Lab 1 terms Anatomy Lab

Abdominal Cavity

• Definition: The superior subunit of the abdominopelvic cavity located between the diaphragm and pelvis. • Function: Houses digestive organs and protects them via peritoneal membranes. • Location: Inferior to the diaphragm, superior to the pelvic brim.

Abdominopelvic Cavity

• Definition: A continuous ventral body cavity subdivided into abdominal and pelvic portions. • Function: Encloses, supports, and protects digestive, urinary, and reproductive organs. • Location: Inferior to the thoracic cavity/diaphragm, extending to the pelvic floor.

Abdominopelvic Region / Regions (9-Region Grid)

• Definition: Anatomical grid dividing the abdomen into 9 sub-regions for clinical localization. • Function: Allows precise anatomical reference and diagnostic charting of internal organs. • Location: Anterior abdominal wall, bounded by subcostal and intertubercular lines.

Anatomical Position

• Definition: Standard reference stance: standing erect, facing forward, arms at sides, palms facing forward. • Function: Serves as the universal baseline for all directional terminology. • Location: Universal body posture reference.

Anterior (Ventral)

• Definition: Directional term meaning toward or at the front of the body. • Function: Establishes spatial orientation relative to the front surface. • Location: Front side of the body (e.g., sternum is anterior to the spine).

Axillary Region

• Definition: Anatomical region corresponding to the armpit. • Function: Passageway for major nerves (brachial plexus), vessels, and axillary lymph nodes. • Location: Pyramidal space beneath the shoulder joint, between arm and lateral chest wall.

Cardiovascular System

• Definition: Organ system consisting of the heart, blood vessels, and blood. • Function: Pumps blood to deliver oxygen/nutrients and remove metabolic wastes. • Location: Thoracic cavity (heart/mediastinum) and distributed throughout the entire body.

Coronal (Frontal) Plane

• Definition: Vertical plane passing longitudinally through the body. • Function: Divides the body or organs into anterior (front) and posterior (back) portions. • Location: Perpendicular to the sagittal plane along the coronal suture axis.

Cranial Cavity

• Definition: Space formed inside the neurocranium of the skull. • Function: Encloses, cushions, and protects the brain and cranial nerve roots. • Location: Superior portion of the dorsal body cavity inside the skull.

Cubital Region (Antecubital)

• Definition: The anterior depression or bend of the elbow joint. • Function: Serves as a landmark for venipuncture and brachial artery auscultation. • Location: Anterior surface of the arm at the junction between brachium and antebrachium.

Deep (Internal)

• Definition: Directional term meaning away from the body surface; further inward. • Function: Specifies relative depth of structures within body tissues. • Location: Internal relative to superficial structures (e.g., bones are deep to skin).

Diaphragm

• Definition: Dome-shaped skeletal muscle sheet separating thoracic and abdominal cavities. • Function: Primary muscle of inspiration; contracts to enlarge thoracic volume. • Location: Floor of thoracic cavity, roof of abdominal cavity.

Digestive System

• Definition: Organ system comprising the gastrointestinal tract and accessory organs. • Function: Ingestion, mechanical/chemical breakdown of food, nutrient absorption, waste elimination. • Location: Head/neck (mouth, pharynx), thoracic (esophagus), abdominopelvic cavities.

Distal

• Definition: Directional term meaning farther from the point of origin or trunk attachment. • Function: Describes relative positions along limbs or tubular structures. • Location: Away from attachment point (e.g., wrist is distal to the elbow).

Endocrine System

• Definition: System of ductless glands secreting chemical messengers (hormones) into blood. • Function: Regulates long-term metabolic, developmental, reproductive, and homeostatic processes. • Location: Distributed glands (pituitary, thyroid, adrenals, pancreas, gonads).

Epigastric Region

• Definition: Superior central region of the 9-region abdominal grid. • Function: Overlies major digestive organs; key area for gastric/pancreatic pain assessment. • Location: Superior to umbilical region, between right and left hypochondriac regions.

