Exam #1 Chapter 4 (Epithelial tissue and connective tissue) Flashcards
collections of specialized cells and the extracellular substances surrounding them.
tissues
four primary types of tissue
1) epithelial
2) connective
3) muscle
4) nervous
which tissues are the most diverse in form?
epithelial and connective
what are epithelial and connective tissue classified by?
structure
what type of structure is looked at for epithelial and connective tissue? 3 (CRC)
1) cell shape
2) relationship of cells to one another
3) composition of the extracellular matrix
what are muscle and nervous tissue classified by? (3) (SFL)
1) structure
2) functional characteristics
3) location
what is an example of the tissues being interdependent on one another?
muscle tissue cannot produce movement unless it receives oxygen carried by red blood cells and bone can’t form unless epithelial tissue absorbs calcium and other nutrients from the digestive tract.
what does epithelial tissue form?
surfaces and glands
what does connective tissue do? (4) (PBSP)
1) protect and support the body
2) bind organs together
3) store energy reserves
4) provide immunity
what does muscle tissue do?
contract
what does nervous tissue do?
conduct nerve impulses
which nerve tissues are more specialized?
nervous and muscle
how do organs do what they do?
because of tissue composition
what do different tissues have?
different characteristics or properties
how can a great deal of information be obtained about a person?
by examining their tissues
what are 3 ways to examine tissues?
1) blood
2) biopsy
3) pap smear
4) autopsy
the process of removing tissue samples from patients surgically or with a needle for diagnostic purposes to examine various disorders
biopsy
examination of organs of a dead body to determine the cause of death or to study changes caused by a disease
autopsy
what is often part of an autopsy?
microscopic examination
what two layers form approximately 13 or 14 days after fertilization?
1) epiblast
2) hypoblast
after the cells of the epiblast migrate between the two layers what forms?
3 embryonic germ layers
what are the 3 embryonic germ layers?
1) endoderm
2) mesoderm
3) ectoderm
what do the germ layers give rise to?
all the tissues of the body
what layer is the endoderm and what does it form?
the inner layer, the lining of the digestive tract and its derivatives
what layer is the mesoderm and what does it form?
the middle layer, tissues such as muscle, bone and blood vessels
what layer is the ectoderm and what does it form?
the outer layer and the neuroectoderm forms the skin.
characteristics of epithelial tissue (5) (LFDAR)
1) little extracellular material
2) found on surfaces and form most glands
3) different surfaces
4) avascular
5) regenerate well when damaged
surfaces of epithelial tissue (3) (ALB)
1) apical (free) that doesn’t face adjacent cells
2) lateral that faces adjacent cells
3) basal surface that faces the basement membrane
a secreted porous layer that allows exchange
basement membrane
since epithelial tissue are avascular what do they diffuse nutrients from?
deeper connective tissue
what is an example of epithelial tissues that regenerate well?
stem cells
how is cell shape seen?
perpendicular to the apical surface
how many simple and stratified epithelia are there?
4 simple and 4 stratified
what is the function of epithelial tissue related to?
their structure
characteristics of simple epithelia (2) (TO)
1) thin
2) occur in protected locations for diffusion, absorption and secretion
characteristics of stratified epithelia (2) (TO)
1) thicker
2) occur in locations that experience stress
in stratified epithelia what is superficial cells replaced by?
cells below which divide
what are the many layers of stratified epithelia also a barrier to?
chemicals and microbes
what does keratanized stratified epithelia contain?
the tough protein keratin
what are squamous cells best for?
diffusion and to form smooth surfaces
what are cuboidal and columnar cells have and what does that do?
more cytoplasm to surface area and are better for absorption and secretion
what can the surface of epithlia be modified for?
specific functions
what does some epithelia have that helps with modification?
cilia and microvilli
what is the plasma membrane of transitional epithelia shaped like?
it’s folded
extensions of cell that greatly increase free surface area
microvilli
contains microtubules, which allow them to move materials across the free surface of the cell
cilia
3 things that the structures that hold cells together or to the basement membrane do (MHP)
1) mechanically bind cells togeher
2) help form a permeability barrier
3 )provide a mechanism for intercellular communication
a relatively strong adhesive between cells and consist of glycoproteins that bind cells together and intracellular proteins attached to immediate filaments that extend into cytoplasm of the cells.
desmosomes
where are many desmosomes found?
in epithelial tissue that are subjected to stress such as stratified squamous epithelial of the skin
similar to one-half of the desmosome and attach epithelial cells to the basement membrane
hemidesmomes
hold cells together and form a permeability barrier.
