BIO 446L 1st Edition Lecture 4 Outline of Last Lecture I. Epithelial Tissuea. Characteristicsb. Basal lamina and basement membranec. Intercellular (lateral)i. Transportd. Structures on the apical surfacei. Microvillie. Structures on all epithelial surfacesi. InterdigitationsOutline of Current Lecture I. Epithelial tissue contda. Types of epitheliai. Squamous, cuboidal, columnarii. Simple and stratifiediii. GlandularII. Connective Tissuea. Fibrocytes and fibroblastsb. Macrophagesc. Mast cellsCurrent LectureEpithelial Tissue Contd- Simple= one layero Simple squamous= one layer of flat epithelial cells Diffusiono Simple cuboidal= one layer of cube shaped cells Transporters, mitochondria present SecretionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Simple columnar= one layer of columnar shaped Absorptive, secretion, protection- Stratified= layers, top layer will slough off and regenerateo Squamous Keratinized= thick layer of keratin, lose nuclei as pushed to surface Nonkeratinized= keep nucleio Transitionalo Pseudostratified= position of cells appear stratified but truly is not All cells are attached to basement membrane- Glandular epitheliao Exocrine gland Secrete on to apical surfaceo Endocrine gland Secrete hormones into blood Completely buds offo Secretory patterns Merocrine= most glands, usually secrete enzymes, exocytosed Holocrine= secretory product and some cytoplasm- Ex: wax onto hair follicle in sebaceous glands Apocrine= mammary glands entire cell pinched off into duct and must be regeneratedo Types of secretion Serum= watery Mucus= viscouso Unicellular glands= one cell that can secrete into lumen or bloodConnective Tissue- Derived from embryonic mesenchyme cellso Can be considered stem cells- Fibroblasts= one of the first cells that will differentiate from mesenchymeo Secreting cell- Fibrocytes= long and thin, mature, maintains tissueo Active and inactive Fibrocytes can revert back to fibroblasts (active) with help of kinases, etc.- Ex: in wound healing- Macrophageso Derived from bone marrow Monocyteo Migrate and enlargeo Prolific phagocytes Eat old RBC’s, apoptotic cellso Can be an APC after digesting a foreign body to signal the immune systemo Also has active/inactive phenotypes- Mast Cellso Small, stain darkly because full of vesicleso Can respond to allergic reactions Anaphylaxis- Exposed to an allergin, accumulate hypersensitivity, IgE antibodiesbind, second exposure to allergin causes clumping of antigens,Calcium enters, microfilaments activate, contract, and cause cytokine vesicles of mast cells to be exocytosed (degranulation)o These chemicals cause itching, swelling, etc.- Plasma Cells and and Leukocyteso B lymphocytes produce plasma cell bodieso Diapedesis= WBC walk, using actin microfilaments, out of blood vessel to chemical attractant Chemotaxis= walking towards chemical
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