CH1

Reviewer: The Human Organism

Anatomy:

  • Study of the structures of the body
  • Anatomy involves dissecting, cutting apart, or separating the body

Approaches to the Study of Anatomy:

  1. Systemic Anatomy: Study of the body by organ system
  2. Regional Anatomy: Study of the body by areas

General Ways to Examine the Internal Structures:

  1. Surface Anatomy: Study of external features to locate deeper structures
  2. Anatomical Imaging: Non-invasive methods such as x-ray, CT scan, PET scan, MRI to examine deep structures

Physiology:

  • Study of the processes and functions of the body
  • Main goals are to understand and predict, and to understand how the body maintains conditions

Structural and Functional Organization:

  1. Chemical Level: How atoms interact and combine into molecules
  2. Cell Level: Cells are the basic structural and functional units of organisms
  3. Tissue Level: Groups of similar cells
  4. Organ Level: Composed of two or more tissue types that perform common functions
  5. Organ System Level: Groups of organs classified as a unit with a common set of functions
  6. Organism Level: Any living thing considered as a whole

Characteristics of Life:

  1. Organization: Interrelationship among the parts of an organism and how they interact to perform specific functions
  2. Metabolism: Ability to use energy to perform vital functions
  3. Responsiveness: Ability to sense changes in the environment and make adjustments
  4. Growth: Increase in size
  5. Development: Changes an organism undergoes through time
  6. Reproduction: Formation of new cells/organisms

Homeostasis:

  • Ability to maintain relatively stable internal conditions
  • Homeostasis involves balance and equilibrium
  • Homeostatic mechanisms maintain body temperature, such as sweating and shivering

Variables:

  • Conditions that can change

Set point:

  • Ideal value

Normal range:

  • Acceptable range of values where homeostasis can still be maintained

Homeostatic Control Mechanisms:

  1. Negative-feedback Mechanism:
  • Regulates most systems of the body to maintain homeostasis
  • Any deviation from the set point is resisted
  1. Positive-feedback Mechanism:
  • Not homeostatic and is rare in a healthy individual
  • When a value deviates from normal, the system's response is to make it greater
  • Examples: massive blood loss, childbirth

Components to Maintain Homeostasis: a. Receptors b. Control center: Analyzes information and determines the appropriate response c. Effector: Provides the means to control the value of a variable

Terminology and The Body Plan: Body Positions:

  • Anatomical Position: A person standing erect with the face directed forward, upper limbs hanging to the sides, and palms facing forward
  • Supine: Lying face upward
  • Prone: Lying face downward

Inferior: Lower Superior: Higher Anterior: Front Posterior: Back Ventral: Belly Dorsal: Back Proximal: Nearest Distal: Distant Lateral: Away from the midline Medial: Towards the midline Superficial: Toward or on the surface Deep: Internal

Directional Terms:

  • Various terms for different body parts and regions

Planes:

  • Different planes used to visualize and study the body

Body Cavities:

  • Thoracic cavity: Bounded by ribs and the diaphragm
  • Mediastinum: Partition containing the heart, thymus, trachea, esophagus
  • Abdominal cavity: Bounded by the diaphragm and the abdominal muscles
  • Pelvic Cavity: Surrounded

by the pelvic bones

  • Pericardial cavity: Surrounds the heart
  • Pleural cavity: Surrounds the lungs
  • Peritoneal cavity: Surrounds certain abdominal and pelvic organs

Serous Membranes:

  • Line the trunk cavities and cover the organs
  • Visceral Serous Membrane: Covers the internal organs
  • Parietal Serous Membrane: Lines the wall of the cavity
  • Mesenteries: Hold the abdominal organs in place and provide a passageway for blood vessels and nerves to organs
  • Pericarditis: Inflammation of the pericardium
  • Pleurisy: Inflammation of the pleura
  • Peritonitis: Inflammation of the peritoneum