tight junctions
how are tight junctions formed?
by proteins in the plasma membranes of adjacent cells that join one another to make a very tight seal.
what is an example of a tight junction?
in the stomach and urinary bladder, chemicals cannot pass between cells but water andother substances must pass which regulates what is absorbed and secreted.
where are tight junctions found
in areas where a layer of simple epithelial forms a permeability barrier
glycoproteins found just below the tight junction.
adhesion belt
where is the adhesion belt located?
between the plasma membrane of adjacent cells and acts as a weak glue that hold cells together.
is the adhesion belt as strong as desmosomes?
no
a small, specialized contact region between cells by allowing ions and small molecules to pass from one cell to another.
gap junctions
in epithelial cells what may coordinate the movement of celia
gap junctions .
in cardiac and smooth muscle tissue what are gap junctions important for?
coordinating important functions
what does a tight junction prevent?
fluid flow
what does an adhesion belt prevent?
the tight junction from being pulled apart
what does a gap junction attach channels through?
the membranes
what does gap junction allow? (2) (IA)
1) ions and small molecules to pass through
2) adjacent cells to coordinate their activity
what type of surfaces does epithelia cover?
protective or selective
what type of organs are glands?
secretory
what type of cells will glands consist of?
single or multiple cells
types of glands
1) exocrine
2) endocrine
glands that lack ducts and release secretions (hormones)into the interstitial fluid, diffuse into the bloodstream, and circulate to the whole body
endocrine glands
release secretions onto an epithelium through a duct
exocrine glands
what type of cells are most exocrine glands?
most are multicellular and some are unicellular
what is an example of a unicellular exocrine gland?
a goblet cell
how are the structure multicellular exocrine glands classified?
1) whether the ducts are branched or not (simple or compound)
2) the shape of the secrtory areas (tubular, acinar or tubuloacinar/tubuloaveolar)
what type of duct do simple glands have?
a single non branched duct
what type of duct do compound glands have?
secretory regions that branch off the duct
glands with secretory regions shaped like tubules (small tubes)
tubular
glands with secretory regions shaped like saclike structures
acinar or aveolar
glands with a combination of a tube shape and sac shape
tubuloaveolar
what is the functional classification of exocrine glands
1) merocrine secretion
2) apocrine secretion
3) holocrine secretion
what is the most common type of secretion in exocrine glands?
merocrine
what happens during merocrine secretion?
the product is released from secretory vessicles by exocytosis
what happens during apocrine secretion?
the product is released by shedding the apical portion of the cell
what happens during holocrine secretion?
the prodouct is released when a cell packed with the secretion lyses. entire cell is shed by the gland and becomes part of the secretion
characteristics of connective tissue (3) (AVD)
1) abundant extracellular matrix which largely determines the properties of the tissues
2) vascular
3) diverse functions
functions of connective tissue (7) (ECSSCTP)
1) enclosing and separating other tissues
2) connecting tissues to one another
3) supporting and moving parts of the body
4) storing compounds
5) cushioning and insulating
6) transporting
7) protecting
types of cells founds in connective tissue (6) (BAMLMM)
1) -blast cells, cyte cells, clast cells
2) adipocytes
3) mast cells
4) leukocytes
5) macrophages
6) mesenchymal
cells that secrete the connective tissue matrix
blast cells
cells that maintain the matrix
cyte cells
cells that degrade the matrix
clast cells
what do adipocytes (fat cells) contain?
a large droplet of fat
cells that release histamine and stimulate inflammation
mast cells
cells that migrate into infected connective tissue
leukocytes (white blood cells)
a type of WBC that phaocytize debris and bacteria
macrophages
stem cells that give rise to certain tissue cells
messenchymal cells
what type of cells are most messenchymal cells?
embryonic
what does the matrix of connective tissue consist of? (3)
1) fibers
2) ground substance
3) fluid
types of protein fibers
1) collagen
2) elastic
3) reticular
abundant fibers that are large, unbranched, very strong (stronger than steel) flexible and resist tension
collagen fibers
fibers made of elastin, are linked and can stretch
elastic fibers
fibers that are thin, branched collagen fibers that form a network primarily for the attachment of cells
reticular fibers
what can the ground substance be?
fluid, viscous or hard
what does ground substance contain? (2) (WPP)
1) water
2) polysacharides
3) proteins
what are connective tissues classified based on?
