Introduction to Anatomy and Physiology

Introduction to Anatomy and Physiology

• Anatomy describes the structures of the body, including its composition (what it's made of), location, and associations/organization with other structures.
• Physiology studies the functions of anatomical structures both individually and as a group (cooperatively), including how specific organs operate at the molecular and cellular levels.
• Anatomy and physiology are intimately related; all physiological functions are performed by specific anatomical structures.
• The principle of complementarity states that structure and function are complementary. A structure's function is determined by its specific form.

Anatomical Positions and Directional Terms

• The standard anatomical position is a universally accepted reference point for describing the human body. In this position, the body is standing upright, with the face and feet pointed forward, and the arms hanging at the sides with palms facing forward.
• Superior (cranial/cephalad): Toward the head end or upper part.
• Inferior (caudal): Away from the head end or toward the lower part.
• Anterior (ventral): Toward or at the front of the body.
• Posterior (dorsal): Toward or at the backside of the body.
• Medial: Toward or at the midline of the body (inner side).
• Lateral: Away from the midline of the body (outer side).
• Proximal: Close to the origin of a 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: Toward or at the body surface.
• Deep: Away from the body surface; more internal.
• Intermediate: Between a more medial and a more lateral structure.

Regional Terms

• Anterior Body Landmarks:
  • Abdominal (below ribs)
  • Acromial (point of shoulder)
  • Antecubital (anterior elbow surface)
  • Axillary (armpit)
  • Brachial (arm)
  • Buccal (cheek area)
  • Carpal (wrist)
  • Cervical (neck)
  • Coxal (hip)
  • Crural (leg)
  • Digital (fingers/toes)
  • Femoral (thigh)
  • Fibular (lateral leg)
  • Inguinal (groin)
  • Nasal (nose area)
  • Oral (mouth area)
  • Orbital (eye area)
  • Patellar (anterior knee)
  • Pelvic (overlying pelvis)
  • Pubic (genital region)
  • Sternal (breastbone area)
  • Tarsal (ankle)
  • Thoracic (chest)
  • Umbilical (navel)
• Posterior Body Landmarks:
  • Cephalic (head)
  • Deltoid (shoulder curve)
  • Gluteal (buttock)
  • Lumbar (back between ribs and hips)
  • Occipital (posterior head)
  • Popliteal (posterior knee)
  • Sacral (between hips)
  • Scapular (shoulder blade region)
  • Sural (posterior lower leg/calf)
  • Vertebral (spine)

Body Cavities

• Ventral body cavity: Contains structures in the chest and abdomen.
  • Thoracic cavity: Contains lungs, heart, and great vessels.
  • Abdominopelvic cavity:
    • Abdominal cavity: Contains stomach, liver, and intestines.
    • Pelvic cavity: Contains reproductive organs, bladder, and rectum.
• Dorsal body cavity: Contains the brain and spinal cord.
  • Cranial cavity: Contains the brain and cranial nerves.
  • Vertebral cavity: Contains the spinal cord.

Homeostasis

• Homeostasis is the body's ability to maintain a stable internal environment despite changes in the external environment, necessary for normal function and life.
• All body systems interact to keep internal conditions (e.g., temperature, fluid balance) within a stable, normal range.
• Homeostasis involves dynamic changes to maintain equilibrium; disruptions can cause disease.

Homeostatic Control Mechanisms

• Homeostasis uses feedback loops to maintain stability.
  • Stimulus: Produces change in a variable.
  • Receptor (Sensor): Detects the change in variable.
  • Control Center: Determines appropriate response.
  • Effector: Provides the response.
• Negative feedback: The response opposes the original stimulus, maintaining homeostasis (e.g., temperature regulation).
• Positive feedback: The response enhances the original stimulus, not for maintaining homeostasis (blood clotting, childbirth).

Homeostatic Imbalance

• Homeostatic imbalance occurs when the negative feedback mechanisms fail to maintain normal conditions, allowing positive feedback to dominate and cause disease.

This quiz covers the fundamental concepts of anatomy and physiology, including the structures of the body and their functions. Explore the principles of complementarity and learn about anatomical positions and directional terms that are essential for understanding human body organization. Test your knowledge and deepen your understanding of this vital field.