Anatomy Overview and Branches

Study Notes

Anatomy is the study of the structure of the body.
The word anatomy comes from Greek, meaning "to cut up" or "to cut open."
Anatomists examine the relationships between parts of the body and the structure of individual organs.
They study the body either regionally or systematically.

Gross anatomy examines structures visible to the naked eye.
- Regional anatomy focuses on specific areas of the body, like the upper and lower limbs, thorax, abdomen, pelvis, and head and neck.
- Systemic anatomy studies the body's organ systems, examining their structure, function, and interrelationships.
  - The three main groups of bodily systems are Somatic (voluntary), Visceral (involuntary), and Operative (Regulatory).
Surface anatomy studies external body features and landmarks.
Developmental anatomy or Embryology studies organism development from embryo to adult.
Microscopic anatomy or Histology studies human and animal tissues and cells at the microscopic level, examining their structure, organization, and function.
Radiological anatomy studies human anatomy using medical imaging technologies.
Comparative anatomy compares anatomical similarities and differences across species to infer evolutionary relationships and adaptations.

Chemical level: The simplest level, composed of atoms and molecules.
- Atoms are the smallest units of matter.
- Molecules are formed when two or more atoms combine, like proteins, water molecules, and vitamins.
- Macromolecules are larger and more complex molecules, including DNA and proteins.
Cellular level: Specialized structural and functional units called organelles allow living cells to share some fundamental functions.
- Cells are the basic units of structure and function within organisms.
- The cell is the smallest living portion of the human body.
Tissues and Organs Levels:
- Tissues are precise organizations of similar cells that perform specific functions.
- Organs are made up of different tissue types that work together to perform complex functions.
Organ-system and Organism levels:
- The organ-system level comprises related organs that work together to coordinate activities and achieve a common function.
- There are 11 organ systems in the human body (CLIMED-R-RUNS).
  - Circulatory (Cardiovascular)
  - Lymphatic (Immune)
  - Integumentary (Skin)
  - Muscular
  - Endocrine
  - Digestive
  - Respiratory
  - Renal (Urinary)
  - Nervous
  - Skeletal
  - Reproductive
- All body systems function interdependently within a single living individual, the organism.

The Four Types of Tissues in the Human Body Are:
- Epithelial tissue covers exposed surfaces and lines body cavities, like the inner lining of the digestive system.
- Connective tissue protects, supports, and interconnects body parts and organs. It can be solid (bone), liquid (blood), or intermediate (cartilage).
- Muscle tissue produces movement. Examples include skeletal muscle, smooth muscle, and cardiac muscle.
- Nervous tissue conducts impulses for internal communication. Examples include the brain, spinal cord, and nerves.

The anatomical position is a standardized starting point for describing body parts and regions, allowing for consistent communication.
In this position:
- The individual stands upright.
- Feet are parallel and flat on the floor.
- Head is level.
- Eyes look forward.
- Arms are at the sides with palms facing forward and thumbs pointing away from the body.

A plane is an imaginary surface that slices the body into specific sections.
The three major anatomical planes of reference are:
- Coronal plane (frontal plane): A vertical plane that divides the body into anterior (front) and posterior (back) parts.
- Transverse plane (cross-sectional plane or horizontal plane): Divides the body into superior (upper) and inferior (lower) parts.
- Sagittal plane or median plane: Divides the body into right and left halves.
  - A sagittal plane in the body midline is a midsagittal plane.