BIO 141 for Exam 2

Low blood pressure--> decreased baroreceptor firing-->decreased cardioinhibitory center-->decreased norepinephrine release

(know this)

Cholinergic neurons secrete norepinephrine to slow down depolarization at the SA Node (true or false?)

false

Adrenergic neurons secrete norepinephrine that interacts with the SA Node to speed up depolarization (true or false?)

true

Adrenergic receptors are associated with the cardio-accelatory response (sympathetic response) (true or false?)

true

Cholinergic neurons secrete acetylcholine which interacts with the SA Node to slow down heart rate (true or false?)

true

The function of the sarcomere is best described by which of the following statements?

A sarcomere is the organization of proteins (myofilaments) in a myofibril

Which of the following places the events in the correct order they occur during excitation and contraction?

Action potential travels down T-tubule --> Calcium released from sarcoplasmic reticulum --> Troponin binds to calcium --> Active sites of actin are exposed --> Myosin interacts with actin

WHICH STATEMENT IS FALSE? A. If a person has been injured in an accident and is losing a lot of blood, you expect the baroreceptors to generate fewer action potentials per second B. As a person's blood pressure rises, your expect the baroreceptors to generate more action potentials per second. As a person's blood pressure rises, you expect the cardioaccelatory center to generate fewer action potentials per second. C. As a person's blood pressure drops, you expect the vasomotor center to generate fewer action potentials per second D. As a person's blood pressure rises, you expect the cardioinhibitory center to generate more action potentials per second.

C. As a person's blood pressure drops, you expect the vasomotor center to generate fewer action potentials per second

Which of the following characteristics do neurons and muscles share?

Excitability

True or False: A whole muscle contraction is the result of one sarcomere shortening

FALSE

Identify the phase of the cardiac cycle when the QRS complex has occurred, but the T wave has not.

Isovolumetric contraction of the ventricles

Cardiac Output is the product of volume (stroke volume) and the rate of ejection of blood from the heart (HR) (true or false?)

TRUE

Which of the following is the correct order of muscle composition from LARGEST structure to SMALLEST structure?

Whole Muscle-->Fascicle-->Myofibril-->Myosin-->Actin