Homework Chapter Question

Which is NOT one of the four general categories of cells that make up the human body? (epithelial, collagen, connective tissue, neuron, muscle)

Collagen cells. The four categories are epithelial, connective tissue, muscle, and nervous (neuron). Collagen is a protein fiber made by connective tissue cells, not a cell type.

Physiology is the study of…

How organisms function.

The study of disease states in the body is called…

Pathophysiology.

Which is NOT a connective tissue cell? (bone, skeletal muscle, blood, fat, cartilage)

Skeletal muscle cells - they are muscle tissue. Bone, blood, fat, and cartilage cells are all connective tissue.

What is the principal function performed by epithelial cells?

Forming boundaries between body compartments.

What is the term for the developmental process that leads to specialized cell types?

Differentiation.

Which best describes the extracellular matrix?

It surrounds cells; it contains proteins, polysaccharides, and minerals; it provides a scaffold for cell attachment; and it transmits chemical messengers to cells.

A person sweats on entering a hot room and continued sweating keeps body temperature constant. Which best describes her condition?

She is in a steady state - a constant value maintained by continuous energy expenditure (ongoing sweating), unlike equilibrium, which needs no energy.

Which concept is the defining feature of the discipline of physiology?

Homeostasis.

Describing a physiological variable as 'homeostatic' means that it…

Is in a state of dynamic constancy that is regulated to remain near a stable set point value.

Which situation best represents a homeostatic mechanism?

After eating a large batch of salty popcorn, levels of salt in the urine increase - the body corrects the disturbance by excreting excess salt (negative feedback).

What term describes the steady-state value for any variable that the body attempts to maintain?

Set point.

List the components of a general reflex arc in the order information flows following a stimulus.

Receptor -> afferent pathway -> integrating center -> efferent pathway -> effector.

What is the general purpose of positive feedback mechanisms?

To bring about a rapid change in the body - amplifying the stimulus to drive a process to completion (e.g., clotting, labor).

Vagus neurons secrete acetylcholine onto sinoatrial pacemaker cells, decreasing heart rate. This is an example of…

Neural control (efferent pathway) - a neuron using a neurotransmitter to control an effector.

Heart rate is increased by epinephrine released by the adrenal medulla into the bloodstream. This is an example of…

Hormonal (endocrine) control - a hormone traveling through the blood to a distant target.

The tall, slender body shape that helps dissipate heat in people native to equatorial regions is an example of…

Adaptation - an inherited trait favoring survival in a specific environment (not reversible).

The number of distinct cell types in the human body is about twenty. (True/False)

False - the body has roughly 200 distinct cell types.

The respiratory system is primarily responsible for transporting blood to the body's tissues. (True/False)

False - that is the circulatory (cardiovascular) system. The respiratory system handles gas exchange.

A person acclimated to a hot environment will react physiologically to a decreased environmental temperature faster than a person who is not. (True/False)

False - acclimatization to heat improves the response to heat, not cold, and does not transfer to a cold challenge.