Question 1

Which of the following best defines homeostasis?

Accepted Answer

The ability to maintain relatively stable internal conditions even though the outside world changes continuously.

Question 2

Which of the following is an example of a positive feedback mechanism?

Accepted Answer

During labor, as uterine contractions begin, levels of the hormone oxytocin continuously rise to further stimulate more contractions.

Question 3

Regulation of heart rate at low normal levels is achieved primarily by the:

Accepted Answer

Parasympathetic division

Question 4

How is it possible that norepinephrine can cause vasoconstriction in one location and vasodilation in another?

Accepted Answer

Receptor types differ in these tissues.

Question 5

A major difference between neurotransmitters and hormones is that hormones reach their destination via:

Accepted Answer

The blood

Question 6

A major determinant of a hormone’s mechanism of action is whether:

Accepted Answer

The hormonal molecule is hydrophobic or hydrophilic.

Question 7

Interaction with a membrane-bound receptor will transduce the hormonal message via:

Accepted Answer

A second messenger

Question 8

Second messenger-activating hormones circulate in minute quantities because:

Accepted Answer

Small concentrations of hormone can activate many intracellular molecules due to amplification.

Question 9

For a hormone to activate a target cell, the cell must possess:

Accepted Answer

A receptor

Question 10

Blood levels of hormones are kept within very narrow ranges by _____ mechanisms.

Accepted Answer

Feedback

Question 11

After centrifuging, which of the separated blood components contains the components of immune function?

Accepted Answer

Buffy coat

Question 12

Which characteristic is the major contributor to the significant oxygen-carrying capacity of a red blood cell?

Accepted Answer

Red blood cells are biconcave discs.

Question 13

Each hemoglobin molecule can transport how many oxygen atoms?

Accepted Answer

$$4$$

Question 14

Oxygen binds to which portion of hemoglobin?

Accepted Answer

The iron atom

Question 15

A patient with low iron levels would expect which of the following symptoms?

Accepted Answer

An increase in fatigue

Question 16

Hematopoietic stem cells give rise to:

Accepted Answer

All of the above (erythrocytes, leukocytes, platelets)

Question 17

Predict the outcome of an overdose of the hormone erythropoietin.

Accepted Answer

The blood viscosity increases to levels that may induce heart attacks or strokes.

Question 18

What is the progenitor of platelets?

Accepted Answer

Megakaryocyte

Question 19

Why don’t platelets form plugs in undamaged blood vessels?

Accepted Answer

Only contact of platelets with exposed collagen fibers and von Willebrand factor causes them to stick and form plugs.

Question 20

Which antibodies are naturally present in someone who is B+?

Accepted Answer

Anti-A

Midterm 2 Practice: Key Concepts in Homeostasis, Endocrine, Blood, and Cardiovascular Physiology

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