Female Reproductive System

• Definition: System of internal/external genital organs in females (ovaries, tubes, uterus, vagina). • Function: Produces oocytes/estrogen, enables fertilization, supports fetal development/childbirth. • Location: Pelvic cavity and perineum.

Fibrous Pericardium

• Definition: Tough, unyielding outer connective tissue sac surrounding the heart. • Function: Prevents overfilling of the heart, anchors heart to mediastinum, protects from infection. • Location: Superficial layer of pericardium, fused to central tendon of diaphragm.

Frontal Region

• Definition: Anatomical region corresponding to the forehead. • Function: Overlies the frontal bone and frontal lobe of the brain; supports facial expression. • Location: Anterior superior skull, above orbits/eyes.

Greater Omentum

• Definition: Large, double-layered apron of visceral peritoneum filled with fat/lymphatics. • Function: Insulates abdominal organs, stores lipid energy, wraps around inflamed organs ("policeman of abdomen"). • Location: Hangs from greater curvature of stomach over small intestine.

Hypogastric (Pubic) Region

• Definition: Inferior central region of the 9-region abdominal grid. • Function: Overlies urinary bladder and pelvic organs; landmark for suprapubic palpation. • Location: Inferior to umbilical region, flanked by right and left inguinal regions.

Inferior (Caudal)

• Definition: Directional term meaning lower, or toward the feet/tail. • Function: Describes vertical position lower down the longitudinal body axis. • Location: Toward the lower part of a structure or body (e.g., belly button is inferior to chest).

Integumentary System

• Definition: Organ system comprising skin, hair, nails, and cutaneous glands. • Function: Protection, thermoregulation, cutaneous sensation, vitamin D synthesis. • Location: External surface covering the entire body.

Lateral

• Definition: Directional term meaning away from the midline; toward the side. • Function: Specifies side-to-side position relative to the central longitudinal line. • Location: Outer sides (e.g., ears are lateral to the nose).

Left Hypochondriac Region

• Definition: Superior left region of the 9-region abdominal grid. • Function: Overlies spleen, stomach fundus, splenic flexure, and left kidney. • Location: Superior-left abdomen, lateral to epigastric region, below lower left rib cage.

Left Inguinal (Iliac) Region

• Definition: Inferior left region of the 9-region abdominal grid. • Function: Overlies descending/sigmoid colon junction and left spermatic cord/ovary. • Location: Inferior-left abdomen, near left iliac crest, lateral to hypogastric region.

Left Lateral Region of Abdomen (Left Lumbar)

• Definition: Middle left region of the 9-region abdominal grid. • Function: Overlies descending colon and lower pole of left kidney. • Location: Middle-left abdomen, lateral to umbilical region.

Left Lower Quadrant (LLQ)

• Definition: Inferior-left fourth of the 4-quadrant abdominopelvic grid. • Function: Clinical mapping zone for sigmoid colon, left ovary/tube, left ureter. • Location: Left side below umbilicus level.

Left Upper Quadrant (LUQ)

• Definition: Superior-left fourth of the 4-quadrant abdominopelvic grid. • Function: Clinical mapping zone for stomach, spleen, body of pancreas, left kidney/adrenal. • Location: Left side above umbilicus level.

Lesser Omentum

• Definition: Double layer of visceral peritoneum spanning between stomach/duodenum and liver. • Function: Transports portal triad structures (hepatic artery, portal vein, bile duct) to liver. • Location: Extends from liver fissure to lesser curvature of stomach and initial duodenum.

Lymphatic System

• Definition: Network of vessels, nodes, ducts, and lymphoid organs (spleen, thymus). • Function: Returns interstitial fluid to blood, absorbs dietary fats, initiates immune responses. • Location: Distributed throughout body tissues parallel to cardiovascular system.

Male Reproductive System

• Definition: System of internal/external genital organs in males (testes, ducts, glands, penis). • Function: Produces sperm and testosterone; delivers sperm to female reproductive tract. • Location: Scrotum, perineum, and pelvic cavity.

Medial

• Definition: Directional term meaning toward or at the midline of the body. • Function: Specifies position closer to the central longitudinal axis. • Location: Inner side relative to lateral structures (e.g., sternum is medial to shoulders).

