Week 5 Flashcards
General somatic afferent fibers
Bring conscious/unconscious sensory memory from body wall and limbs
General visceral afferent fibers
Bring sensory information from visceral structures to CNS
General somatic efferent fibers
Innervation of voluntary skeletal muscles
General visceral efferent fibers
Innervation of cardiac muscles, smooth muscles, and glands
Dorsal root ganglions
Afferent nerve fibers
Dorsal horn
Entry of sensory information
Ventral horn
Location of motor neurons
Lateral Horn (Thoracolumbar)
T1-L2Location of preganglionic sympathetic neurons
Craniosacral preganglionic nerves
Parasympathetic originsBrainstem and S2-S4
Path of efferent sympathetic nerve transmission
Information from CNS –> Travel down to spinal cord –> Leave through lateral horn via ventral root –> Enter spinal nerve –> Enter sympathetic ganglion via white ramus –> Exit sympathetic ganglion via gray ramus –> Travel through spinal nerve to target
White ramus
Myelinated connection between spinal nerve and sympathetic ganglionOnly T1-L2
Gray ramus
Unmyelinated connection between sympathetic ganglion and spinal nerveAll levels
Path of efferent sympathetic nerve transmission (to cervical/lumbar area)
Information from CNS –> Travel down to spinal cord –> Leave through lateral horn via ventral root –> Enter spinal nerve –> Enter sympathetic ganglion via white ramus –> TRAVEL UP OR DOWN SYMPATHETIC CHAIN –> Synapse –> Exit sympathetic ganglion via gray ramus –> Travel through spinal nerve to target
Tyrosine –> Epinephrine synthesis pathway
Tyrosine –> DOPA –> Dopamine –> Norepinephrine –> Epinephrine
Neurotransmitter synthesis enzymes (Tyrosine –> Epi)
Tyrosine HydroxylaseDOPA decarboxylase D-beta-hydroxylasePNMT
Major mechanism for termination of NE action
Reuptake pumpUptake-1
Monoamine oxidase
Oxidizes NE to be degraded
Cocaine
Inhibits NE re-uptake into nerve terminalMore NE –> enhanced response
Imipramine
Tricyclic antidepressantInhibits NE reuptake
Tyramine
Indirectly acting sympathomimeticMimics NE activity by using NETaken up by uptake-1 pump –> oxidized by MAOIf MAO-inhibitor –> Not oxidized –> displaces NE from vesicles
Resperpine
Root of Rauwolfia serpentinaInhibits vesicular uptake of NE –> depletes vesicle so less NT when released
D-beta hydroxylase location
Within vesicle, released during exocytosis
Readily Reversible AChE inhibitor
Binds to active site but no covalent bond formation
Intermediate reversible AChE inhibitor
Covalent bond formation and then bond hydrolyzed - carbamates
Irreversible AChE inhibitor
Non hydrolysable covalent bondOrganophosphate
Regeneration
Proliferation of cells and tissue with host replacement tissueLiver regeneration after resection
Repair
Combination regeneration and deposition of collagen (scar formation)Dermal wound healing
Stimulatory control of cell proliferation and growth
Growth factors and cytokinesHormonesCell-cell interactionsCell matrix interaction
Inhibitory control of cell proliferation and growth
Contact inhibitionGrowth factors
Stages of liver regeneration
Priming: IL-6 produced by Kuppfer cells make hepatocytes competent to respond to growth factorsGrowth factors: HGF, TGF-a act on primed hepatocytesHepatocytes move from G0 to G1 phase of cell cycle
Kuppfer cells
Resident liver macrophages
Oval cells
Hepatic ductal cells which accumulate during toxin exposureReplace parenchymal cells and restore function
Primary union of skin incision
Clean injurySpace clots –> neutrophil infiltrate –> epithelial cell migration/proliferation –> Macrophage –> Granulation tissue forms –> Collagen begins to bridge wound ~1 week
Angiogenesis
Blood vessel formationNotch signaling pathway
Secondary union of skin
Larger wound, more inflammation, more granulation tissue fills defect, longer healing timeWound contraction reduces size
Labile cells
Continuously dividingEpidermis, bone marrow, GI mucosa
Stable/Quiescent cells
Potential to divideHepatocytes, renal tubular epithelium, endothelium, connective tissue, smooth muscle
Permanent cells
Unable to divideNeurons, cardiac myocytes, skeletal muscle
Determinants of quality of healing
Regenerative capacity, stromal injury, contamination, proliferative activity of connective tissue
Excessive repair
Hypertrophic scarsKeloids
Characteristics of benign neoplasms
Pushing, smooth borderHistology looks like normal tissueDo no metastasize
Malignant neoplasms
Hard tumorInfiltrating, invasive locallyLack of differentiation: anaplasiaMay extend into adjacent tissue or invade nerve sheaths (perineural invasion) and blood vessels (vascular invasion)
Invasion of matrix across basement membrane
Tumor cells lose cohesion –> secrete proteolytic enzymes –> Attach to extracellular matrix via receptors for laminin/fibronectin –> locomote through matrix
Alpha-1 receptor activation effects
Vasoconstriction
Alpha-2 receptor activation effect
Inhibition of transmitter release (NE and ACh)
Beta-1 receptor activation effects
Increased cardiac rate (SA node) and force (and output)
Beta-2 receptor activation effects
Bronchodilation, vasodilation Only Epinephrine
Beta-1 agonist activity
Increased cardiac output, HR
Beta-1 antagonist activity
Prevent increase in cardiac output
Beta-2 agonist activity
Dilate airways, decrease resistance
Beta-2 antagonist activity
Constrict airways, increase resistance