Biology 235 Final Exam Questions With 100%
Correct Answers 2024/2025
What is afterload with regards to artery anatomy?
Elastic arteries - stretch and recoil during pressure pulses
Amount of elasticity determines force of afterload
How do arterioles affect afterload?
Provide vascular resistance and regulate regional blood flow via sympathetic vasomotor tone and pre-
capillary sphincters
What 4 mechanisms regulate blood pressure in the body?
Baroreflex
Chemoreceptor reflex
Cholinergic
Adrenergic
What are baroreceptors and what do they stimulate?
Pressure 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?
Sympathetic outflow to blood vessels
How does the cardioregulatory center regulate blood pressure?
Sympathetic 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?
Carotid 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?
Cholinergic
Adrenergic
Describe cholinergic regulation of BP
ACh 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
Sympathetic 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?
Tyrosine - amino acid
What are the 5 receptors that NE, E bind to?
Alpha1, Alpha2, Beta1, Beta2, Beta3
Where are beta1 receptors located?
Myocardium, SA and AV nodes
What do beta1 agonists cause?
Increased 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?
Down-regulation by receptor internalization
Where are beta2 receptors located?
Vascular and bronchial smooth muscle
What occurs when catecholamines bind to beta2 receptors?
G-protein mediated removal of Ca from the cytoplasm to the sarcoplasmic reticulum
Relaxes actin/myosin contraction
Bronchodilation, vasodilation
Where are alpha1 receptors located?
Vascular smooth muscle
What occurs when agonists bind to alpha1?
G-protein coupled
Sarcoplasmic reticulum releases Ca
Vasoconstriction
Where are alpha2 receptors located?
Sympathetic pre-synaptic terminals
What happens with agonists bind alpha2?
Inhibition of Ca into nerve terminal
Reduced NE release
Reduced sympathetic vasomotor tone
During normal daily activities, which receptors are bound in vascular smooth muscle?
Beta2 receptors - vasodilation, increased blood flow to muscles and organs
Correct Answers 2024/2025
What is afterload with regards to artery anatomy?
Elastic arteries - stretch and recoil during pressure pulses
Amount of elasticity determines force of afterload
How do arterioles affect afterload?
Provide vascular resistance and regulate regional blood flow via sympathetic vasomotor tone and pre-
capillary sphincters
What 4 mechanisms regulate blood pressure in the body?
Baroreflex
Chemoreceptor reflex
Cholinergic
Adrenergic
What are baroreceptors and what do they stimulate?
Pressure 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?
Sympathetic outflow to blood vessels
How does the cardioregulatory center regulate blood pressure?
Sympathetic 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?
Carotid 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?
Cholinergic
Adrenergic
Describe cholinergic regulation of BP
ACh 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
Sympathetic 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?
Tyrosine - amino acid
What are the 5 receptors that NE, E bind to?
Alpha1, Alpha2, Beta1, Beta2, Beta3
Where are beta1 receptors located?
Myocardium, SA and AV nodes
What do beta1 agonists cause?
Increased 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?
Down-regulation by receptor internalization
Where are beta2 receptors located?
Vascular and bronchial smooth muscle
What occurs when catecholamines bind to beta2 receptors?
G-protein mediated removal of Ca from the cytoplasm to the sarcoplasmic reticulum
Relaxes actin/myosin contraction
Bronchodilation, vasodilation
Where are alpha1 receptors located?
Vascular smooth muscle
What occurs when agonists bind to alpha1?
G-protein coupled
Sarcoplasmic reticulum releases Ca
Vasoconstriction
Where are alpha2 receptors located?
Sympathetic pre-synaptic terminals
What happens with agonists bind alpha2?
Inhibition of Ca into nerve terminal
Reduced NE release
Reduced sympathetic vasomotor tone
During normal daily activities, which receptors are bound in vascular smooth muscle?
Beta2 receptors - vasodilation, increased blood flow to muscles and organs
