Respiratory System Flashcards
What evolutionary changes have occurred to optimize the rate of diffusion R?
- increase surface area
- decrease distance
- increase concentration
Gases diffuse directly in to unicellular organisms. However, most multicellular animals require system adaptations to enhance gas exchange by:
- amphibians respire across their skin
- echinoderm have protruding papulae
- insects have an main tracheal system
- fish use gills
- mammals have a large network of alveoli in lung tissue
_____ are not enclosed within the body, found in immature fish and amphibians. Disadvantages: must constantly move to have contact with oxygen rich fresh water, and are easily damaged.
External gills
Each gill filament consists of _____.
- thin membrane plates that project into water flow
- water flows pass lamellar in one direction (opposite to blood flow)
Lamellae
Fish gills are the most _____ of all respiratory organs
Efficient
In _____ air exerts a pressure downward, due to gravity. A pressure of 760 mm is defined as 1.0 atm of pressure.
Lungs
_____ pressure is the pressure contributed by a gas to the total atmospheric pressure.
Partial
Frogs have _____ pressure breathing, force air into their lungs by creating a positive pressure in the buccal cavity.
Positive
_____ is passive, driven only by the difference in O2 and CO2 concentrations, and their relative solubilities in the plasma membrane.
Diffusion
The volume of air moving in and out of lungs in a person at rest
Tidal volume
Maximum amount of air that can be expired after a forceful inspiration
Vital capacity
Insufficient breathing, high CO2
Hypoventilation
Excessive breathing, low CO2
Hyperventilation
_____ consists of 4 polypeptide chains: 2 alpha and 2 beta. Each chain associated with a heme group, each heme group has a central iron atom that can bind a molecule of O2.
Hemoglobin
It loads up with oxygen in the lungs, forming oxyhemoglobin.
Hemoglobin
Hemoglobin a affinity for oxygen is affected by ____ and ____
pH, and temperature
The pH affect is know as the Bohr affect.
- Increased CO2 in blood increases H
- Lower ph reduces hemoglobin affinity for O2.
- Facilitates oxygen unloading
Transportation of CO2 is different than O2.
CO2: 8% dissolved in plasma
20% bound to hemoglobin
72% diffuses into red blood cells
____ are sensitive to blood pCO2 changes. Rise in CO2 causes more carbonic acid, lowering the pH. Stimulates chemioensitive neurons. Increase rate of breathing.
Neurons
Allergen triggers the release of histamine causing intense constricting of bronchi
Asthma
Alveolar walls break down, larger but fewer alveoli
Emphysema
