Epithelium and Glands Flashcards
4 types of tissue
Nervous, Epithelial, Muscle, Connective
Nervous Tissue
Transmission of nerve pulses
Epithelial Tissue
Tissue that lines the outer surface of body cavities except for joints. They are avascular, contain secretory cells and keratin filaments, they have polarity and an ability to regenerate. Desmosomes make them act like a continuous sheet.
Muscle Tissue
Movement
Connective Tissue
Support and protection
3 germ layers
Ectoderm, Mesoderm, Endoderm
Functions of Epithelial Tissue
Protection, secretion, absorption (diffusion), and sensory reception
Simple cuboidal
Located within the thyroid, choroid plexus
Simple columnar
Located in the stomach, intestine
Transitional epithelium
Contains a binucleated upper layer that can change shape. Ex/ bladder
Psedostratified epithelium
A rare type of layer that is falsely stratified with nuclei that intervene the membrane. Ex/ epididymus, trachea
Parenchyma
Secretory portion of an exocrine gland
Stroma
Connective tissue that surrounds the parenchyma and supports the secretory cells
Endocrine
Glands that secrete into blood vessels
Exocrine
Glands that secrete onto the surface or into the cavity of a hollow organ
Acinus
Secretory portion of a gland
Duct
Conducting portion of a gland
Serous cells
Acinar glands that secrete aqueous substances and contains more proteins. It stains darker.
Mucous cells
Secretes mucous polysaccharide. Stains lighter.
Merocrine gland
Most common type of gland that uses exocytosis to transport small vesicles to the apical part of the membrane for release
Apicrine gland
a large chunk of the apical cytoplasm is released. (ex/ mammory glands)
Holocrine gland
whole cell is released, it ruptures and releases its contents. (ex/ sebaceous glands)
Microvilli
contains actin filaments, fuzzy, brush border looking, skinnier than cilia.
Cilia
Contains an axoneme, more defined structure, wider and longer than micivilli.
Stereocillia
Longer and skinnier than microvilli
Glycocalyx
Contains sugar residues that coat surface of microvilli
Common defects in cilia
Missing central pair, radial spoke defect, and absent inner and outer dynein arms
