BIOL 5600 Notes 2/8/16
BIOL 5600 Notes 2/8/16 BIOL 5600
Popular in Biomedical physiology
Popular in Biology
This 2 page Class Notes was uploaded by LaurenC on Thursday February 4, 2016. The Class Notes belongs to BIOL 5600 at Auburn University taught by Dr. Mendonća in Winter 2016. Since its upload, it has received 60 views. For similar materials see Biomedical physiology in Biology at Auburn University.
Reviews for BIOL 5600 Notes 2/8/16
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/04/16
Cardiac muscle cells: Striated Banding pattern Thick and thin filaments arranged in sarcomeres *Sarcomeres are the basic functioning unit Uninucleate Very well developed ttubules 5X diameter of what’s found in skeletal muscle cells Sarcoplasmic reticulum are less developed and hold less Ca+2 Well developed glycocalyx *glycocalyx is a place of calcium storage external to the/ right next to the cell membrane *Extra supply of external ca2+ *Most of Ca2+ comes from the outside/ external sources Can generate more tension (more contractile strength) due to ca+2 coming from outside Lots of mitochondria (more than type 1 skeletal) Behave like aerobic Innervation pattern is the main difference Occur in sheets, united by gap junctions Each sheet has one axon terminal Smooth muscle cells: Spindle shape Small cells Can be single cell, individually innervated multi unit Can be sheet connected by gap junctions single unit, visceral *Nerve ending to one cell, spreads by gap junctions 2 types with difference in base state 1) Phasic Usually relaxed Contract in cycles: relaxation/contraction Ex. smooth muscle layer of GI tract (peristalsis) 2) Tonic Usually contracted Periods of relaxation to allow things to pass Not as controlled. Ex. sphincter muscle In smooth muscle cells: >How do you get sustained contracted without burning through ATP? Through different way of contracting Not striated, no banding They do have thin and thick filaments, just in different arrangement No sarcomeres Do have actin, myosin, tropomyosin, but no troponin Ratio of 1215 thin filaments: 1 thick Contraction of smooth muscle fiber is a “corkscrew contraction” because of the way fibers are attached to cell membrane Intermediate filaments are anchored to dense bodies Dense bodies are plasma membrane integral proteins of sarcolemma in smooth muscle cell that function like a z line. They are the anchor point. They are not anchored to actin, but anchored to intermediate filaments. Intermediate filaments are attached to actin. When actin moves, it moves the intermediate filaments. This contraction is not fast like heart or skeletal muscle cell. Corkscrew movement, actually twisting cell, is slow, strong and prolonged. No ttubules because of small cell size Don’t need increase in surface area to propagate action potential deep into cell Sarcoplasmic reticulum is not well developed Just have voltage regulated Ca+2 in sarcolemma and sarcoplasmic reticulum. Not a lot of Ca2+ storage, because it is not needed. No massive releases of calcium. Slow release spread of calcium is slower. Calcium calmodulin complex initiates cascade causing myosin kinase to get phosphorylated. Myosin light chain kinase (MLCK) is a small regulatory protein at the base of the myosin head. MLCK donates phosphorous group to myosin head. It phosphorylates the myosin heads. Phosphorylation of myosin head creates myosin ADP~P, which causes myosin head to act as ATPase to hydrolyze the ATP being formed. The hydrolyzed ATP will attach to the actin Because of these differences, contraction and attachment occurs at a much slower rate than skeletal or cardiac muscle cells Slowly develops a great amount of tension Relaxation is also very different Whole other enzyme complex to make it let go To dephosphorylate the myosin light chain, you have a myosin light chain phosphatase Myosin light chain phosphatase is trying to dephosphorylate but as long as you have high levels of ca+2 calmodulin, the kinase is working to fast for phosphatase to work. This is how you relax, by the calmodulin levels going down. It dissociates. When you don’t have the calmodulin, it allows phosphatase to dephosphorylate. And you relax. There are sustained levels of contraction because connections stay longer. Because of this, not as much ATP is needed. You can have slow sustained contractions without fatiguing. Know: different types of cells, morphology, and contraction patterns. Twitch profiles. END OF TEST ONE MATERIAL
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'