Human Anatomy & Physiology with Pathophysiology

Anatomy, Physiology, and Pathophysiology

Anatomy: The scientific discipline that investigates the structure of the body.

Physiology: The scientific discipline that deals with the processes or functions of living things.

Pathophysiology: The study of how a disease, injury, or other condition affects a patient, including both the physical and functional changes that occur.

Approaches to Study Anatomy

Systemic Anatomy: The study of the body by systems (e.g., skeletal, muscular, nervous).

Regional Anatomy: The study of the organization of the body by area (e.g., head, abdomen, arm).

Surface Anatomy: The study of external features (e.g., bone markings).

Anatomical Imaging: Uses X-rays, ultrasound, MRI, etc.

Structural and Functional Organization

Chemical Level: Atoms combining to form molecules (water, sugar, fats, proteins, DNA).

Cellular Level: Molecules combining to form organelles, the basic structural and functional units of organisms.

Tissue Level: Groups of similar cells and surrounding materials performing specific functions.

Organ Level: Two or more tissue types performing one or more common functions.

Organ System Level: Group of organs classified as a unit due to a common function.

Organism Level: Any living thing considered as a whole.

Organ Systems

Integumentary System: Protection, temperature regulation, water loss reduction, vitamin D precursor production. (Skin, hair, nails, sweat glands)

Skeletal System: Protection, support, body movement, blood cell production, mineral and fat storage. (Bones, cartilages, ligaments, joints)

Muscular System: Body movements, posture maintenance, body heat production. (Muscles attached to skeleton by tendons)

Nervous System: Major regulatory system; detects sensations, controls movements, physiological processes, intellectual functions. (Brain, spinal cord, nerves, sensory receptors)

Endocrine System: Regulatory system influencing metabolism, growth, reproduction, and other functions via hormones. (Glands such as pituitary, thyroid, adrenals, pancreas, ovaries, testes)

Cardiovascular System: Transports nutrients, waste products, gases, and hormones; immune response and temperature regulation. (Heart, blood vessels, blood)

Lymphatic System: Removes foreign substances from blood and lymph, combats disease, maintains fluid balance, transports fats. (Lymphatic vessels, lymph nodes, spleen, thymus, tonsils)

Respiratory System: Exchanges oxygen and carbon dioxide between blood and air, regulates blood pH. (Lungs, respiratory passages)

Digestive System: Digestion (mechanical and chemical), nutrient absorption, waste elimination. (Mouth, esophagus, stomach, intestines, accessory organs)

Urinary System: Removes waste products, regulates blood pH, ion balance, and water balance. (Kidneys, urinary bladder, ureters, urethra)

Female Reproductive System: Produces oocytes, site of fertilization and fetal development, milk production, hormone secretion. (Ovaries, uterine tubes, uterus, vagina, mammary glands)

Male Reproductive System: Produces and transfers sperm cells, hormone secretion. (Testes, epididymis, ductus deferens, penis, accessory glands)

Characteristics of Life

Organization: Parts of an organism have specific relationships and interact to perform specific functions.

Metabolism: All chemical and physical changes taking place in an organism (breaking down food for energy/materials and synthesizing needed compounds).

Responsiveness: Ability to sense changes in internal or external environments and adjust accordingly.

Growth: Increase in size of all or part of an organism.

Development: Changes an organism undergoes through time (fertilization to death).

Reproduction: Formation of new cells or new organisms.

Homeostasis and Feedback Mechanisms

Homeostasis: The existence and maintenance of a relatively constant environment within the body.

Negative-Feedback Mechanism: Maintains homeostasis by resisting or decreasing any deviation from the set point. Maintains variation within a normal range.

Receptor: Monitors the value of a variable.

Control Center: Receives information about the variable from the receptor.

Effector: Produces responses that adjust the variable.

Examples: Thermoregulation, blood sugar regulation, osmoregulation.

Positive-Feedback Mechanism: Non-homeostatic and rare in healthy states; increases deviation from normal values, creating a cycle leading away from homeostasis.

Examples: Childbirth, lactation, ovulation, blood clotting.

Anatomical Terminology and Body Positions

Anatomical Position: Standing erect, face forward, upper limbs hanging to the sides, palms facing forward.

Supine Position: Lying face upward.

Prone Position: Lying face downward.

Directional Terms

Superior: Structure above another.

Inferior: Structure below another.

Cephalic: Closer to the head than another structure.

Caudal: Closer to the tail than another structure.

Anterior (Ventral): Front of the body / toward the belly.

Posterior (Dorsal): Back of the body / toward the back.

Proximal: Closer to the point of attachment to the body than another structure.

Distal: Farther from the point of attachment to the body than another structure.

Lateral: Away from the midline of the body.

Medial: Toward the midline of the body.

Superficial: Toward or on the surface.

Body Regions & Subdivisions

Central Region: Head, neck, and trunk.

Trunk: Thorax (chest), abdomen, and pelvis.

Upper Limb: Arm (shoulder to elbow), forearm (elbow to wrist), wrist, hand.

Lower Limb: Thigh (hip to knee), leg (knee to ankle), ankle, foot.

Abdominal Quadrants: Right-upper, Left-upper, Right-lower, Left-lower.

Nine Abdominal Regions: Right hypochondriac, Epigastric, Left hypochondriac, Right lumbar, Umbilical, Left lumbar, Right iliac, Hypogastric, Left iliac.

Body Planes and Sections

Sagittal Plane: Runs vertically, separating the body into right and left parts.

Median Plane: Sagittal plane passing directly through the midline (equal halves).

Transverse (Horizontal) Plane: Runs parallel to the ground, dividing the body into superior and inferior parts.

Frontal (Coronal) Plane: Runs vertically right to left, dividing the body into anterior and posterior parts.

Sections through an Organ:

Longitudinal Section: Cut through the long axis.

Cross (Transverse) Section: Cut at a right angle to the long axis.

Oblique Section: Cut across the long axis at any angle other than a right angle.

Body Cavities and Serous Membranes

Trunk Cavities:

Thoracic Cavity: Surrounded by rib cage, separated from abdominal cavity by diaphragm. Divided into right and left pleural cavities by the mediastinum (contains heart, thymus, trachea, esophagus, blood vessels).

Abdominopelvic Cavity: Divided into Abdominal Cavity (stomach, intestines, liver, spleen, pancreas, kidneys) and Pelvic Cavity (urinary bladder, part of large intestine, internal reproductive organs).

Serous Membranes:

Visceral Layer: Covers the organ.

Parietal Layer: Lines the cavity wall.

Serous Fluid: Located between layers to reduce friction.

Pericardial Cavity: Surrounds heart (visceral & parietal pericardium).

Pleural Cavity: Surrounds lungs (visceral & parietal pleura).

Peritoneal Cavity: Located in abdominopelvic cavity (visceral & parietal peritoneum).

Mesenteries: Two fused layers of peritoneum anchoring organs to the body wall and routing nerves/blood vessels.

Retroperitoneal Organs: Organs located behind parietal peritoneum with no mesenteries (kidneys, adrenal glands, pancreas, parts of intestines, urinary bladder).