Module 4 Flashcards
Define tissue
a group of cells that have a similar embryological origin and are specialized.
What are the 3 embryonic germ layers that form tissues?
ectoderm
mesoderm
endoderm
What is the ectoderm
outer layer
skin cells, neurons, pigment cells
What is the mesoderm
middle layer
cardiac, skeletal, smooth muscle, RBC
What is endoderm
inner layer
lung cell, thyroid cell, pancreatic cell
What are the 4 primary adult tissue types
epithelial
connective
muscle
nervois
What is epithelial tissue
covers body surfaces, lines hollow organs, body cavities, and ducts, forms glands.
provides protection
What is connective tissue
protects and supports the body and organs, binds organs together, stores energy reserves as fat, and provides immunity
What is muscle tissue
responsible for movement and generation of force.
What is nervous tissue
initiates and transmits action potentials that help coordinate body activities, monitors the external environment, and contributes to homeostasis
What is the structure of epithelial tissue
arranged in sheets in single/multiple layers
consists mostly of packer cells with little extracellular material.
many cell junctions
has an apical surface (exposed) and a basal surface (close to the underlying body structures)
What is the function of epithelial cells
protection
filtration
lubrication
secretion
digestion
absorption
transportation
excretion
sensory reception
reproduction
What are the major features of epithelial cells?
nearly completely avascular
all substances that enter the body must cross the epithelium
high capacity for renewal
Describe the classification scheme of epithelia
stratified or simple
squamous, cuboidal, or columnar
psuedostratified columnar (misshapen tall)
Where are simple squamous cells found
where there is little wear and tear
where rapid passage of chemicals is observed
ex. alveoli, lining capillaries, lining body cavities
Where are simple cuboidal cells found?
where secretion and absorption of molecules is observed
ex. lining of kidney tubules and in ducts of glands
Where are simple columnar cells found?
ciliated or non ciliated, found at sites of absorption and secretion
ex. lining the fallopian tubes and parts of the respiratory system
Where are pseudostratified columnar cells found?
have goblet cells that secrete mucous inbetween
ex. respiratory tract
Where are stratified squamous cells found?
protects against abrasion
lines esophagus, mouth, and vagina
Where are stratified cuboidal cells found
protective tissue
sweat glands, salivary glands, mammary glands
Where are stratified columnar cells found
secretes and protects
male urethra, and the ducts of some glands
Where are transitional cells found
allows the urinary organs to expand and stretch
lines bladder, urethra, and the ureters
What is a gland
a single cell or a mass of epithelial cells adapted for secretion
What are endocrine glands?
ductless
their secretory products (hormones) enter the extracellular fluid and diffuse into blood
What do endocrine glands secrete?
hormones
What are exocrine glands?
secrete products into ducts that empty at the surface of the covering and lining of the epithelium or directly onto a free surface
What do exocrine glands secrete?
sweat, mucous, saliva, breast milk
What are the 3 types of exocrine glands
merocrine
apocrine
holocrine
How do merocrine glands secrete?
they release their secretions via exocytosis
ex. eccrine sweat gland
How do apocrine glands secrete?
they pinch off their apical surfaces along with their secretory vesicle
ex. apocrine sweat gland
How do holocrine glands secrete?
they rupture and destroy the entire gland cell
ex. sebaceous glands that lubricate and protect skin and hair
What is a serous type
watery, blood plasma-like secretions rich in enzymes
What is a mucous type
watery to viscous products rich in the glycoprotein mucin
What are the main characteristics of CT
most abundant and widely distributed tissue in body
don’t occur on free surfaces
highly vascular (except cartilage and tendons)
has a nerve supply
dispersed in a matrix
What 3 things make up CT
cells
ground substance
proteins
What is the matrix made of
ground substance and proteins
What 3 categories can CT be classified into
CT proper
Supportive CT
Fluid CT
what is CT proper
loose CT
areolar, adipose, reticular
What is supportive CT
cartilage, hyaline, fibrocartilage, bones
What is fluid CT
blood, lymph
immature cells
-blast
mature cells
-cyte
what do fibroblasts do
secrete fibres and matrix
what do macrophages and histiocytes do
develop from monocytes and are phagocytic
what do mast cells do
produce histamine
what do adipocytes do
store energy
which substances are found in ground substance
hyaluronic acid
chondroitin sulfate
dermaten sulfate
keraten sulfate
What is the structure of mesenchyme
can differentiate into any type of CT cell required
what is the function of mesenchyme
supply the cells needed for replacement and repair after a CT injury