Human Body Systems and Anatomical Terminology

Directional Terminology in Anatomy

  • Special Rule for Limb Terminology: The terms distal and proximal can only be used when describing limbs because limbs can move in all directions relative to the trunk of the body.

  • Anterior

    • Definition: In front of

    • Sentence Application: The gallbladder is anterior to the kidney.

  • Posterior

    • Definition: Behind

    • Sentence Application: The kidney is posterior to the gallbladder.

  • Inferior

    • Definition: Below

    • Sentence Application: The mouth is inferior to the nose.

  • Superior

    • Definition: Above

    • Sentence Application: The nose is superior to the mouth.

  • Medial

    • Definition: Towards the middle

    • Sentence Application: The heart is medial to the lungs.

  • Lateral

    • Definition: Towards the side

    • Sentence Application: The lungs are lateral to the heart.

  • Distal

    • Definition: Further away from the point of attachment (used only for limbs)

    • Sentence Application: The foot is distal to the knee.

  • Proximal

    • Definition: Closer to the point of attachment (used only for limbs)

    • Sentence Application: The knee is proximal to the foot.

  • Superficial

    • Definition: Closer to the surface

    • Sentence Application: The skull is superficial to the brain.

  • Deep

    • Definition: Further away from the surface

    • Sentence Application: The brain is deep to the skull.

  • Ventral

    • Definition: Closer to the belly

    • Sentence Application: The belly button is ventral to the spine.

  • Dorsal

    • Definition: Closer to the spine

    • Sentence Application: The spine is dorsal to the belly button.

Regional Terminology in Anatomy

  • Abdominal: Abdomen / stomach area

  • Antecubital: Front of elbow

  • Axillary: Armpit

  • Brachial: Arm

  • Buccal: Cheek

  • Calcaneal: Heel

  • Carpal: Wrist

  • Cephalic: Entire head (front and back)

  • Cervical: Neck

  • Coxal: Hip

  • Digital: Toes, fingers, or phalanges

  • Femoral: Thigh

  • Gluteal: Butt / buttocks

  • Inguinal: Groin / area where lower abdomen meets inner thighs

  • Lumbar: Lower back / loins

  • Nasal: Nose

  • Occipital: Base of skull / towards back of head

  • Olecranal: Back of elbow

  • Oral: Mouth

  • Orbital: Eye

  • Patellar: Anterior surface of the knee / front of knee / kneecap

  • Pelvic: Pelvis / base of trunk

  • Popliteal: Back of knees

  • Sacral: Tail bone

  • Scapular: Shoulder blade / scapula

  • Sternal: Breast bone

  • Tarsal: Ankle

  • Thoracic: Chest (front and back of chest area)

  • Umbilical: Belly button

  • Vertebral: Spine

Human Body Composition and Levels of Organization

  • Body Water Content: Water accounts for approximately 60%60\% of the total human body composition.

  • Atomic Level Elements: Primary constituent chemical elements include:

    • Oxygen

    • Hydrogen

    • Carbon

    • Calcium

    • Potassium

    • Sodium

    • Nitrogen

  • Structural Hierarchy: Atomic level components organize sequentially up to the Organ System level.

Major Human Body Systems

  • Integumentary System

    • Components: Skin

    • Functions:

    • Forms the external body covering

    • Protects tissue underneath

    • Regulates body temperature

    • Houses numerous nerve receptors

  • Skeletal System

    • Components: Cartilage and bones

    • Functions:

    • Protects and supports internal organs

    • Provides attachment points for muscles

    • Manufactures blood cells

    • Stores minerals

  • Muscular System

    • Components: Skeletal muscles

    • Functions:

    • Produces bodily movement

    • Maintains posture

    • Produces heat

  • Nervous System

    • Components: Brain, spinal cord, and nerves

    • Functions:

    • Functions as a fast-acting control system

    • Responds to internal and external changes/stimuli

    • Activates muscles and glands

  • Endocrine System

    • Components: Glands

    • Functions:

    • Secretes hormones to regulate growth, reproduction, and metabolism

  • Cardiovascular System

    • Components: Heart and blood vessels

    • Functions:

    • Transports materials throughout the body via blood pumped by the heart, including oxygen, carbon dioxide, nutrients, and wastes

  • Lymphatic System ("Immune System")

    • Components: Lymph nodes and lymph vessels

    • Functions:

    • Returns leaked fluid to blood vessels

    • Cleanses and filters the blood

  • Respiratory System

    • Components: Lungs

    • Functions:

    • Supplies oxygen to the blood

    • Removes carbon dioxide

  • Digestive System

    • Components: Stomach and intestines

    • Functions:

    • Breaks down food

    • Facilitates nutrient absorption into the blood

    • Eliminates indigestible material

  • Urinary System

    • Components: Kidneys and bladder

    • Functions:

    • Eliminates nitrogenous wastes

    • Maintains pH balance

    • Regulates water and electrolyte levels

  • Reproductive System

    • Components: Testes (Male) and Ova / Ovaries (Female)

    • Functions:

    • Produces offspring