Mesothelium is made up by ______________ epithelium.
simple squamous
Mesothelium characteristics (2)
1. Lines surfaces of body cavities
2. Peritoneal (abdomen), pleural (lungs), and pericardial (heart)
Endothelium lines (1) _______ vessels and (2) ________ vessels.
1. blood
2. lymphatic
Simple cuboidal forms a sheet or covering as over the (1)____, and forms (2)_____ of _______.
1. ovary
2. ducts, glands
Simple columnar may have secretory cells called (1) _______ that produce (2)_______ for lubrication. They line the (3)_________ and function in (4)___________ and (5) _____________.
1. goblet cells
2. mucus
3. intestine
4. secretion
5. absorption
Simple columnar may be ciliated as in these 4 locations:
1. Bronchioles
2. Oviducts
3. Fallopian Tubes
4. Efferent ductiles
(1)________________ may or may not be ciliated. If epithelium appears (2)_______, but is ciliated, it is (3)_________ epithelium, because stratified epithelium is never (3) _______.
1. Pseudostratified columnar
2. stratified
3. Pseudostratified columnar
4. ciliated
Pseudostratified columnar (ciliated with goblet cells) lines (1) ___________ and functions in (2)___________.
1. respiratory passages (trachea, bronchi)
2. moving surface material
Pseudostratified columnar function:______________.
absorption of materials (particles, mucus).
Pseudostratified columnar with stereocilia lines _____________.
part of the male reproductive tract (epididymis).
Cross linking protein found in keratinized stratified squamous.
Filaggrin
All epithelia possess ____________ (3 words).
keratin intermediate filaments.
Stratified cuboidal and columnar are (1) _____. They line (2) ______________ of some glands.
1. rare
2. large ducts
(1a) ______ can become (1b)_______ when very active and (2a)_______ can become (2b)______ when activity decreases a lot. Depends on (3) _______ of cell.
1. cuboidal, columnar
2. columnar, cuboidal
3. metabolic rate
Transitional epithelium (urothelium) characteristics (5)
1. Large dome shaped surface cells (unlike cuboidal)
2. Binucleated cells
3. Thin basement membrane
4. Not all cells attach to basement membrane
5. Lines urinary bladder and ureter
Transitional epithelium function
accomodates stretch - protects underlying tissue from hypertonic urine
Transitional epithelium can be (1)________ or (2)________. The latter looks like simple squamous.
1. contracted
2. distended.
Serous membrane. AKA? Type of secretion? Looks like what on LM?
aka "serosa"
watery secretion
pink and grape-like clusters on LM
Mucous membrane. AKA? Type of secretion? Looks like what on LM?
aka "mucosa"
mucus
white and puffy on LM
Tissue - definition
A group of cells that assemble to perform a common function - e.g. muscle cells form a muscle that can move a bone across a joint or a group of gland cells form a gland that can secrete a common product.
4 basic tissues in the body
1. Epithelium - covers body surface and cavities and forms glands
2. Connective - supporting tissue (e.g., bone)
3. Nervous - integrates and coordinates body activies
4. Muscle - produces movement in the body
Epithelium definition
the purely cellular, avascular, layer or layer of cells that covers body cavities (both inside and out) and forms glands - typically one side is exposed to air or fluid (apical) and the other is attached (basal)
2 types of epithelium
1. Lining or membranous epithelium - covers the surface of the body and lines organs (digestion, respiratory, and urogenital tracts - lines blood vessels, the heart, and body cavities)
2. Glandular epithelium - forms glands (exocrine and endocrine) and is
9 Characteristics of epithelium
1.Protection - skin, against mechanical trauma
2. Secretion - glands
3. Excretion - kidneys
4. Absorption - intestines
5. Filtration - renal corpsucle in kidney
6. Lubrication - glands in GI tract
7. Reproduction - germinal cells in testis
8. Transport -
Histogenesis of epithelium
Epithelium is derived from all 3 germ layers (endoderm, mesoderm, and ectoderm)
Microdomain definition
region of epithelial cell membrane that has a distinct structure or function (apical, lateral, basal, etc..)
Apical surface definition
Free Surface"
Faces air or fluid
Apical surface specializations
1. Cilia, microvilli, or stereocilia
2. Clathrin-coated vesicles
3. Glycocalyx
Apical surface function
Absorption
Recognition
Lateral surface definition
attached surface, usually to other epithelial cells
Lateral surface specialization
1. Junctional complexes
2. Gap junctions
3. Cell adhesion molecules (CAMs - involved in communication)
Lateral surface function
Attachment
Communication
Basal surface definition
often attached to connective tissue
Basal surface specialization
1. hemidesmosomes
2. membrane folds
Basal surface function
Attachment
Transport
Absorption
Zymogen granules
Have certain precursors that are proteins, but are not found in all epithelium cells.
More zymogen at 1. _______ surface. More mitochrondria at 2._________ surface.
1. apical
2. basal
All epithelium rest on __________________.
Basement membrane
Basement membrane is what + what?
Basal lamina + reticular lamina
Basal lamina is produced by ______________.
Epithelia.
Two parts of basal lamina
Lamina lucida (clear) and
Lamina densida (dark)
Basal lamina constituents (3)
1. Glycosaminoglycans (GAGs)
2. Collagen Type IV (Type IV does not form fibrils)
3. Laminin - glycoprotein, connects lamina to epithelial cells
Reticular lamina is produced by ______________.
Connective tissue.
Reticular lamina constituents (2)
1. Collagen type III (reticular collagen)
2. Glycosaminoglycans (GAGs)
Reticular lamina functions (2)
Support - physical, structural
Selective Filtration
1. Where is the nucleus found in epithelial cell?
2. The rough ER?
1. Middle or near base
2. Towards the base
What are found near the apical surface in epithelial cells?
