Human Anatomy: Foundations, Tissues, and Early Embryology

Vocabulary flashcards covering foundational anatomical terminology, directional terms, body cavities, tissue types, epithelial specializations, connective tissue classifications, muscle and neural tissues, and early embryological development.

Anatomy

The study of external and internal body structures and the physical relationships among body parts.

Physiology

The study of how the human body functions and the underlying mechanisms involved.

Cytology

The microscopic study of the internal structure of individual cells, which are the smallest units of life.

Histology

The microscopic study of tissues, which are groups of specialized cells and cell products that perform specific functions.

Gross Anatomy

The study of structural features visible to the unaided eye, also referred to as macroscopic anatomy.

Surface Anatomy

The study of general anatomical form, or morphology, and the superficial anatomical markings on the body.

Regional Anatomy

An approach to gross anatomy that examines all internal and external structures in a specific body region, such as the head, neck, or trunk.

Systemic Anatomy

An approach to gross anatomy that studies the structures of major organ systems, such as the cardiovascular or digestive system.

Clinical Anatomy

The subspecialty of anatomy that focuses on anatomical features that undergo physical changes during illness or disease.

Radiographic Anatomy

The study of anatomical structures visualized through noninvasive imaging techniques such as X-rays, CT scans, MRIs, or ultrasound.

Anatomical Position

The standard anatomical reference stance where the body is standing upright, feet flat on the floor, hands at the sides, and palms facing forward (anterior).

Supine

The position of lying down face up in the anatomical position.

Prone

The position of lying down face down in the anatomical position.

Anatomical Sectional Planes

Orientations used to slice tissue for examination, including the frontal (coronal) plane, sagittal plane (midsagittal and parasagittal), and transverse (horizontal) plane.

Midsagittal Section

A sagittal section where the plane passes directly through the midline, dividing the body into equal right and left halves.

Parasagittal Section

A sagittal section where the plane misses the midline, dividing the body into unequal right and left portions.

Abdominopelvic Quadrants

The four regions dividing the abdominopelvic surface: Right Upper Quadrant (RUQ), Left Upper Quadrant (LUQ), Right Lower Quadrant (RLQ), and Left Lower Quadrant (LLQ).

Abdominopelvic Regions

The nine precise anatomical divisions of the abdomen and pelvis: Epigastric, Umbilical, Hypogastric (pubic), Right and Left Hypochondriac, Right and Left Lumbar, and Right and Left Inguinal (iliac) regions.

Diaphragm

A flat muscular sheet that separates the superior thoracic cavity from the inferior abdominopelvic cavity.

Mediastinum

A tissue mass in the thoracic cavity that separates the left and right pleural cavities and surrounds the pericardial cavity.

Epithelial Tissue

A primary tissue type characterized by high cellularity, layered arrangement, polarity, basal attachment, avascularity, and high regenerative capacity.

Types of Intercellular Connections in Epithelia

Specialized cell attachments including gap junctions, tight junctions (zonula occludens), spot desmosomes (macula adherens), adhesion belts (zonula adherens), and hemidesmosomes.

Microvilli

Small, membrane-covered projections on the apical surface of epithelial cells that increase surface area for absorption, commonly found in the digestive and urinary tracts.

Stereocilia

Exceptionally long microvilli found along portions of the male reproductive tract and in sensory cells of the inner ear.

Simple Epithelium

An epithelium consisting of a single layer of cells covering the basement membrane, typically found in protected internal compartments.

Stratified Epithelium

An epithelium consisting of two or more layers of cells, providing protection in areas subject to mechanical or chemical stress.

Mesothelium

A simple squamous epithelium that lines the ventral body cavities, including the pleural, pericardial, and peritoneal cavities.

Endothelium

A simple squamous epithelium lining the inner surface of the heart and blood vessels.

Keratinized Stratified Squamous Epithelium

Stratified squamous tissue whose superficial layers are packed with keratin, making them tough and water-resistant, found on the surface of the skin.

Nonkeratinized Stratified Squamous Epithelium

Stratified squamous tissue that provides resistance to abrasion but must be kept moist, lining the oral cavity, pharynx, esophagus, anus, and vagina.

Transitional Epithelium

A stratified epithelium consisting of cuboidal and uniquely shaped cells that can stretch extensively without damage, found in the urinary bladder, renal pelvis, and ureters.

