Anatomy & Physiology Chapter 1 - 3

Study of structure (shape of the body and its parts)

Study of function (how the body and its parts work or function)

Structure determines function

Study of structural changes that lead to disease

Chemicals -> organelles -> cells -> tissues -> organs -> organ system -> organism

Ability to sense changes (stimuli) and respond to them [Nervous, Endocrine]

All chemical reactions within the body (building things up and breaking them down)

Breaks things down (produces energy)

Builds things up (makes body structures)

• Produce energy
• 60-80% of body weight
• Involved in metabolic reactions

• Maintaining a stable internal environment withing narrow limits, regardless of environmental changes.
• Must be maintained for normal body functioning and to sustain life
• Maintaining Homeostasis
• Feedback Mechanisms
• Homeostatic Imbalance

• Body communicates through nerual & hormonal control system
• 1. Receptor
• 2. Control Center
• 3. Effector (muscles or glands)

• Negative Feedback (moving back to the set point)
• Positive Feedback (pushes away from the set point)

• Has an amplifying effect that increases the original stimulus to push the variable further away from the set point
• Only normal occurrences are in blood clotting, birth of a baby, and sexual response.
• i. Others are result of pathology and are harmful
• a. ex: heart attack due to restricted blood flow to the heart eventually results in less cardiac output which again decreases blood flow.

• A disturbance in homeostasis resulting in disease
• May be cause by infection injury or genetic abnormality

• A special terminology is used to prevent misunderstanding
• Orientation and Directional Terms
• Regional Terms
• Body planes and sections
• Body cavities and membranes
• Abdominal regions and quadrants

• 1. Position
• 2. Direction
• 3. Regions
• 4. Structures

• 1. Proper anatomical position
• 2. Directional Terms
• 3. Regional Terms

A point of reference

• Superior [above]/ Inferior [below]
• Anterior (ventral) [front]/ Posterior (dorsal) [behind]
• Medial [inner side]/ Lateral [outer side]
• Proximal [closer]/ Distal [Far]
• Superficial (external)/ Deep (internal)

• a. Axial
•      i. Head
•      ii. Neck
•      iii. Trunch
• b. Thorax, abdomen, pelvis
• c. Appendicular (Relating to the limbs; one of the two major divisions of the body)
• d. Specific body areas

• 1. Frontal (coronal)
• 2. Transverse (cross sections) [superior and inferior parts]
• 3. Median or Midsagittal [lies in the midline]
• 4. Sagittal [A longitudianal (vertical) plane that divides the body or any of its parts into right and left portions]
• 5. Oblique [A cut made diagonally between the horizontal and vertical (front) plane of the body or an organ]

• 1. Dorsal Cavity
• 2. Ventral Cavity
• 3. Other body cavities

Composed of the cranial and vertebral (spinal) cavities

• a. Contains visceral organs
• b. Composed of the thoracic, mediastinum (pericardial), and abdominoperlvic cavities
• c. Membranes

• Line the cavities and cover outside of organs
• Named by lining location + cavity word
• Thoracic cavity lined by parietal+pleura= parietal pleura
• Thoracic organs covered by visceral pleura
• Abdominopelvic cavity line by parietal peritoneum
• Abdominopelvic organs covered by visceral peritoneum
• Pericardial cavity lined by parietal pericardium
• Peridardial organ (heart) covered by visceral pericardium

Oral and digestive, nasal, orbital, middle ear, synovial etc.

• 1. 9 regions (specific anatomical areas)
• 2. 4 quadrants (common clinical use)

• Anything that occupies space and has mass (weight)
• Composition of matter

• 1. i.e. The physical (living and non-living) "stuff" of the universe
• 2. Can exist as a solid, liquid, or gas
• 3. Weight (mass)
•  a. We quantify the amount of a substance by its mass. Under the influence of gravity on the earth's surface, mass is equal to the more familiar term "weight".

• 1. Elements
• 2. Atoms

• a. Fundamental units of matter
•   i. They cannot be broken down into other substances
• b. 96% of life is made up of 4 elements
•   i. H, O, N, C

• a. Building blocks of elements
• b. Atomic structure
•  i. Nucleus
•    a. Protons (p+)
•    b. Neutrons (n0)
•  ii. Outside of nucleus
•    a. Electrons (e-)

• Elements differ in the number of subatomic particles in their atoms
• 1. Chemical Symbol
• 2. Atomic Number
• 3. Mass Number/Atomic Mass
• 4. Isotopes

Number of p+s that the atom contains

Protons + Neutrons

• a. Same number of p+s and e-s
• b. Vary in number of neutrons
• c. Radioisotope
• d. Radioactivity

• Heavy isotope
• Tends to be unstable
• Decomposes to more stable isotope

• i. Process of spontaneous atomic decay
• ii. As some isotopes adjust to a more stable form, they will emit a measurable energy. Thy energy release is called "radiation".
• iii. We can make use of radioactive isotopes in medicine (low level radiation) 
•  a. Remember the organization of the human body: chemical, cell, tissue, organ, organ system etc.
•  b. Normally cells (epithelial tissue) in the thyroid gland (organ) take up the element iodine (I) from your diet to make a thyroid hormone. If we want to check the activity of your thyroid gland we can feed you radioactive iodine. As your thyroid cells take up the radioactive iodine, energy emitted from your thyroid gland is captured by a machine (scanned) and used to make an image (picture) of your gland. We may see cancer tumors, an under active, overactive or normal gland. This procedure is often called a "thyroid scan".