their composition
types of tissue found in embryonic connective tissue not found in adults
1) mesenchyme
2) mucous connective tissue
what does mesenchyme contain and what does it form?
mesechymal cells with fine fibers and forms other connective tissue
protects the umbilical cord’s blood vessels
mucous connective tissue
types of adult connective tissue
1) connective tissue proper
2) supporting connective tissue
3) fluid connective tissue
types of connective tissue proper
loose and dense
what do loose connective tissues have and lack?
they have abundant ground substance and few fibers
types of loose connective tissue (3)
1) areolar
2) adipose
3) reticular
contains different cells and fibers and can distort easily, appears open and is often filler material in the body
areolar tissue
contains many adipocytes almost filled with lipid to store energy and provides padding and insulation
adipose tissue
contains reticular fibers that form a 3D framework to support cells in certain organs
reticular tissue
what does dense connective tissue contain?
many fibers
what kind of fibers does dense regular connective tissue contain and what does it form?
parallel fibers and form cords and sheets
what does irregular connective tissue form?
sheets
what is the structure of Dense Regular collagenous connective tissue/
the matrix is composed of collagen fibers running in somewhat the same direction
what is the function of Dense Regular collagenous connective tissue?
it’s able to withstand great pulling forces exerted in the direction of fiber orientation. great tensile strength and stretch resistance
where are Dense Regular collagenous connective tissue located?
tendons and ligaments
what is the structure of Dense Regular Elastic connective tissue/
the matrix is composed of regularly arranged fibers and elastic fibers
what is the function of dense regular elastic connective tissue?
able to stretch and recoil like a rubber band with strength in the direction of fiber orientation
where are dense regular elastic connective tissue located? (3)
1) vocal folds
2) elastic ligaments between vertibrae
3) dorsal aspect of the neck
what is the structure of dense irregular collagenous connective tissue?
the matrix is composed of collagen fibers that run in all directions or in alternating planes of fibers in a somewhat single direction
what is the function of dense irregular collagenous connective tissue?
tensile strength capable of withstanding stretching in all directions
what is the location of dense irregular collagenous connective tissue?
1) sheaths
2) most of the dermis of the skin
3) organ capsules
4) septa
5) outer covering of body tubes
what is the structure of dense irregular elastic connective tissue?
the matrix is composed of bundles of sheets of collagenous and elastic fibers oriented in multiple directions
what is the function of dense irregular elastic connective tissue?
capable of strength with stretching and recoil in several directions
where are dense irregular elastic connective tissue located?
elastic arteries
what do supporting connective tissues have?
abundant fibers and a rigid hard matrix
what does cartilage contain?
a rigid, gel-like matrix with fibers, chondrocytes (if fully formed)
where does cartilage live?
in cavaties called lucunae
what is cartilage surrounded by?
fibrous perichondrium
what is the most common cartilage?
hyaline cartilage
what does hyaline cartilage contain
invisible, closely packed collagen fibers
what does hyaline cartilage provide?
flexible support
how does the matrix appear in hyaline cartilage?
transparent (glassy)
what is the function of hyaline cartilage? (4) (APFF)
1) allows the growth of long bones
2) provides rigidity with some flexibility in the trachea, bronchi, ribs and nose
3) forms strong, smooth yet somewhat flexible articulating surfaces
4) forms the embryonic skeleton
what does hyaline cartilage NOT have?
a periochdondrium
what is the location of hyaline cartilage? (6) (GCCNAE)
1) growing long bones
2) cartilage of rings of the respiratory system
3) coastal cartilage of ribs
4) nasal cartilages
5) articulating surface of bones
6) embryonic skeleton
what does fibrocartilage contain?
interwoven collagen fibers
what is the toughest cartilage that can withstand pressure?
fibrocartilage
how are the fibers in fibrocartilage arranged?
in thick bundles
what is the function of fibrocartilage?
1) somewhat flexible and capable of withstanding considerable pressure
2) connects structures subjected to great pressure
where is fibrocartilage located?
1) intervertebral disks
2) symphysis pubis
3) articular disks (knee and temporomandibular jaw joints)
what is the structure of the elastic cartilage?
similar to hylaine cartilage but matrix also contain elastic fibers
what is the function of the elastic cartilage?
provides rigidity with even more flexibility than hyaline cartilage
why is elastic cartilage more flexible than hyaline cartilage?
because elastic fibers return to their original shape after being strtched
where is elastic cartilage located? (3) (EEA)
1) external ears
2) epiglottis
3) auditory tubes
