Biology 235 Final Exam Questions With 100% Correct Answers 2024/2025

Biology 235 Final Exam Questions With 100% Correct Answers 2024/2025 What is afterload with regards to artery anatomy? - answerElastic arteries - stretch and recoil during pressure pulses Amount of elasticity determines force of afterload How do arterioles affect afterload? - answerProvide vascular resistance and regulate regional blood flow via sympathetic vasomotor tone and pre-capillary sphincters What 4 mechanisms regulate blood pressure in the body? - answerBaroreflex Chemoreceptor reflex Cholinergic Adrenergic What are baroreceptors and what do they stimulate? - answerPressure receptors in the aortic arch and carotid sinus, stimulate vasomotor center and cardioregulatory center in the medulla oblongata How does the vasomotor center regulate blood pressure? - answerSympathetic outflow to blood vessels How does the cardioregulatory center regulate blood pressure? - answerSympathetic excitation of SA, AV nodes Parasympathetic inhibition of SA node, heart muscle (vagus nerve) Describe chemoreceptors - what do they measure and what do they stimulate? - answerCarotid bodies and aortic bodies Monitor CO2, O2, H+ Innervate vasomotor, cardioregulatory and respiratory centers in the medulla oblongata What are the 2 autonomic receptor mechanisms that regulate BP? - answerCholinergic Adrenergic Describe cholinergic regulation of BP - answerACh is released at parasympathetic post- ganglionic synapse on SA/AV nodes (vagus nerve) Muscarinic receptor binding closes Ca channels (slows depolarization) and opens K channels (speeds up repolarization) - slows HR Describe adrenergic regulation of BP - answerSympathetic post-ganglionic nerves release NE Adrenal medulla releases NE, E NE, E bind to alpha and beta receptors What are NE, E, and DA derived from? - answerTyrosine - amino acid What are the 5 receptors that NE, E bind to? - answerAlpha1, Alpha2, Beta1, Beta2, Beta3 Where are beta1 receptors located? - answerMyocardium, SA and AV nodes What do beta1 agonists cause? - answerIncreased force of contraction, increased heart rate Coupled to G-protein second messenger system Ca influx activates actin/myosin binding (cardiac muscle contraction) Ca speeds up depolarization of nodal tissue (incr HR) What can occur if Beta-1 receptors are subjected to chronic stimulation? - answerDown- regulation by receptor internalization Where are beta2 receptors located? - answerVascular and bronchial smooth muscle What occurs when catecholamines bind to beta2 receptors? - answerG-protein mediated removal of Ca from the cytoplasm to the sarcoplasmic reticulum Relaxes actin/myosin contraction Bronchodilation, vasodilation Where are alpha1 receptors located? - answerVascular smooth muscle What occurs when agonists bind to alpha1? - answerG-protein coupled Sarcoplasmic reticulum releases Ca Vasoconstriction Where are alpha2 receptors located? - answerSympathetic pre-synaptic terminals What happens with agonists bind alpha2? - answerInhibition of Ca into nerve terminal Reduced NE release Reduced sympathetic vasomotor tone