Anatomy and Physiology - Chapter 1

Using the Text and Art

• Study text and art together.

• Each topic is in a section.

• Text-art integration ensures figures are near relevant text.

• Learning outcomes are educational objectives at the start of each chapter, based on a learning classification scheme.

Anatomy and Physiology

• Anatomy: Describes body structures, their composition, location, and associated structures.

• Physiology: Study of the functions of anatomical structures, both individual and cooperative.

  • Human Anatomy:

  • Gross (macroscopic) anatomy: Examines large, visible structures.

    • Surface anatomy: Exterior features.

    • Regional anatomy: Body areas.

    • Sectional anatomy: Cross-sections.

    • Systemic anatomy: Organ systems.

    • Clinical anatomy: Medical specialties.

    • Developmental anatomy: Conception to adulthood, including embryology.

  • Microscopic anatomy: Examines cells and molecules.

    • Cytology: Study of cells.

    • Histology: Study of tissues.

  • Human Physiology:

  • Cell physiology: Functions of cells.

  • Organ physiology: Functions of specific organs.

  • Systemic physiology: Functions of organ systems.

  • Pathological physiology: Effects of diseases on organs or systems.

• Clinical Presentation:

  • Signs: Objective, observable indicators (e.g., fever).

  • Symptoms: Subjective experiences reported by the patient (e.g., tiredness).

• Diagnosis:

  • Physicians use the scientific method to diagnose by evaluating observations.

  • Form a hypothesis.

  • Test the hypothesis by collecting and analyzing data.

Levels of Organization

• Chemical Level:

  • Atoms: Smallest stable units of matter.

  • Molecules: Groups of atoms.

• Cellular Level:

  • Cells: Smallest living units in the body.

• Tissue Level:

  • Tissue: Group of cells working together.

• Organ Level:

  • Organs: Made of two or more tissues working together.

• Organ System Level:

  • Organ System: Group of interacting organs.

  • Humans have 11 organ systems.

• Organism Level:

  • Organism: An individual life form.

Organ Systems

• Integumentary System:

  • Major Organs: Skin, hair, sweat glands, nails.

  • Functions: Protects against environmental hazards, regulates body temperature, provides sensory information.

• Skeletal System:

  • Major Organs: Bones, cartilages, associated ligaments, bone marrow.

  • Functions: Supports and protects other tissues, stores calcium and other minerals, forms blood cells.

• Muscular System:

  • Major Organs: Skeletal muscles and associated tendons.

  • Functions: Provides movement, protection, and support for other tissues; generates heat to maintain body temperature.

• Nervous System:

  • Major Organs: Brain, spinal cord, peripheral nerves, sense organs.

  • Functions: Directs immediate responses to stimuli, coordinates organ systems, provides and interprets sensory information.

• Endocrine System:

  • Major Organs: Pituitary, thyroid, and adrenal glands; pancreas and gonads; endocrine tissues in other systems.

  • Functions: Directs long-term changes in organ systems, adjusts metabolic activity and energy use, controls structural and functional changes during development.

• Cardiovascular System:

  • Major Organs: Heart, blood, blood vessels.

  • Functions: Distributes blood cells, water, nutrients, waste products, oxygen, and carbon dioxide; distributes heat to control body temperature.

• Lymphatic System:

  • Major Organs: Spleen, thymus, lymphatic vessels, lymph nodes, tonsils.

  • Functions: Defends against infection and disease, returns tissue fluids to the bloodstream.

• Respiratory System:

  • Major Organs: Nasal cavities, sinuses, larynx, trachea, bronchi, lungs, alveoli.

  • Functions: Delivers air to alveoli (gas exchange sites), provides oxygen to bloodstream, removes carbon dioxide from bloodstream, produces sounds for communication.

• Digestive System:

  • Major Organs: Teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas.

  • Functions: Processes and digests food, absorbs and conserves water and nutrients, stores energy reserves.

• Urinary System:

  • Major Organs: Kidneys, ureters, urinary bladder, urethra.

  • Functions: Excretes waste products from the blood, controls water balance by regulating urine volume, stores urine, regulates blood ion concentrations and pH.

• Male Reproductive System:

  • Major Organs: Testes, epididymides, ductus deferentia, seminal vesicles, prostate gland, penis, scrotum.

  • Functions: Produces sperm, seminal fluids, and hormones; involved in sexual intercourse.

• Female Reproductive System:

  • Major Organs: Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands.

  • Functions: Produces oocytes and hormones, supports developing embryo from conception to delivery, provides milk to nourish newborn, involved in sexual intercourse.

Medical Terminology

• Medical terminology: Terms related to the body in health and disease.

• Eponyms: Most commemorative names have been replaced by precise terms.