Structural Classification of Exocrine Glands

Classification based on duct structure (simple vs. compound) and secretory portion shape (tubular, coiled tubular, branched tubular, alveolar/acinar, or tubuloalveolar).

Mechanisms of Glandular Secretion

The three modes of exocrine secretion: merocrine (release via exocytosis), apocrine (loss of apical cytoplasm), and holocrine (cell destruction).

Merocrine Secretion

The most common mode of secretion in which the secretory product is packaged into vesicles and released by exocytosis without damaging the cell.

Apocrine Secretion

A mode of secretion involving the loss of the apical portion of the cell cytoplasm packed with secretory vesicles, seen in lactiferous cells of mammary glands.

Holocrine Secretion

A mode of secretion that destroys the gland cell as it becomes packed with secretions and bursts apart, as seen in sebaceous glands.

Connective Tissue Matrix

The collective extracellular substance of connective tissue consisting of ground substance and extracellular protein fibers.

Classification of Connective Tissues

The division of connective tissue into three major categories: Connective Tissue Proper (loose and dense), Fluid Connective Tissue (blood and lymph), and Supporting Connective Tissue (cartilage and bone).

Areolar Tissue

A loose connective tissue with an open framework of collagen and elastic fibers that cushions organs, attaches skin to underlying muscles, and allows independent movement.

White Fat

The most common type of adipose tissue in adults, containing unilocular cells with a single large lipid droplet that store energy, insulate, and provide padding.

Brown Fat

A multilocular type of adipose tissue found mainly in infants that is highly vascularized and packed with mitochondria, functioning to generate heat.

Reticular Tissue

A loose connective tissue containing a network of reticular fibers that forms a supportive framework (stroma) for organs like the liver, spleen, lymph nodes, and bone marrow.

Dense Regular Connective Tissue

A connective tissue featuring densely packed collagen fibers aligned parallel to applied forces, forming tendons, aponeuroses, and ligaments.

Tendon

A cord-like band of dense regular connective tissue that connects skeletal muscle to bone.

Ligament

A band of dense regular connective tissue that connects bone to bone or stabilizes positions of internal organs.

Aponeurosis

A broad, collagenous fibrous sheet that attaches a muscle to another muscle or to bone.

Dense Irregular Connective Tissue

A connective tissue containing interwoven collagen fibers oriented in various directions, providing strength to resist forces applied from multiple directions.

Erythrocytes

Red blood cells that lack nuclei, make up about half of whole blood volume, and function in transporting oxygen and carbon dioxide.

Leukocytes

White blood cells that function in defending the body against infection and disease.

Platelets

Small, membrane-enclosed packets of cytoplasm present in blood that function in the clotting response to seal leaks in broken vessels.

Chondrocytes

Cartilage cells that reside within small chambers called lacunae embedded in a gel-like matrix.

Perichondrium

A fibrous membrane wrapping cartilage, composed of an outer fibrous layer for support and an inner cellular (chondrogenic) layer for growth.

Osteon

The basic functional unit of compact bone consisting of osteocytes in lacunae arranged in concentric lamellae surrounding a central canal.

Lamina Propria

The layer of areolar connective tissue that anchors an epithelium to underlying structures in a mucous membrane.

Transudate

The watery fluid produced on the free surfaces of serous membranes to reduce friction between opposing parietal and visceral surfaces.

Synovial Membrane

An incomplete lining found in joint cavities that lacks a basement membrane, has gaps between cells, and secretes fluid to lubricate joint surfaces.

Myosatellite Cells

Unspecialized stem cells associated with skeletal muscle fibers that can divide to assist in muscle tissue repair.

Intercalated Discs

Specialized intercellular junctions connecting adjacent cardiac muscle cells that allow ion movement and synchronized contraction.

Neuroglia

Non-neuronal supporting cells in neural tissue that isolate, protect, and support neurons.

Blastocyst

An early stage of embryonic development consisting of a hollow ball of cells formed by cleavage about a week after fertilization.

Trophoblast

The outer layer of cells in a blastocyst that delivers nutrients to the developing embryo and contributes to placenta formation.

Inner Cell Mass

The cluster of cells inside the blastocyst that gives rise to the actual embryo and its primary germ layers.

Primitive Streak

A longitudinal line on the embryonic shield where migrating superficial cells move between ectoderm and endoderm to form the mesoderm.

Primary Germ Layers

The three embryonic tissue layers formed during the second week of development: ectoderm, mesoderm, and endoderm, which give rise to all body tissues.