Chp 6
What is the threshold for an action potential?
-55mV
The globular heads on myosin binding sites are _____ and _______.
Actin and ATP
A neuron that drives a signal to the next neuron
Interneuron
What is the difference between an endocrine and an exocrine gland?
An endocrine gland secretes hormones into the interstitial fluid, which then diffuses into the blood. An exocrine gland secretes a product via a duct.
What is Stroke Volume
Volume the ventricles pump per heart beat! (Difference between the end diastolic volume and the end systolic volume).
What brings the cell back to the resting membrane potential after hyperpolarization
Na+/K+ ATPase Pump. It Pumps out 3 Na+ and Brings in 2K+
The layers of skeletal muscle structure from smallest to largest
Muscle, Fascicle(Bundle of muscle fibers), Muscle fibers(muscle cells), Myofibrils, sarcomeres, thick and thin protein filaments
Reaction to painful stimulus
Withdrawal Reflex
This class of hormone is derived from the amino acid tyrosine, is water soluble, and an example of one hormone is epinephrine.
Amine
This valve prevents blood from moving back into the right atrium after it has moved into the right ventricle.
Tricuspid valve
An Influx of _____ causes neurotransmitter________ to be released into the synaptic cleft.
Influx of Ca2+. Neurotransmitter Acetylcholine
The action that the myosin heads do to be able to bring actin filaments closer to the M-line. Also what is necessary for Myosin heads to be detached from the binding sites on actin.
Power stroke, ATP
Cerebral Cortex
Plays an important role in planning and ongoing control of voluntary movement>
Sensorimotor cortex- all parts of the cerebral cortex that act together to control muscle movement
This class of hormone uses albumin to travel through the blood.
Steroid hormones
In an ECG, what does the P wave, QRS complex, and T wave represent?
P wave: depolarization of the atria
QRS complex: Depolarization of the ventricles
T wave: Repolarization of the ventricles
What are the steps of neurotransmitter release? (6)
1. The impulse reaches the axon ending of the presynaptic membrane
2. Synaptic vesicles release neurotransmitter into the synaptic cleft
3. Neurotransmitter diffuses across the synaptic cleft
4. Neurotransmitter molecules bind to receptors on the postsynaptic neuron
5. Sodium ion channel opens
6. Sodium ions enter the postsynaptic neuron, causing depolarization and potential action potential
Explain the General process of the Cross-bridge cycle
Cross-bridge binds to actin
Cross-bridge moves and ADP + P come off the myosin head
ATP binds to the myosin head, myosin head detaches from Actin.
Hydrolyzed ATP energizes Cross-bridge ro be ready to bind to actin
Describe the muscle spindle fibers and the motor neurons that innervate them
Extrafusal muscle fibers provide force and movement. Innervated by alpha motor neurons
Intrafusal muscle fibers provide sensory input. Innervated by Gamma motor neurons.
*Alpha-gamma Coactivation allows the nervous system to be informed about muscle length at all times.
Name the hormones secreted by the anterior pituitary gland
FSH, LH, ACTH, TSH, Prolactin, Growth Hormone (A mnemonic to remember them is “FLAT PiG”
Summarize the blood flow through the heart.
Vena Cava, Right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, lungs, back through the pulmonary vein, left atrium, mitral valve (bicuspid valve), left ventricle, aortic valve, aorta…takes it to the body and then it will eventually return through the vena cava back to the right atrium again.
Describe the steps of an action potential (resting potential, depolarization, repolarization, hyperpolarization, Na+/K+ ATPase Pump).
Resting potential- -70mV, more (-) inside, more Na+ outside
Depolarization- AP begins once -55mV (threshold) is reached, Large influx of Na+, neuron is becoming more positive than at rest
Repolarization- Large efflux of K+, neuron becoming more negative again
Hyperpolarization- even more (-) than at rest,
Na+/K+ ATPase pump establishes resting potential by pumping out 3Na+ and pumping in 2K+
Describe the Muscle contraction steps starting at
Acetylcholine(Neurotransmitter) binds to muscle fibers.
Neurotransmitter acetylcholine binds to muscle fibers.
This sends an action potential down the t-tubules
That AP triggers sarcoplasmic reticulum to release Ca2+
Ca2+ binds to troponin
This causes a conformational change and pulls tropomyosin away from binding site
Binding site on actin is now exposed =cross bridge cycle starts
Myosin head will bind to binding site on actin with the help of hydrolysis of ATP---> ADP + P
Power stroke occurs(actin to m-line)-sliding filament mechanism
Reflex type that occurs when the doctor taps on your patellar tendon. Is it monosynaptic or polysynaptic?
Answer: Knee Jerk Reflex, Monosynaptic.
Where on the target cell are receptors for peptide, amine, and steroid hormones?
receptors for peptide and amine hormones? A: Cell surface
receptors for steroid hormones? A: intracellular
Name and describe the 3 factors that control stroke volume.
Changes in Preload (how much blood is loaded to ventricles before they contract (During preload blood returns back to heart passively).
Sympathetic input to ventricles (Ventricles contract with more force with increased sympathetic stimulation).
Changes in afterload. Pressure ventricles must overcome to force open semilunar valves. (High BP or atherosclerosis increases pressure that ventricles work against).