PSL300H1 Study Guide - Polydipsia, Thyroid Peroxidase, Reuptake
Document Summary
Gap junction direct cytoplasmic connection between adjacent cell. Small molecule can pass (atp, camp) ; electrical signals pass directly: contact dependent signal interaction between membrane molecule of 2 cells. Cell adhesion molecules (cam) link to cytoskeleton transfer signals in both side of cell membrane: local commmunicate = chemical in extracell fluid ; limited by distance. Autocrine signal acts on same cell that secreted it. Paracrine secreted by one cell, diffuse to adjacent. i. e. histamine ; @injury, make capillaries permeable. I. e. cytokine > peptides ; i. e. eicosanoids peptide auto + paracrine: long distance communicate = electrical signal by nerve cells. Chemical signal secreted by cell to extracellular fluid. Hormone secreted by endocrine cells in blood > circulation. Peptide hormones made in advance. (1) control enzyme rate (2) control cell transport (3) control gene expression. I) hormone deficient, remove gland ; ii) replacement therapy, put gland back ; iii) hormone excess ; implant additional ; iv) purify extract ; isolate active.
