of the respiratory system
A
- exchange gases with the environment to obtain O2 and to excrete sufficient CO2
2
Q
why do we need O2
A
- perform oxidative phosphorylation for cellular respiration to produce ATP
3
Q
why do we need to excrete CO2 (2)
A
- excess CO2 in blood will cause the blood to become acidic
- lead to protein denaturing and malfunction
4
Q
what are the major processes necessary for gas exchange with the environment
A
- ventilation
- perfusion
5
Q
ventilation
A
- moving air/water across the gas exchange surface (breathing)
6
Q
perfusion
A
- pumping blood through the capillaries of an organ; pumping blood through the capillaries of the gas exchange surface
7
Q
diffusion
A
- spontaneous movement of molecules/atoms from a region of high [ ] to a region of low [ ]
8
Q
what are the 3 important structural adaptations that increase diffusion rate
A
- large surface area
- thin tissue
- highly vascularized
9
Q
fick’s equation
A
- used to calculate the diffusion rate of a gas
10
Q
dV/dt
A
- diffusion rate: volume of gas (O2, CO2) moving through a given area (epithelium of the alveoli) in a given amount of time
11
Q
A (2)
A
- surface area of the gas exchange surface
- the total SA of all the alveoli in the lung that is being ventilated and perfused
12
Q
D
A
- diffusion coefficient, a constant that represents how easily a specific gas can diffuse through a certain medium (epithelium of alveoli and capillaries)
13
Q
dx
A
- thickness of the tissue separating the blood from the air inside the alveoli
14
Q
(P1 - P2)
A
- partial pressure gradient across the gas exchange surface
- P1: partial pressure of O2 in the air inside the alveoli
- P2: partial pressure of the O2 passing through the capillaries
15
Q
gill structure - chondrichthyes (4)
A
- gill rays project from pharyngeal arches III - VII and support the interbranchial chambers
- complete interbranchial septae separate the parabranchial chambers
- distal ends of each septum forms a flap valve that covers the parabranchial chamber
- gill rakers project into the pharynx, forming a screen across openings to parabranchial chambers, preventing food from entering and damaging delicate gills
16
Q
respiratory gill structure
A
- primary lamellae project from sides of interbranchial septum
- fragile secondary lamellae on both sides of primary lamellae form tiny vertical ridges and are the site for gas exchange
17
Q
gill structure - actinopterygii
A
- gill rays project from pharyngeal arches III - VII and support the interbranchial chambers
- complete interbranchial septae separate the parabranchial chambers
- distal ends of each septum forms a flap valve that covers the parabranchial chamber
- gill rakers project into the pharynx, forming a screen across openings to parabranchial chambers, preventing food from entering and damaging delicate gills
18
Q
structure of gills - amphibians (2)
A
- many larval amphibians have external gills that project into the surrounding water
- most lose these gills during transition from larval to adult form; however, some salamanders retain their gills as adults
19
Q
disadvantages of external gills (2)
A
- more exposed to the environment and susceptible to damage
- if taken out of H2O, gills will collapse and SA will decrease = decreased in diffusion rate
20
Q
suction phase
A
- chamber is expanded, increasing its volume and decreasing its pressure
21
Q
pressure phase
A
- chamber is compression, decreasing its volume and increasing its pressure
22
Q
the dual pump (4)
A
- buccal + pharyngeal pump and a parabranchial/opercular pump working together
- uses branchiomeric and hypobranchial muscles
- produces unidirectional flow of water
- gnathostomata fish
23
Q
chondrichthyes dual pump: suction phase (2)
A
- buccal cavity, pharynx and parabranchial chambers expand, generating low pressure inside
- draws water through the mouth and spiracles (flap valves closed), into the parabranchial chambers, and over the gills
24
Q
chondrichthyes dual pump: pressure phase (3)
A
- buccal cavity, pharynx, parabranchial chambers compress
- mouth and spiracle close and high pressure forces flap valves open
- water flows from buccal cavity and pharynx, through the parabranchial chambers, over the gills, and out through the external gill slits
25
Q
during what phase of the dual pump are the gills ventilated
A
- both suction and pressure phase
26
Q
dual pump: actinopterygii & sarcoptergii (2)
A
- they do not have spiracles, so water is only taken in through the mouth
- the gills are located in one large pair of opercular chambers: dual pump is composed of buccal + pharyngeal pump and the opercular pump
27
Q
ram ventilation (3)
A
- chondrichthyes, actinopterygii
- alternative to dual pump when swimming: only saves energy if axial muscles are more efficient than dual pump muscles because swimming with mouth open produces drag (increases axial muscle work)
- side effect of swimming where water flows into mouth, over gills and out of gill slits
28
Q
buccal force pump (air) (3)
A
- amphibians and air-breathing sarcopterygii
- uses branchiomeric and hypobranchial muscles
- use of the buccal cavity and pharyx as a pump to force air into the lungs
29
Q
buccal force pump: suction phase (2)
A
- buccal cavity and pharynx expand while glottic and nares/mouth are open
- spent air from lungs and fresh air from outside enter and mix together in buccal cavity and pharynx
30
Q
buccal force pump: pressure phase (2)
A
- buccal cavity and pharynx are compressed while glottic and nares/mouth stay open
