Chapter 3-Tissues and Early Embryology Flashcards
4 basic tissue types
epithelial, connective, muscle, neural tissue
Epithelial tissue characteristics
- covers all body surfaces
- cellularity
- polarity
- attachment
- avascularity
- regeneration
Functions of Epithelia cells
- physical protection
- control permeability (absorption)
- sensation
- secretion
Epithelial cellularity
very little space
- no matrix
- connected by junctions
- may contain fluids (stomach lining)
Avascularity of Epithelial cells
no blood vessels found within epithelial tissues
-nutrients are supplied from blood in underlying tissue
Basal side of epithelial tissue
grows off a basal lamina
lateral side of epithelial tissue
contacts adjacent cells
-cell junctions
apical side of epithelial cells
- exposed to lumen
- specializations
- -microvilli, cilia
Basal Lamina of Epithelial cells
- Divided into lamina lucida (clear layer) and Lamina densa (dense layer)
- exists on top of connective tissue
3 layers of epithelial
simple
pseudostratified
stratified
simple epithelial
secretion/absorption
pseudostratified epithelium
nuclei found at different levels so it looks multilayered
stratified epithelium
protection
Epithelial cell shape
- squamous (cells are flattened)
- cuboidal (cells are usually cube shaped or hexagons)
- columnar-cells are tall and cylindrical
- transitional-shape changes
simple squamous structure
one layer thin flat cells
simple squamous function
absorption, diffusion, reduce friction
simple squamous location
serous membranes, blood vessels, lungs, kidney tubules
Simple Cuboidal structure
one layer, hexagonal box shaped cells
simple cuboidal function
absorption, secretion, limited protection
simple cuboidal location
glands, ducts, kidney tubules
simple columnar structure
one layer, hexagonal column shaped cells
simple columnar function
protection, absorption, secretion
simple columnar location
stomach, intestine, gall bladder, uterine tubes
pseudostratified columnar structure
one layer, multi-shaped cells, nuclei at varied heights
pseudostratified columnar function
protection, secretion
pseudostratified columnar
respiratory tract, male reproductive tract
stratified squamous structure
- thin, flat, irregular cells
- multiple layers
stratified squamous function
protects against frequent abrasion
stratified squamous location
skin, mouth, throat, esophagus, rectum, anus, vagina
stratified cuboidal structure/ function/location
multiple layered, hexagonal shaped boxes
- secretion
- rare; sweat gland ducts
stratified columnar structure/function/location
- multiple layers, hexagonal, column shaped cells
- protection, secretion
- rare; pharynx, epiglottis, anus, glands
transitional structure/function/location
multiple layers, can change shape
- expansion and recoil without tearing
- urinary bladder, renal pelvis
what is a gland
when epithelial cells aggregate together to produce a specific product
exocrine gland
secrete products into ducts that open on a surface
endocrine gland
secrete products into tissue fluid or blood
exocrine gland cellularity
unicellular-single cell; goblet cell
multicellular-secretory sheets, multicellular simple gland, multicellular compound gland
exocrine secretory sheets
one large sheet covering a surface
- rarely have ducts or pockets
ex. stomach lining
exocrine simple glands
- one distinct duct with outpocketing
- defined by number and shapes of pockets
pockets of exocrine multicellular simple glands
tubular: elongate
coiled: winds
Alveolar: lobed
divisions of simple exocrine glands
simple tubular (intestinal glands)
- simple coiled tubular (merocrine sweat glands)
- simple branched tubular (gastric glands, mucous glands of toung)
- simple alveolar (found in development of branched glands)
- simple branched aveolar (subaceous glands)
multicellular compound glands
many distinct ducts with outpocketing
-tubular, coiled, alveolar, tubuloalveolar
Classification of Exocrine glands
functionally classified based on how secretions are released
- merocrine glands
- apocrine gland
- holocrine glands
merocrine glands
Ex. salivary glands
- secrete product by exocytosis
- vesicles within cytoplasm bring product to the surface
apocrine glands
ex. mammary glands
- pinching off of cell portion
- product is within this portion
holocrine glands
ex. sebaceous glands
- product accumulates in cytosol
- cell ruptures and becomes the product
Connective tissue traits
- most abundant
- multiple functions
- spread apart
- able to reproduce
- well nourished; good blood supply
- vary in structure
Connective tissue is derived from what?
Mesenchymal cells
-stem cells that differentiate into multitude of cell types in all connective tissue
Where doesnt connective tissue occur?
free surfaces
except for cartilage and tendons, connective tissue has what?
good blood and nerve supply
Connective tissue is composed of what?
