Chapter 4 Flashcards
Pertaining to a primary tissue that covers the body surface, lines its internal cavities, and forms glands.
Epithelial tissue
Special Characteristics of Epithelial Tissues
- Polarity
- Specialized contacts
- Supported by connective tissue
- Avascular but innervated
- Regeneration
Description: Single layer of flattened cells with Deric-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia
Epithelium: simple squamous
Function: Allows materials to pass by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae (lining of ventral body cavity)
Epithelium: Simple Squamous
Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; serosae
Epithelium: Simple Squamous
Description: Single layer of cube-like cells with large, spherical central nuclei
Epithelium: Simple Cuboidal
Function: Secretion and absorption
Epithelium: Simple Cuboidal
Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface
Epithelium: Simple Cuboidal
Description: Single layer of tall cells with rounded dot oval nuclei; many cells bear microvilli, some bear cilia,; layer may contain mucus-secreting unicellular glands (goblet cells)
Epithelium: Simple Columnar
Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus 9or reproductive cells) by ciliary action
Epithelium: Simple Columnar
Location: Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus
Epithelium: Simple Columnar
Description: Singe 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
Epithelium: Pseudostratified columnar
Function: Secrete substances, particularly mucus; propulsion of mucus by ciliary action
Epithelium: Pseudostratified columnar
Location: Ciliated variety lines the trachea and most of the upper respiratory tract; nonciliated type in males’ sperm-carrying ducts and ducts of large glands
Epithelium: Pseudostratified columnar
Description: Thick epithelium composed of several layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers
Epithelium: Stratified Squamous
Function: Protects underlying tissues in areas subjected to abrasion
Epithelium: Stratified Squamous
Location: Nonkeratinized type form the moist lining of the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin, a dry epithelium
Epithelium: Stratified Squamous
Description: Resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamous like, depending on degree of organ stretch
Epithelium: Transitional
Function: Stretched readily, permits stored urine to distend urinary organ
Epithelium: Transitional
Location: Lines the ureters, bladder, and part of the urethra
Epithelium: Transitional
Glands that have ducts through which their secretions are carried to a particular site.
Exocrine glands
Ductless glands that empty their hormonal products directly into the blood.
Endocrine glands
Description: Gel-like matrix with all three fibre types; cells: fibroblasts, macrophages, mast cells, and some white blood cells
Function: Wraps and cushions organs; its macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fluid
Location: Widely distributed under epithelia of body, e.g., forms laminate proprietors of mucous membranes; packages organs; surrounds capillaries
Connective Tissue ->Proper -> Loose -> Areolar
A primary tissue; form and function vary extensively. Functions include support, storage, and protection.
Connective tissue
Description: Matrix as in Areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet
Function: provides reserve food fuel; insulates against heat loss; supports and protects organs
Location: Under skin in subcutaneous tissue; around kidneys and eyeballs; within abdomen; in breasts
Connective Tissue -> Proper -> Loose -> Adipose
Description: Loose network of reticular fibres in a gal-like ground substance; reticular cells lie on the fibres
Function: Fibres form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages
Location: Lymphoid organs (lymph nodes, bone marrow, and spleen)
Connective Tissue -> Proper -> Loose -> Reticular
Description: Primarily parallel collagen fibres; a few elastic fibres; 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 -> Dense -> Regular
Description: Primarily irregularly arranged collagen fibres; some elastic fibres; fibroblast is the major cell type
Function: Withstands tension exerted 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 -> Dense -> Irregular
Description: Dense regular connective tissue containing a high proportion of elastic fibres
Function: Allows tissue to recoil after stretching; maintains pulsation 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 -> r -> Dense -> Elastic
Description: Amorphous but firm matrix; collagen fibres form an imperceptible network; chondrblasts produce the matrix and when mature (as chondrocytes) lie in lacunae
Function: Supports and reinforces; serves as resilient cushion; resists compressive stress
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 -> Cartilage -> Hyaline
Description: Similar to hyaline cartilage, but more elastic fibres in matrix
Function: Maintains the shape of a structure while allowing great flexibility
Location: Supports the external ear (pinnacle); epiglottis
Connective Tissue -> Cartilage -> Elastic
Description: Matrix similar to but less firm than that in hyaline cartilage; thick collagen fibers predominate
Function: Tensile strength allows it to absorb compressible shock
Location: Intervertebral discs; pubic symphysis; discs of knee joint
Connective Tissue-> Cartilage -> Fibrocartilage
Description: Hard, calcified matrix containing many collagen fibres; osteocytes lie in lacunae. Very well vascularized
Function: Supports and protects (by enclosing); provides levers for the muscles to act on; stores calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoietic)
Location: Bones
Connective Tissues -> Bones
Description: Red and white blood cells in a fluid matrix (plasma)
Function: Transports respiratory gases, nutrients, wastes, and other substances
Location: Contained within blood vessels
Connective Tissue -> Blood
