What would happen to heart rate if we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid?
To reach threshold more quickly
Define peripheral resistance and how does an increase in blood viscosity affect peripheral resistance
blood viscosity increases peripheral resistance.
What physiological processes provides a long-term response to blood pressure changes?
Define tissue perfusion
the flow of blood through arteries and capillaries delivering nutrients and oxygen to cells and removing cellular waste
List three factors that aid in venous return.
2. Pressure changes in the thorax;
3. Skeletal muscle activity.
Secondary hypertension can be caused by what condition(s)?
What is intrapulmonary pressure?
pressure within alveoli
Describe the effects of hypovolemic shock on the blood vessels and the heart.
blood vessels constrict, increase venous return, maintains pressure
Describe atherosclerosis as a disease process, noting the involvement of specific cell/tissue types and molecules.
damage to endothelial lining of blood viscosit
What affects would a hypothalamic tumor resulting in excess ADH production have on blood pressure and describe the anticipated physiological response.
Blood pressure would increase because ADH would increase water reabsorption in the collecting ducts, thus increasing blood pressure.
Know the events that occur in an action potential
a. rapid depolarization -rapid influx of
What would happen to the heart rate if the connection between the SA node and the AV node becomes blocked?
ventricles will beat more slowly because the nodal cells in that area discharge at a slower rate (Purkinje fiber system).
What descriptive term is used to describe the spontaneous depolarization nature of cardiac pacemaker cells?
Know the position of the valves when the ventricles contract.
both AV valves are forced shut while both semilunar valves are forced open.
what is preload
the length or degree of stretch experienced by the sarcomeres in the ventricle cells before they contract is called preload.
What is afterload?
afterload is the force the ventricles must overcome to eject blood into their respective arteries.
Which property is inotropic agents associated with?
Icontractility. Chronotropy is associated with heart rate.
What is the Frank-Starling law?
the more the ventricular muscle cells are stretched, the more forcefully they contract.
Which hormones decrease heart rate?
What is the response of the brain stem (medulla) to maintain delivery of oxygen to cells when central chemoreceptors detect a decrease in pH of the interstitial fluids in the brain?
feedback loop is initiated that indirectly increases sympathetic activity which results in vasoconstriction and an increase in blood pressure.
When hydrostatic pressure exceeds colloid osmotic pressure at the arteriolar end of the capillary, what direction will fluid move?
water is pushed out of the capillary by filtration.
What happens to the lungs if the intrapleural pressure equals or increases above atmospheric pressure?
collapse of the lungs (atelectasis).
Know the three functions of the respiratory system
a. acid-base homeostasis;
b. odor detection;
c. speech production.
What gas exchange problems do you expect to see when surface area is lost due to emphysema?
both low oxygen (hypoxemia) & increased carbon dioxide levels (hypercapnia) occur in emphysema because of respiratory membrane damage.
What is the partial pressure of oxygen in pulmonary capillaries?
What is the partial pressure of oxygen in the alveolus from inspired air?
What are the physiological and anatomical abnormalities seen in emphysema
alveolar collapse and total reduction in surface area.
The affinity of hemoglobin for oxygen increases with which factors
a. slower metabolic rate;
b. decreased body temperature
c. decreased hydrogen concentration.
Know the triggers for hyperventilation.
high partial pressure of carbon dioxide in arterial blood is a trigger for hyperventilation. Any condition which results in acidosid (high H+ conc.) will trigger hyperventilation.