Respiratory Systems Flashcards
What are respiratory organs?
surfaces that capture O2 and release CO2
How to determine how much O2 is available?
Concentration
Partial Pressure
Respiratory Media
What is concentration?
the amount of gas in a mixture
What affects concentration?
temperature
altitude
salinity
What is partial pressure?
the pressure exerted by gas in a mixture
determines diffusion by looking at gradient between high and low partial pressure in a system
What does partial pressure allow?
exchange of gases across cell membranes
How is partial pressure calculated?
concentration x barometric pressure
What is total barometric pressure?
the sum of all partial pressures of the different mixed gases
What are the two respiratory medium?
water (less O2 available due to higher viscosity and lower solubility and air (more O2 available due to lower viscosity)
What do respiratory organs need?
moisture: plasma membranes need to contract with aqueous solution for diffusion
large surface area: to conduct enough gas exchange via skin, gills, lungs and/or tracheae
What animals use skin as a respiratory system?
annelids and amphibians
What animals use tracheae as a respiratory system?
insects
have tiny branching tubes that penetrate body bringing O2 directly to body cells
What are gills?
extensive out-folding of body that create a large surface area for gas exchange
What is ventilation in gills?
movement over the respiratory surface, is required to maintain pressure gradients
What is countercurrent exchange in fish?
blood flows in opposite direction of water passing over gills
ensures that water always has higher O2 partial pressure than blood
What are lungs?
derived from the gut in development and are subdivided into numerous pockets
they need a circulatory system that transports gases between the lungs and rest of the body
most species are vertebrates, spiders, and snails
Describe the steps of the mammalian respiratory system.
1: air enters the nostrils to get filtered, warmed and humidified in the nasal cavity
2: air moves to the pharynx, where it proceeds through the larynx
3: air passes the epiglottis/esophagus, and moves down the trachea
4: trachea branches into two bronchi, one leading to each lung
5: bronchi branch repeatedly in each lung, into finer-and-finer tubes called bronchioles
What do the smallest bronchioles have?
air sacs clustered at their tips called alveoli
What happens at the alveoli?
gas exchange between the epithelial cells and senses capillaries
What do alveoli lack?
cilia and mucus for protection
What does the surfactant film do?
protects alveoli and reduces surface tension to keep sacs open
How does gas exchange occur?
O2 rapidly diffuses across the epithelium into capillaries and the circulatory system
CO2 rapidly diffuses from the capillaries, across the epithelium and into alveoli
What is breathing?
the process that conducts ventilation with alternation of inhalation and exhalation
How does the thoracic cavity move during breathe?
expands during contraction of rib cage, moves down
relaxes during exhalation and moves up
What is negative pressure breathing?
expansion pulls air into lungs
What is tidal volume?
the volume of air inhaled with each breath
What is vital capacity?
the maximum tidal volume for the lungs
What is residual volume?
the air that remains in the lungs
What is hemoglobin?
what most vertebrates and some invertebrates use to move O2
produced by red blood cells
What is needed in hemoglobin?
essential mineral: Fe, iron to build a functional heme group needed to carry O2
has four chains that can each bind to an O2 molecules
What is cooperative binding?
each addition of a bond becomes easier, the first bond always requires the most energy
What does the dissociation curve of hemoglobin show?
that the protein also can release O2 in response to just small changes in partial pressure
How are blood pH and hemoglobin efficiency related?
Increase in pH decreases hemoglobin efficiency
What does blood play a role in?
CO2 produced by cellular respiration helps lower affinity for O2
When is the partial pressure of blood different?
Low partial pressure of O2 when blood arrives in lungs
High partial pressure of CO2 when blood arrives in lungs
