Introduction to Anatomy

Introduction to Anatomy

• Anatomy is the study of the structures of the body.
• Different levels of organization range from chemical level to the organismal level.
• Atoms combine to form molecules.
• Molecules combine to form organelles.
• Organelles combine to form cells.
• Similar cells working together form tissues.
• Different tissues working together form organs.
• Different organs working together form organ systems.
• All organ systems working together form the organism or whole body.

Levels of Organization

• Chemical level (atoms, molecules, DNA)
• Cellular level (cells, organelles)
• Tissue level (epithelial, connective, muscle, nervous tissues)
• Organ level (e.g., heart, stomach)
• System level (cardiovascular, digestive)
• Organismal level (human body)

Systems

• Integumentary System:

  • Protection from external environment
  • Produces vitamin D
  • Retains water
  • Regulates body temperature
  • Examples include skin, hair,nails.

• Skeletal System:

  • Supports the body
  • Protects organs
  • Provides leverage for movement (biomechanics)
  • Produces blood cells
  • Stores calcium salts
  • Examples include bones and joints.

• Muscular System:

  • Movement
  • Controls body openings
  • Generates heat
  • Skeletal muscle helps with movement with bones
  • Smooth muscle helps move things through the body
  • Cardiac muscle helps with heart function
  • Examples include skeletal, smooth, and cardiac muscles.

• Nervous System:

  • Regulates many functions, including sensation, movement and higher mental functions
  • Central nervous system (brain, spinal cord)
  • Examples include brain, nerves , spinal cord and sensory organs.

• Endocrine System:

  • Regulates hormones
  • Regulate nutrient levels, iron levels, and emotional/behavioral activity
  • Examples include pineal , pituitary glands, thyroid, thymus, adrenal glands, pancreas, ovaries and testes .

• Cardiovascular System:

  • Protection: carries immune cells
  • Transport: nutrients, ions, wastes, hormones, proteins, O2, CO2
  • Temperature regulation: can dump heat to skin.
  • Water balance
  • Heart as a pump, blood is mostly water (H2O)
  • Examples include blood vessels and heart.

• Lymphatic System:

  • Protection: lots of immune cells
  • Helps maintain water balance
  • Helps absorb fats (fats absorbed via lacteals
  • Examples include lymph nodes, thymus, spleen.

• Respiratory System:

  • Delivers oxygen to blood
  • Removes CO2 from body
  • Maintains acid-base balance of blood
  • Examples include lungs, trachea, larynx.

• Digestive System:

  • Digests food
  • Absorbs nutrients into the blood
  • Removes food waste
  • Regulates fluid, electrolyte, acid-base balance
  • Examples include mouth, stomach, intestines, liver, etc.

• Urinary System:

  • Removes metabolic waste from the blood
  • Regulates fluid, electrolyte, and acid-base homeostasis.
  • Stimulates blood cell production
  • Examples include kidneys, ureters, bladder and urethra.

• Reproductive System:

  • Produces gametes
  • Transports gametes
  • Nourishes and protects developing offspring
  • Examples include gonads, ducts, and external genitalia

Homeostasis

• The maintenance of a stable internal environment.
• Homeostatic imbalances lead to disease or death.
• Regulatory mechanisms and feedback loops are constantly active in the body.

Directional Terms

• Terms to describe location of body structures relative to one another or to a specific reference point. -Example: anterior, posterior; superior, inferior; medial, lateral

Anatomical Planes

• Sagittal: Dividing the body into left and right sections (midsagittal, parasagittal)
• Frontal (coronal): Dividing the body into front and back sections.
• Transverse (horizontal): Dividing the body into top and bottom sections
• Oblique: Dividing the body at an angle.

Body Cavities

• Dorsal (posterior): Cranial (brain) and vertebral (spinal cord) cavities.
• Ventral (anterior): Thoracic and abdominopelvic cavities, further subdivided into specific compartments.

Membranes

• Serous membranes : line body cavities and cover organs