Term
| What are the 4 types of tissue? |
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Definition
| Epithelial, connective, muscle, and neural |
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Term
| Characteristics of epithelia |
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Definition
1.Cellularity:composed almost entirely of cells held together by cell junctions
2.Polarity: exposed apical surface and an attached basal surface.
3. Attachment: bound to a thin noncellular basement membrane (basal lamina).
4. Avascularity: no blood vessels, obtain nutrients through diffusion
5.Regeneration: damaged & lost cells continuously replaced through stem cell division, very high rates. |
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Term
| 4 Essential functions of epithelia |
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Definition
1. Provide physical protection from abrasion, dehydration, and destruction by chemical or biological agents.
2.Control permeability.
3. Provide sensation: neuroepithelium provide sensations of smell, taste, sight, equilibrium, and hearing.
4.Produce specialized secretions: glandular epithelia |
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Term
| 3 types of cell junctions |
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Definition
1. tight junctions (occluding junction)
2. Gap junctions
3. Desmosomes (Macula adherens)
a)spot desmosomes
b)hemidesmosomes |
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Term
| Where is epithelia found? |
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Definition
-Covers exposed surfaces
-Lines internal passageways
-Forms glands |
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Term
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Definition
Fills internal spaces
Supports other tissues
Transports materials
Stores energy |
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Term
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Definition
| Specialized for contraction: found in skeletal muscle, heart muscle, and walls of hollow organs. |
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Term
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Definition
| Carries electrical signals from one part of the body to another. |
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Term
| In order to perform functions, highly specialized structure- polarity: cell divided into 2 distinct regions |
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Definition
Apical surfaces: exposed to internal or external environment
Microvilli increase absorption or secretion
Cilia (ciliated epithelium) move fluid
Basolateral surfaces:
Base- cellular attachment
Sides- cells contact neighbors |
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Term
| Intercellular connections |
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Definition
Epithelial cells tightly bound together
CAMs (cell adhesion molecules)- transmembrane proteins
Intercellular cement- proteoglycans contain hyaluronan (hyaluronic acid) |
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Term
| Occluding (tight) junctions |
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Definition
Between two plasma membranes
Adhesion belt attaches to terminal web
Prevents passage of water and solutes
Isolates wastes in the lumen of GI tract |
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Term
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Definition
Allow rapid communication
Held together by connexons (channel proteins)
Allow ions to pass between cells
Coordinate contractions in heart muscle |
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Term
| Desmosomes (Macula adherens) |
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Definition
CAMs, dense areas, intercellular cement link plasma membranes
Spot desmosomes- tie cells together & allow bending, twisting
Hemidesmosomes- attach cells to the basal lamina |
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Term
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Definition
| Small discs connected to intermediate filaments, which function to stabilize cell shape |
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Term
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Definition
Attach cell to extracellular filaments in basal lamina
Stabilize cell position and anchor to underlying tissues |
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Term
| Where are simple squamous epithelia found? |
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Definition
| Mesothelia line pleural, pericardial, and peritoneal cavities; endothelia line heart and blood vessels, portions of kidney tubules; inner lining of cornea; alveoli of lungs |
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Term
| Functions of simple squamous epithelium? |
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Definition
| Reduces friction, controls vessel permeability, performs absorption and secretion |
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Term
| Where are stratified squamous epithelia found? |
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Definition
| surface of skin; lining of mouth, throat, esophagus, rectum, anus, and vagina. |
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Term
| what are the functions of stratified squamous epithelium? |
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Definition
| Provides physical protection against abrasion, pathogens, and chemical attack. Apical layers of epithelia are packed with filaments of the protein keratin, making the cells tough and water resistant. Non-keratinized cells are found in the oral cavity, pharynx, esophagus, anus, and vagina. |
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Term
| Where are simple cuboidal epithelia found? |
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Definition
| Glands, ducts, portions of kidney tubules, thyroid gland |
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Term
| what are the functions of simple cuboidal epithelia? |
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Definition
| Provide limited protection, secretion, and absorption |
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Term
| Where are stratified cuboidal epithelia found? |
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Definition
| Rare; Found along the ducts of sweat glands, and in the larger ducts of the mammary glands. |
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Term
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Definition
Tolerates repeated cycles of stretching and recoiling without damage.
