Class 2 - Major Themes in A&P

Question 1

Ways of studying human anatomy (7)

Answer 1

1. Exploratory surgery
2. Medical imagery; radiology
3. Gross anatomy (naked eye)
4. Cytology (cell structure/function)
5. Histology (cells w/ microscope)
6. Ultrastructure (molecular detail w/ electron microscope)
7. Histopathology (microscopic examination of tissues for signs of disease).

Question 2

Evolution, natural selection, adaptation, and selection pressure definitions

Answer 2

Evolution - changes in genetic composition of a population of organisms over time.

Natural selection - Some individuals in a species have hereditary advantage over competitors.

Adaptation - features of an organism that have evolved in response to selection pressures

Selection pressures - national forces which promote reproductive success of certain individuals.

Question 3

Levels of human structure (8)

Answer 3

1. Organism
2. Organ systems - Group of organs with a collective function
3. Organs - Structure with 2+ tissue types functioning together
4. Tissues - Similar cells form discrete regions which perform specific functions
5. Cells - Smallest unit of life
6. Organelles - Structure within a cell with a function
7. Molecule - Particle of 2+ atoms
8. Atom - Smallest particle with a unique chemical identity

Question 4

Reductionistic vs holistic viewpoints

Answer 4

Reductionistic - See body as large system only understood by studying its simpler components. Essential to scientific thinking

Holistic - Assert that properties of an organisms cannot be predicted from properties of separate parts; body must be studied as a whole

Question 5

Clinical significance of anatomical variation in humans

Answer 5

70% of body structure is the same for everyone but there’s a normal 30% of anatomical variation.

Clinicians must know this to determine what’s normal and what is unhealthy. Different ages, sexes, etc may require different treatment (e.g. dosage)

Question 6

Define negative feedback + example, importance to homeostasis

Answer 6

Allows dynamic equilibrium: Sense change and take corrective action.

Example: if too warm, vasodilation of skin blood vessels occurs, meaning blood vessels move toward skin surface and sweating occurs.

Question 7

Positive feedback + example, beneficial and harmful effects

Answer 7

A self amplifying cycle which produces rapid change and increases until trigger is removed.

Example: Fever. presence of virus causes immune response and metabolic rate increases, producing heat faster; cycle reinforces itself

Harmful if body goes too far from homeostasis; body processes stop working

Question 8

Characteristics of life (9)

Answer 8

1. Organization
2. Cells
3. Metabolism
4. Responsiveness and movement
5. Homeostasis - Ability to maintain stable internal environment
6. Development
7. Growth
8. Reproduction
9. Evolution

Question 9

Homeostasis and its importance

Answer 9

Ability to detect change, activate mechanisms to oppose it, and thereby maintain stable internal conditions.

Loss of homeostatic control means unsuitable conditions for cell function and eventual illness and death.

Question 10

Three components of a feedback loop

Answer 10

1. Receptor
2. Integrating center
3. Effector

Question 11

Types of medical imaging (5)

Answer 11

1. Radiography (X-rays) - Penetrate tissues to darken photographic film beneath the body
2. Computed tomography (CT scan) - low intensity x-rays and computer analysis. Slice-type image. Sharp.
3. Magnetic resonance imaging (MRI) - superior quality to CT scan and no x-ray exposure. Functional MRI shows real time changes in brain
4. Positron emission tomography (PET) - Assesses metabolic state of tissue. inject radioactively labeled glucose.
5. Sonography - High-frequency sound waves echo back from organs. Avoids harmful x-rays but image not sharp.