Download EPITHELIAL AND CONNECTIVE TISSUES, 50 point quiz help. I

EPITHELIAL AND CONNECTIVE TISSUES, 50 point quiz help.
I. Types of Basic Tissues
A.
B.
C.
D.
Epithelial - covers body surfaces, lines body cavities and lumens, forms glands.
Connective - supports and protects, binds organs together.
Muscle- moves parts of the body by contraction.
Nerve- conducts impulses and coordinates activities of other tissues.
II. Epithelial Tissue
A. Functions
1. Forms physical barriers, allows for sensation, absorption and secretion\diffusion.
2. Forms unicellular and multicellular glands (endocrine and exocrine).
B. Characteristics
1. Rests on a basement membrane (basal and reticular lamina).
2. Tightly packed cells with very little to no intercellular matrix or fluid between cells.
3. Cells are arranged in continuous sheets either singly or multilayered.
4. Avascular- receives nutrients by diffusion nutrients/gases through the lamina.
5. Highly regenerative- cells can divide and produce more epithelium (basal cell layer).
C. Two specific types (membranous and glandular epithelium)
1. Membranous (covering and lining- external and internal surfaces)
a.
b.
c.
d.
Named by number of layers, shape of superficial cells, and modifications.
Arrangement of layers
1) simple- one layer (diffusion, secretion)
2) stratified- more than one layer (protection)
Cell shapes- (remember that for stratified types use the superficial cells only)
1) squamous- flat
2) cuboidal- cube shaped
3) columnar- long and cylindrical
4) transitional- many shapes
Surface Specializations or modifications
1) microvilli, cilia and/or stereocilia
2)Keratinized (keratin- protein provides water resistance/proofing)
Classification (specific name for type of epithelial tissue)
1) simple squamous- endothelium (vessels), mesothelium (body cavities)
2) simple cuboidal- ovary, thyroid gland
3) simple columnar
a) non-ciliated – GI system
b) ciliated -- respirator
3) simple columnar
a) non-ciliated – GI system
b) ciliated – respiratory system
1. Membranous continued:
4) pseudo-stratified –respiratory system
some are goblet (mucus secreting) cells most have cilia
5) stratified squamous
a) keratinized – skin
b) non-keratinized – digestive system
6) stratified cuboidal - sweat gland ducts
7) stratified columnar - large ducts
8) transitional- urinary system
2. Glandular
a. endocrine – ductless, discharge into blood
b. exocrine – duct to where needed
1) structural classification
a) unicellular – mucous producing goblet cells
b) multicellular
i) simple- cluster of secretory cells associated with one duct
ii) compound-branching duct
2) functional classification
a) holocrine – accumulates secretion, cell dies, cell disintegrates to release
secretion.
b) meocrine – secretions are synthesized, packaged in membrane-encased
granules released at the cell surface without significant change in the cell.
c) aprocine- accumulate produces at the apex of the cell and release them
by pinching off parts of the cell, cells survive and continue to secrete
III. Connective Tissue
A. Functions
1.Supportive framework
2.Protection of internal organs and nerves
3. Bind organs and structures together
4. Stores fat
5. Defends against disease
6. Transports essential substances
B. Characteristics
1. Do not occur on free or exposed surfaces
2. Cells are widely scattered- not closely packed
3. Much intercellular fluid called matrix (varies in texture)
4. Most have a very rich blood supply
C. Embryonic Connective Tissues
1. Mesenchyme- “magic” gives rise to almost all other connective tissue elements
2. Mucous –found in umbilical cord of fetus (which gives support for wall of cord)
D. Adult Types
1. Connective tissue proper
a.
Components
1) Ground substance- provides a pathway through which the exchange of nutrients and
waste products can take place between the blood and connective tissue cells; is relatively
fluid and provides greater freedom for exchange of materials than does the dense matrix
of cartilage and bone; hyaluronic acid.
2) Fibers
- nonliving strands of complex proteins
- products of living cells
- provide most of the strength because they resist stretch without breaking.
a) Collagenous – white, very strong, do not stretch. Made up of collagen proteins from
fibrils which then form layer bundles called fibers, are located in the body where
great strength is need; found in ligaments and tendons.
b) Elastic – yellow, does stretch, smaller freely branched, made of protein calls elastin;
found in walls of blood vessels and resp. system.
c) Reticular – very thins strands of collagen that branch to form a fine, delicate network
to support structures such as small blood vessels and nerve fibers, located near the
basement membrane; found in stroma of organs.
3) Cells
a) fibroblasts- elongated, stellate cell that produces and maintains fibers
b) macrophage – motile cells capable of ingesting particulate matter by phagocytosis,
defend against disease
c) plasma cell – produce antibodies
d) fat cell (adipose cell) – stores large amounts of fat in the form of oil droplets which can
be used for energy.
e) Mast cell – non motile cell which contains heparin (prevent blood clotting) and
histamine (increase capillary permeability)
f) leukocytes (WBC) – motile, body defense
g) primitive reticular cell- produces reticular fibers
B. Types
1. Loose, areolar connective tissue- contains several types of cells widely separated by
amorphous ground substance and a sparse network of intercellular fibers.
2. Reticular connective tissue- contains specialized phagocytic cells and is found in the liver,
spleen and lymph nodes, and bone marrow.
3. Adipose tissue- stores fat and provides protection and insulation. It is found in the hypodermis
of the skin, surrounding the kidneys and the surface of the heart and surrounding joints.
4. Dense connective tissue- more fibers, less cells, less amorphous ground substance, fibers
mostly collagenous, cell mostly fibroblasts, fibers oriented in direction of tension.
a) dense irregular c.t.- found in regions where tension is exerted in several
directions (dermis of skin and covering of muscle)
b) dense regular c.t. – many bundles of collagen oriented in same
direction; (tendons and ligaments)
5. Elastic connective tissue- has a predominance of elastic fibers and
in large arteries, the respiratory tract, and between vertebrae.
E. Specialized Connective Tissue
1. Cartilage
a.
Components
1. Ground substance- polysaccharides( i.e., chondroitin sulfates - gelatinous)
2. Fibers
a) Collagen
b) Elastic
3. Cells- chondrocytes in lacunae
b. Types
1) hyaline- most common type, glassy white or slightly bluish, firm, chondrocytes
produce collagen fibers and chondrocytes produce not very many collagen fibers; found
in joints, ends of ribs, nose, and trachea
2) fibrocartilage- many collagen fibers, very strong, found in sites where stress is great
and little movement is necessary; found in intervertebral discs, pubic symphysis.
3) elastic- contains many elastic fibers, more flexible than hyaline cartilage, flexibility
retained throughout life; found in epiglottis, ear, Eustachian tube.
2. Bone (osseous) Tissue – Consists of osteocyte, collagenous fibers, and a durable matrix of
minerals. There are two types of bone tissue: compact and spongy.
3. Blood- is vascular connective tissue which consists of formed cellular elements suspended in
a fluid plasma matrix.