week 8 (resp.) Flashcards
(27 cards)
question: external vs internal respiration?
- external = involves gas exchange
⤷ mvt. of O2 from envrt. into cell + CO2 in opp. direction - internal = metabolic process of cellular resp. w/in cells
name: steps of O2 cascade/O2 transport pathway
- ventilation (air coming in)
2 diffusion across respiratory surface - circulation
- tissue diffusion
- cellular utilization or production
**CO2 moves same pathway but opp. direction
explain: relationship between diffusion rate and diffusion coefficient, cross sectional area, partial psi gradient, diffusion distance
DIFFUSION COEFFICIENT
- in air vs water
⤷ depends
- increases in air, decreases in water
- proportional
CROSS SECTIONAL AREA
- A across which diff. will occur
- proportional (A increase, rate increase)
PARTIAL PSI GRADIENT
- diff. in psi
- proportional to conc.
- proportional to rate
DIFFUSION DISTANCE
- inverse proportional (increase distance, decrease rate)
explain: fick’s laws about diffusion
- solute moves from region of high conc. to low conc. across conc. gradient
- amount of substance diffuses across surface is proportional to area of surface and inversely proportional to distance it travels
question: when does simple diffusion work well for respiration?
- large SA:V ratio
- org. too large (small SA:V) -> need to improve O2 uptake
⤷ ex. gills, lungs
question: how do gills help with breathing?
- evaginations of body
- allows water to flow in causing gas exchange
⤷ more O2 uptake - countercurrent = water flows in one direction and blood flows in capillaries in the opp. direction
⤷ allows efficient O2 capture from the water as it passes gills bc diffusion gradient - O2 moves from higher to lower conc
⤷ going opp. direction ensures water always has a higher O2 so it will always move from water to blood
question: what would happen is flow of water in gills were concurrent?
- same direction -> diffusion gradient not as efficient or disappears completely
- water doesn’t always have a higher O2 conc. than blood so less/no diffusion
explain: spiracular breathing
- insects
- has series of air filled tubes (spiracles)
- bring O2 directly to aerobic tissues
- controls water loss and keeps dust out
explain: lung ventilation in birds
- have rigid lungs that can’t expand
- have extensible air sacs to expand and contract instead
- needs 2 cycles of inhalation and exhalation
⤷ air flows through bronchi to air sacs
⤷ first exhalation pushes air from posterior sacs into lungs
⤷ second inhalation causes old air from lungs to anterior sacs
⤷ second exhalation pushes air out vis trachea - allows air to flow crosscurrent to blood
⤷ perpendicular
question: where is the main site of gas exchange in mammalian respiration?
- alveoli
- round sacs on bronchioles
- increases SA
question: conducting zone vs respiratory zone?
CONDUCTING
- reinforced w/ cartilage and smooth musc.
- no gas exchange between air and blood
- cartilage in rings
⤷ allows expansion but also keep struc.
- NS impacts smooth musc.
⤷ SNS activation -> bronchodilation -> more air in
⤷ PSNS activation -> bronchoconstriction -> harder to breathe
RESPIRATORY
- little cartilage and smooth musc.
- efficient gas exchange
explain: allergies, epipens, and respiration
- allergies -> tight throat and hard to breath
- epipen = epinephrine -> SNS
- SNS activation -> bronchodilation -> more air in -> relieves symptoms
name: dalton’s law, boyle’s law, henry’s law
DALTON
- total psi = sum of all partial psi
BOYLE
- gases move from high psi to low psi
HENRY
- conc. of gas in a liquid = proportional to solubility and partial psi of the gas
⤷ ex. psi of O2/CO2 = proportional to conc. in blood
question: does chest expand before or air comes into lungs?
- before
- increase V -> decrease psi
⤷ causes air to move in bc gases move from high to low psi
name + explain: types of pressure differences in mammalian ventilation (3)
-
atmospheric
- 760 mmHg at sea lvl -
intra-alveolar
- intrapulmonary psi
- psi of air w/in alveoli
⤷ changes w/ breathing -
intrapleural
- psi of air w/in pleura cav.
⤷ between visceral and parietal pleurae
- always lower than intrapulmonary
explain: structure of lungs and pleural sac
- lungs = surrounded by pleural sac
- sac has 2 sheets and fluid in between
- fluid lubricates pleura and allows layers to slide during ventilation
**parietal = closer to chest wall, visceral = closer to lungs
explain: intrapleural psi during rest
- subatmospheric
- chest wall pulls on parietal
- elasticity pulls on visceral
- keeps pleural sac psi -ive
question: what’s happening to pleural sac as thorasic cav. expands (inhalation)?
- fluid makes lungs pull on sac
⤷ glass on table analogy - makes intrapleural psi more -ive
⤷ pulls lungs out -> inflates them
explain: inhalation
- external intercostal musc. contraction
⤷ pulls ribs up and out
⤷ diaphragm contracts and moves down - thorasic V increases
- lung V increases
- -ive intrapleural psi -> inflates lungs -> air flows in
explain: passive and active exhalation
PASSIVE
- quiet breathing
- natural elastic recoil of thorasic musc. and lungs
- thorasic and lung V decrease
⤷ musc. back in + diaphragm back up
- +ive psi
⤷ boyles law (derease V -> increase psi)
- air flows out
ACTIVE
- intense breathing (exercise)
- internal intercostal musc. contract
⤷ pulls ribs in and down
- ab musc. contract
⤷ pushes diaphragm back up
recap: what are the psi and V changes in inhalation vs exhalation?
INHALATION
- V increase
- psi decrease
EXHALATION
- V decrease
- psi increase
question: what coordinates ventilation patterns?
- medulla oblongata
⤷ sends excitatory sig. to somatic neurons
⤷ triggers contraction of diaphragm and intercostal musc.
question: ventilation vs perfusion?
- vent = active mvt. of respiratory medium
⤷ bulk flow - perfusion = flow of blood in pulmonary capillaries which ensures gas delivery w/in body
name + explain: cells in respiratory alveolar membrane (3)
- type I epithelial cells
⤷ contact air - type II surfactant cells
⤷ important for lung compliance
⤷ reducing surface tension (prevents cells from collapsing) - macrophages
⤷ help w/ immune surveillance
