General Physiology-Exam 1

On his midsummer trek through the desert, Josh ran out of water. Why is this particularly dangerous?

Dehydration can occur and he will be unable to sweat to cool his body

What regulatory processes would your body use if you were trapped by a blizzard in an unheated, uninsulated cabin in the woods?

Homeostasis; and the brain would activate the heat-gain center.

What materials can easily diffuse through the lipid bilayer, and why?

Only materials that are relatively small and nonpolar can easily diffuse through the lipid bilayer.

Why is receptor-mediated endocytosis said to be more selective than phagocytosis or pinocytosis?

Receptor-mediated endocytosis is more selective because the substances that are brought into the cell are the specific ligands that could bind to the receptors being endocytosed. Phagocytosis or pinocytosis, on the other hand, have no such receptor-ligand specificity, and bring in whatever materials happen to be close to the membrane when it is enveloped.

The female ovaries and the male testes are a part of which body system? Can these organs be members of more than one organ system? Why or why not?

Reproductive system; they are also apart of the endocrine system because they secrete hormones

What do osmosis, diffusion, filtration, and the movement of ions away from like charge all have in common? In what way do they differ?

These four phenomena are similar in the sense that they describe the movement of substances down a particular type of gradient. Osmosis and diffusion involve the movement of water and other substances down their concentration gradients, respectively. Filtration describes the movement of particles down a pressure gradient, and the movement of ions away from like charge describes their movement down their electrical gradient.

Which of the following statements about nutrients is true? a. All classes of nutrients are essential to human survival b. Because the body cannot store any micronutrients, they need to be consumed nearly every day. c. Carbohydrates, lipids, and proteins are micronutrients. d.Macronutrients are vitamins and minerals.

a. all classes of nutrients are essential to human survival

After you eat lunch, nerve cells in your stomach respond to the distension (the stimulus) resulting from the food. They relay this information to: a. a control center b. a set point c. effectors d. sensors

a. the control center

Which of the following is an example of a normal physiologic process that uses a positive feedback loop? a. blood pressure regulation b. childbirth c. regulation of fluid balance d. temperature regulation

b. childbirth

Because they are embedded within the membrane, ion channels are examples of: a. receptor proteins b. integral proteins c. peripheral proteins d. glycoproteins

b. integral proteins

Diffusion is to ______ as endocytosis is to ______. a. filtration; phagocytosis b. osmosis; pinocytosis c. solutes; fluid d. gradient; chemical energy

b. osmosis; pinocytosis

Ion pumps and phagocytosis are both examples of : a. endocytosis b. passive transport c. active transport d. facilitated diffusion

c. active transport

C.J. is stuck in her car during a bitterly cold blizzard. Her body responds to the cold by a. increasing the blood to her hands and feet b. becoming lethargic to conserve heat c. breaking down stored energy d. significantly increasing blood oxygen levels

c. breaking down stored energy

Humans have the most urgent need for a continuous supply of a. food b. nitrogen c. oxygen d. water

c. oxygen

Stimulation of the heat-loss center causes ________. a. blood vessels in the skin to constrict b. breathing to become slow and shallow c. sweat glands to increase their output d. all of the above

d. all of the above

The diffusion of substances within a solution tends to move those substance ____________ their _________ gradient. a. up; electrical b. up; electrochemical c. down; pressure d. down; concentration

d. down; concentration

Identify the four components of a negative feedback loop and explain what would happen if secretion of a body chemical controlled by a negative feedback system became too great.

stimulus, sensor, control center, effector; The sensors would activate the control center which would activate an effector.