Introduction to Anatomy and Physiology (A&P)

Overview

• Anatomy: Study of body structures.
• Physiology: Study of body functions.
• Relevance: Important for careers in medical fields such as nursing, physical therapy, physician assistant (PA) school, etc.

Characteristics of Living Organisms

• Ability to respond to the environment
• Growth and development
• Reproduction
• Movement and adaptability
• Composed of one or more cells

Levels of Organization

1. Organ Systems: e.g., cardiovascular, digestive, respiratory systems
2. Organs: Comprised of different tissue types
3. Tissues: Made up of cells
4. Cells: Contain organelles like mitochondria, endoplasmic reticulum, etc.
5. Molecules: Composed of atoms (e.g., water molecule H2O)

Types of Anatomy

• Systemic Anatomy: Study of organ systems
• Regional Anatomy: Study of specific regions of the body
• Surface Anatomy: Study of surface markings, often on bones
• Gross Anatomy: Structures visible without a microscope
• Microscopic Anatomy: Study of cells and tissues (histology and cytology)

Anatomical Position

• Standing upright
• Feet shoulder-width apart
• Head and palms facing forward
• Arms at sides

Body Cavities

• Dorsal Body Cavities (Posterior)
  • Cranial cavity: Contains the brain
  • Vertebral (spinal) cavity: Contains the spinal cord
• Ventral Body Cavities (Anterior)
  • Thoracic cavity: Contains heart and lungs
  • Abdominopelvic cavity: Contains digestive organs and reproductive structures

Thoracic Cavity Details

• Pleural Cavities: House the lungs
• Pericardial Cavity: Contains the heart
• Mediastinum: Contains the heart, trachea, esophagus

Abdominopelvic Cavity

• Abdominal Cavity: Digestive organs (stomach, liver, etc.)
• Pelvic Cavity: Urinary and reproductive organs
• Peritoneal Cavity: Sub-cavity of the abdominal cavity

Serous Membranes

• Reduce friction between moving organs and cavity walls
• Components:
  • Parietal Membrane: Lines the cavity
  • Visceral Membrane: Touches the organ
  • Serous Fluid: Lubricant

Homeostasis

• Maintenance of stable internal conditions
• Negative Feedback: Regulates around a set point (e.g., body temperature, blood sugar)
• Positive Feedback: Amplifies response (e.g., childbirth, blood clotting)

Feedback Mechanisms

• Negative Feedback: E.g., thermostat regulation of body temperature, insulin regulation of blood sugar
• Positive Feedback: E.g., oxytocin in childbirth, blood clotting processes

Gradients

• Difference in concentration, pressure, or temperature between two areas
• Important for processes like diffusion

Cell Communication

• Essential for triggering feedback loops and coordinating functions
• Involves receptors and chemical signals (neurotransmitters)
• Critical for muscle contraction and nerve cell communication

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Additional information can be found in the textbook on the specified pages for further reading.