Tissues Flashcards
Define tissue
a group of 2 or more cells functioning together for a specific task
What are the four types of tissues?
connective, muscle, epithelial, neural (CMEN)
What are the 2 types of epithelial tissue?
covering & lining, glandular
T/F: epithelial tissue contains blood vessels
False; epithelial tissue is avascular
T/F: epithelial tissue does not need blood supply since it is avascular
False; epithelial tissue gets its blood supply from the connective tissue beneath it
What are the functions of epithelial tissue?
secretion, absorption, boundaries, excretion, sensory reception, protection, filtration (SABE SPF)
Why is secretion an important function for epithelial tissue?
secrete things that go places (glands)
Why is absorption an important function for epithelial tissue?
allows things to enter into our bodies
Why are boundaries an important function for epithelial tissue?
help to divide/separate internal and external environments
Why is excretion an important function for epithelial tissue?
exiting process
Why is sensory reception an important function for epithelial tissue?
epithelial tissue can detect stimuli (nervous stimulation)
Why is protection an important function for epithelial tissue?
first line of defense against pathogens
Why is filtration an important function for epithelial tissue?
only certain things are allowed to cross into the body
What is an apical surface?
the upper free surface that is exposed to the external environment
What is the basal surface?
the deeper attached surface that is exposed to the underlying layers
What 2 layers make up the basement membrane?
basal lamina, reticular lamina
What is the basal lamina made of?
a non-cellular sheet of glycoproteins (proteins attached to a carbohydrate) that is anchored to the basement membrane
T/F: the basal lamina does not have cells
T; it is acellular
What is the basal lamina’s function?
to act as a selective filter between the epithelial and connective tissues
Where is the basal lamina located?
immediately deep to to the basal surface layer
Where is the reticular lamina located?
immediately deep to the basal lamina layer
What is the reticular lamina comprised of?
an extracellular network of collagen fibers
What is the function of the reticular lamina?
to provide strength and help things stay together (AKA integrity)
Where are covering & lining epithelial tissues found?
across all free surfaces of the body - line the inside of the body and those that are open to the external environment
What are some examples of places that would contain covering & lining epithelial tissues?
reproductive tract, esophagus, digestive tract
There are 3 classifications for coverings and lining epithelial tissues. Name them:
simple, stratified, pseudostratified
How many cell layers are present in simple epithelial tissue?
one
What is the function of a simple epithelial tissue?
absorption and filtration
Where can simple epithelial tissue be found?
in low friction areas/areas that are not prone to wear and tear (ex: respiratory tract, alveoli in the lungs, etc.)
How many cell layers are present in stratified epithelial tissue?
2 or more
What is the function of stratified epithelial tissue?
protection
Where can stratified epithelial tissue be found?
in high friction areas that experiences lots of wear and tear (ex: soles of feet, hands, anus, lining of vagina, etc.)
How many cell layers are present in pseudostratified epithelial tissue?
one, but it appears like there is more - the nuclei don’t line up which gives away that is is pseudostratified epithelial tissue
Where can pseudostratified epithelial tissue be found?
areas with limited movement (ex: respiratory tract, female reproductive tract, etc.)
There are 4 subtypes of epithelial tissue - name them:
squamous, cuboidal, columnar, transitional
What is transitional epithelial tissue used for?
can change shape and become flat to help with storage (ex: a bladder holding urine)
What is glandular tissue used for?
composes our glands
T/F: there are no desmosomes in glandular epithelium
True
Define glands
a cell or group of cells that secrete substances into ducts, onto surfaces, or into the blood
T/F: secretion does not require energy
False; secretion requires energy
What is the difference between exocrine and endocrine glands?
exocrine secrete substances either into a duct, or onto a surface, whereas endocrine glands secrete substances directly into the bloodstream
Which type of gland contains goblet cells?
exocrine glands
How many cells comprise a goblet cell?
one - they are unicellular
What are some examples of exocrine glands?
sweat, gallbladder, pancreas, etc.
What are some examples of endocrine glands?
pancreas, thyroid (think of hormones)
T/F: parts of the body are limited to only one type of gland
False; some places have both exocrine and endocrine glands (ex: pancreas)
Exocrine glands can be structurally classified in 2 ways:
unicellular vs. multicellular
What is the only type of unicellular gland?
goblet cells
Where can unicellular glands be found?
generally located with PCCE, line digestive and respiratory tract
Multicellular glands contain _______
ducts
What are some examples of multicellular glands?
mammary, salivary, sebaceous (oil) glands, etc.
Exocrine glands can be functionally classified in 2 ways:
merocrine glands, holocrine glands
Explain how a merocrine gland works
cells package the product into a sac and release it into the duct via exocytosis - the cell is not harmed during this process
Explain how a holocrine gland works
the entire cell enters the duct and lyses in order to release the product inside - cell is destroyed in the process so must continuously replicate these cells
What are some examples of merocrine glands?
salivary glands, sweat glands, milk production glands, parts of the pancreas, etc.
What are some examples of holocrine glands?
sebaceous glands
What are the 3 layers of embryonic tissue?
ectoderm (outer), mesoderm (middle), endoderm (inner)
What are the 4 classes of connective tissue?
connective tissue, cartilage, bone, blood
What are the 6 types of connective tissue?
areolar (loose), dense regular, dense irregular, elastic, reticular, adipose
What are the 3 types of cartilage connective tissue?
hyaline, fibro, elastic
What are the 2 types of bone connective tissue?
spongy, compact
All connective tissues have what 3 structural elements?
ground substance, fibers, cells
What is a ground substance?
a background substance that contains everything; typically composed of interstitial fluids with proteins
What 3 fibers can be present in connective tissue?
elastic fibers, collagen fibers, reticular fibers
What are some examples of types of cells that can be found in connective tissues?
osteocytes, chondrocytes, fibrocytes
Fibers + Ground Substance = ?
extracellular matrix
When a muscle contracts, it creates _____ as a by-product
heat
All muscle cells have:
sarcolemma and sarcoplasm
What is the sarcolemma?
plasma membrane of a muscle cell?
What is the sarcoplasm?
cytoplasm of a muscle cell
How many nuclei are present in skeletal muscle?
multiple
Where is skeletal muscle located?
attaches to bone
How many nuclei are present in cardiac muscle?
one
How many nuclei are present in smooth muscle?
one
Where is smooth muscle located?
in the walls of visceral organs (ex: liver, pancreas, intestines, etc.)
Neurons make up ___% of nervous tissue
50%
Neuroglia make up ___% of nervous tissue
50%
What is the function of neuroglia?
to support, protect, and nourish the neurons
What is a nickname used to describe neuroglia?
“nerve glue”
T/F: neuroglia carry the electrical signals
False