Test 1 Flashcards
(33 cards)
Why is the L.Ventricle more muscular then the R.Ventricle?
It contracts with force sufficient to push blood through the systemic circuit.
What event is taking place during the Q-T interval?
A single cycle of ventricular depolarization and repolarization.
What statement is true of peptide hormone?
They are chains of amino acids such as glycoproteins, small proteins, or polypeptides.
Which of the following is true of cardiac muscle tissue?
Cardiac muscle cells have intercalated discs.
What characteristic of blood contribute to its high viscosity?
Interactions among proteins, formed elements and water molecules in plasma.
What characteristic is exclusive to the endocrine system compared to the nervous system?
Effective in coordinating cell, tissue, and organ activities on a sustained, long-term basis.
What condition contributes to a reduction in the size of the T wave?
Coronary ischemia
What is not a major function of blood?
Storage for calcium ions
How is eversion of the AV valves and back flow of blood into the atria prevented?
Tightening of chordae tendineae and contraction of papillary muscles.
Why is resting HR somewhat slower than the 80-100 bpm set by the SA node?
Parasympathetic effects dominate in a resting individual.
How does damage to the cardioinhibitory center of the medulla affect heart rate? why?
Heart rate increases; sympathetic dominance
If levels of calcium are low in the blood, what hormone would restore calcium to homeostasis?
Parathyroid Hormone
During ventricular systole of the cardiac cycle, what would not occur?
Pressure in ventricles would force the semilunar vales closed.
Why is cross matching performed, even though both donor and recipient are known to be the same blood type?
It reveals the presence of potential cross-reactions with surface antigens other than A, B, and Rh.
Frank has just run marathon and his heart is beating extremely rapidly. What happens to the length of diastole and filling time?
Both decrease
What is the phase in cardiac cycle when the mitral valve is closed and the aortic valve is open?
Systolic ejection phase
What is the effect of renin secretion by the kidneys?
Converts into angiotensinogen to angiotensin 1
What is the best way to describe Platelets?
Adhere to collagen beneath endothelium
During the cardiac cycle do ventricles contain their maximal amount of blood? what is this quantity called?
At the end of atrial systole; EDV
At the end of ventricular diastole; EDV
A substance that activates plasminogen might be useful to?
Cause clot dissolution to proceed faster.
Why is ESV lower when you are actively exercising?
EDV increases and ventricular muscle produces more forceful contractions ejecting more blood.
Which phase is after Vascular?
Platelet phase
The vascular arrangement of the hypophyseal portal system?
Provides efficient means of ensuring that all hypothalamic hormones will reach target cells in the adenohypophysis before being diluted in general circulation.
In cardiac muscle, the fast depolarization phase of the action potential is the result of?
Increased membrane permeability to sodium ions.
