Chapter 1 - Module 2: Sections 1.03-1.04 Dynamic Study Module
Approximately what percentage of the air we breathe is oxygen?
20%
Which of the following is false concerning the survival need of water?
The body is 98% water and is thus crucial to survival.
Which of the following is not an example of the body's use of homeostasis to regulate the internal environment?
Being covered with a blanket when you are cold
Which of the following events is an example of a positive feedback mechanism?
Blood clotting when the lining of a blood vessel is injured
Which of the following is true of positive feedback mechanisms?
The result or response enhances the original stimulus, and the response is accelerated.
Which of the following is true for the positive feedback mechanism shown?
Typically only a local effect, not spreading to the entire circulation
Failure of homeostatic mechanisms often lead to pathological symptoms. Which of the following represent an inaccurate pairing between parts of a homeostatic mechanism and disease?
Vitamin deficiencies that damage nerves and cause numbing in the hands may lead to failure to withdraw from a painful stimulus. This represents a failure in the effector portion of the homeostatic mechanism.
In feedback, which statement is true?
Positive and negative feedback mechanisms are named for the direction of the response relative to the initial stimulus.
Which choice below is not one of the three components of homeostatic control systems?
Positive feedback
What is the primary function of Dynamic Study Modules?
Receptor perceives a stimulus by sending input along the afferent pathway.
Match the following: Example of negative feedback system
Regulation of body temperature
Which of the following is an example of positive feedback?
Release of oxytocin to increase the strength of labor contractions
Movement ________.
is defined as both moving the organism through the environment using the muscular system as well as moving substances through the internal organs of the body
If the human body temperature drops below 37°C (98.6°F), the body's __________.
metabolic reactions become slower
The ability to sense changes in the environment and respond to them is a physiological ability known as __________.
responsiveness
Reproduction refers __________.
to both cellular reproduction (where a cell divides producing two identical daughter cells) and organismal reproduction (making a new person)
Which of the figures represents a full positive feedback system?
A.
Which of the following is true concerning appropriate atmospheric pressure?
Breathing and gas exchange in the lungs depend on appropriate atmospheric pressure.
Which of the following components of a feedback cycle represents the control center?
C
When considering nutrients as a survival need, which of the following is true?
Carbohydrates are the major energy fuel for body cells and are found primarily in plant-derived foods.
As blood sugar rises, receptors in the body sense this change, and the pancreas (the control center) secretes insulin into the blood. This change in turn prompts body cells to absorb more glucose, removing it from the bloodstream. As blood sugar falls, the stimulus for insulin release ends. Which of the following best describes this example of a feedback system?
Endocrine system maintaining homeostasis by negative feedback
Excretion is the process of removing wastes from the body. If the body is to operate as we expect it to, it must get rid of nonuseful substances produced during digestion and metabolism. Which of the following is untrue with regards to excretion?
Every organ system plays a direct role in excretion.
Metabolism is a broad term that includes all chemical reactions that occur within body cells. It includes breaking down substances into simpler building blocks (the process of catabolism), synthesizing more complex cellular structures from simpler substances (anabolism), and using nutrients and oxygen to produce (via cellular respiration) ATP, the energy-rich molecules that power cellular activities. Given what you know about metabolism, which of the following statements is false?
Metabolism is regulated largely by the nervous system.
In feedback, which statement is true?
Most medical situations can be viewed from the point of view of a failure of homeostasis. Disease can be regarded as a disturbance of homeostasis.
Which of the following is not true of the necessary life function of growth?
In growth, destructive activities must occur at a faster rate than constructive ones.
Which of the following does not represent a negative feedback mechanism?
Increasing the muscle in the heart to cope with high blood pressure
Which of the following is not a necessary human life function?
Intelligence
Which of the following is true of digestion?
It involves the breaking down of ingested foodstuffs to simple molecules.
The human body as a whole is enclosed and protected by the integumentary system. This is an example of a necessary life function. Select the correct function from the list below.
Maintaining boundaries
A result of homeostatic imbalance could be __________.
disease
A home heating system connected to a temperature-sensitive thermostat is a nonbiological example of a negative feedback system. Which of the following best describes the heating element of the furnace?
effector
