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.
