9/23 Class Lecture Chapter 4 Flashcards
Where do tissues fall on the organization chain
after the first level of life, cells
individual body cells are
specialized
how are individual body cells specialized
Each type performs specific functions that maintain homeostasis
what is due to the specific functions of cells
specific structure is because of specific function
what is an example of interrelationship
structure allows for function
tissues
Groups of cells similar in structure that perform common or related function
histology
study of tissues
what are the types of primary tissues
epithelial
connective
muscle
nervous
what do epithelial tissues do
cover or lines
forms boundaries between different environments protects, secretes, absorbs, filters
where can epithelial tissues be
exterior or interior
skin
what do connective tissues do
support
links body tissues together
support protects binds other tissues together
what do muscle tissues do
produce movement
muscles contracting with force
contracts to cause movement
what do nerve tissues do
controls everything going on inside the cell
transmits chemical impulses
internal communication
what types of tissues do plants have
epithelial and connective
which tissue is the most diverse
connective
where are nervous tissues found
brain, spinal cord, nerves
what muscles are included in muscular tissues
Muscles attached to bones (skeletal)
Muscles of heart (cardiac)
Muscles of walls of hollow organs (smooth
examples of epithelial tissues
the lining of digestive tract organs and other hollow organs skin surface (epidermis)
where are connective tissues found
bones
tendons
fats and other soft padding tissue
what must tissues go through before they can be viewed under a microscope
the tissue is fixed, cut, and stained
what does it mean that the tissue was fixed
preserved through a lot of treatment
what does a tissue go through when it is cut
Sliced thin enough to transmit light or electrons
microtone-slicing machine with a big blade
tissue is embedded in wax
what does a tissue do when it is stained
enhanced contrast
certain parts will absorb more stain than others
what are the 2 main types of epithelial tissues
covering and lining epithelial
glandular epithelial
where is the covering and lining of epithelial tissues located
skin, inside the digestive tract, mouth
external and internal surface
can you see glandular epithelia tissues
no
examples of glandular epithelia
secretory tissues in glands
On both sides of the frenulum, part of salivary glands
how is salvia stimulated
something present in mouth
epithelial tissue functions
Protection Absorption Filtration Excretion Secretion Sensory reception
filtration
separation, some things pass through some things don’t make it
excretion
waste given off, most common urea (nitrogen waste)
secretion
useful ex: saliva
sensory reception
bringing things in, sense of touch when related to skin
5 characteristics of epithelial tissues
polarity, specialized contracts supported by connective tissue avascular, inervated can regenerate
what does specialized contracts mean
touch to other systems
avascular
without blood vessels
innervated
has nerves
how do avascular cells get their nutrients
diffusion
what is the apical surface
(upper free) exposed to exterior or cavity
what is the basal surface
(lower, attached)
how do the apical and basal surface differ
differ in structure and function
characteristics of apical surface
smooth and slick, some have microvilli (e.g., brush border of intestinal lining), some have cilia
what do microvilli do
Increase surface area
In digestive system it would be most
what do cilia do
moves things across the cell
characteristics of noncellular basal lamina
Glycoprotein and collagen fibers lies adjacent to basal surface
Adhesive sheet
Selective filter things passing through or passing out
Scaffolding for cell migration in wound repair
Specialized Contacts of Epithelial tissues
Covering and lining epithelial tissues fit closely together
Specialized contacts bind adjacent cells
what type of contacts are the adjacent cells
lateral contacts
what were the lateral contacts
Tight junction- increase security
Desmosomes- increases security
what are the types of connective tissue support
reticular lamina, basement membrane
reticular lamina
Deep to basal lamina
Network of collagen fibers
basement membrane
Basal lamina + reticular lamina
Reinforces epithelial sheet
Resists stretching and tearing only happens to a limited degree
Defines epithelial boundary
are there blood vessels in epithelial tissues
no
why arent there blood vessels in epithelial tissues
thin so diffusion cant afford
what are epithelial cells supported by
nerve fibers
why is regeneration important to epithelial cells
