Download 3.1 Answers

SECTION 3.1 QUESTIONS
(Page 166)
Understanding Concepts
1. A cell (either plant or animal) is the smallest unit of life. Tissues are groups of similarly shaped cells that carry
out the
same function (e.g., muscle tissue). Organs are groups of tissues working together for a common function (e.g.,
heart).
Organ systems are composed of many organs, which carry out a common function (e.g., circulatory system).
2. Organs can be classified according to related functions (physiology) or structures (anatomy).
3. Examples of organs playing roles in more than one organ system: pancreas (digestive, endocrine); liver
(digestive,
excretory); blood vessels (circulatory, respiratory)
4. Classification of organ systems according to location:
Organ systems spread throughout body Organ systems located together
Locomotion Digestive
Circulatory Respiratory
Endocrine Urinary
Nervous Reproductive
5. Organ systems do not function in isolation. Not only do some organs play major roles in more than one system
(as in
question 3, above); systems are interconnected structurally and functionally. The circulatory system requires gas
exchange by the respiratory system; nutrients released by the digestive system are transported by the circulatory
system; the nervous system directs the functioning of other systems.
84 U nit 3 Student Book Solutions NEL
6. Comparison of four diagnostic tools:
Similarities:
– images appear on computer screens for assessment and diagnosis
– high energy electromagnetic rays are used in both X-ray and CT technologies to show internal structure
Differences:
– X-ray technology shows structure of bone; CT scans also show structure of soft tissue
– X-ray images are one dimensional, whereas in CT scans, many X-rays are taken from different angles and
reassembled to form 3-D images
– nuclear imaging techniques involve injection of radionuclides to provide information about function
– MRI technology uses magnetic forces and radio waves to provide information about structure and function
7. A CT scan provides information about brain structure, or anatomy. The 3-D image might show the location of
blood
clots. Further tests (nuclear imaging or MRI) would be necessary to indicate how the function of brain tissue is
affected.