Anatomy Basics Quiz

Anatomy

• Definition: The study of the structure of living organisms and the relationships between those structures.
• Types:
  • Gross anatomy: Study of structures visible to the naked eye.
  • Surface anatomy: Study of the form and markings of the body surface.
  • Histology: Microscopic study of tissues.

Anatomical Position

• Description: Subject stands erect facing the observer, upper extremities at the sides, palms forward.

Directional Terms

• Superior: Toward the head or upper part of a structure.
• Inferior: Away from the head or toward the lower part of a structure.
• Anterior: Nearer to or at the front of the body.
• Posterior: Nearer to or at the back of the body.
• Medial: Nearer to the midline of the body or a structure.
• Lateral: Farther from the midline of the body or a structure.
• Intermediate: Between two structures.
• Ipsilateral: On the same side of the body.
• Contralateral: On the opposite side of the body.
• Proximal: Nearer to the attachment of an extremity to the trunk or a structure.
• Distal: Farther from the attachment of an extremity to the trunk or a structure.
• Superficial: Toward or on the surface of the body.
• Deep: Away from the surface of the body.
• Parietal: Pertaining to or forming the outer wall of a body cavity.
• Visceral: Pertaining to the covering of an organ.

Body Planes and Sections

• Sagittal Section: A cut made along the longitudinal plane of the body, dividing it into right and left halves.
  • Midsagittal or Median Section: A sagittal section where the halves are equal in size.
• Frontal Section: A cut made along the longitudinal plane of the body, dividing it into anterior and posterior parts. Also known as a coronal section.
• Transverse Section: A cut made along a horizontal plane of the body, dividing it into superior and inferior parts. Also known as a cross section.

Body Cavities & Membranes

• Dorsal Body Cavity:

  • Cranial Cavity: Encloses the brain and is within the cranium.
  • Vertebral Canal: Encloses the spinal cord and is within the vertebral column.
  • Meninges: The 3 membranes lining the dorsal body cavity.

• Ventral Body Cavity:

  • Thoracic Cavity: Contains the lungs and heart, separated from the abdominopelvic cavity by the diaphragm.
  • Abdominopelvic Cavity: Contains the abdominal and pelvic organs.
  • Serous Membranes: Line the cavities and cover the viscera, holding them in place. Examples include the pleura, peritoneum.

Physiology

• Definition: The science of the functional mechanisms of living organisms.
• Examples:
  • Processes that maintain the identity of a living body during exchange with its surroundings.
  • How information is received from the surroundings and how the organism reacts to influence its environment.

Hierarchy of Complexity

• Levels:
  • Chemical: The most basic level, involves atoms and molecules.
  • Cellular: The basic structural and functional unit of a living organism.
  • Tissue: A group of similar cells working together to perform a specific function.
  • Organ: Structures composed of two or more tissue types working together for a specific function.
  • Organ System: A group of organs with a unique collective function.
  • Organism: A living being composed of multiple organ systems working in coordination.

Organ Systems

• Integumentary System: Skin, hair, nails, cutaneous glands.
• Skeletal System: Bones, cartilage, ligaments.
• Muscular System: Skeletal muscles.
• Nervous System: Brain, spinal cord, nerves, ganglia.
• Endocrine System: Glands, hormones.
• Reproductive System: Gonads, ducts, accessory glands, external genitalia.
• Circulatory System: Heart, blood vessels.
• Lymphatic System: Lymph nodes, lymphatic vessels, thymus, spleen, tonsils.
• Respiratory System: Nose, pharynx, larynx, trachea, bronchi, lungs.
• Urinary System: Kidneys, ureters, bladder, urethra.
• Digestive System: Teeth, tongue, salivary glands, esophagus, stomach, small & large intestine, liver, gallbladder, pancreas.

Life Processes

1. Metabolism: Sum of chemical reactions in the body.
   • Anabolism: Building up body structures using energy.
   • Catabolism: Breaking down substances to provide energy.
2. Excitability: Ability to sense changes and respond beneficially.
3. Conductivity: Ability to carry the effect of a stimulus from one part of a cell to another.
4. Contractility: Capacity of cells to shorten and change shape.
5. Growth: Increase in cell size and numbers.
6. Differentiation: Unspecialized cells becoming specialized with a specific structure and function.
7. Reproduction: Formation of new cells or individuals.

Homeostasis

• Definition: Maintenance of constant conditions in the body's internal environment.
• Importance: Cells can only live, grow, and function if proper concentrations of substances (oxygen, glucose, ions, fatty substances) are maintained.
• Organ Roles: All organs contribute to homeostasis. For example, lungs provide oxygen, kidneys maintain ion balance, gastrointestinal tract provides nutrients.

Control Systems

• Feedback Systems: Information is continually reported (fed back) to a control center that responds in a positive or negative way.
• Negative Feedback:
  • Reverses the direction of the initial condition.
  • Example: Nervous control of blood pressure.
  • Pressure-sensitive cells in arteries detect increased blood pressure, send information to the brain.
  • Brain signals heart to beat slower and arterioles to dilate, decreasing blood pressure until it reaches its normal level.
• Positive Feedback:
  • Amplifies the initial condition.
  • Often leads to instability and death.
  • Example: Blood clotting, childbirth.
• Predominance of Negative Feedback: Nearly all body control systems operate by negative rather than positive feedback. This is crucial for maintaining stability.