W15N Anatomy

• These notes cover anatomy, physiology, directional terms, body sections, body cavities, and abdominopelvic regions.

Anatomy and Physiology Subspecialties

• Embryology studies the first eight weeks of human development post-fertilization.
• Developmental biology covers the full development of an individual from egg fertilization to death.
• Cell biology examines cellular structure and functions.
• Histology focuses on the microscopic structure of tissues.
• Surface anatomy uses surface markings to understand internal anatomy through visualization and palpation.
• Gross anatomy studies structures visible without a microscope.
• Systemic anatomy studies specific body systems, like the nervous or respiratory systems.
• Regional anatomy studies specific body regions such as the head or chest.
• Radiographic anatomy visualizes body structures using x-rays. The term "radio-" means ray, and "-graphic" means to write.
• Pathological anatomy studies structural changes, from gross to microscopic, associated with disease. The term "path-" means disease.
• Neurophysiology studies the functional properties of nerve cells.
• Endocrinology studies hormones and their control over body functions. The term "endo-" means within, and "-crin" means secretion.
• Cardiovascular physiology studies the functions of the heart and blood vessels. The term "cardi-" means heart, and "vascular" means blood vessels.
• Immunology studies how the body defends itself against disease-causing agents; "immun-" means not susceptible.
• Respiratory physiology studies the functions of air passageways and lungs; "respire-" means to breathe.
• Renal physiology is the study of the kidneys' functions.
• Exercise physiology looks at changes in cell and organ functions due to muscular activity.
• Pathophysiology examines functional changes linked to disease and aging.

Introduction to Organ Systems

• The Integumentary System includes skin, hair, nails, sweat, and oil glands.
  • It regulates body temperature, protects the body, eliminates wastes, helps make vitamin D, and detects sensations.
• The Skeletal System consists of bones, joints, and cartilages.
  • It supports and protects the body, provides muscle attachment points, assists body movements, stores blood cell-producing cells, minerals, and lipids.
• The Muscular System refers to skeletal muscle tissue attached to bones.
  • It facilitates body movements, maintains posture, and produces heat.
• The Nervous System includes the brain, spinal cord, nerves, and special sense organs.
  • It regulates body activities via nerve impulses by detecting and responding to environmental changes.
• The Endocrine System comprises glands and tissues that produce hormones.
  • It regulates body activities through hormones transported by the blood.
• The Cardiovascular System includes blood, the heart, and blood vessels.
  • The heart pumps blood, which carries oxygen and nutrients to cells, removes waste, regulates body fluids, and defends against diseases.
• The Lymphatic System and Immunity includes lymphatic fluid and vessels, spleen, thymus, lymph nodes, tonsils, and immune cells.
  • It returns proteins and fluid to the blood, transports lipids, and protects against disease-causing microbes.
• The Respiratory System includes the lungs and air passageways like the pharynx, larynx, trachea, and bronchial tubes.
  • It transfers oxygen to blood and carbon dioxide from blood, regulates body fluid acidity, and produces sounds via vocal cords.
• The Digestive System includes the gastrointestinal tract and accessory organs like salivary glands, liver, gallbladder, and pancreas.
  • It involves the physical/chemical breakdown of food, nutrient absorption, and waste elimination.
• The Urinary System includes kidneys, ureters, urinary bladder, and urethra.
  • It produces, stores, and eliminates urine, regulates blood volume and composition, maintains acid-base and mineral balance, and regulates red blood cell production.
• The Reproductive System includes gonads and associated organs, producing gametes and hormones for reproduction and other body processes; also includes mammary glands in females.

