The Human Body

1. Objectives

  1. Practice anatomical terminology

  2. Identify anatomical regions of the body

  3. Understand anatomical systems

  4. Identify key anatomical features in each system


2. Anatomical Position & Planes

  • Anatomical Position:

    • Standing, face forward, arms at side, palms forward, toes forward.

Anatomical Planes

Plane

Description

Coronal (Frontal)

Divides the body into front & back halves.

Sagittal

Divides the body into right & left halves.

Transverse

Divides the body into top & bottom halves.


3. Spatial Relationships (Directional Terms)

Term

Meaning

Superior

Above (towards the head).

Inferior

Below (towards the feet).

Anterior (Ventral)

Front of the body.

Posterior (Dorsal)

Back of the body.

Medial

Towards the midline.

Lateral

Away from the midline.

Proximal

Closer to the body’s center (e.g., shoulder is proximal to hand).

Distal

Farther from the body’s center (e.g., fingers are distal to the elbow).

Superficial

Closer to the surface (e.g., skin is superficial to muscles).

Deep

Further from the surface (e.g., bones are deep to muscles).


4. Anatomical Study Approaches

  1. Anatomical Regions

    • Head & Neck

    • Thorax

    • Abdomen

    • Pelvis & Perineum (genital region)

    • Back

    • Upper Limb

    • Lower Limb

  2. Anatomical Systems

    • Integumentary

    • Gastrointestinal

    • Respiratory

    • Urinary

    • Reproductive

    • Endocrine

    • Circulatory

    • Nervous

    • Musculoskeletal


5. Integumentary System (Skin, Hair, Nails)

  • Functions:

    • Protection against microorganisms.

    • Regulates body temperature.

    • Sensory reception.

    • Produces Vitamin D.

    • Absorbs/secretes substances.

📌 Fun Fact: Your face has Demodex mites living in your pores!


6. Gastrointestinal System (Digestive System)

Organ

Function

Pharynx & Esophagus

Swallowing & food transport.

Stomach

Digestion of food with acids & enzymes.

Liver & Pancreas

Produces bile (liver) & digestive enzymes (pancreas).

Small Intestine

Nutrient absorption.

Large Intestine

Water absorption & waste processing.

Rectum & Anus

Waste storage & elimination.

Embryology

  • The digestive system starts as a simple gut tube and develops into specialized structures.


7. Respiratory System (Breathing)

Organ

Function

Pharynx & Larynx

Air passage; Adam’s apple = larynx cartilage.

Trachea & Bronchi

Conducts air to lungs.

Lungs

Gas exchange (O₂ CO₂).

Embryology

  • The lungs developed as an offshoot of the digestive tract.

  • Important in the water-to-land transition in vertebrates.


8. Urinary System (Excretion)

Organ

Function

Kidneys

Filters blood, removes waste.

Ureters

Transports urine to bladder.

Bladder

Stores urine.

Urethra

Excretes urine from the body.


9. Reproductive System

Male

Female

Testes (sperm production)

Ovaries (egg production)

Ductus deferens & Prostate (sperm transport)

Fallopian tubes & Uterus (egg transport & fertilization)

Penis & Scrotum

Clitoris & Labia

Embryology

  • Males & females start as identical structures until 6 weeks of development.

  • Male & female structures develop from the same embryonic tissues.


10. Circulatory System

Component

Function

Heart

Pumps blood.

Arteries

Carry oxygenated blood away from heart.

Veins

Carry deoxygenated blood towards the heart.

Lymphatic System

Returns interstitial fluid to circulation.

📌 Hint: Arteries "Away" from the heart.


11. Nervous System (Command Center)

Component

Function

Brain & Spinal Cord

Controls body functions.

Motor Nerves

Control movement.

Sensory Nerves

Receive sensory information.

Special Senses

Vision, hearing, taste, etc.

Brain Regions

Region

Function

Cerebrum

Higher-order thinking.

Cerebellum

Balance & coordination.

Brainstem

Basic life functions (breathing, heartbeat).


12. Musculoskeletal System

  • Muscle Types:

    • Skeletal (striated) – Movement.

    • Smooth (organs) – Involuntary functions.

    • Cardiac (heart) – Heart contractions.

  • Functions of Skeleton:

    • Provides structure & protection.

    • Stores calcium & minerals.


13. The Human Skeleton

Component

Function

Axial Skeleton

Skull, spine, ribs, sternum.

Appendicular Skeleton

Limbs, pectoral & pelvic girdles.

Bones of the Skull

  • Cranium = Skull (excluding jaw).

  • Mandible = Lower jaw.

Vertebral Column

Region

# of Vertebrae

Cervical

7 (Neck)

Thoracic

12 (Upper back)

Lumbar

5 (Lower back)

Sacrum

5 (Fused)

Coccyx

4 (Tailbone)

Dentition

  • Humans have 2 sets of teeth:

    • Deciduous (baby teeth)

    • Permanent teeth

  • Dental Formula: 2-1-2-3 (Incisors-Canines-Premolars-Molars).


14. Sex & Age Estimation in Skeletons

Feature

Male

Female

Pelvis (Most Reliable)

Narrow, deep

Wide, shallow

Skull

Brow ridge, larger jaw

Rounder forehead, smaller jaw

📌 Important: You cannot sex juvenile skeletons!


15. Bone as a Living Tissue

  • Bone adapts to stress.

  • Astronauts lose 1–2% of bone mass per month in space.


16. Summary

  • Anatomy uses standard terminology & planes.

  • The body is divided into regions & systems.

  • Bones provide structure, movement, & mineral storage.

  • Nerves & hormones regulate bodily functions.

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