Chapters 4-6 Flashcards
(27 cards)
Which types of tissues regenerate if they are damaged?
Epithelial tissue
Connective tissue
* muscle can regenerate at a slow pace if it has satellite cells.
What is a tissue
The living fabrics of life.
Collections of singular cells that act together to perform a function (organ)
4 types of tissues
Epithelial tissue
Connective tissue
Muscle tissue
Neural tissue
What is a Gland?
Structures that produce fluid secretions.
Attached to or derived from Epithelium
Characteristics of Epithelia
Cellularity (cell junctions)
Polarity
Apical surface: Microvilli increase absorption or
secretion Cillia move fluid Basolateral surface Attachment (to basement membrane/basal lamina) Avascularity Regeneration
Functions of Epithelia
Physical protection (stratified)
Control permeability
Provide sensation
Produce specialized secretions (glandular epithelium)
Absorption
Filtration
Elimination
Maintaining integrity of Epithelia
(what keeps epithelial healthy and intact)
Intercellular connections: support and communication
Connection to basement membrane
Epithelial maintenance and repair
Cell Junctions: 3 Types
Cell Junctions: form bonds with other cells or extracellular material
Tight junctions: Between two plasma membranes
Adhesion belt attaches to terminal web
Prevents passage of water and solutes between the cells
Isolates content of lumen from basolateral surface
Gap junctions: Allow rapid communications
Held together by channel proteins (junctional proteins, connexons)
Allows ions to pass
Coordinate contractions in heart muscle
**Desmosomes** : CAMs (cell adhesion molecules) desne areas, and intercellular cement.
Very strong and resist twisting
1. Spot desmosomes: Tie cells together
Allow bending and twisting
2. Hemidesmosomes: Attach cells to basal lamina
How is Epithelium Classified?
Shape: Squamous, Cuboidal, Columnar
Layers: Simple, Stratified
Simple Squamous Epithelium
Simple Squamous Epithelium: Most delicate epithelium
Absorption and diffusion
Locations: Kidney tubules, linner lining of cornea, alveoli of lungs
Mesothelium: Lines ventral body cavities
Derived from embryionic mesoderm
_Endothelium: _ Lines the inner surface of the heart and all blood vessels.
Stratified Squamous Epithelium
Protects against attacks, abrasion and pathogens
Keratin protein adds strength and water resistance
Keratinized – where there is no moisture surface of skin
Non-keratinized – where there is moisture Oral cavity, esophagus
Simple Cuboidal Epithelium
Secretion and absorption, limited portection
Locations: Glands, ducts, portions of kidney tubules, thyroid gland, glomerulus
Stratified Cuboidal Eithelium
Protection, secretion, absorption
Locations: lining of some ducts (rare)
Transitional Epithelium
Permits expansion and recoiling after stretching.
Locations: Urinary bladder, male urethra
Simple Columnar Epithelium
Absorption and secretion
Microvilli: increase surface area
Cillia: some have it and some don’t
Goblet Cells: Only place they exist.
Unicellular exocrine gland - secretes
Locations: Lining of stomach, intestines gallbladder, uterine tubes and collecting ducts of kidneys
Pseudostratified Columnar Epithelium
Move mucus w/cillia
False layers –nucleus overlap
Cillia or microvilli might be present.
Locations: Lining of nasal cavity, trachea, bronchi, male reproductive tract
Stratified Columnar Epithelium
Protection
Locations: Salivary glands, pharynx, epiglottis, anus, mammary glands and urethra.
2 Types of Glandular Epithelum
Endocrine: Release hormones into interstitial fluid
No ducts – release into body cavities
Most abundant
Exocrine Glands: Secrete onto epithelial surfaces through ducts
Glandular Epithelia: Modes of Secretion
Merocrine Secretion (eccrine)
Produced in Golgi Apparatus
Released by vesicles (Exocytosis)
Sweat glands, salivary glands
Perspiraton, mucus
Apocrine Secretion
Produced in Golgi apparatus
Released by shedding cytoplasm
Mammary glands, axilary, pubic
Holocrine Secretion
Released by cells bursting, killing gland cells
Gland cells replaced by stem cells
Sebacious glands
Types of Secretions
Types of secretions:
Serous glands: watery secretions
Mucous Glands – mucins
Mixed exocrine glands
Both serous and mucous
(Salivary glands)
Gland Structure
Unicellular glands: Mucus (goblet) cells are the only unicellular exocrine glands.
Scattered among epithelia, intestinal lining
Multicellular glands
Structure of the duct (simple or compound)
Shape of secretory portion of the gland (tubular, alveolar, acinar, tubuloalveolar, and tubuloacinar)
Relationship between ducts and glandular area. (branched)
Functions of Connective TIssues
Main Function: Binding and Support.
Fills internal spaces
Supports other tissues
Transports materials
Stores energy
Protection
Defense
Highly vascularized
Characteristics of Connective Tissue
Specialized Cells
Matrix
Made from: Extracellular protein fibers
Fluid extracellular ground substance
Majority of tissue volume
Determines specialized functions
Classifications of Connective Tissue
Classifications of Connective Tissue:
Connective Tissue Proper:_ _ Connects and protects
Loose Connective Tissue: More ground substance, fewer fibers
Areolar, Adipose, Reticular
Dense Connective Tissue: More fibers, less ground substance
DRCT: Ligaments, aponeurosis, Tendons
DICT: Dermis
Elastic
Fluid Connective Tissue: Transport
Supporting Connective Tissue: Structural strength
