(Ch1) Introductory Anatomy and Physiology (copy)

The upcoming schedule involves studying the biology of the cell next week, which consists of four parts. This Sunday, students have one chapter to complete.
Essential Preparation: Students must print the chapter outline for every class. This outline is critical for guidance through the material and should be filled out during lectures.
Vocabulary Management: The course contains extensive vocabulary. It is recommended to keep a separate piece of paper specifically for new words. If a term is unknown, it should be recorded, defined later, and maintained in a running list. Familiar terms do not need to be recorded.

Anatomy: Defined as "form and structure." It is considered the unchanging part of the study; for example, the head and ankles do not move positions. Anatomy is primarily the memorization of where structures are located.
Physiology: Defined as "function." This is the more difficult aspect of the course because it deals with how structures work and interact within the body. Physiology requires understanding dependencies between systems.
Interdependence Example: The cardiovascular system contains blood, but it is not an "island." Its function depends entirely on the respiratory system and the urinary system (which regulates ions in the blood). Understanding physiology requires putting all these interlocking pieces together.

Microscopic Anatomy: Requires a microscope to see structures.
- Histology: The study of tissues.
- Cytology: The study of cells.
Gross Anatomy (Macroscopic Anatomy): The investigation of structures visible to the naked eye. This involves dissection and the examination of organs like the heart, lungs, and kidneys.
Systemic Anatomy: The study of specific organ systems (e.g., circulatory, respiratory, urinary, digestive).
Regional Anatomy: The examination of specific body regions:
- Cephalic: Head region.
- Thoracic: Chest region.
- Dorsal: Back region.
Surface Anatomy: The study of superficial markings, including markings on bones, lines, folds, fossa, and breasts.
Comparative Anatomy: The study of differences between species (e.g., comparing a dog to a human). This is typically the focus of veterinary courses.
Embryology: The study of developmental changes from the point where sperm meets egg through birth.
Specialized Focuses:
- Pathological Anatomy: Focuses on pathogens (bacteria, viruses, parasites, and fungi) that cause disease.
- Radiographic Anatomy: Uses machines for diagnostics and research, such as $\text{MRI}$ , $\text{CT}$ scans, and $\text{X-rays}$ to visualize features (e.g., a healthy liver vs. a liver with cirrhosis).

Cardiovascular Physiology: Specific to the heart, blood vessels, and blood.
Neurophysiology: Specific to the nerves and the nervous system.
Respiratory Physiology: Focuses on breathing functions.
Reproductive Physiology: Focuses on male and female portions and how they come together.
Pathophysiology: Focuses on how disease affects body systems.

The central principle is that form follows function and function follows form. Both disciplines are interdependent; one cannot understand function without anatomical knowledge.
Biological Shape: The heart is shaped specifically to do its job. If it were a square, it would not work correctly.
Mechanical Metaphor: Trying to drive a nail with a toothpick will not work because a toothpick is not a hammer. Similarly, anatomical structures like the humerus and femur are shaped specifically for their roles.
Textbook Resource: The textbook contains "summary figures" that condense 10-15 minutes of lecture into one picture. Understanding these figures is equivalent to understanding the lecture material.

To be considered alive, an organism must meet specific biological criteria:
- Organization: All living things are organized (e.g., brains are located in heads, not in buttocks, in organisms ranging from humans to earthworms).
- Metabolism: The process of breaking things down (catabolism) and building things up (anabolism).
- Growth and Development: This is a biological requirement. If an organism is not growing or developing, there is a biological issue.
- Responsiveness: The ability to respond to stimuli. Stimuli can be external (e.g., being stuck with a pen) or internal (e.g., dropping blood sugar levels).
- Regulation: The maintenance of internal conditions (e.g., staying warm or cool).
- Reproduction: The ability to make offspring.
The Five-Criteria Rule for Life: There are five specific things that decide if a thing is alive. If one is missing, it is not alive. For example, viruses are not considered alive because they do not meet all criteria.

Definition: Homeostasis is the body’s ability to respond to both internal and external stimuli and maintain acceptable limits. Failure to maintain homeostasis results in illness or death.
Components of a Homeostatic Feedback Loop:
1. Receptor (Receiver): Perceives the problem or change. It detects a stimulus.
2. Control Center (Interpreter): Resides in the brain. It interprets the message and decides on a response.
3. Effector (Fixer): Addresses the issue and brings about change.
Negative Feedback Loops:
- Definition: Makes the stimulus go away by negating it.
- Example: A thermostat set to $72^{\circ}$ . If temperature rises to $74^{\circ}$ , the $AC$ kicks on. Once it returns to $72^{\circ}$ , it shuts off.
- Physiological Examples: Blood sugar regulation (insulin/glucagon), heart rate, blood pressure, breathing rate, and parathyroid response to decreased calcium.
Positive Feedback Loops:
- Definition: Makes the stimulus worse so that the body can eventually feel better.
- Example: Vomiting (getting sicker until the bad food is expelled).
- Example: Childbirth/Labor (contractions become increasingly intense until the baby is born).
- Example: Breastfeeding (triggered by internal stimuli like full breasts or external stimuli like a baby crying). Lactation is a unique positive feedback loop.
- Example: Blood Clotting ( $Vitamin K$ , $Prothrombin$ , $Fibrin$ ). Blood must gush to release these factors to plug a hole.