Histology Flashcards
Smooth Muscle
Description: spindle shaped cells with central nuclei; no striations; cells arranged closely to form sheets
Function: propels substances (food stuff, urine, baby) along internal passageways; involuntary control
Location: mostly in the walls of hallow organs
Skeletal Muscle
Description: long, cylindrical, multinucleated cells; obvious striations.
Function: voluntary movement; locomation; manipulation of the enivornment; facial expression; voluntary control
Location: in skeletal muscles attached to bones or occasionally to skin
Cardiac Muscle
Description: branching, straited, generally uninucleate
Function: as it contracts, it propels blood into circulation; involuntary control
Location: the walls of the heart
Nervous tissue
Description: neurons are branching cells; wilth cell process that may be quite long extend from the nucleus containign cells body
Function: transmit electrical signals from sensory recpetors into effectors (muscles and glands) with control their activity.
Location: brain, spinal cord, and nerves
Connective Tissue: Blood
Description: RBC and WBC in a plasma
Function: transport of respiratory gases, nutrients, wastes, and other substances
Location: contained within blood vessels
Connective Tissue: Bone (osseous tissue)
Description: hard, calcified matrix containing many collagen fibers; osteocytes lay lacunae. Very well vascularized
Function: supoorts and protect organs; provides levers for the muscles to act on; stores calcium and fat; marrow inside of bones is the site of blood cell formation (hematopoiesis)
Connective Tissue: Fibrocartilage (Cartilage)
Description: martix similar to but less firm that hyaline cartlage; thick collagen fiber predominate
Function: tensile strength with the ability to absorb compressive shock
Location: intervertebral disc; pubic symphysis; disc of knee joints
Connective Tissue: Elastic Cartilage
Description: similar to hyaline catilage but, more elastic fibers in the matrix
Function:maintains the shape of a structure while allowing great flexibility
Location: supports the external ear: epiglottis
Connective Tissue: Hyaline Cartilage
Description: Amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae.
Function: Supports and reinforces; has resilient cushing properties; resists compressive.
Location: Forms most of the embryonic skeleton; covers the ends of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx
Connective tissue proper: dense irregular
Description: primarily irregularly arranged collagen fiber; some elastic fibers; major cell type is the fibroblast.
Function: able to withstand tension extered in many directions; provides structural strength.
Location: Fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract.
Connective tissue proper: elastic (dense)
Description: dense regular connective tissue containing a high proporation of elastic fibers.
Function: Allows recoil of tissue folloowing stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration.
Location: Walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes.
Connective tissue proper: dense regular
Description: Primarily parallel collagen fibers; a few elastic fibers; major cell type is the fibroblast.
Function: Attaches muscles to bones or to muscles; attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction.
Location: Tendons, most ligaments, aponeuroses
Connective tissue proper: reticular (loose)
Description: network of reticular fibers in a typical loose ground substance; reticular cells lie on the network
Function: fibers form a soft internal skeleton that supports other cell types, including white lood cells, mast cells, and macrophages.
Location: lymphoid organs (lymph nodes, bone marrow, and spleen)
Connective tissue proper: areolar (loose)
Description: gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells.
Function: wraps and cushions organs; it macrophages phagocytize bacteria; plays important role in inflammation: holds and conveys tissue fluid.
Location: widely distributed under epithelia of body. forms lamina propia of mucous membranes; packages organs; surrounds capillaries.
Connective tissue proper: adipose (loose)
Description: matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplets.
Function: provides reserve fuel; insulates agasinst heat loss; supports and protects organs.
Location: under skin; around kidneys and eyealls; within abdomen; in breasts.
Embryonic connective tissue: mesenchyme
Description: Embryonic connective tissue; gel-like ground substance containing fibers; star-shaped mesenchmall cells.
Function: gives rise to all other connective tissue types
Location: primarily in embryo
Simple squamous epithelium
Description: single layer of flattened of cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia
Function: allows passage of material by diffusion adn filteration in sites where protection is not important; secretes lubricating substances in serosae.
Location: kidney glomeruli; air sacs of lungss; lining of heart; blood vessels, and lympathic vessels; lining of ventral body cavity (serosae)
Simple cuboidal epithelium
Description: single layer of cublike cells with large, spherical central nuclei.
Function: secretion and absorption
Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface
Simple columnar epithelium
Description: Single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain goblet cells
Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated types propel mucus or reproductive cells.
Location: nonciliated type lines from stomach to anal canal, gallbladder, and excretory ducts of some glands, ciliated lines small branchi, uterine tubes, and some regions of the uterus
Pseudostratified columnar epithelium
Description: Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia.
Function: secretion (mucus); propulsion of mucus
Location: nonciliated in male’s sperm-carrying ducts and large gland; ciliated line the trachea and most of the upper respiratory tract.