- mixture of spent air and fresh air is formed from buccal cavity and pharynx into lungs and excess air is expelled
31
Q
buccal force pump: how do vertebrates minimize amount of mixing of spent and freshair
A
- differences in precise timing of opening glottic and nares
32
Q
during which phase of the two-stroke buccal force pump are lungs ventilated
A
- pressure phase
33
Q
aspiration pump (3)
A
- amniotes
- expansion and compression of the thoracic cavity/ribcage
- functions using axial muscles
34
Q
aspiration pump: mammals
A
- use diaphragm to aid in expansion of thoracic cavity
35
Q
aspiration pump: suction phase (2)
A
- inhalation: axial muscles expand the thoracic cavity, generating region of low pressure inside the lungs
- air is aspirated (sucked) through the trachea into the lungs
36
Q
aspiration pump: pressure phase (2)
A
- exhalation: muscles relax and thoracic cavity compresses, increasing pressure inside lungs
- forces the air out of the lungs
37
Q
aspiration pump: crocodilia (2)
A
- use axial muscles to expand and compress ribcage
- use specialized muscles to power the hepatic piston: liver is pulled toward the tail during suction to increase cavity volume, an liver moves anteriorly when muscles relax to decrease the cavity volume during pressure phase
38
Q
challenge of air breathing
A
- for rapid diffusion of gasses, surface must be moist
39
Q
how do air breathers minimize water loss on gas exchange surfaces (2)
A
- air breathing organs are located deep within body to minimize water loss by evaporation and prevent desiccation of surface
- tidal airflow allows for some recapture of water vapour during exhalation
40
Q
challenges of tidal flow (2)
A
- not all the inhaled air reaches the gas exchange surfaces; volume of inhaled air that is not used for gas exchange is called dead space
- not all the air within the respiratory system is expelled during exhalation; some air inhaled will contain spent air
41
Q
what structure hold dead air in mammalian lungs
A
- trachea, bronchi, bronchioles, alveoli
42
Q
how does inhaling mixture of fresh and spent air affect diffusion rate or oxygen
A
- decreases partial pressure gradient, decreasing the diffusion rate
43
Q
challenges of water breathing (3)
A
- oxygen availability is much lower in water than in air and decreases as temperature or salt [ ] increases
- water is more dense than air, so pumps for water are more energetically expensive to operate than air pumps
- if gills are taken out of water, thin tissue of secondary lamellae will collapse due to gravity and diffusion rate will fall
44
Q
labyrinth organ (4)
A
- located dorsal to the gills
- formed by extensive folding of one dorsal bone of pharyngeal arch III
- folded bone is covered in thin, highly vascularized epithelium
- epithelium does not collapse out of water due to support from the bone
45
Q
facultative air-breathers (2)
A
- taxa have both gills and air-breathing organs
- gills are used for gas exchange with water when water O2 levels are high, but air-breathing organs can be used for gas exchange when water O2 levels are low
46
Q
obligate air-breathers (2)
A
- gills are greatly reduced (decreases SA and thicker), such that gills have insufficient SA to provide O2 for metabolic requirements even in well-oxygenated water
- if fish is prevented from reaching surface to breath air, then they will drown
47
Q
why do obligate air-breathers retain their gills
A
- osmoregulation
48
Q
amphibia, lepidsauria, testudinata: lungs (2)
A
- faveoli: small compartments in the lungs which open into a hollow chamber in centre of the lungs; extremely thin and contain many capillaries for gas exchange
- air is pumped through trachea into the central chamber of the lung, before diffusing into the falveoli
49
Q
mammalia: lungs (2)
A
- air is draw through trachea and enters lungs via a series of branching tubes of smaller and smaller diameter: bronchi, bronchioles, alveoli
- alveoli: saccular compartments with extremely thin walls and highly vascularized
50
Q
archosauria: lungs (3)
A
- air flow through the lungs is unidirectional, allowing for gas exchange during suction and pressure phase
- trachea branches into two primary bronchi (one for each lung), and each bronchi branches into a series of secondary bronchi
- bronchi are connected to another series of secondary bronchi via tiny one-way air passages called parabronchi
51
Q
archosauria: gas exchange surface (2)
A
- air capillaries extend from walls of parabronchi
- air passing through diffuses into the air capillaries, which are highly vascularized
52
Q
aves: lungs (3)
A
- lungs are connected to a series of hollow, elastic air sacs
- air sacs expand when aspiration pump expands the thoracic cavity and compress when the aspiration pump compresses the thoracic cavity, but are not involved in gas exchange
- airs sacs are divided into anterior and posterior air sacs, with the parabronchi of the lungs connecting them
53
Q
aves: lungs during suction phase (3)
A
- axial muscles expand rib cage, decreasing pressure inside thoracic cavity and the air sacs expand
- decrease in pressure draws air through the trachea
- fresh air enters the posterior AS and parabronchi, while spent air in the parabronchi enters the anterior AS
54
Q
aves: lungs during pressure phase
A
- thoracic cavity is compresses and air sacs decrease in volume
- forces fresh air in the posterior AS through the parabronchi and the spent air in the parabronchi and anterior AS out through the trachea
