Flashcards in Cardiac, Neuro, and Respiration for physiology Deck (115)
What is the normal heart rhythm and what is it controlled by?
sinus rhythm and by the SA node
when the heart rate is too fast or too slow
What is the contractility of the myocardium determined by?
calcium ions with actin and myosin
What greatly impacts the contractilty of the myocardium?
the sympathetic NS
What is heart rate determined by?
the automatic system and the SA node
How is heart rate determined?
from the balance between the sympathetic and the parasympathetic ns
Which makes the heart rate faster?
Which makes the heart rate slower?
What's an electrocardiogram?
graphic recording of electrical activity of the heart showing the directions impulses are traveling
In an ECG what does the P, QRS, and T mean?
atrial depolarization, ventricular depolarization, ventricular repolarization
What is heart rate?
frequency of cardiac cycle bpm
Do smaller or larger animals have higher rates and why?
smaller due to large surface area per unit of body mass
What is a cardiac auscultation?
listening to the heart
What does Lub do?
closes the AV valves
What does Dub do?
closes the semilunar valves
What is cardiac muscle fiber made up of?
striated, involuntary, branched with a single central nuclei and intercalculated discs
How do impulses travel in cardiac muscle fiber?
from cell to cell in intercalculated discs
Where is the SA node and what originates there?
the right atrium and impulses originate there
What is peripheral resistance?
blood flow that is limited by friction
How can blood flow through peripheral resistance?
blood pressure must be greater
The difference between the systolic and diastolic pressures is?
What is blood pressure?
the force exerted by the blood against inner walls of blood vessels
Maintenance of normal blood pressure prevents what?
What is the maximum pressure achieved during ventricular contraction?
systolic blood pressure
What are the functions of the cardiovascular system?
maintenance of normal blood pressure with the arteries, maintenance of blood flow to the tissues, maintenance of normal blood pressure within the capillaries and veins
What is the mode of travel of an impulse along a myelinated nerve?
Do impulses travel faster in myelinated fibers or nonmyelinated fibers?
In myelinated axons depolarization can only occur at?
nodes of ranvier
What are meninges?
connective tissue surrounding the brain and spinal cord