Chapter One

ANSWER KEY END OF CHAPTER QUESTIONS / REVIEW EXERCISES
CHAPTER 1
Introduction to Human Anatomy and Physiology
Part A 1. Briefly describe the early development of knowledge about the
human body.
Our earliest ancestors probably became curious about the body during
illnesses and injuries. At these times, they visited shamans who relied
on superstition and magic. Throughout early time, this curiosity lead to
discoveries of the healing powers of certain herbs and potions,
especially to treat coughs, headaches, and other common problems. Not
until about 2,500 years ago did these superstitious attitudes change and
the body was looked at in the new light of modern science. Experiments,
accurate observations, and tried techniques rapidly expanded knowledge
of the human body. Greek and Latin words were used as a basis to
describe body part locations and to explain their functions. This formed
the basis for anatomy and physiology. 2. Distinguish between the activities of anatomists and physiologists.
Anatomists deal with the structure (morphology) of the body parts. This
includes the shapes, forms, and placement of body organs and appendages.
Physiologists deal with the functions of body parts, what the body parts
do, and how this is accomplished. 3. How does a biological structure's form determine its function? Give an
example.
The functional role will depend upon the manner in which the part is
constructed. The human hand with its long, jointed fingers makes it
possible for human beings to grasp things. 4. List and describe the ten characteristics of life.
Movement is the ability to self-initiate position changes of either the
entire organism or a part of the organism, externally from place to
place and/or internally, such as in peristalsis. Responsiveness refers to the ability of an organism to detect changes
either within itself or the environment surrounding it and then react to
these changes. Growth generally refers to an increase in body size without important
changes to its general shape. Reproduction is the process of making a new organism, as in parents
producing offspring. It also discusses the process whereby cells can
produce others like themselves to take the place of damaged or destroyed
cells. Respiration refers to the process of obtaining oxygen, using the
obtained oxygen in release of energy from foods, and removing waste
gases that are produced in the process. Digestion is the chemical change of ingested foods into simpler
substances that can be taken in and used by body parts. Absorption is the passage of digested substances through membranes 5. Define metabolism.
The totality of chemical changes that occur within body parts. 6. List and describe five requirements of organisms.
Water, the most abundant substance in the body, is required for many
metabolic processes. It provides the environment for the metabolic
processes to take place and then transports substances within the body.
It is also important in the process of regulating body temperature. Food is the substances that provide the body with the necessary chemical
to sustain life, in addition to water. These chemicals are used in a
variety of ways by the body. Oxygen, which makes up about one-fifth of air, is used in the process of
releasing energy from food substances. Heat, a form of energy, is a product of metabolic reactions. The rate at
which these reactions occur is partly governed by the amount of heat
present. Pressure is a state in which a force is applied to something.
Atmospheric pressure is an important role in breathing. Hydrostatic
pressure, the pressure of fluid, plays an important role in the
circulatory system. 7. Explain how the idea of homeostasis relates to the five requirements you
listed in item 6.
Homeostasis refers to the stable internal environment of an organism. In
human beings, if the requirements listed above become unstable, the body
will react in certain ways to regain its stable internal environment. An
example would be sweating to help decrease body temperature. 8. Distinguish between heat and temperature.
Heat is a form of energy that is a product of metabolic reactions.
Temperature is the amount of heat that is present at any given time. 9. What are two types of pressures that may act upon organisms?
Atmospheric pressure is the pressure of the atmospheric air on the
outside of an organism. Hydrostatic pressure is the pressure exerted by
a liquid on the outside of an organism. 10. How are body temperature, blood pressure and blood glucose
concentration controlled?
Homeostasis is maintained in each of these situations by a self-
regulating control mechanism that can receive signals about changes away
from the normal set points and cause reactions that return conditions to
normal. 11. In what ways do homeostatic mechanisms act by negative feedback?
Homeostatic mechanisms detect changes away from the normal state. This
stimulates responses in the opposite directions, which are called
negative responses. This process is called negative feedback. 12. How does the human body illustrate the levels of anatomical
organization?
The basic unit of structure and function in the human body is the
microscopic cell. These cells organize into layers that have common
functions. These layers are called tissues. These tissues then group
together to form organs. Groups of organs make up organ systems. Groups
of organ systems make up the organism, which in this case is the human. 13. Distinguish between the axial and appendicular portions of the body.
Axial portion-This consists of the head, neck, and trunk. Appendicular portion-This consists of the arms and the legs. 14. Distinguish between the dorsal and ventral body cavities, and name the
smaller cavities within each.
The dorsal cavity is located at the back of the organism. It can further
be subdivided into two parts-the cranial cavity within the skull, which
houses the brain; and the spinal cavity, which contains the spinal cord
and is surrounded by sections of the backbone (vertebrae). The ventral
cavity is the front part of the organism. It is subdivided into two
parts-a thoracic cavity, which houses the lungs and heart; and a
abdominopelvic cavity, which houses the stomach, liver, spleen,
gallbladder, small and a large intestines, urinary bladder, and the
internal reproductive organs. 15. What are the viscera?
The viscera are the organs found deep within a body cavity. 16. Where is the mediastinum?
The mediastinum is the region that separates the thoracic cavity into
two compartments, which contain the right and left lungs. 17. Describe the locations of the oral, nasal, orbital, and middle ear
cavities.
Oral cavity is the mouth area and contains the teeth and the tongue. Nasal cavity is located within the nose and is divided into right and
left portions by a nasal septum. Air-filled sinuses are connected to the
nasal cavity, including the sphenoidal and frontal sinuses. Orbital cavities contain the eyes and associated skeletal muscles and
nerves. Middle ear cavities are found inside the ear and contain the middle ear
bones.
18. How does a parietal membrane differ from a visceral membrane?
A parietal membrane refers to a membrane that is attached to the wall
and forms the lining of a cavity whereas a visceral membrane refers to a
membrane that is deeper toward the interior and covers the internal
organs contained within a cavity. 19. Name the major organ systems, and describe the general functions of
each.
Integumentary system-It protects underlying tissues, helps regulate body
temperature, houses a variety of sensory receptors, and synthesizes
certain products. Skeletal system-It provides frameworks and protective shields for softer
tissues; serves as attachments for muscles when body parts move. It also
has a role in blood cell production and storage of inorganic salts. Muscular system-It provides the forces that cause body movements. They
also maintain posture and are the main source of body heat. Nervous system-It provides the ability to detect changes that occur
inside and outside the body. It interprets the sensory impulses and what
to do in response to these impulses. It also plays a role in muscle
contraction and gland secretions. Endocrine system-It secretes hormones that alter metabolism of a target
tissue. Cardiovascular system-It pumps blood throughout the body. The blood
serves as a fluid for transporting gases, nutrients, hormones, and
wastes. Lymphatic system-It transports tissue fluid back to the bloodstream and
carries certain fatty substances away from the digestive organs. It also
plays a role in immunity. Digestive system-It receives various food molecules from the outside and
converts them into simpler ones that can be absorbed. Respiratory system-It provides for the intake and output of air and for
the exchange of gases between blood and air. Urinary system-It removes various wastes from the blood and assists in
maintaining the body's water, electrolyte, and acid-base balances. Reproductive system-It is responsible for the production of whole new
organisms like itself. 20. List the major organs that comprise each organ system.
Integumentary system-It consists of the skin and various accessory
organs such as the hair, nails, sweat glands, and sebaceous glands. Skeletal system-It consists of the bones, ligaments, and cartilages. Muscular system-It consists of the muscles. Nervous system-It consists of the brain, spinal cord, nerves, and sense
organs. Endocrine s