Human AP Chapter 4-6

Stratified cuboidal epithelium

Rare epithelium with multiple layers and cuboidal surface cells; functions in protection and secretion and occurs in some gland ducts.

Stratified columnar epithelium

Rare epithelium with multiple layers and columnar surface cells; functions in protection and secretion.

Transitional epithelium

Stratified epithelium specialized to stretch. It lines parts of the urinary system such as the bladder and ureters.

Goblet cell

A unicellular exocrine gland that releases mucus directly onto an epithelial surface.

Multicellular exocrine gland

An exocrine gland made of many secretory cells and a duct system; examples include sweat, oil, and salivary glands

Simple exocrine duct

An exocrine duct that is unbranched.

Compound exocrine duct

An exocrine duct that is branched.

Tubular secretory unit

An exocrine secretory portion shaped like a tube.

Acinar secretory unit

An exocrine secretory portion shaped like a sac or cluster.

Merocrine secretion

The product is released by exocytosis with little or no loss of cell material.

Gland

An epithelial structure specialized to produce and release a secretion.

Exocrine gland

Releases products through a duct to an epithelial surface; most products act locally.

Endocrine gland

Ductless gland that releases hormones into interstitial fluid and then the bloodstream, allowing effects on distant target cells.

Unicellular exocrine gland

A single secretory epithelial cell, such as a goblet cell.

Connective tissue - basic composition

Cells embedded in an extracellular matrix composed of fibers and ground substance.

General connective tissue functions

Connecting and binding, support, strengthening, protection, insulation, transport, immune responses, and energy storage.

Two broad connective tissue categories

Connective tissue proper and specialized connective tissue

Resident connective tissue cells

Cells that normally remain in the connective tissue.

Migrant connective tissue cells

Cells that move into connective tissue from the blood or other locations when needed.

Fibroblast

A major connective tissue cell that synthesizes fibers and ground substance.

Adipocyte

A fat-storing connective tissue cell.

Mast cell

A connective tissue immune cell that releases inflammatory mediators.

Dense regular collagenous connective tissue

Dense connective tissue with parallel collagen bundles; strong in one direction and found in tendons and many ligaments.

Dense regular elastic connective tissue

Dense tissue dominated by parallel elastic fibers; allows stretch and recoil.

Specialized connective tissues

Cartilage, bone, and blood

Cartilage

A tough but flexible connective tissue that absorbs shock and resists tension and compression. Chondrocytes lie in lacunae.

Chondrocyte

A mature cartilage cell found in a lacuna.

Lacuna

A small space in the extracellular matrix that houses a chondrocyte in cartilage or an osteocyte in bone.

Hyaline cartilage

The most common cartilage. It contains fine collagen fibers and is found at articular surfaces, in the nose, parts of the respiratory tract, and at costal cartilages.

Fibrocartilage

Strong cartilage with abundant collagen bundles and no perichondrium; found in intervertebral discs and some joints.

Leukocyte

A white blood cell involved in immune defense.

Plasma

The fluid extracellular matrix of blood.

Muscle tissue

Tissue specialized for contraction, converting chemical energy from ATP into mechanical energy of movement.

Excitable muscle cell

A muscle cell that responds to electrical or chemical stimulation.

Actin and myosin

Contractile proteins that generate force in muscle cells

Striation

A banded appearance produced by the regular organization of contractile proteins.

Skeletal muscle tissue

Voluntary muscle composed of long, striated, multinucleated fibers; usually attached to bones.

Cardiac muscle tissue

Involuntary, striated muscle found only in the heart. Cells are short, branched, and joined by intercalated discs.

Neuroglia / glial cell

Supporting cells of nervous tissue.

Organ

A structure composed of several tissue types that work together to perform one or more functions.

Tissue cooperation in organs

Different tissues within an organ contribute complementary functions so the organ can perform its overall role

Body membrane

A thin sheet of one or more tissues that can anchor organs, serve as a barrier, participate in immunity, and/or secrete substances.

Serous membrane

A true membrane that lines body cavities closed to the exterior and secretes serous fluid; forms pleural, pericardial, and peritoneal membranes.

Synovial membrane

A true membrane that lines freely movable joint cavities and secretes synovial fluid for lubrication; it lacks an epithelial layer.

Mucous membrane

A membrane-like structure that lines body passages and hollow organs that open to the exterior and secretes mucus.

High-regeneration tissues

Epithelial tissue, most connective tissues, and smooth muscle typically have relatively good regenerative capacity.

Low-regeneration tissues

Epithelial tissue, most connective tissues, and smooth muscle typically have relatively good regenerative capacity.

Mitosis and repair

In general, tissues with greater mitotic ability have a greater capacity for repair

Skin

The body's cutaneous membrane, composed of the superficial epidermis and deeper dermis.