Anatomical Terminology

• Surface Anatomy: Locating structures on or near the body surface.

• Anatomical Landmarks:

  • Anatomical Position: Hands at sides, palms forward.

  • Supine: Lying down, face up.

  • Prone: Lying down, face down.

• Anatomical Regions:

  • Abdominopelvic Quadrants: Four quadrants formed by two perpendicular lines intersecting at the navel.

  • Abdominopelvic Regions: Nine regions providing more precise descriptions.

• Anatomical Directions:

  • Reference terms based on the subject.

  • Superior: Above; at a higher level (toward the head).

  • Inferior: Below; at a lower level (toward the feet).

  • Anterior (Ventral): The front surface (belly side).

  • Posterior (Dorsal): The back surface.

  • Medial: Toward the midline.

  • Lateral: Away from the midline.

  • Proximal: Toward the point of attachment of a limb to the trunk.

  • Distal: Away from the point of attachment of a limb to the trunk.

  • Cranial (Cephalic): Toward the head.

  • Caudal: Toward the tail (coccyx in humans).

  • Superficial: At, near, or relatively close to the body surface.

  • Deep: Toward the interior of the body; farther from the surface.

• Sectional Anatomy:

  • A section is a slice through a three-dimensional object.

  • Used to visualize internal organization.

  • Important in radiological techniques (MRI, PET, CT).

• Sectional Plane:

  • A single view along a two-dimensional flat surface.

  • Frontal (Coronal) Plane:

  • The vertical plane that divides the body into anterior and posterior portions.

  • A cut in this plane is a frontal (coronal) section.

  • Sagittal Plane:

  • Vertical plane dividing the body into left and right portions.

  • A cut in this plane is a sagittal section.

  • Midsagittal plane: Lies in the middle.

  • Parasagittal plane: Offset from the middle.

  • Transverse Plane:

  • Divides the body into superior and inferior portions.

  • A cut in this plane is called a transverse section (cross-section).

Body Cavities

• Essential Functions:

  • Protect organs from shocks and impacts.

  • Permit significant changes in size and shape of internal organs.

• Ventral Body Cavity (Coelom):

  • Divided by the diaphragm.

  • Thoracic cavity.

  • Abdominopelvic cavity.

  • Body cavities contain viscera (internal organs).

• Serous Membrane (Serosa):

  • Lines body cavities and covers organs.

  • Consists of parietal and visceral layers.

  • Parietal serosa lines the cavity.

  • Visceral serosa covers the organ.

• Thoracic Cavity:

  • Right and left pleural cavities: Contain right and left lungs.

  • Mediastinum:

  • Upper portion: Filled with blood vessels, trachea, esophagus, and thymus.

  • Lower portion: Contains pericardial cavity. The heart is located within the pericardial cavity.

• Abdominopelvic Cavity:

  • Peritoneal cavity: Chamber within the abdominopelvic cavity.

  • Parietal peritoneum: Lines the internal body wall.

  • Visceral peritoneum: Covers the organs.

  • Abdominal cavity: Superior portion from diaphragm to top of pelvic bones; contains digestive organs.

  • Retroperitoneal space: Area posterior to peritoneum and anterior to muscular body wall; contains pancreas, kidneys, ureters, and parts of the digestive tract.

  • Pelvic cavity: Inferior portion medial to pelvic bones; contains reproductive organs, rectum, and bladder.

Homeostasis

• Homeostasis: All body systems work together to maintain a stable internal environment.

  • Systems respond to external and internal changes to keep variables within normal ranges (body temperature, fluid balance).

• Homeostatic Regulation:

  • Autoregulation: Automatic response in a cell, tissue, or organ to an environmental change.

  • Extrinsic Regulation: Responses controlled by nervous and endocrine systems.

• Homeostatic Regulatory Mechanism:

  • Receptor: Receives the stimulus.

  • Control Center: Processes the signal and sends instructions.

  • Effector: Carries out instructions.

  • Limits fluctuations of internal conditions to keep them close to a set point, or desired value.

Negative and Positive Feedback

• Negative Feedback:

  • The response of the effector negates the stimulus.

  • Body is brought back into homeostasis; normal range is maintained.

• Positive Feedback:

  • Initial stimulus produces a response that amplifies the original change in conditions.

  • Body is moved away from homeostasis; normal range is not maintained.

  • A positive feedback loop completes a dangerous process quickly to reestablish homeostasis (e.g., blood clotting).

• Systems Integration:

  • Systems work together to maintain homeostasis.

• Homeostasis as Equilibrium:

  • Opposing forces are in balance.

  • Dynamic equilibrium: Continual adaptation.

• Physiological Systems:

  • Work to maintain balance. Failure results in disease.