Anatomy is the scientific discipline that describes structures of the human body, including:
Shape
Size
Composition
Location
Relationships between structures
The term comes from Greek:
ana = up
tome = cutting
→ “cutting up” the body (dissection).
🔑 Fundamental Principle: Structure Determines Function
This is the first and most important concept in anatomy and physiology.
Examples:
Bone: Mineralised matrix → rigidity → protection + support.
Red blood cells: Biconcave shape → ↑ surface area → efficient gas exchange.
Neurons: Long axons → rapid communication over distance.
Heart valves: Thin cusps + connective tissue → allow unidirectional blood flow.
Understanding structure–function relationships makes anatomy predictable.
2. Branches and Levels of Anatomical
Study
A. Gross Anatomy (Macroscopic Anatomy)
Structures visible to the naked eye.
Approaches:
1. Systemic Anatomy
o Study of the body by systems.
o Examples:
Skeletal system
Muscular system
Nervous system
, Cardiovascular system
Respiratory system
2. Regional Anatomy
o Study of the body by regions.
o Examples:
Head and neck
Thorax
Abdomen
Pelvis
Upper limb / lower limb
o Useful in surgery and physical examination.
Additional gross anatomy divisions:
Surface anatomy — using landmarks to project internal structures (e.g., ribs, pulse
points).
Clinical anatomy — applying anatomy to diagnosis and treatment.
B. Microscopic Anatomy
Requires magnification to study structures too small for the naked eye.
1. Cytology
Study of cells:
Cell membrane
Organelles (nucleus, mitochondria, ER, etc.)
Specialised cell types: neurons, myocytes, erythrocytes
2. Histology
Study of tissues:
There are four primary tissue types:
1. Epithelial tissue
o Lines organs and surfaces, forms glands
o Functions: protection, absorption, secretion
2. Connective tissue
o Bone, blood, cartilage, fat
o Functions: support, transport, insulation
3. Muscle tissue
o Skeletal, cardiac, smooth
o Function: movement
4. Nervous tissue
o Neurons + glial cells
o Function: communication and control