A & P UNIT 2 Flashcards
Histology
Study of Tissues
Tissue
Group of cells
Types of cell connections
Tight junction
Gap junction
Desmisome
Hemidesmosome
Tight Junction
Use interlocking membrane proteins
both cells have the same membrane proteins
Gap Junction
Use interlocking membrane proteins (Channels)
Allows Cell to communicate
Desmisome
Use membrane proteins that are attached the the cytoskeleton
goes through the cell membrane; welded together
Hemidesmisome
Attach the cell to a foundation/base
cell is anchored in place (stationary); attaches to cytoskeleton and basement protein
Basement membrane
foundation in hemidesimose
Epethielal Tissue
lines spaces in the body (where there is a hole)
Covers the body and forms the glands of the body
Epithelial Characteristics
Lots of tightly packed cells
ALWAYS has one side exposed
Cells are highly mitotic (needed to be replaced frequently)
Cells exhibit polarity
Attached to basement membrane
Cells form layers/sheets
ALL epithelial is avascular
Apade
Exposed side
Avascular
Means no blood vessels
What is epithelial classification based on?
Shape of cell
Cell arrangement
Types of cell arrangments
Simple- single layer
pseudostratified- single layer that appears multilayered
stratisfied- multiple layers of cells
transitional- layers of cells that can change their appearance
Types of cell shapes
squamous- flat
cuboidal- square
columnar-tall
Types of covering & lining epethilial
Simple Squamous
Stratisfied Squamous
simple cuboidal
stratified cuboidal
transitional
simple columnar
stratified columnar
pseudostratified ciliated columnar
Simple squamous
Single layer of flat cells
functions: Permeability and secretion
locations: blood vessels, kidneys, alveoli
Stratified squamous
multiple layers of flat cells
functions: Protection
locations: esophagus, epidermis… anywher with direct contact outside
Simple cuboidal
single layer of square cells
functions:absorption and secretion
locations: thyroid gland, kidney
stratified cuboidal
multiple layers of square cells
functions: protection
locations: ducts of glands
Transitional
multiple layers of square cells that can change their shape
functions: stretches and recoils
locations: uterus, bladder
Simple columnar
single layer of tall cells
functions: absorption, secretion, protection
locations: stomach, small intestine, larger intestine…
Stratified columnar (rare)
multiple layers of tall cells
functions: protection
locations: ducts of some glands
Psuedostratisfied ciliated columnar
single layer of tall cells that appear multi layered
cells have cillia
Usually has goblet cells
functions: secretion, protection
locations: nasal cavity, trachea, bronchi
Glandular epithelium
forms the glands
secretes
Types of glands
endocrine
exocrine
Exorine gland
has a duct that releases its secretions onto epithelial surface
Endocrine gland
does not have ducts
releases secretion (hormones) into the blood
What are exocrine glands based on?
Type of secretion
Mode of secretion
Structure of the gland
Types of secretion
Serous- watery secretion (ex. saliva)
Mucous- viscous secretion (ex. earwax)
Mixed- watery and viscous secretion (ex. breast milk)
Mode of secretion
(How they release secretion)
Merocrine- via exocytosis
Apocrine- top 1/2 of cells fills with secrottory vesicles-> breaks off-> regenerates new 1/2 (REPEATS)
Holocrine- cell fills with secretory vesicles and ruptures (lysis) everything releases
Structure of the glands
unicellular- a single cell (ex. goblet cell)
multicellular:
simple- unbranched (single) duct
compound- branched (multiple) duct
Connective tissue
largest tissue
supports, binds, connects, or separates other tissues and or organs
Connective Tissue Characteristics
not exposed
cells are spaced apart
area between cells is filled with matrix
variety of cells
vascular (except cartilage)
Matrix
ground substance
protein fibers
Ground substance
H2O-> liquid
hyaluronic acid-> slimey
chondoitin sulfacte-> rubbery
mineral salts-> solid
Protein fibers
Collagen-> strung and flexible (thick)
elastic-> stretch and recoil
reticular-> provides physical support (thin)
Variety of cells
_blasts
_cyte
blasts
immature cell,
makes up part of the matrix
cyte
mature cell,
maintains the matrix
types of connective tissue
embryonic/fetal
adult
types of embryonic/fetal tissue
mesenchyme
Wharton’s jelly
types of adult tissues
connective tissue proper
cartilage
ostious (bone)
blood
mesenchyme connective tissue
contains undifferentiated connective tissue & stem cells
develops into all adult types of connective tissues
Wharton’s jelly connective tissue
protects the blood vessels in the umbilical cord
has a lot of hyaluronic acid
types of adult connective tissue proper
loose
dense
elastic
types of loose connective tissue proper
areolar
adipose
reticular
loose connective tissue proper
alot of cells
protein fibers are loosely packed
areolar CT
CELLS: fibroblasts & macrophages
PROTEIN FIBERS: all 3 types
GROUND SUBSTANCE: hyaluronic acid
LOCATIONS: around organs, under all epithelial tissues
FUNCTIONS: reduces friction & protection
adipose CT
CELLS: adipocytes
PROTEIN FIBERS: reticular
LOCATION: around spinal cord, heart, kidneys, behind eyeballs, & mammory glands. Hypodermis & yellow bone
FUNCTIONS: Protection, cushioning, insulation, & energy storage
Reticular CT
CELLS: fibroblasts
PROTEIN FIBERS: reticular
LOCATION: liver, spleen, & red bone marrow
FUNCTIONS: provide physical support
dense connective tissue proper
less cells, lots of tightly packed protein fibers
types of dense connective tissue proper
dense regular
dense irregular
elastic
dense irregular CT
CELLS: fibroblasts
PROTEIN FIBERS: collagen-
LOCATION: tendons & ligaments
FUNCTIONS: high tensile strength in a single direction
dense irregular CT
CELLS: fibroblasts
PROTEIN FIBERS: collagen-
LOCATION: heart valves, elura matter, perichondrium, periosteum & dermis
FUNCTIONS: high tensile strength in all planes/directions
elastic CT
CELLS: fibroblasts
PROTEIN FIBERS: a lot of elastic fibers tightly packed togetgher
LOCATION: lungs, & major arteries
FUNCTIONS: stretch and recoil
