Anatomy and Physiology Notes

Anatomy and Physiology

• Anatomy: Describes the structures of the body.
  • What they are made of.
  • Where they are located.
  • Associated structures.
• Physiology: Study of the functions of anatomical structures.
  • Individual functions.
  • Cooperative functions.

Human Anatomy

• Gross Anatomy (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: From 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 Observations

• Signs: Objective indications of disease (e.g., fever).
• Symptoms: Subjective experiences of disease (e.g., tiredness).

Scientific Method in Diagnosis

• Physicians use the scientific method to reach a diagnosis 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: A group of cells working together.
• Organ level
  • Organs: Made of two or more tissues working together.
• Organ system level
  • Organ system: A group of interacting organs.
  • Humans have 11 organ systems.
• Organism level
  • Organism: An individual life form.

Organ Systems

• Integumentary
  • Major organs: Skin, hair, sweat glands, nails.
  • Functions: Protects against environmental hazards, regulates body temperature, provides sensory information.
• Skeletal
  • Major organs: Bones, cartilages, associated ligaments, bone marrow.
  • Functions: Provides support and protection, stores calcium and other minerals, forms blood cells.
• Muscular
  • Major organs: Skeletal muscles and associated tendons.
  • Functions: Provides movement, protection and support, generates heat to maintain body temperature.
• Nervous
  • Major organs: Brain and spinal cord, peripheral nerves, sense organs.
  • Functions: Directs immediate responses to stimuli, coordinates organ systems, provides sensory information.
• Endocrine
  • Major organs: Pituitary, thyroid, and adrenal glands; pancreas and gonads; endocrine tissues in other systems.
  • Functions: Directs long-term changes, adjusts metabolic activity and energy use, controls structural and functional changes during development.
• Cardiovascular
  • 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
  • Major organs: Spleen, thymus, lymphatic vessels, lymph nodes, tonsils.
  • Functions: Defends against infection and disease, returns tissue fluids to the bloodstream.
• Respiratory
  • Major organs: Nasal cavities, sinuses, larynx, trachea, bronchi, lungs, alveoli.
  • Functions: Delivers air to alveoli, provides oxygen to bloodstream, removes carbon dioxide from bloodstream, produces sounds for communication.
• Digestive
  • Major organs: Teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas.
  • Functions: Processes and digests food, absorbs water and nutrients, stores energy reserves.
• Urinary
  • Major organs: Kidneys, ureters, urinary bladder, urethra.
  • Functions: Excretes waste products from the blood, controls water balance, stores urine, regulates blood ion concentrations and pH.
• Male Reproductive
  • Major organs: Testes, epididymides, ductus deferentia, seminal vesicles, prostate gland, penis, scrotum.
  • Functions: Produces sperm, seminal fluids, and hormones; sexual intercourse.
• Female Reproductive
  • Major organs: Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands.
  • Functions: Produces oocytes and hormones, supports developing embryo, provides milk, sexual intercourse.

Medical Terminology

• Terms related to the body in health and disease.
• Most commemorative names or eponyms 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
  • Abdominopelvic regions
• Anatomical Directions: Reference terms based on subject.

Directional References

• Superior: Above; at a higher level (in the human body, toward the head). The head is superior to the chest.
• Inferior: Below; at a lower level; toward the feet. The knee is inferior to the hip.
• Anterior (Ventral): The front surface. The umbilicus (navel) is on the anterior (or ventral) surface of the trunk.
• Posterior (Dorsal): The back surface. The scapula (shoulder blade) is located posterior to the rib cage.
• Medial: Toward the midline.
• Lateral: Away from the midline.
• Proximal: Toward the point of attachment of a limb to the trunk. The shoulder is proximal to the wrist.
• Distal: Away from the point of attachment of a limb to the trunk. The fingers are distal to the wrist.
• Cranial (Cephalic): Toward the head. The cranial nerves are in the head.
• Caudal: Toward the tail (coccyx in humans). Fused caudal vertebrae form the skeleton of the tail (coccyx).
• Superficial: At, near, or relatively close to the body surface. The skin is superficial to underlying structures.
• Deep: Toward the interior of the body; farther from the surface. The bone of the thigh is deep to the surrounding skeletal muscles.

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: Vertical plane that divides body into anterior and posterior portions. A cut in this plane is a frontal section (coronal section).
  • Sagittal plane: Vertical plane dividing body into left and right portions. A cut in this plane is a sagittal section.
    • Midsagittal plane lies in the middle.
    • Parasagittal plane is offset from the middle.
  • Transverse plane: Divides body into superior and inferior portions. A cut in this plane is called a transverse section (cross section).
  • Oblique: divides body at an angle (non-90○).

Body Cavities

• Essential functions of body cavities
  • 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 cavity.
  • Visceral serosa covers 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.

• Membranes of the Lungs

  • Visceral pleura
  • Parietal pleura

Abdominopelvic Cavity

• Abdominal cavity—superior portion

  • 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.

• Parietal Peritoneum: Lines the internal body wall

• Visceral Peritoneum: Covers the organs

• Peritoneal cavity: Chamber within abdominopelvic cavity

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

• Consists of:
  • 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.

Systems Integration

• Systems work together to maintain homeostasis.

• Homeostasis is a state of equilibrium

  • Opposing forces are in balance.
  • Dynamic equilibrium—continual adaptation.

• Physiological systems work to maintain balance

  • Failure results in disease.## Systems Integration

• Systems work together to maintain homeostasis.

• Homeostasis is a state of equilibrium

  • Opposing forces are in balance
  • Dynamic equilibrium - continual adaptation

• Physiological systems work to maintain balance

  • Failure results in disease.