Secretion granules
Golgi
1. points away from nucleus
2. points towards the nucleus
1. maturing face (trans)
2. forming face (cis)
Base of epithelium tends to be more (1)___________, staining the color (2)____ with (3)______ stain. This is because of the high concentration of (4)____________. Also known as (5)_____________ in neurons.
1. basophilic
2. blue
3. H&E (Hematoxylin & Eosin)
4. Ribosomes in ER
5. Nissl bodies
3 Types of Simple Epithelium
squamous, cuboidal, and columnar
Stratified squamous can be __________ or __________.
Keratanized (cornified) or nonkeratinized (noncornified)
Stratified epithelium always goes by the name of the ____ layer.
top
Simple squamous forms (1) ___________ in kidney and lines (2) ___________ in lungs.
1. Bowman's capsule
2. alveoli
Acinus (pl. acini) definition
secretory unit that has a grape-like shape with a small lumen
Mucous membrane characteristics (2)
1. Rich in proteins O-glycosylated with anionic oligosaccharides (more viscous)
2. Lines gastrointestinal and respiratory tracts
Mucous membrane function: In GI tract? In Respiratory tract?
In GI tract, mucus protects against chemical irritation.
In respiratory tract, traps inhaled particles.
Serous demilune
cap of serous cells on a mucous acinus
Blood in (1)________ gives serosa its fluid beause (2)________ are leaky.
1. mesothelium
2. capillaries
All (1)_________ and most (2)__________ glands are made up of epithelia. Two (3)__________ exceptions are (4)________ and _________.
1. exocrine
2. endocrine
3. endocrine
4. posterior pituitary, adrenal medulla
Products are secreted into ducts - (1)_____________
Hormones secreted into bloodstream - (2)___________
1. exocrine
2. endocrine
Exocrine glands can be (1)__________ or (2)__________.
1. unicellular (goblet cells)
2. multicellular
Multicellular exocrine glands can be further classified based on (5 things):
1. Shape (simple vs complex - tubular vs alveolar)
2. Type of secretion (mucous vs serous)
3. Mode of release (eccrine vs apocrine vs holocrine)
4. Shape (tubular, alveolar or acinar)
5. Complexity (simple - one duct, compound - multiple ducts)
Simple tubular gland (1):
Intestinal glands
Simple coiled tubular gland (1):
Eccrine sweat glands
Simple branched tubular gland (2):
1. Axillary glands
2. Glands of stomach
Simple alveolar gland (1):
Eyelid glands
Simple branched alveolar gland (2):
1. Seminal vesicle gland
2. Sebaceous glands of skin
Compound tubular gland (2):
1. some oral cavity glands
2. Brunner's glands of duodenum
Compound acinar (3):
1. Excretory portion of pancreas
2. Lacrimal gland
3. Mammary glands
Compound tubuloalveolar gland:
Salivary glands: sublingual, submandibular
6 characteristics of Serous Acinus
1. Pyramidal-shaped cells
2. Cell boundary indistinct
3. Spherical, big, round nucleus
4. Apical secretory granules - stain acidophilic (red/pink) with H&E
5. Basophilic cytoplasm around nucleus (much RER)
6. Secretory product is proteinaceous, thin, wate
6 characteristics of Mucous Acinus
1. Pyramidal-shaped cells
2. Cell boundary distinct
3. Nucleus flattened and at base of cell
4. Secretory product (mucinogen) is lost during prep of tissue so apical part of cell is clear with H&E. Secretory material is PAS+ (purple, stains basic).
5. Onl
Modes of secretory release (4):
1. Merocrine (eccrine)
2. Apocrine
3. Holocrine
4. Cytogenous
Merocrine (eccrine):
Secretory granules fuse with cell membrane and contents are released (serous or mucus).
Ex. pancreas or some sweat glands
Apocrine
Secretion is released with plasma membrane enveloping the particle (part of the cytoplasm leaves the cell)
Ex. mammary gland, axillary, and circumanal modified sweat glands
Holocrine
Whole cell dies and is secreted
Ex. sebaceous glands of skin
Cytogenous
Whole living cell is released
Ex. testis and ovary
Merocrine (eccrine) examples:
Pancreas or some sweat glands.
Apocrine examples:
Mammary gland
Axillary gland
Circumanal modified sweat glands
Holocrine examples
Sebaceous glands of skin
Cytogenous examples
Testis and ovary
Epitheloid cells definition
Cells with epithelial characteristics but lack a free surface.
Epitheloid cell examples (4):
1. Leydig cells (testis)
2. Luteal cells (ovary)
3. Adrenal parenchyma
4. Reticulo-epithelial cells of the thymus
Ectoderm (7):
1. Epidermis and its derivatives (hair, nail, sweat glands, sebaceous glands and the parenchyma and ducts of mammary glands)
2. Corenea and lens epithelia
3. Enamel of teeth
4. Inner ear
5. Neural tube and its derivatives (CNS)
6. Neural crest and its der
Mesoderm (4):
1. Epithelium of the kidney and gonads
2. Mesothelium - epithelium lining of the pericardial, pleural and peritoneal cavities.
3. Endothelium - epithelium lining of the cardiovascular and lymphatic vessels.
4. Adrenal cortex
Endoderm (5)
1. Respiratory system epithelium
2. Alimentary canal epithelium (excluding the epithelium of the oral cavity and anal region, which are of ectodermal origin)
3. Extramural digestive gland epithelium, e.g., liver, pancreas, and gall bladder
4. Thyroid, par
3 Types of Acini
Serous, Mucous, or Mixed (may or may not have serous demilunes)