Median (Midsagittal) Plane

• Definition: Specific sagittal plane passing directly through the longitudinal midline. • Function: Divides the body/head into perfectly equal right and left halves. • Location: Centered longitudinally from anterior to posterior along midline.

Mediastinum

• Definition: Central anatomical compartment of the thoracic cavity between pleural sacs. • Function: Encloses heart, pericardium, esophagus, trachea, thymus, and major blood vessels. • Location: Thoracic cavity, bounded by sternum anteriorly and vertebral column posteriorly.

Mental Region

• Definition: Anatomical region corresponding to the chin. • Function: Overlies mental protuberance of mandible; attachment site for mentalis muscle. • Location: Inferior anterior portion of face.

Mesentery of Small Intestine

• Definition: Fan-shaped double fold of parietal/visceral peritoneum anchoring small intestine. • Function: Suspends jejunum/ileum from posterior wall; routes intestinal nerves, blood, lymphatics. • Location: Connects posterior abdominal wall to loops of jejunum and ileum.

Muscular System

• Definition: Organ system consisting primarily of skeletal muscles. • Function: Enables locomotion, maintains posture, produces body heat via contraction. • Location: Attached to bones and fascia throughout the entire body.

Nervous System

• Definition: Fast-acting control system made of brain, spinal cord, nerves, and sensory receptors. • Function: Detects sensory input, processes/integrates information, coordinates motor output. • Location: Dorsal cavity (CNS: brain/spinal cord) and body periphery (PNS: nerves).

Oblique Plane

• Definition: Sectioning plane that passes through body at an angle between transverse and sagittal/coronal. • Function: Provides diagonal anatomical cross-sections for advanced medical imaging (CT/MRI). • Location: Any non-standard angular plane across body axes.

Occipital Region

• Definition: Region of head corresponding to lower posterior skull. • Function: Overlies occipital bone and visual cortex of brain. • Location: Inferior posterior surface of head.

Parietal Layer of Serous Pericardium

• Definition: Serous membrane lining internal surface of tough fibrous pericardium. • Function: Secretes serous fluid into pericardial cavity to reduce heart friction. • Location: Outer wall of pericardial cavity, fused to fibrous pericardium.

Parietal Peritoneum

• Definition: Outer layer of serous membrane lining walls of abdominopelvic cavity. • Function: Lines abdominal wall, secretes peritoneal fluid, contains somatic sensory innervation. • Location: Internal surface of abdominal and pelvic cavity walls.

Parietal Pleura

• Definition: Outer layer of serous membrane lining thoracic cavity walls and diaphragm superiorly. • Function: Secretes pleural fluid; adheres lungs to chest wall for respiratory expansion. • Location: Thoracic cavity wall, lateral mediastinum, superior surface of diaphragm.

Parietal Region

• Definition: Superior lateral region of head over parietal bones. • Function: Overlies parietal lobes of brain (somatosensory processing). • Location: Superior and lateral skull, between frontal and occipital regions.

Parotid Region

• Definition: Facial region over angle of mandible and anterior ear. • Function: Encloses parotid salivary gland and branches of facial nerve ($CN\text{ VII}$). • Location: Anteroinferior to ear, superficial to masseter muscle.

Pelvic Cavity

• Definition: Inferior subunit of abdominopelvic cavity enclosed by pelvis. • Function: Encloses urinary bladder, internal reproductive organs, and rectum. • Location: Inferior to abdominal cavity, bounded by pelvic brim and pelvic floor.

Pericardial Cavity

• Definition: Fluid-filled potential space between parietal and visceral pericardial layers. • Function: Contains serous fluid to allow frictionless cardiac contraction. • Location: Middle mediastinum surrounding the heart.

Peritoneal Cavity

• Definition: Potential space between parietal peritoneum and visceral peritoneum. • Function: Contains serous fluid lubricated for organ movement without friction. • Location: Abdominopelvic cavity surrounding abdominal viscera.

Pleural Cavity

• Definition: Potential space between parietal pleura and visceral pleura around each lung. • Function: Contains pleural fluid maintaining surface tension to keep lungs inflated during breathing. • Location: Lateral pulmonary cavities of thoracic cavity.

