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
during what phase of the dual pump are the gills ventilated
- both suction and pressure phase
26
dual pump: actinopterygii & sarcoptergii (2)
- 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
ram ventilation (3)
- 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
buccal force pump (air) (3)
- 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
buccal force pump: suction phase (2)
- 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
buccal force pump: pressure phase (2)
- 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
buccal force pump: how do vertebrates minimize amount of mixing of spent and freshair
- differences in precise timing of opening glottic and nares
32
during which phase of the two-stroke buccal force pump are lungs ventilated
- pressure phase
33
aspiration pump (3)
- amniotes
- expansion and compression of the thoracic cavity/ribcage
- functions using axial muscles
34
aspiration pump: mammals
- use diaphragm to aid in expansion of thoracic cavity
35
aspiration pump: suction phase (2)
- 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
aspiration pump: pressure phase (2)
- exhalation: muscles relax and thoracic cavity compresses, increasing pressure inside lungs
- forces the air out of the lungs
37
aspiration pump: crocodilia (2)
- 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
challenge of air breathing
- for rapid diffusion of gasses, surface must be moist
39
how do air breathers minimize water loss on gas exchange surfaces (2)
- 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
challenges of tidal flow (2)
1. 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
2. not all the air within the respiratory system is expelled during exhalation; some air inhaled will contain spent air
41
what structure hold dead air in mammalian lungs
- trachea, bronchi, bronchioles, alveoli
42
how does inhaling mixture of fresh and spent air affect diffusion rate or oxygen
- decreases partial pressure gradient, decreasing the diffusion rate
43
challenges of water breathing (3)
- 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
labyrinth organ (4)
- 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
facultative air-breathers (2)
- 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
obligate air-breathers (2)
- 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
why do obligate air-breathers retain their gills
- osmoregulation
48
amphibia, lepidsauria, testudinata: lungs (2)
- 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
mammalia: lungs (2)
- 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
archosauria: lungs (3)
- 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
archosauria: gas exchange surface (2)
- air capillaries extend from walls of parabronchi
| - air passing through diffuses into the air capillaries, which are highly vascularized
52
aves: lungs (3)
- 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
aves: lungs during suction phase (3)
- 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
aves: lungs during pressure phase
- 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
