Anatomy and Physiology Overview

Anatomy and Physiology Overview

• Anatomy studies the structure of the body, how parts are organized and their relationships.
• Physiology studies the function of the body, how parts work together.
• Homeostasis is the body's ability to maintain a stable internal environment.
• Negative feedback loops counteract changes from set points, maintaining homeostasis.
• Positive feedback loops amplify changes to achieve specific outcomes.
• Receptors monitor changes, control centers process information and effectors produce the response.

Levels of Organization

• Chemical level: atoms combine to form molecules.
• Cellular level: smallest units of living things; cells made up of molecules.
• Tissue level: similar cells forming a tissue.
• Organ level: tissues combine to form organs.
• Organ system level: groups of organs working together.
• Organismal level: the whole organism formed by functioning organ systems.

Human Anatomy: Areas of Specialization

• Gross anatomy: study of large body structures (macroscopic anatomy).
  • Surface anatomy: external features.
  • Regional anatomy: body sections.
  • Systemic anatomy: relationship of the body's structures (cross sections and other body regions/sections).
  • Clinical anatomy: applies to clinical practices (pathological anatomy, radiographic anatomy, surgical anatomy)
• Microscopic anatomy: deals with structures too small to see unaided (cytology, histology, molecular anatomy).
  • Cytology: study of cells.
  • Histology: study of tissues.
  • Molecular anatomy: examines cells components (molecular biology).
• Systemic physiology: the functions of specific organ systems (cardiovascular, reproductive, etc.).
• Pathological physiology: effects of disease on organ or system functions.

Organ Systems

• Every organ system works with different other organ systems to maintain homeostasis.
• Imbalances in organ systems can lead to diseases.

Homeostasis Control System

• Control center determines level to maintain variable.
• Effector provides means for control center's response to the stimulus.
• Receptors detect changes in a variable, send input to control center which processes the information and sends output instructions for the effector to carry out the necessary response which serves to return variable to homeostasis.

Anatomical Terminology

• Directional terms: describe the position of one body part relative to another (e.g., superior/inferior, anterior/posterior, medial/lateral).
• Regional terms: specific body areas (e.g., thoracic, abdominal, pelvic).

Body Cavities

• Dorsal cavity (cranial and spinal cavities).
• Ventral cavity (thoracic and abdominopelvic cavities).
  • Mediastinum: space between the lungs, containing the heart, esophagus, trachea, and major blood vessels.
  • Thoracic cavity: bordered by the rib cage, contains the pericardial cavity and pleural cavities (lungs).
  • Abdominopelvic cavity: contains the digestive organs and other organs, kidneys, stomach, etc.

Anatomical Planes

• Sagittal plane: divides the body into right and left portions.
• Midsagittal plane: divides the body into equal left and right halves.
• Coronal (frontal) plane: divides the body into anterior and posterior portions.
• Transverse (horizontal, axial) plane: divides the body into superior and inferior portions.
• Oblique plane: passes through the body at an angle.

Imaging Techniques

• X-rays: high energy radiation passing through living tissues (radiopaque tissues and bones show up as white).
• CT scans: combines multiple 2D X-ray images to create a 3D image; useful for diagnosing injuries and locating tumors, and identifying tissues or structures of similar density as an issue.
• MRI scans: powerful magnets and radio waves to create detailed images of soft tissues; helps examine soft tissues, joints, and ligaments more efficiently; useful for evaluating spinal issues and ligaments.
• PET scans: radioactive tracer highlights metabolic activity in tissues; useful for early cancer, heart disease, and brain condition detection.

Anatomical Landmarks and Regions

• Landmarks are specific points or locations to help identify areas or structures of the human body.
• Regions within the various body cavities include sections such as hypochondriac, lumbar, iliac, etc.