Popliteal Fossa

• Definition: Diamond-shaped posterior depression behind knee joint. • Function: Passageway for popliteal artery/vein, tibial nerve, common fibular nerve. • Location: Posterior surface of knee.

Posterior (Dorsal)

• Definition: Directional term meaning toward or at the back of the body. • Function: Specifies position relative to back surface. • Location: Back side of body (e.g., vertebral column is posterior to aorta).

Prone

• Definition: Body posture lying flat face-down horizontally. • Function: Clinical positioning for posterior trunk, spine, or popliteal procedures. • Location: Entire anterior body resting against supporting surface.

Proximal

• Definition: Directional term meaning closer to point of origin or trunk attachment. • Function: Describes relative position along limbs/tubular structures toward body core. • Location: Closer to limb attachment (e.g., shoulder is proximal to elbow).

Pulmonary Cavity

• Definition: Bilateral compartments of thoracic cavity housing lungs and pleurae. • Function: Encloses pleural sacs and lungs for respiration. • Location: Thoracic cavity, lateral to central mediastinum.

Respiratory System

• Definition: Organ system consisting of nasal cavity, pharynx, larynx, trachea, bronchi, lungs. • Function: Gas exchange (supplies $O_2$, removes $CO_2$), blood pH regulation, vocalization. • Location: Head, neck, thoracic cavity.

Right Hypochondriac Region

• Definition: Superior right region of 9-region abdominal grid. • Function: Overlies liver right lobe, gallbladder, right kidney upper pole. • Location: Superior-right abdomen below lower right rib cage, lateral to epigastric region.

Right Inguinal (Iliac) Region

• Definition: Inferior right region of 9-region abdominal grid. • Function: Overlies cecum, appendix, right spermatic cord/ovary. • Location: Inferior-right abdomen near iliac crest, lateral to hypogastric region.

Right Lateral Region of Abdomen (Right Lumbar)

• Definition: Middle right region of 9-region abdominal grid. • Function: Overlies ascending colon, right colic flexure, lower pole right kidney. • Location: Middle-right abdomen lateral to umbilical region.

Right Lower Quadrant (RLQ)

• Definition: Inferior-right fourth of 4-quadrant abdominopelvic grid. • Function: Clinical mapping zone for cecum, appendix, ascending colon, right ovary/ureter. • Location: Right side below umbilicus level.

Right Upper Quadrant (RUQ)

• Definition: Superior-right fourth of 4-quadrant abdominopelvic grid. • Function: Clinical mapping zone for liver, gallbladder, duodenum, head of pancreas, right kidney. • Location: Right side above umbilicus level.

Sacral Region

• Definition: Posterior region between hip bones over sacrum. • Function: Overlies sacral vertebrae, sacral plexus nerves, posterior pelvic wall. • Location: Inferior posterior trunk superior to gluteal cleft.

Sagittal Plane

• Definition: Longitudinal vertical plane dividing body into right and left portions. • Function: Enables sectioning parallel to median plane. • Location: Runs anterior to posterior along longitudinal body axis.

Skeletal System

• Definition: System of bones, cartilages, ligaments, and joints. • Function: Structural framework, organ protection, blood cell formation (hematopoiesis), mineral storage. • Location: Forms central framework of entire body.

Superficial (External)

• Definition: Directional term meaning toward or at the body surface. • Function: Specifies proximity to body surface. • Location: Outer relative to deep tissues (e.g., epidermis is superficial to dermis).

Superior (Cranial)

• Definition: Directional term meaning higher up, or toward head. • Function: Specifies position higher along longitudinal body axis. • Location: Upper relative to inferior structures (e.g., head is superior to neck).

Supine

• Definition: Body posture lying flat face-up horizontally. • Function: Standard clinical positioning for anterior physical exam and abdominal procedures. • Location: Posterior body surface resting against supporting surface.

Temporal Region

• Definition: Lateral facial/head region over temporal bone superior to zygomatic arch. • Function: Overlies temporalis muscle and temporal lobe of brain. • Location: Lateral head anterior/superior to ear.