- extracellular matrix
- -secreted by cells, has protein fibers, ground substance (consistency from liquid to gel to solid) - cells
- -produce the matrix, rarely touch
connective tissue functions
- bind structures
- support and protection
- fill spaces
- store fat
- produce blood
- repair damage
- protect against infection
- transport fluids and dissolved materials
what is connective tissue proper (CTP)
connective tissue with cells and fibers in gel like ground substance
- loose connective tissues (areolar, adipose, reticular)
- dense connective tissues (regular, irregular, elastic)
Major Cell type CTP: Fixed Cell
- fixed cells
- mesenchymal
- fibroblasts (produce protein fibers
- fixed macrophages (white blood cells that consume damaged cells and invaders
- adipocytes (fat cells)
- melanocytes (produce melanin
Major Cell Type CTP: wandering cell
- free macrophages (what blood cells consume damaged cells and invaders)
- other white blood cells (secrete histamine; produce antibodies; consume damaged cells/invaders)
Major Fiber Type CTP: Collagen Fiber
- 25% of protein in body
- arranged into thick fibers
- tough, resistant to pull, pliable
- formed from protein collagen
- found in bone, cartilage, tendons, ligaments
Major Fiber type of CTP: Elastic Fiber
Formed from proteins elastin and fibrillin
- smaller diameter fibers than collagen
- rubbery, resilient
- can stretch up to 150% of relaxed length
- found in lungs, blood vessels, skin
Major fiber types of CTP: reticular fibers
formed from protein collagen as well
- thin, branched fibers that form framework of organs
- spleen and lymph nodes, basal lamina
Types of Cellular CTP
- fixed cell
2. wandering cell
Types of fiber CTP
- collagen
- elastic
- reticular
Areolar CTP: Structure
loosely arranged fibers, mast cells, macrophages, fibrocytes, adipocytes
Areolar CTP: function
hold skin to underlying organs; fill spaces between muscles
Areolar CTP: location
digestive, repiratory and urinary tracts, nerves and joints, around and between skeletal/smooth muscles; hypodermis of skin
Adipose CTP: structure and function
- mostly adipocytes
- cushions joints, insulation, store energy, support
Adipose CTP: location
hypodermis, between muscles, around kidney, behind eye, joints, abdominal membrane, surface of heart
Reticular CT: Structure
fibroblasts, reticular fibers in 3-D web
Reticular CT: function
support tissue in walls of organs
Reticular CT: Location
Lymphoid organs, liver and spleen
dense regular CT:structure
many collagen fibers densely packed, parallel, little open space
dense regular CT: function
reinforces structures in one direction
Dense regular CT: location
tendons and ligaments
Dense Irregular CT: structure
same as regular except no pattern
dense irregular CT: function
reinforces in several directions
dense irregular CT: location
dermis, joint capsules, capsules of organs
elastic CT: structure
elastic fibers in parallel strands or branched networks; fibroblasts
elastic CT: locations
between vertebrae, walls of hollow organs
Elastic CT: functions
provide elasticity
Fluid Connective tissue
- blood
- lymph (interstitial fluid being transported in lymphatic vessels
Fluid Connective Tissue: blood
- connective tissue with liquid matrix (plasma)
- cell types= erythrocytes, leukocytes (white), platelets (cell fragments)
- provide clotting, immune functions, carry O2 and CO2
Supporting Connective Tissue
provide a framework that supports the rest of the body
-ex. cartilage, bone
membranes
made of epithelial and connective tissue
- form barriers
- cover and protect
mucous membranes
- lines passageways; open to exterior
- moistened by mucous
- contain areolar tissue
ex: respiratory passages, mouth, digestive tract
serous membrane
- simple squamous mesothelium; secretes watery fluid
- location: lining of pleural cavity, abdominopelvic cavity, scrotal cavity and pericardical cavity
cutaneous membrane
- skin
- covers body surface
- thick
- waterproof
- dry
synovial membrane
- in joint cavities
- produces synovial fluid
- lubricates joints
- promotes smooth movement
Types of membranes
- mucous membrane
- serous membrane
- cutaneous membrane
- synovial membrane
outer layer of connective tissue
superficial fascia
- areolar and adipose tissue layer
- sits deep to cutaneous membrane (skin)
middle layer of connective tissue framework
deep fascia
- dense CT sheets
- binds to tendons, ligaments, capsules, and bones
- deep to superficial fascia
bottom layer of connective tissue
subserous fascia
- areolar CT sheet
- binds to serous membranes
- deep to deep fascia
General characteristics of muscle tissue
- contractile
- elastic
- extensible
- excitable
types of muscle tissue
- skeletal
- cardiac
- smooth
skeletal muscle: structure
large cylindrical muscle fibers, multinucleated, striated, has satellite cells
skeletal muscle: function
voluntary control of skeleton, controls opening into digestive system, heat generation
skeletal muscle: location
skeletal muscles (with connective/nervous tissue)
cardiac muscle: structure
unicellular branched cariocytes, uninucleate, striated, involuntary
cardiac muscle: function
heartbeat
smooth muscle: structure
short tapered cells, uninucleated, non-striated, involuntary, can divide and regenerate
smooth muscle: location
lines tracts, BV’s and hollow organs
smooth muscle: function
involuntary control of respiratory, digestive, and circulatory systems
nervous tissue cell types
- neurons (transmit impulse for cell communication)
- neuroglia (support, nourish and protect neurons)