Hypodermis

Layer deep to the dermis that anchors the skin to underlying structures and commonly contains adipose tissue.

Major integumentary functions

Protection, sensation, thermoregulation, excretion, and vitamin D synthesis.

Epidermis

Superficial, avascular layer of the skin composed of keratinized stratified squamous epithelium.

Five epidermal strata - deep to superficial

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.

Stratum basale

Deepest epidermal layer; contains dividing basal cells and also melanocytes and tactile cells.

Stratum spinosum

Epidermal layer superficial to the basale; contains keratinocytes linked strongly by desmosomes and contains dendritic cells.

Stratum granulosum

Epidermal layer superficial to the spinosum in which keratinization becomes prominent.

Stratum lucidum

Clear epidermal layer found only in thick skin, between the granulosum and corneum.

Stratum corneum

Most superficial epidermal layer composed largely of dead, keratinized cells.

Thick skin

Skin with all five epidermal strata, especially a thick stratum corneum; found on palms and soles.

Thin skin

Skin with four epidermal strata; it lacks a stratum lucidum and covers most of the body.

Carotene

Yellow-orange pigment that can contribute to skin color.

Hemoglobin

Blood pigment whose color contributes to the visible color of skin, especially where blood flow is near the surface.

Skin color and pathology

Abnormal color changes can reflect disease or altered blood flow/oxygenation; the course objective expects skin coloration to be used as a clinical clue.

Hair / pilus

A filament of dead, keratinized keratinocytes that protects and helps sense the environment.

Hair shaft

Part of a hair that projects above the skin surface

Hair root

Part of a hair anchored within the follicle below the skin surface.

Hair follicle

Epidermal invagination/sac in the skin from which hair grows

Hair bulb

Expanded base of the hair root.

Nail root

Proximal part of the nail from which the nail grows

Nail matrix

Proliferative region that produces the nail.

Nail bed

Epidermal surface on which the nail body rests

Lunula

Pale crescent at the proximal nail body over the matrix.

Eponychium / cuticle

Fold of epithelium at the proximal nail that overlaps the nail body.

Hyponychium

Thickened epidermis under the free edge of the nail.

Sweat / sudoriferous gland

A gland in the dermis that produces sweat. Sweat glands use merocrine secretion in the broad course classification.

Eccrine sweat gland

Most common sweat gland; a coiled gland that releases watery, hypotonic sweat onto the skin surface and is important in thermoregulation.

Second-degree burn

Partial-thickness burn involving the epidermis and part of the dermis; often produces blisters.

Third-degree burn

Full-thickness burn that destroys the epidermis and dermis and may destroy sensory endings

Basal cell carcinoma

Skin cancer arising from cells in the stratum basale; generally the most common type.

Squamous cell carcinoma

Skin cancer arising from keratinocytes of the stratum spinosum.

Malignant melanoma

Cancer of melanocytes; highly aggressive because of its ability to metastasize.

ABCDE melanoma warning signs

Asymmetry, irregular Borders, varied Color, Diameter greater than about 6 mm, and Evolving/changing appearance.

Skeletal system - major components

Bones, joints, and other supporting structures.

Spongy bone

Honeycomb-like internal bone composed of trabeculae.

Diaphysis

Shaft of a long bone.

Epiphysis

Expanded end of a long bone.

Metaphysis

Region between the diaphysis and epiphysis; contains the epiphyseal plate in growing bone.

Medullary cavity

Hollow cavity in the diaphysis of a long bone; commonly contains yellow marrow in adults.

Endosteum

Delicate membrane lining the medullary cavity and internal bone surfaces.

Articular cartilage

a type of hyaline cartilage covering bone surfaces at synovial joints; reduces friction and absorbs shock.

Red bone marrow

Marrow containing hematopoietic tissue that produces blood cells.

Osteoclast

Bone-resorbing cell that breaks down bone matrix.

Bone deposition

Formation of new bone matrix, primarily by osteoblasts.

Bone resorption

Breakdown of bone matrix, primarily by osteoclasts.

Osteon / Haversian system

Basic cylindrical structural unit of compact bone.

Concentric lamellae

Rings of calcified matrix arranged around the central canal of an osteon

Central / Haversian canal

Canal running through the center of an osteon containing blood vessels, nerves, and lymphatic vessels.

Perforating / Volkmann canal

Canal running across osteons that connects central canals with vessels of the periosteum and endosteum.

Bone lacuna

Small space in bone matrix that contains an osteocyte.

Intramembranous ossification - sequence

Mesenchymal cells form ossification centers, become osteoblasts, secrete osteoid, osteoid calcifies, trabeculae form, and surrounding tissue develops into periosteum and compact bone.