Thoracic Cavity

• Definition: Superior division of ventral body cavity enclosed by rib cage. • Function: Protects lungs, heart, esophagus, trachea via pleural/pericardial sacs. • Location: Superior to diaphragm, bounded by ribs and sternum.

Transverse (Cross-Sectional) Plane

• Definition: Horizontal plane passing crosswise through body perpendicular to longitudinal axis. • Function: Divides body or organ into superior (upper) and inferior (lower) portions. • Location: Horizontal slice across longitudinal body axis.

Triangle of Auscultation

• Definition: Thin muscular gap on posterior chest wall bordered by latissimus dorsi, trapezius, and scapula. • Function: Allows clearer stethoscopic auscultation of lung sounds due to reduced muscular thickness. • Location: Posterior thorax medial to inferior angle of scapula.

Umbilical Region

• Definition: Centermost region of 9-region abdominal grid surrounding belly button. • Function: Overlies transverse colon, small intestine, abdominal aorta, inferior vena cava. • Location: Center of abdominal wall.

Urinary System

• Definition: Organ system consisting of kidneys, ureters, urinary bladder, urethra. • Function: Filters blood, regulates electrolyte/water balance, excretes nitrogenous metabolic wastes. • Location: Posterior abdominal wall and pelvic cavity.

Vertebral Canal

• Definition: Tubular space formed by stacked vertebral foramina within vertebral column. • Function: Encloses, supports, and cushions spinal cord and spinal nerve roots. • Location: Dorsal body cavity running longitudinally through spine.

Visceral Layer of Serous Pericardium (Epicardium)

• Definition: Innermost serous membrane layer tightly adhering directly to heart surface. • Function: Secretes serous fluid into pericardial cavity; forms outer wall of heart tissue. • Location: External surface of myocardium.

Visceral Peritoneum

• Definition: Inner layer of serous membrane wrapped directly around abdominal organs. • Function: Secretes peritoneal fluid; reduces friction between sliding internal viscera. • Location: External surface of intraperitoneal organs (stomach, intestines, liver).

Visceral Pleura

• Definition: Inner serous membrane tightly adhering to surface of lungs and fissures. • Function: Secretes pleural fluid allowing lungs to glide smoothly along parietal pleura during breathing. • Location: Direct outer surface of lung tissue.

Zygomatic Region

• Definition: Facial region over cheekbone (zygomatic bone). • Function: Overlies zygomaticus muscles (smiling muscles) and zygomatic arch. • Location: Upper cheek below orbit and lateral to nasal region.

Bilateral

• Definition: Paired structures present on both right and left sides of body midline. • Function: Provides symmetrical sensory/motor function and organ redundancy. • Location: Whole body (e.g., eyes, ears, lungs, kidneys).

Unilateral

• Definition: Pertaining to or occurring on only one side of the body. • Function: Clinical designation for asymmetrical structures/conditions. • Location: Single organs (e.g., spleen on left, liver mostly on right).

Ipsilateral

• Definition: Located on or affecting the same side of the body as another structure. • Function: Describes spatial relationships on the same side. • Location: Relative reference (e.g., right gallbladder and right ascending colon).

Contralateral

• Definition: Located on or affecting the opposite side of the body relative to another structure. • Function: Describes spatial relationships on opposite sides. • Location: Relative reference (e.g., right hemisphere controls contralateral left arm).

Pelvic Brim (Pelvic Inlet)

• Definition: Ridge formed by the sacral promontory, arcuate line, pectineal line, and pubic crest. • Function: Serves as anatomical boundary between abdominal and pelvic cavities. • Location: Superior border of true pelvis.

Serous Fluid

• Definition: Clear, watery fluid secreted by parietal and visceral serous membranes. • Function: Lubricates serous cavities to reduce friction between moving organs. • Location: Pleural, pericardial, and peritoneal potential spaces.

Systems-Based Anatomy vs. Regional Anatomy

• Systems-Based: Studies organ systems individually across the whole body (e.g., nervous system). • Regional: Studies all organ systems within a specific anatomical area together (e.g., head & neck).