physio: CHAPTER 12,13,14,15 Study Guide

what is the second heart sound

"dub" closing of the pulmonary valve and aortic valve

what is first heart sounds

"lub" closing of the tricuspid valve and mitral valve

how many elements (bands) are there in a sarcomere? name them

- 5 - Z disks - I bands - A bands - H zone - M line

what are the events at the isovolumic contraction of ventricular systole

- Phase of the cardiac cycle when the ventricles are contracting but all valves are closed and the volume of blood in them is not changing - Ventricles begin to contract - Atrial muscle fibers are repolarizing and relaxing - When atrial pressure falls below in the veins, blood flows from the veins into the atria again - Closure of the AV valves isolated the upper and lower cardiac chambers

what are the phases of the cardiac cycle

- The cardiac cycle is the period of time from the end of one heartbeat through the end of the next beat - Beginning of the cardiac cycle begins with both atria and ventricles at rest - ECG begins with atrial depolarization - Atrial contraction starts during the latter part of the P wave and continues during the P-R segment. - During the P-R segment, the electrical signal is slowing down as it passes through the AV node (AV node delay) and AV bundle - Ventricular contraction begins just after the Q wave and continues through the T wave. - The ventricles are repolarizing during the T wave, followed by ventricular relaxation - During the T-P segment the heart is electrically quiet

define crossed- extensor reflex

- a flexion reflex in one limb causes extension in the opposite limb

describe isotonic contraction

- actually doing work allowing for muscles to contract - reach threshold and you to move the object

define motor units

- basic unit of contraction in a skeletal muscle - one motor neuron and its muscle fiber that controls or innervates them

what are intercalated discs

- contains gap junctions - they shorten the time of communication btwn the cardiac cells

describe isometric contraction

- initial force that is applied but does not reach threshold which means contractions does not move the load

why is the closing of valves during the first and second sound important

- it is important because it allows for one direction of blood flow to prevent blood flow from coming back into the heart

describe the sliding filament theory

- muscle proteins slide past each other to generate force - explains how a muscle can contract and create force without creating movement

why are development of new blood vessels important

- necessary for normal development - wound healing & uterine line growth - enhances heart and skeletal muscle growth - needed for malignant tumor growth

what are the three waves of ECG

- p wave -QRS complex - T wave

define latent period

- short delay btwn the muscle action potential and the beginning of muscle tension development - time required for calcium to bind to troponin

what are the three types of muscles

- skeletal - cardiac - muscle

what do autonomic reflexes control

- smooth and cardiac muscle - adipose tissue

define A band

-encompasses the entire length of a thick filament -center of a band occupied by only thick filaments

define transverse tubules (t-tubules)

-invaginations of the muscle fiber -allow action potential to move rapidly

define I bands

-only occupied by thin filaments

define sarcomere

-the contractile unit of a myofibril

define skeletal muscle

-they position and move the skeleton -striated and voluntary

define Z disk

-zig zag protein structures that serve as the attachment site for thin filaments

describe the excitation contraction coupling

1. Action potential enters from adjacent cell 2. Voltage gated Ca2+ channels open. Ca2+ enters the cell 3. Ca2+ induces Ca2+ release through ryanodine receptor-channels (RyR) 4. Local release causes Ca2+ spark 5. Summed Ca2+ sparks create a Ca2+ signal 6. Ca2+ ions bind to troponin to initiate contraction 7. Relaxation occurs when Ca2+ unbinds from troponin 8. Ca2+ is pumped back into the sarcoplasmic reticulum for storage 9. Ca2+ is exchanged with Na+ by the NCX antiporter 10. Na+ gradients is maintained by the Na+-K+ ATPase

name the reflex arc and integration centers

1. receptor 2. sensory neuron (afferent) 3. integration center (brain and spinal cord) 4. motor neurons (efferent) 5. effector

what is the percent of the cardiac output that is pumped by the heart and goes to the brain

15%

It is the middle of winter and you walk over an icy patch and lose your balance. As you begin to fall, you react by extending your arms to catch yourself. In this instance, what type of reflex is occurring? 1. tendon reflex 2. crossed-extensor reflex 3. reciprocal reflex 4. stretch reflex 5. flexion reflex

2

Place these structures in the correct order for an autonomic reflex: 1) Postganglionic autonomic neuron 2) Target cell 3) Receptor 4) CNS integrating center 5) Preganglionic autonomic neuron 6) Sensory neuron

3,6,4,5,1,2

how do you calculate MAP

Diastolic P + 1/3 (pulse pressure)

how do you calculate cardiac output

HR X SV

describe smooth muscles and its characteristics

Smooth no sarcomeres forms the wall of hollow organs and tubules uninucleate small spindle shaped fibers no t-tubules sarcoplasmic reticulum actin, myosin, tropomyosin slowest autonomic neurons multiple hormones

what are the effectors in a reflex ?

a muscle or a gland that responds with a contraction or a secretion

define metarterioles

a type of vessel that has structural characteristics of both an arteriole and a capillary

what causes a skeletal muscle action potential to begin excitation-contraction coupling

acetylcholine from a somatic motor neuron

describe active hyperemia

an increase in blood flow accompanies an increase in metabolism

describe reactive hyperemia

an increase in tissue blood flow following a period of low blood flow

p wave

atrial depolarization

what are angiogenesis controlled by

cytokines

define angiogenesis

development of new blood vessels

what does EDV stand for

end diastolic volume

name ALL the local vasodilators and vasoconstrictors

know the table !

what is ascultation

listening to the heart through the chest wall through a stethoscope

what are osmotic, oncotic, and colloid pressure

non-penetrating large plasma proteins

define H zone

occupied by thick filaments only

define M line

represents proteins that form the attachment site for thick filaments

what are baroreceptors

responsible for detecting any changes in blood pressure and reports back to medulla oblongata (control center)

what do somatic reflexes control

skeletal muscles

what is MAP measured by

sphygmomanometer and stethoscope

describe cardiac muscles and its characteristics

striated sarcomeres heart muscle uninucleate shorter branching fibers t-tubule sarcoplasmic reticulum actin, myosin, troponin, and tropomyosin intermediate autonomic neurons epinephrine

describe skeletal muscles and its characteristics

striated sarcomeres attached to the bones multinucleate large T-tubule sarcoplasmic reticulum, actin, myosin, troponin, and tropomyosin, fastest somatic motor neuron no hormones

how is pulse pressure measured

systolic pressure - diastolic pressure

where are skeletal muscles usually attached to bones

tendons

what is EDV

the maximal volume that occurs at the end of ventricular relaxation (diastole)

define the starling's law of the heart

the more blood there is in the ventricles, the more blood ejected out

what happens during isovolumic ventricular contraction

the ventricular blood volume does not change, but pressure rises.

QRS complex

ventricular depolarization

T wave

ventricular repolarization

define cardiac output

volume of blood pumped by one ventricle in a given period of time