chapter 4 part 1 epithelium Flashcards
which germ layer does the skull develop from
mesoderm
intermediate mesoderm
-urogenital system (gonads, ducts, accessory glands)
paraxial mesoderm
-skeletal muscle of trunk and limbs (NOT THE SKULL)
-muscles of head
-skin dermis
-connective tissue
endoderm
-lining of respiratory tract, gi tract, urinary bladder and urachus
-epithelial parts of the thyroid, lymphatic cavity, auditory tube, tonsils, parathyroid glands, liver and pancreas
head mesoderm
-skull
-connective tissue of the head
-dentin
neuroectoderm (neural tube)
-CNS
-retina
-pineal body
-posterior pituitary gland
embryonic development
1st part of the pregnancy
fetal development
2nd part is fetal development (taking human shape)
-including birth and post natal developent
embryology
-development of human child from egg adn sperm fusion into diploid
teratology
study of things wrong with the fetus/ development that results in birth defects
cells are in 4 tissue categories
epithelial, connective, muscular and neuro
simple squamous
can be found as an exchange barrier in the central nervous system
simple squamous
can be found as an exchange barrier in the central nervous system
exocrine glands
release into ducts
endocrine glands
release into blood stream
merocine glands/ eccrine glands
sweat gland to maintain homeostasis, lots on the feet and palms
apocrine glands
only active after puberty, arm pit glands, nipple glands for baby, “scent glands”
paracrine glands
short distance
epithelia
line passages of intestines, heart and stomach
goblet cells
secrete to protect epithelial cells from hydrochlauric acid
epithelial tissue characteristics
-cellularity (cells bound close together with no intercellular space), lateral surface distance is negligible
-polarity (have an exposed apical surface and an attached basal surface)
-attachment (basal layer is attached to the basal lamina)
-avascularity (do not consist of blood vessels)
-arranged in sheets (one or more layers)
-regeneration (cells are continuously replaces via cell reporoduction)* mitosis in stratum basal
apical structure examples
cilia and microvilli
epithelial tissue functions
physical protection, control permeability (water resistant), sensation (Merkel cells), secretion (sebaceous glands and some glands produce acidic secretions to protects from pathogens)
epithelial cells specialization
-microvilli (absorption and secretion) *short
-stereocilia (long microvilli and found in the inner ear, contain actine and lack axonene)
-required for hearing and balance
-ciliated epithelium (move substances over apical surface of cells)
epithelium maintenance
-intercellular connections (lateral intercellular passageways)
-attachment to the basal lamina
-epithelial maintenance and renewal is self perpetuated
proteoglycans
-type of glycoprotein that regulates cell functions like adhesion, proliferation, migration, differentiation, survival and death