Important to regenerate bc these cells are often rubbed away
what is regeneration stimulated by
by loss of apical-basal polarity and lateral contacts:
why does regeneration happen
Some exposed to friction
Some exposed to hostile substances (cancer)
what is needed for regeneration to be successful
adequate nutrients replace lost cells by cell division
what are the 2 classifications of epithelia related to layers
simple and stratified
what are the classifications of shape for epithelia
squambous
cuboidal
columnar
what does simple epithelia mean
single layer of cells
what does stratified epithelia mean
two or more layers of cells
squamous
squashed
Flattened and scalelike
Nucleus flattened nucleus is flat
cuboidal
cube
Boxlike
Nucleus round
columnar
tall like a column
Tall; column shaped
Nucleus elongated, nucleus shaped like a column
how are stratified epithelia classified for shape
in the apical layer
simple epithelia classifications
absorption, secretion, filtration, very thin
why are simple epithelia so thin
all the functions have material passing through them so it has to be very thin
simple squamous epithelium
Cells flattened laterally, Cytoplasm sparse, function where rapid diffusion is priority,
why is cytoplasm sparse in simple squamous
since its thin-not a lot of cytoplasm, not a lot of cytoplasm then it is not going to produce a lot of chemicals
what are the two locations for simple squamous
endothelium and mesothelium
endothelium
means inside layer
The lining of lymphatic vessels, blood vessels, and heart- circulatory system
mesothelium
idea of middle
The epithelium of serous membranes in the ventral body cavity- certain membranes
simple cuboidal classifications
Single layer of cells
Secretion
Absorption
Forms walls of smallest ducts of glands and many kidney tubules
simple columnar classifications
Single layer of tall, closely packed cells
Absorption
Secretion
Pseudostratified columnar epithelium
Cells vary in height: Cell nuclei at different levels Appears stratified, but is not so its simple Secretion Absorption
stratified epithelial tissues
Two or more cell layers
Regenerate from below
More durable than simple epithelia
Protection is major role
how to stratified epithelial regenerate
Basal cells divide, cells migrate to surface
push up to surface
what is the most widespread of the stratified epithelial
stratified squamous
where are stratified squamous cells found
on skin
inside and outside
what are stratified squamous important for
wear and tear
where are the stratified squamous farthest away from
basal layer
why are nutrients less viable in the stratified squamous
as the layers build up it is harder to get the oxygen supply under the first layer
what are stratified cuboidal epithelium
Quite rare
Found in some sweat and mammary glands
Typically two cell layers thick
where are stratified columnar epithelium found
Small amounts in pharynx, male urethra, and lining some glandular ducts
transition areas between two other types of epithelia
Only apical layer columnar
what does transitional epithelium mean
going from one to another
where are the transitional epithelium
Forms lining of hollow urinary organs
what type of transitional epithelium are basal cells
cuboidal or columnar
what can transitional epithelium do
Ability to change shape with stretch
examples where transitional epithelium are found
stomach
bladder
**places that stretch
what type of transitional epithelium are apical cells
vary in appearance
what is a gland
One or more cells that make and secretes an aqueous fluid (water base) called a secretion
what are glandular epithelia classified by
side of product release (endo or exocrine)
the relative number of cells forming the gland
what is endocrine
on the inside, secrete into blood
what is the exocrine
enzymes secreted, has a tube that takes things out
what organ is both endo and exocrine
pancreas- secretes insulin
what is a ductless gland
Secretions not released into a duct
what do endocrine glands secrete
Secrete (by exocytosis) hormones that travel through lymph
what do exocrine glands secrete
Secretions released onto body surfaces (skin) or into body cavities
examples of exocrine gland secretions
(oil and sweat glands on skin or inner body surfaces in the digestive system)
what is there more of endo or exocrine glands
endo
where do exocrine glands secrete products to
into ducts
examples of exocrine glands
mucous, sweat, oil, and salivary glands
mucous
adjective
mucus
noun, water + mucin- the solution itself
mucin
noun, the chemical itself
what are important unicellular exocrine glands
mucous cells and goblet cells
where are unicellular exocrine glands found
in epithelial linings of intestinal and respiratory tracts