Introduction to Anatomy

• Anatomy is the study of the structure of living organisms.

Subdivisions of Anatomy

• Gross Anatomy (Macroscopic Anatomy): Study of structures visible to the naked eye.
  • Regional Anatomy: Focuses on specific regions of the body (e.g., the head, thorax).
  • Systemic Anatomy: Focuses on specific organ systems (e.g., the nervous system, cardiovascular system).
  • Surface Anatomy: Study of internal structures as they relate to the overlying skin.
• Microscopic Anatomy: Study of structures at the microscopic level.
  • Histology: Study of tissues.
  • Cytology: Study of cells.
• Developmental Anatomy: Study of the changes in structure from conception to adulthood.
  • Embryology: Study of development before birth.
• Comparative Anatomy: Study of the similarities and differences in the anatomy of different species.
• Clinical Anatomy: Application of anatomical knowledge to the diagnosis and treatment of disease.

Anatomical Position

• Standard reference point for anatomical descriptions.
• Body is erect, feet slightly apart, palms facing forward, thumbs point away from the body.

Anatomical Planes

• Sagittal Plane: Divides the body into right and left parts.
  • Midsagittal (Median) Plane: Sagittal plane that lies exactly in the midline.
  • Parasagittal Plane: Sagittal plane offset from the midline.
• Frontal (Coronal) Plane: Divides the body into anterior and posterior parts.
• Transverse (Horizontal) Plane: Divides the body into superior and inferior parts.
• Oblique Plane: Passes through the body at an angle between the transverse plane and either the sagittal or frontal plane.

Anatomical Directional Terms

• Superior (Cranial): Toward the head end or upper part of a structure or the body; above.
• Inferior (Caudal): Away from the head end or toward the lower part of a structure or the body; below.
• Anterior (Ventral): Toward the front of the body; in front of.
• Posterior (Dorsal): Toward the back of the body; behind.
• Medial: Toward the midline of the body; on the inner side of.
• Lateral: Away from the midline of the body; on the outer side of.
• Intermediate: Between a more medial and a more lateral structure.
• Proximal: Closer to the origin of the body part or the point of attachment of a limb to the body trunk.
• Distal: Farther from the origin of a body part or the point of attachment of a limb to the body trunk.
• Superficial (External): Toward or at the body surface.
• Deep (Internal): Away from the body surface; more internal.

Body Cavities

• Dorsal Body Cavity: Protects the fragile nervous system organs.
  • Cranial Cavity: Contains the brain.
  • Vertebral Cavity: Contains the spinal cord.
• Ventral Body Cavity: Houses the internal organs (collectively called viscera).
  • Thoracic Cavity: Surrounded by the ribs and muscles of the chest.
    • Pleural Cavities: Each enveloping a lung.
    • Mediastinum: Contains the pericardial cavity and surrounds the remaining thoracic organs (esophagus, trachea).
    • Pericardial Cavity: Encloses the heart.
  • Abdominopelvic Cavity:
    • Abdominal Cavity: Contains the stomach, intestines, spleen, liver, and other organs.
    • Pelvic Cavity: Lies in the pelvis and contains the urinary bladder, reproductive organs, and rectum.

Membranes of the Ventral Body Cavity

• Serous Membrane (Serosa): Thin, double-layered membrane that covers the walls and organs in the ventral body cavity.
  • Parietal Serosa: Lines the body cavity walls.
  • Visceral Serosa: Covers the organs in the cavity.
  • Serous Fluid: Separates the parietal and visceral serosae, allowing organs to slide without friction.
• Specific Serous Membranes:
  • Pleura: Lines the pleural cavity and covers the lungs.
  • Pericardium: Lines the pericardial cavity and covers the heart.
  • Peritoneum: Lines the abdominopelvic cavity and covers its organs.

Quadrants and Regions of the Abdominopelvic Cavity

• Quadrants: Division of the abdominopelvic cavity into four quadrants by two perpendicular planes that intersect at the umbilicus.
  • Right Upper Quadrant (RUQ)
  • Left Upper Quadrant (LUQ)
  • Right Lower Quadrant (RLQ)
  • Left Lower Quadrant (LLQ)
• Regions: Division of the abdominopelvic cavity into nine regions.
  • Right Hypochondriac Region
  • Epigastric Region
  • Left Hypochondriac Region
  • Right Lumbar Region
  • Umbilical Region
  • Left Lumbar Region
  • Right Iliac (Inguinal) Region
  • Hypogastric (Pubic) Region
  • Left Iliac (Inguinal) Region

Skeletal System

• Bones, cartilage, ligaments, and joints.
• Provides support, protection, movement, mineral storage, and blood cell formation.

Muscular System

• Skeletal muscles.
• Allows movement, maintains posture, and produces heat.

Nervous System

• Brain, spinal cord, nerves.
• Controls and coordinates bodily functions via electrical and chemical signals.

Endocrine System

• Glands that produce hormones.
• Regulates bodily functions through hormones.

Cardiovascular System

• Heart, blood vessels, blood.
• Transports oxygen, carbon dioxide, nutrients, and wastes.

Lymphatic System

• Lymph vessels, lymph nodes, lymphoid organs.
• Returns leaked fluid to the bloodstream and involved in immunity.

Respiratory System

• Lungs, trachea, bronchi.
• Exchanges oxygen and carbon dioxide.

Digestive System

• Mouth, esophagus, stomach, intestines, liver, pancreas.
• Breaks down food and absorbs nutrients.

Urinary System

• Kidneys, ureters, urinary bladder, urethra.
• Filters blood and eliminates wastes.

Reproductive System

• Male: Testes, penis, duct system.
• Female: Ovaries, uterus, vagina.
• Produces offspring.

Connective Tissue

• Connective tissue is one of the basic types of animal tissue.
• Connective tissue includes fibrous tissues, fat, cartilage, bone, bone marrow, and blood.
• Functions include:
  • Connecting and binding organs and tissues
  • Support
  • Transport
  • Immune protection

Epithelial Tissue:

• Epithelial tissue is a sheet of cells that covers a body surface or lines a body cavity.
• Functions include:
  • Protection
  • Absorption
  • Filtration
  • Excretion
  • Secretion
  • Sensory reception

Muscle Tissue

• Muscle tissue is responsible for movement.
• Types include:
  • Skeletal muscle
  • Cardiac muscle
  • Smooth muscle

Nerve Tissue

• Nerve tissue is the main tissue component of the two parts of the nervous: the brain and spinal cord of the central nervous system (CNS), and the branching peripheral nerves of the peripheral nervous system (PNS), which regulates and controls bodily functions and activity.
• Nerve tissue is composed of neurons, or nerve cells, which receive and transmit impulses, and neuroglia, also known as glial cells or simply glia (from Greek γλία 'glue'), which assist the propagation of the nerve impulse as well as provide nutrients to the neuron