Anatomy

### 1. Definitions

* Anatomy → Study of structure (e.g., bones, organs).

* Physiology → Study of function (e.g., how the heart pumps blood).

### 2. Life Functions

* Necessary life functions: maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth.

* Survival needs: nutrients, oxygen, water, normal body temperature, atmospheric pressure.

### 3. Metabolism

* Definition: All chemical reactions within the body.

Includes *catabolism** (breaking down) + anabolism (building up).

### 4. Levels of Organization

* Chemical → Cellular → Tissue → Organ → Organ System → Organism.

(Example: atoms → heart cell → cardiac tissue → heart → circulatory system → human.)

### 5. Anatomical Position

* Standing, facing forward, arms at sides, palms facing forward, feet slightly apart.

### 6. Axial vs. Appendicular Skeleton

* Axial: skull, vertebral column, thoracic cage.

* Appendicular: limbs and girdles (arms, legs, pelvis, shoulders).

### 7. Directional Terms

* Superior/Inferior → above/below.

* Ventral/Dorsal → front/back.

* Posterior/Anterior → back/front.

* Lateral/Medial → side/center.

* Distal/Proximal → farther/closer to attachment.

* Deep/Superficial → inside/surface.

### 8. Body Planes

* Median (Sagittal) → left/right halves.

* Frontal (Coronal) → front/back halves.

* Transverse (Horizontal) → top/bottom halves.

### 9. Body Cavities & Organs

* Cranial → brain.

* Vertebral → spinal cord.

* Ventral → thoracic + abdominopelvic cavities.

* Thoracic → lungs, heart.

* Pleural → lungs.

* Pericardial → heart.

* Abdominal → stomach, liver, intestines.

* Pelvic → bladder, reproductive organs.

### 10. Serous Membranes

* Visceral → covers organs directly.

* Parietal → lines cavity walls.

### 11. Body Regions

* (e.g., epigastric, umbilical, hypogastric, etc.—identify on diagrams).

### 12. Homeostatic Control Mechanisms

Components: *stimulus → receptor → control center → effector → response.**

* Negative feedback: reverses change (ex: body temperature).

* Positive feedback: amplifies change (ex: childbirth contractions).

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🔹 Part 2: Cytology

1. Definition

* Cytology → the study of cells, their structure, and function.

2. Organelles

* Nucleus: control center; contains DNA.

* Mitochondria: powerhouse; produces ATP.

* Vesicles: transport/storage sacs; move materials in/out of cells.

3. Movement Across Membranes

* Diffusion → movement of molecules from high to low concentration.

* Facilitated Diffusion → diffusion with help of transport proteins.

* Osmosis → diffusion of water across a semipermeable membrane.

* Endocytosis → taking substances into the cell (phagocytosis, pinocytosis).

* Exocytosis → releasing substances outside the cell.

4. Solutions and Osmosis

* Isotonic: equal solute concentrations (no net water movement).

* Hypertonic: higher solute outside → water leaves cell (shrinks).

* Hypotonic: lower solute outside → water enters cell (swells).

* Disruption: extreme imbalance = cell lysis (burst) or crenation (shrink).

5. Cell Cycle

* Interphase: growth, DNA replication (G1, S, G2).

* Mitosis: division of nucleus (PMAT: prophase, metaphase, anaphase, telophase).

* Cytokinesis: cytoplasm divides → two daughter cells.

6. Mitosis vs. Meiosis

* Mitosis: produces 2 identical diploid cells (growth/repair).

* Meiosis: produces 4 non-identical haploid cells (gametes, sexual reproduction).