Anatomy

We begin our overview with an introduction to anatomy and physiology. Anatomy, the study of structure, involves naming and identifying body parts, while physiology studies the functions of these parts. The relationship between anatomy and physiology is critical, as the structure of a body part dictates its function. For example, the small bones in our fingers, called phalanges, allow for fine motor movements, whereas the larger femur supports and enables movement.

Pathology is a field that examines structural changes leading to diseases, like cancer, where cells undergo unregulated growth.

Levels of Study

  1. Gross Anatomy: Study of structures visible to the naked eye.

    • Utilize models and dissections (not performed in this course).

  2. Microscopic Anatomy: Focus on structures small enough to require a microscope, such as cells (cytology) and tissues (histology).

  3. Developmental Anatomy: Examines structural changes throughout the lifespan, including embryology.

  4. Physiology: Can be subdivided based on the organ's specific functions, e.g., neurophysiology (brain and nervous system) and cardiovascular physiology (heart).

Levels of Structural Organization

  1. Chemical Level: Smallest unit, includes atoms and molecules.

  2. Cell Level: Where organelles combine to form cells.

  3. Tissue Level: Groups of similar cells working together.

  4. Organ Level: Different tissues forming organs.

  5. Organ System Level: Groups of organs performing related functions.

  6. Organism Level: All organ systems working together to function as a complete organism.

Emergent properties indicate that higher levels of organization can perform functions not possible at lower levels. Issues at lower levels can affect higher levels (e.g., cancer affecting tissues, organs, and systems).

Organ Systems Overview

The human body has 11 organ systems, remembered using the mnemonic "I LOVE NERD MUSIC":

  • I: Lymphatic

  • L: Lymphatic

  • O: Nervous

  • V: Endocrine

  • E: Respiratory

  • N: Reproductive

  • E: Digestive

  • R: Muscular

  • D: Urinary

  • M: Skeletal

  • U: Cardiovascular

Functions of these systems range from protection, support, transport of nutrients, and excretion of wastes.

Maintaining Life

Necessary functions to maintain life include:

  1. Boundaries: Keeping internal environments distinct from external

  2. Movement: Both body and transport of substances

  3. Responsiveness: Ability to detect stimuli

  4. Digestion: Breakdown of food for nutrient absorption

  5. Metabolism: All chemical reactions in the body, encompassing anabolism (building) and catabolism (breaking down)

  6. Excretion: Removal of waste

  7. Reproduction: Production of offspring

  8. Growth: Increase in size or number of cells.

Survival Needs

  • Nutrients: Chemicals for energy and building blocks

  • Oxygen: Required for ATP production

  • Water: Essential for metabolic reactions

  • Normal Body Temperature: Usually 98.6°F, critical for metabolic processes

  • Atmospheric Pressure: Necessary for proper gas exchange

Homeostasis

Defined as maintaining a stable internal environment despite external changes. Achieved primarily through the nervous and endocrine systems. Key components include receptors, control center (brain), and effectors (muscles or glands).

Feedback Mechanisms

  1. Negative Feedback: Body's response counteracts the stimulus (e.g., temperature regulation).

  2. Positive Feedback: Amplifies the response, typically in specific scenarios like childbirth.

Anatomical Terminology

Proper anatomical position: standing upright, feet forward, palms facing forward.
Directional terms include:

  • Superior/Inferior: Up/down

  • Anterior/Posterior: Front/back

  • Medial/Lateral: Towards/Away from midline

  • Proximal/Distal: Closer/Further from the point of attachment

  • Superficial/Deep: Closer/Further from body surface.

Regional Terms

Key regions include axial (head, neck, trunk) versus appendicular (limbs).

Body Planes

  • Frontal: Divides body into anterior and posterior sections

  • Transverse: Divides into superior and inferior sections

  • Sagittal: Divides into right and left sections

  • Oblique: Cuts at an angle

Body Cavities

  • Dorsal Cavity: Cranial (brain) and vertebral (spinal cord)

  • Ventral Cavity: Thoracic (heart/lungs) and abdominal pelvic (digestive organs).

Membrane Names

  • Visceral: On the organ

  • Parietal: On the cavity

  • Pleura: Lungs; Peritoneum: Abdominal; Pericardium: Heart.

Abdominal Regions and Quadrants

  • Quadrants: Right Upper, Left Upper, Right Lower, Left Lower

  • Regions: Epigastric, Umbilical, Hypogastric, Left and Right Hypochondriac, Left and Right Lumbar, Left and Right Iliac.

The first lecture concludes here, and for any questions, please feel free to reach out in office hours or via email.