Anatomy and Physiology Overview

Study Notes

Microscopic anatomy (Histology) studies structures too small to be seen with the naked eye, including cells and tissues.
Skin, kidney, intestine, and lung are examples of microscopic anatomy.

Epigenetics, such as methylation, acetylation, and microRNAs, lead to different gene expression profiles, resulting in various types and amounts of proteins.
This diversity in proteins leads to differences in:
- Cell function
- Cytoskeleton, which provides structural support and determines cell shape
- Cell junctions and adhesion.
- Cellular memory (Differentiated cell)

Homeostasis is the maintenance of relatively stable conditions in the body's internal environment.
Maintaining homeostasis is a dynamic condition that occurs through the interplay of the body's regulatory systems, mainly the nervous system and the endocrine system.
Homeostatic control mechanisms have three components:
- Receptor: Responds to changes in the environment (stimuli), sending information to the control center.
- Control Center: Determines the set point, analyzes information, and determines the appropriate response.
- Effector: Provides a means for response to the stimulus.

Negative Feedback: Reverses a change in a controlled condition, returning the variable to its "ideal" value.
- Most homeostatic control mechanisms are negative feedback.
- Examples include regulation of body temperature, heart rate, blood pressure, breathing rate, and blood levels of glucose, oxygen, carbon dioxide, and minerals.
Positive Feedback: Strengthens or reinforces a change in the body's controlled conditions.
- Positive feedback is rare in the human body.
- Examples include blood clotting and labor contractions.

Movement: Motion of the whole body, individual organs, single cells, and even tiny structures inside cells.
Growth: An increase in body size resulting from an increase in the size of existing cells, the number of cells, or both.
Differentiation: The development of a cell from an unspecialized to a specialized state.
Reproduction: The formation of new cells for tissue growth, repair, or replacement, or the production of a new individual.