Found in urinary bladder, renal pelvis, and ureters. |
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Term
| Where is simple columnar epithelium found? |
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Definition
| Lining of stomach, intestines, gall bladder, uterine tubes, and collecting ducts of kidneys. |
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Term
| What are the functions of simple columnar epithelia? |
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Definition
| The secretions protect against chemical stresses, move mucus with cilia |
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Term
| Where is stratified columnar epithelium found?w |
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Definition
| Small areas of the pharynx, epiglottis, anus, mammary glands, salivary gland ducts, and urethra. |
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Term
| What is the function of stratified columnar epithelia? |
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Definition
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Term
| What is an endocrine gland do? |
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Definition
| Produces endocrine secretions (hormones)that are released directly into the surrounding interstitial fluid. No ducts. |
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Term
| Where are endocrine glands found? |
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Definition
| Lining of the digestive tract, or as separate organs, such as pancreas, thyroid gland, pituitary gland, thymus |
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Term
| What are exocrine glands? |
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Definition
| Produce exocrine secretions which are discharged onto an epithelial surface through tubular ducts.Ex: sweat, tears, milk, and enzymes entering the digestive tract. |
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Term
| Where are pseudostratified ciliated columnar epithelia found? |
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Definition
| Lining of nasal cavity, trachea, and bronchi; portions of male reproductive tract. |
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Term
| functions of pseudostratified ciliated columnar epithelia? |
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Definition
| Protection, secretion, move mucus with cilia |
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Term
| What are 3 modes of secretion? |
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Definition
| Merocrine, apocrine, and holocrine |
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Term
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Definition
| most common, the product is released from secretory vessels by exocytosis. |
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Term
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Definition
| Involves the loss of cytoplasm as well as the secretory product. The apical portion of the cytoplasm becomes packed with secretory vesicles and is then shed. |
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Term
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Definition
| The entire cell becomes packed with secretory vesicles and then bursts, releasing the secretion but killing the cell. |
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Term
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Definition
| Secrete a watery solution that contains enzymes. Ex: parotid salivary glands |
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Term
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Definition
| Secrete mucins that hydrate to form mucus. Ex: sublingual salivary glands, submucosal glands of the small intestine. |
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Term
| Describe mixed exocrine glands. |
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Definition
| Contain more than 1 type of gland cell. May produce 2 different exocrine secretions, 1 serous and 1 mucous. Ex:submandibular salivary gland |
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Term
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Definition
| The only unicellular exocrine gland, secrete mucins. |
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Term
| What are 3 characteristics describing the structure of multicellular exocrine glands? |
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Definition
1. The structure of the duct.
2. The shape of the secretory portion of the gland.
3. The relationship between the ducts and the glandular areas. |
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Term
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Definition
Simple Tubular: ex. intestinal glands
Simple coiled tubular ex: merocrine sweat glands
Simple branched tubular: ex:gastric glands, mucous glands of esophagus, tongue, duodenum
Simple alveolar (acinar) ex: not found in adult, a stage in development of simple branched glands
Simple branched alveolar: ex: sebaceous (oil) glands |
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Term
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Definition
Compound tubular ex: mucous glands in mouth, bulbourethral glands, seminiferous tubules
Compound alveolar ex: mammary glands
Compound tubuloalveolar ex: salivary glands, glands of respiratory passages, pancreas |
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Term
| 3 basic components of connective tissue |
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Definition
1.specialized cells
2.extracellular protein fibers
3.ground substance |
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Term
| What are the functions of connective tissue? |
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Definition
*establishing a structural framework for the body-bone
*transporting fluids and dissolved materials-blood
*Protecting delicate organs
*Supporting, surrounding, and interconnecting other types of tissue
*Storing energy, esp. in the form of triglycerides-fat
*Defending the body from invading microorganisms
Have no contact with the outside environment |
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Term
| What are the 3 categories of connective tissue? |
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Definition
Connective tissue proper
Fluid connective tissue
Supporting connective tissue |
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Term
| What are the cells in connective tissue proper? |
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Definition
Fibroblasts
Fibrocytes
Mesenchymal cells
Macrophages
Mast cells
Lymphocytes
Microphages
Adipocytes
Melanocytes |
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Term
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Definition
| Most abundant, only cells that are always present in connective tissue proper, secrete hyaluronan (cellular cement). Extracellular fluid, hyaluronan, and proteins interact to form the proteoglycans that make ground substance viscous. Secrete protein subunits that assemble to form large extracellular fibers. |
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Term
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Definition
| the 2nd most abundant fixed cell. They differentiate from fibroblasts.Spindle shaped cells that maintain the connective tissue fibers of connective tissue proper. |
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Term
