Histology Flashcards
4 Main Tissue Types
Epithelial
Connective
Muscular
Nervous
Defining Characteristics of Muscle Tissue
Ability to contract
3 Subtypes - Skeletal, Cardiac, and Smooth
3 Subtypes of Muscle Tissue
Skeletal Muscle - Voluntary
DC - Multinucleated
Cardiac Muscle - Involuntary
DC - Intercalated Discs
Smooth Muscle - Involuntary
DC - No Striations
Nervous Tissue Defining Characteristic
Abiltiy to send and recieve nervous impulses
Subtypes of Nervous Tissue
Neurons - Send and Recieve nervous impulses
Neuroglia - Protect, nourish, and support neurons
Epitheleal tissue defining characteristics
Very Little ECM
Free Surface
Basement Membrane
No blood Vessels
(Regeneration)?
Simple Squamous Epithelium
Single Layer of flat cells
Common functions include diffusion and filtration
Air sacs of lungs, lines blood vessels, and kidney tubules
Stratified Squamous
Many layers with cuboidal or columnar cells at basement membrane that become flattened at the surface
Protects from abrasion and infection
Skin, cornea, mouth, throat, anus, vagina
Simple Cuboidal
Functions in secretion and absorbtion
Mostly in kidney tubules
Found in kidney tubules, glands, choroir plexus, terminal bronchioles, and ovaries
Simple Columnar
Sometimes have cillia or microvilli
function in secretion, absorbtion, and movement of mucus
Found in linging of stamach, intestines, glands, bronchioles, suditory tubes, uterus, and uterine tubes
Psuedostratified Ciliated Coumnar Epithelium
Looks Stratified but isn’t
Nuclei are at different levels
Function in movement of mucus or fluids
Lining of nasal cavity, sinuses, auditory tubes, pharynx, traches, and bronchi
Transitional Epithelium
Stratified Cells - appear uboidal when relaxed, squamous when stretched
Special tissue ot allow for the fluctuations of teh urinary system
Found in Urinary Bladder, ureters, and superior urethra
Epithelial Cell Connections
Tight Junctions
Desmosomes
Gap Junctions
Tight Junctions
Bind adjacent cells forming permeability barrier
Prevents Passage between cells
Desmosomes
Mechanical (protein) links; often in stratified squamous
Gap Junctions
Channels between cells that allow material (Small molecules or ions) to pass easily
Connective Tissue
Primary Characteristic - Large ECM
Function - joins tissues together, provides support, stores energy, and transports materials
ECM Components
Protein Fibers
Ground Substances
Fluid
Protein Fibers
Collagen Fibers
Rope-Like
Reticular Fibers
String-like; fine, short collagen fibers
Elastic Fibers
Coiled: Re-coil to original shape
Connective Tissue Cell Types
Blasts
Build Tissue
Cytes
Maintain Tissues
Clasts
Break Down Tissues
Dense Connective Tissue
Collagen fiber matrix
Able to withstand great pulling forces
When collagen fibers run in same direction: tendons and ligaments
When collagen fibers run in all directions: dermis and organ capsules
Loose Connective Tissue
A.K.A. - Areolar Tissue
ECM - Network of collagen fibers and more fluid
Function - loose packing, support, and nourishment for sorrounding tissue
Most epithelial tissue rests on this hypodermis
Adipose
Very little ECM
Cells full of lipids
Function - energy storage, packing, protection, and insulation
Found under skin, organs, breasts, and bone cavities
Catilage
Solid ECM
Composed of fiber and ground substances
Three Types
Hyaline, Fibrocartilage, and elastic
Hyaline Cartilage
Support; provide a smooth surface; bone growth
Ribs, traches, nasal, and epiphyseal plates
Fibrocartilage
Withstand pressure
Between Vertebrae, pubic symphysis, and discs between bones
Elastic Cartilage
Returns to original shape
External ear
Bone
Hard Mineralized ECM
Provides strength, suppor, and protection
Found in all bones of the body
Blood
Large Fluid ECM
Transports Nutrients, waste products, and others
Protects from infection
Temperature regulation
