Week 2 Flashcards
gene
is a segment of DNA that encodes an inherited trait.
DNA replication
a DNA molecule is copied to create two identical molecules.
transcription
a segment of DNA is copied into RNA (mRNA) and moved outside the nucleus.
translation
the mRNA molecule is decoded by a ribosome to produce a specific amino acid chain, later folded into a protein.
what is the central dogma
Dna is split and then made into RNA and then read and made into protien
histology
is the study of tissues. A tissue sample must be fixed (preserved) before being sectioned and stained.
Epithelium
Epithelial tissue covers body surfaces (internal or external), lines cavities, and forms glands.
what are the six characteristics of epithelia?
cellularity, polarity
attachment to connective tissue, avascular, inerviated and highly regenerative
what is celularity
lateral contacts between cells that hold them together and allow for communication: part of the skin has desmosomes that are a kind of cell junction)
what is polarity
apical and basal surfaces have different function; basal cells are attached to a basement membrane, apical surface often has villi or cilia)
what is epithelia connected to?
connected to basal lamina and reticular lamina
what is avascular
no blood supply
what is inerviated
supplied by nerves
why is epithelia highly regenerative?
a majority of cells are lost due to flaking so the body has stem cells to replace the lost cells
what are microvilli
little arms on the apical surface that protrude from cells that are used for absorption/secretion
what are cilia
arms that move fluids across surface
where is simple squamous mesothelium located
visceral side of serous membranes.
what is the meaning of visceral
relating to an internal organ
where is endothelium located?
it lines the interior blood and lymphatic vesels also form capillaries
What is Stratified squamous epithelium?
protects structures from abrasion.
- keratinized
- water resistant
- found in the epidermis and external openings of the body mouth anus vagina
Stratified squamous epithelium
protects secretion and absorption.
-in the lining of ducts in sweat and mammary glands
simple cuboidal epithlium
in the Glandular tissue, Ducts/kidney tubules
Transitional epithelium
is found in the wall of hollow urinary organs (urethra, ureter, urinary bladder)
Pseudostratified columnar epithelium
- found in the respiratory tract and male reproductive tract.
- in the respiratroy tract, it is ciliated and has goblet cells
what is a goblet cell?
a column-shaped cell found in the respiratory and intestinal tracts, which secretes the main component of mucus.
glandular epithelia types
endocrine and exocrine glands
what do endocrine glands do?
glands that release hormones to intestinal fluid to blood
what do exocrine glands do
release secretions to the epithelia (ducted)
what types of types of secretion do exocrine glands have
merocrine; product released by exocytosis
Holocrine; product released by destruction of cells.
what types of gland structures are there?
unicellular; goblet cells
multicellular; simple or complex, tubular or aveolar
what are the four types of connective tissue?
- connective tissue proper
- cartilage
- bone
- blood
functions of CT
- structural framework
- transport substances
- protect delicate organs
- insulate body
- defend body
- store energy
- connect structues
what is extracellular matrix
the majority of the volume of CT.
- a collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells
ground substance
the fluid that holds the ECM
protein fibers
produced by fibroblasts