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Definition
| Form tubes, straight or coiled |
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Term
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Definition
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Term
| Tubuloalveolar exocrine glands |
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Definition
| Both tubes and blind pockets |
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Term
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Definition
Big eaters” immune system:
Eat pathogens & damaged cells
Fixed macrophages- stay in tissue
Free macrophages- migrate |
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Term
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Definition
| Fat cells- each cell stores a single, large fat droplet |
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Term
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Definition
Stem cells that respond to injury or infection:
Differentiate into fibroblasts, macrophages |
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Term
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Definition
| Synthesize and store the brown pigment melanin. |
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Term
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Definition
Stimulate inflammation after injury or infection:
Release histamine and heparin
Basophils (white blood cells) also contain histamine and heparin |
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Term
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Definition
Specialized immune cells in lymphatic system:
B-cells (plasma cells)- produce antibodies
T-cells |
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Term
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Definition
neutrophils and eosinophils-Phagocytic white blood cells:
Respond to signals from macrophages & mast cells |
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Term
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Definition
| Synthesize and store melanin.Abundant in the connective tissues of the eye and the dermis of the skin. |
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Term
| What are the 3 types of connective tissue fibers? |
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Definition
| Collagen, Reticular, and Elastic |
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Term
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Definition
most common in connective tissue proper. Long, straight, and unbranched. Strong and flexible.
Ex. tendons and ligaments |
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Term
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Definition
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Term
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Definition
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Term
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Definition
Network of interwoven fibers- stroma
Strong & flexible
Stabilize functional cells (parenchyma) & blood vessels, nerves
Sheaths around organs |
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Term
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Definition
| Contain elastin, branched and wavy. Elastic ligaments are rare, but have important functions such as interconnecting vertebrae |
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Term
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Definition
| fills the spaces between cells and surround connective tissue fibers Clear, colorless, viscous. Slows the spread of pathogens. |
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Term
| Embryonic Connective tissue (mesenchyme) |
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Definition
| 1st connective tissue in an embryo. Gives rise to all other connective tissues. |
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Term
| Mucous connective tissue (Wharton's jelly) |
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Definition
| loose connective tissue found in the umbilical cord |
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Term
| 4 types of loose connective tissue |
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Definition
Mucous connective tissue in embryos
Areolar
Reticular
Adipose |
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Term
| Functions of loose connective tissue |
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Definition
Fill spaces between organs
cushion and stabilize specialized cells
support epithelia |
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Term
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Definition
Least specialized
Open framework
Viscous ground substance most volume
Elastic fibers
Holds blood vessels & capillary beds
Under skin (subcutaneous layer), padding |
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Term
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Definition
Contains many adipocytes (fat cells)
Types of adipose tissue
White fat:
Most common
Stores fat, absorbs shocks, slows heat loss (insulation)
Brown fat:
More vascularized
Adipocytes have many mitochondria
When stimulated by nervous system, fat break down accelerates, releasing energy
Energy absorbed from surrounding tissues- heats body |
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Term
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Definition
Adipose cells
Adipocytes in adults do not divide:
Expand to store fat
Shrink as fats are released
Mesenchymal cells divide and differentiate:
Produce more fat cells when more storage is needed |
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Term
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Definition
Provides support
Complex, 3D network- stroma
Support functional cells (parenchyma)
Reticular organs
Spleen, liver, lymph nodes, and bone marrow |
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Term
| Where is areolar tissue found? |
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Definition
| within and deep to the dermis of the skin,between muscles, around joints, blood vessels, and nerves |
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Term
| Where is adipose tissue found? |
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Definition
| deep to the skin, esp.at sides, buttocks, and breasts; padding around eyes and kidneys |
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Term
| What are the functions of adipose tissue? |
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Definition
| Provides padding and cushions shocks;insulates (reduces heat loss); stores energy |
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Term
| what are the functions of areolar tissue? |
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Definition
| cushions organs, provides support but permits independent movement; phagocytic cells provide defense against pathogens. |
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Term
| Where is reticular tissue found? |
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Definition
| liver, kidney, spleen, lymph nodes, and bone marrow |
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Term
| What is the function of reticular tissue? |
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Definition
| Provides supporting framework. |
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