Anatomical and Directional Terms

• Anatomical Position is a standardized method of observing or imaging the body.
• Supine Position: the body is lying face up
• Prone Position: the body is lying face down
• Head - skull and face
• Neck - supports the head and attaches to the trunk
• Trunk - chest, abdomen, and pelvis
• Upper limbs - attaches to trunk(shoulder, armpit and arm)
• Lower limbs - attaches to trunk (buttock, thigh, leg, ankle and foot)
• Superior (cranial or cephalic) refers to being toward the head or upper part of a structure.
  • The heart is superior to the liver.
• Inferior (caudal) refers to being away from the head or toward the lower part of a structure.
  • The stomach is inferior to the lungs.
• Anterior (ventral) means nearer to the front of the body.
  • The sternum is anterior to the heart.
• Posterior (dorsal) means nearer to the back of the body.
  • The esophagus is posterior to the trachea.
• Medial means nearer to the midline of the body.
  • The ulna is medial to the radius.
• Lateral means farther from the midline.
  • The lungs are lateral to the heart.
• Intermediate is between two structures.
  • The transverse colon is intermediate to the ascending and descending colons.
• Ipsilateral is on the same side of the body as another structure.
  • The gallbladder and ascending colon are ipsilateral.
• Contralateral is on the opposite side of the body from another structure.
  • The ascending and descending colons are contralateral.
• Proximal means nearer to the attachment of a limb to the trunk.
  • The humerus is proximal to the radius.
• Distal means farther from the attachment of a limb to the trunk.
  • The phalanges are distal to the carpals.
• Superficial (external) is toward or on the surface of the body.
  • The ribs are superficial to the lungs.
• Deep (internal) is away from the surface of the body.
  • The ribs are deep to the skin of the chest and back.

Planes and Sections

• Sagittal plane: Vertical that divides the body into left and right sides
  • Midsagittal plane divides the body into equal right and left sides
  • Parasagittal plane divides the body into unequal right and left sides
• Frontal or coronal plane: Divides the body into anterior (front) and posterior (back) portions.
• Transverse plane: Divides the body into superior (upper) and inferior (lower) portions and is also called cross-sectional or horizontal plane.
• Oblique plane: Passes through the body at an angle between transverse with sagittal or frontal planes.
• Sections: Is a cut of the body made along a plane.

Body Cavities

• Body Cavities are spaces that protect, separate, and support internal organs.
• Cranial cavity formed by cranial bones contained the brain.
• Vertebral canal formed by vertebral column, contains spinal cord.
• Thoracic cavity the chest cavity; includes pleural and pericardial cavities and the mediastinum.
• Abdominopelvic cavity subdivided into abdominal and pelvic cavities..
• The thoracic cavity (chest cavity) contains the pleural, pericardial cavities, and the mediastinum
• Pericardial activity is a fluid-filled space that surrounds the heart.
• Pleural cavity are fluid filled spaces that surrounds each lung.
• mediastinum - contains the heart, oesophagus, trachea, thymus, and several large blood vessels that enter and exit the heart.
• The Diaphragm is a dome-shaped muscle separating the thoracic cavity from the abdominopelvic cavity.
• The abdominopelvic cavity is inferior to the diaphragm; consists of the abdominal and pelvic cavities.
• The abdominal cavity contains most abdominopelvic organs such as stomach, spleen, liver, gallbladder, small and large intestine.
• Subdivided into nine regions or four quadrants.
• The pelvic cavity contains the bladder, the lowest portions of digestive tract (large intestine) and internal reproductive organs

Abdominopelvic Regions and Quadrants

• The nine abdominopelvic regions include the right hypochondriac, epigastric, left hypochondriac, right lateral (lumbar), umbilical, left lateral (lumbar), right inguinal (iliac), hypogastric (pubic), and left inguinal (iliac).
• The four abdominopelvic quadrants are the right upper (RUQ), right lower (RLQ), left upper (LUQ), and left lower (LLQ).

Thoracic and Abdominal Cavity Membranes

• Serous Membranes are thin, slippery, double-layered membranes in thoracic and abdominopelvic cavities that cover viscera.
• Their functions are protections and reduce friction.
• pleura covers the lungs, lines the thorax.
• pericardial covers the heart, lines central part of thorax.
• peritoneal covers organs, lines abdominopelvic cavity.
• Visceral peritoneum covers the abdominal viscera (organs)
• Parietal peritoneum lines the abdominal wall, covering the inferior surface of the diaphragm.
• Other cavities:
  • oral (mouth) cavity: tongue and teeth
  • nasal cavity: nose
  • orbital (orbit) cavity: eyeball
  • middle ear cavity: small bones of the middle ear
  • Synovial cavity: joints between neck vertebrae