In what part of the resp. tract do asthma reactions occur? What anatomical reason allows asthma reactions to occur here?
Within the terminal bronchioles. Anatomical reasons are that there is smooth muscle, but no cartilage.
Describe the role of pressure during inspiration.
When pressure decreases, air flows in.
Describe Boyles law. Explain why this law is important in our study of respiration.
When Volume increases, Pressure decreases. When Volume decreases, Pressure increases. This is important because air always moves from high pressure to low.
List 2 factors which aid in lung recoil.
Lung recoil is during expiration. The factors are elastic fibers and surface tension.
List 2 factors which prevent lung recoil.
This is during inspiration. The factors are negative plural pressure and surfactant.
The ease of Inspiration.
Explain the term airway resistance.
The flow of the air Decreases when the diameter of the passageway Decreases.
List 2 anatomical features facilitating gas exchange in the lungs.
Thin respiratory membrane and large surface area.
List 2 physiological processes ensuring gas exchange in the lungs.
1. Blood flow is directly proportional to ventilation rate.
2. Large Functional Residual Capacity.
Define Functional Residual Capacity. Why is it important?
The amount of air left in the lungs after a normal expiration. There must be air left in the lungs because the blood needs to be constantly oxygenated.
Explain the term Diffusion gradient. What is meant by "diffusing down the gradient".
High concentration of O2 in alveoli diffuses to low O2 in the blood. High concentration of CO2 in blood diffuses to low concentration of CO2 in alveoli. There is higher concentration in the blood, and diffusion always goes from high to low.
What is Daltons Law? Explain why this law is important in our study of respiration.
That each gas in a mixture behaves as if no other gas is present. The gases always go from high partial pressure to low partial pressure.
What is Henrys Law? Explain why this law is important in our study of respiration.
How much of a gas dissolves in a liquid depends on the pressure of the gas above the liquid. High partial pressure=much gas dissolved and vice versa.
Solubility of gases
N2=very poor solubility
Gases diffuse because of differences in partial pressure from areas of higher pressure to areas of lower partial pressure. True or False.
Rank PO2 of the capillaries, the cells, and the ISF from highest PO2 to lowest PO2 in the area of the arterial end of the tissue capillaries.
Tissue Capillaries, ISF, Cells.
95 40 20
What is the PCO2 of alveolar gas? PO2 of alveolar gas?
What is the PCO2 of ISF? PO2 of ISF?
What is the PCO2 of deoxygenated blood leaving the tissues? PO2 of deoxygenated blood leaving the tissues?
This is because the blood is now deoxygenated (blue) blood, and is in the systemic veins returning towards the alveoli to pick up more O2 and drop off more CO2.
Oxygen is transported in Hemoglobin. Explain the structure of Hb, and what fully saturated means.
The structure contains 4 protein chains, each with a heme. When Hb is fully saturated, it means that an O@ is bound to each heme. 4 O2=fully saturated.
Hb is fully loaded at what plasma PO2? Where does this happen?
At plasma PO2 of 104. This happens at the alveoli.
As plasma PO2 drops from 104 to 40, Hb will __________ O2.
Describe how plasma pH affects the unloading of oxygen.
As pH drops, Hb unloads O2 to cells.
Explain how CO2 levels affect unloading of oxygen.
Drop in pH forces the unloading of O2.
Explain how temp affects the unloading of oxygen.
Increased temp means that the cells are more active, therefore causing more O2 to unload.
List the ways CO2 is transported from highest percentage to lowest percentage.
70% is carried in plasma as bicarbonate, 20% transported on Hb, 7% dissolved in plasma as CO2.
Write the equation showing what happens when Carbon dioxide combines with water.
CO2 + O2--> H2CO3--> H+ + HCO3-
What part of the brain controls the respiratory center?
Inspiration is controlled by _________ neurons.
Ventral respiratory neurons cause ____________.
What is the function of the pontine respiratory group?
Switching from Inspiration to Expiration.
What is the function of the Hering-Breuer reflex? What nerve is involved?
It prevents overinflation of the lungs. The Vagus nerve.
What molecule controls ventilation rate? Explain.
CO2 via pH is the major control, due to the formation of carbonic acid.
Define Hypercapnia. What is the cause?
Too much CO2. Cause is decrease in ventilation rate.
What type of receptors are PO2 receptors? What color is the blood that they sample? Where are they located?
They are chemoreceptors. Sample red blood. And are found in the carotid and aortic arteries.
PO2 receptors respond only to large decreases in PO2 of plasma.
Why does ventilation increase immediately during exercise?
Joint receptors are stimulated.
During exercise, average PO2, PCO2 and pH of the blood _________________.
Stay the same.
If anaerobic threshold is exceeded, lactic acid levels ____________, and ventilation rate _____________.
Explain the differences between pulmonary and systemic vessels.
Pulmonary: To and from the lungs
Systemic: Out to the body
Explain the difference between artery and vein.
Artery: Vessel that carries blood away from the heart
Vein: Vessel that carries blood toward the heart.
Why are capillaries considered the most important vessels of the circulatory system?
Because they are microscopic exchange vessels throughout the tissues which connect the tiniest arteries to the tiniest veins, ensuring full saturation of tissues.
What is the primary function of the heart?
Pump the blood.
List the structures of the circulatory system in the order that the blood flows through the heart.
Blue blood: Superior&Inferior vena cava& coronary sinus--> Right atrium--> Through tricuspid valve--> Right ventricle--> Through pulmonary semilunar valve--> Pulmonary artery--> Alveoli
Red Blood: From lungs--> 4 pulmonary veins--> Left atrium--> Bicuspid valve--> Left ventricle--> Through aortic semilunar valve--> aorta--> all of the body except alveoli.
Compare and contrast cardiac muscle and skeletal muscle.
Cardiac: Striated, single nucleus, Involuntary contract, Only twitch contractions.
Skeletal: Striated, single nucleus, Voluntary contract, Sustained contractions.
Explain the differences of the action potential in skeletal and cardiac muscle.
Cardiac: Long action potential causes long refractory period, which prevents heart from prolonged contractions. Can only undergo twitch contractions. Plateau phase allows for large amounts of Ca++ to diffuse in.
Skeletal: Short action potential causes short refractory period, allows prolonged contractions. Can undergo sustained and twitch contractions. No plateau phase.
What is the skeleton of the heart?
Fibrous connective tissue between atria and ventricles.
List the functions of the skeleton of the heart.
1.Supports openings of the heart.
2. Attaches cardiac muscle
3. Insulates atria from ventricles
Significance: Need a way to get action potential from atria to ventricles.
What is the pacemaker of the heart?
List the order of conduction of the heart tissues.
S-A Node--> Atrial muscle cells--> A-V Node--> Atrioventricular bundle--> Left and right bundle branches--> Purkinje fibers--> Ventricular muscle cells.
List the electrical events of the heart cycle in order. What does each event signal?