Exam 2 Flashcards
What are different types of movement?
Intracellular, muscle, cell motility/shape
What are the two components of movement?
Cytoskeleton that provides movement and motor proteins that provide movement.
What are microtubules?
Tubulin polymers that conduct intracellular traffic and are part of a dynamic system. Make up cellular components like flagella and cilia.
What is the MTOC?
Microtubule organization center where microtubules of cell are organized from
What is the sliding filament theory?
Myosin pulls actin past itself to cause contraction. Force is generated by muscle shortening and increased cross bridges is directly proportional to tension generation.
What is a sarcomere?
Subunit of striated muscle bundled together in myofilament inside a myofibril.
What are motor units?
Somatic motors neuron and all the muscle fibers it innervates.
What are transverse tubules?
Tubules that carry action potentials deep into the muscle cell and is perpendicular to the myofibril
What is the sarcoplasmic reticulum>
Stores calcium which regulates muscle contraction. Calciums leaves down its gradient via voltage-gated ion channels and reenters through an ATPase pump.
What are myofibrils?
Bundles of actin and myosin.
What is the first step of skeletal muscle contraction?
The somatic motor neuron releases ach
What is the second step of skeletal muscle contraction?
Ach binds receptors which opens channels to cause an action potential
What is the third step of skeletal muscle contraction?
Action potential travels down t-tubules
What is the fourth step of skeletal muscle contraction?
Voltage-gated channels trigger calcium channels on sarcoplasmic reticulum to open
What is the fifth step of skeletal muscle contraction?
Calcium diffuses into cytosol and some binds to troponin.
What is the sixth step of skeletal muscle contraction?
Troponin changes shape and pulls tropomyosin away from binding spots on actin.
What is the seventh step of skeletal muscle contraction?
Myosin heads are able to form cross bridges with actin.
What is the eighth step of skeletal muscle contraction?
The powerstroke cycle occurs with actin being pulled past myosin causing sarcomere shortening.
What is the ninth step of skeletal muscle contraction?
Calcium is pumped back into the sarcoplasmic reticulum by calcium ATPase
What is the tenth step of skeletal muscle contraction?
Troponin releases calcium and tropomyosin slips back over binding spots preventing cross bridge formation.
What is the first step of cardiac muscle contraction?
Pacemaker cells depolarize which generates an action potential
What is the second step of cardiac muscle contraction?
The action potential travels along the conduction pathway and through cells via gap junctions.
What is the third step of cardiac muscle contraction?
Calcium entering as part of the action potential triggers the release of more calcium from the sarcoplasmic reticulum
What is the fourth step of cardiac muscle contraction?
Calcium that diffused into the cytosol binds to troponin
What is the fifth step of cardiac muscle contraction?
Troponin changes shape and pulls tropomyosin away from binding spots on actin
What is the sixth step of cardiac muscle contraction?
Myosin heads are able to form cross bridges with actin
What is the seventh step of cardiac muscle contraction?
Powerstroke cycle occurs with actin being pulled past myosin causing sarcomere shortening
What is the eighth step of cardiac muscle contraction?
Calcium is pumped back into the sarcoplasmic reticulum and extracellular fluid by calcium ATPase
What is the ninth step of cardiac muscle contraction?
Troponin releases calcium and tropomyosin slips back over binding spots preventing cross bridge formation
What is the first step of smooth muscle contraction?
Pacemaker cells depolarize which causes hormones or local chemicals to bind receptors or stretch and stimulates a mechanoreceptor. Autonomic neurons release neurotransmitters generating an action potential
What is the second step of smooth muscle contraction?
Calcium entering as part of the action potential triggers the release of calcium from the sarcoplasmic reticulum.
What is the third step of smooth muscle contraction?
Calcium that diffuses into the cytosol binds to calmodulin
What is the fourth step of smooth muscle contraction?
The calcium calmodulin complex removes caldesmon from actin and activates the MLCK.
What is the fifth step of smooth muscle contraction?
MLCK adds a phosphate/phosphate group onto myosin which increases its affinity for actin
What is the sixth step of smooth muscle contraction?
Myosin heads are able to form cross bridges with actin
What is the seventh step of smooth muscle contraction?
Powerstrok cycle occurs with actin being pulled past myosin causing shortening and contracting.
What is the eighth step of smooth muscle contraction?
Calcium is pumped back into the sarcoplasmic reticulum and extracellular fluid by ATPase.
What is the ninth step of smooth muscle contraction?
Calcium is released from calmodulin so no new MLCK is activated, caldesmon rebinds to actin, and MLCP removes phosphate from myosin so that cross bridges are no longer formed.
What is calsequestrin?
Proteins in the sarcoplasmic reticulum that bind calcium to decrease the concentration of free calcium
What is parvalbumin?
A protein in the cytosol that binds calcium to decrease the free calcium concentration.
What are the different types of circulatory fluid?
interstitial, blood, lymph, hemolymph, and water for some animals.
What is bulk flow?
The circulation system of organisms that do not have a direct circulatory system. It relies on external fluid like water, they have a thin outer layer/membrane and usually have a gastrovascular system.
What organisms use bulk flow?
Sponges, cnidaria, and platyhelminths
What is an open circulatory system?
Circulatory systems that have direct contact with tissue, has a large volume, low pressure, low control over flow, and slow metabolism.
What organisms use open circulatory systems?
Arthropods and molluscs
What is a closed circulatory system?
Circulatory systems with all blood vessels connected which allows for directed movement of fluid
What are organisms that use closed circulatory systems?
Fish and mammals
What is a single chamber heart?
Hearts that pull fluid in similarly to placentas. Used by arthropods.
What is a two chamber heart?
Hearts with one atrium (blood in) and one ventricle (blood out). Used by fish.
What is a three chambered heart?
A heart with two atria and one ventricle. Used by amphibians.
What is a four chambered heart?
A heart with two atria and two ventricles. No mixing of high and low oxygen blood. Used by mammals.
What is a five chambered heart?
A heart with five chambers and a shunt leads to some mixing of high and low-oxygenated blood. Used by non crocodilian reptiles.
What is the first step of the cardiac cycle in mammals?
Ventricular diastole which is when the pressure in the atria exceeds ventricular pressure. AV valves open and ventricles fill passively.
What is the second step of the cardiac cycle in mammals?
Atrial systole, when atrial contraction forces additional blood into the ventricles.
What is the third step of the cardiac cycle in mammals?
Ventricular systole (isovolumetric contraction), when ventricular contraction occurs and pushes the AV valves closed and increases pressure in the ventricles.
What is the fourth step of the cardiac cycle in mammals?
Ventricular systole, when there is increased ventricular pressure forces the semilunar valves open and blood ejects
What is the fifth step of the cardiac cycle in mammals?
Ventricular diastole, when the ventricles relax, pressure in the arteries exceeds ventricuar pressure closing semilunar valves.
What is the structure of pyruvate?
