Physiology Exam Ch 3&4

The muscles of a professional sprinter are most likely to have

80 percent fast-twitch muscle fibers and 20 percent slow twitch muscle fibers

Which of the following is a positive inotrope?

Ca2+

Which of the following phases is characterized by preparation for DNA synthesis?

G1

Which component of the heart conduction system would have the slowest rate of firing?

Purkinje fibers

What phase of mitotic interphase is missing from meiotic interkinesis?

S phase

A mutation in the gene for a cyclin protein might result in which of the following?

a cell with additional genetic material than normal, cancer, a cell with less genetic material than normal

The force the heart must overcome to pump blood is known as

afterload

In the renin-angiotensin-aldosteron mechanism

aldosterone prompts the kidneys to reabsorb sodium

Venoconstriction increases which of the following?

all of the above; blood pressure within the vein, blood flow within the vein, return of blood to the heart

At which stage of meiosis are sister chromatids separated from each other?

anaphase II

Which of the following properties is not common to all three muscle tissues?

at rest, uses shielding proteins to cover actin-binding sites

In which septum is it normal to find openings in the adult?

atrioventricular septum

Which of the following statements about blood is true?

blood is slightly more viscous than water

Nervi vasorum control

both vasoconstriction and vasodilation

Autolysis

breakdown of cells by their own enzymatic action

Muscle fatigue is caused by

buildup of ATP and lactic acid levels

Which primitive area of the heart will give rise to the right ventricle?

bulbus cordis

The influx of which ion accouts for the plateau phase?

calcium

Which element is important in directly triggering contraction?

calcium

According to the sliding filament model, binding sites on actin open when

calcium ion levels rise

Muscle relaxation occurs when

calcium ions are actively transported into the sarcoplasmic reticulum

During muscle contraction the cross-bridge detaches when

calcium ions bind to troponin

The two tubes that eventually fuse to form the heart are referred to as the

cardiogenic tubes

What multipotent stem cells from children sometimes banked by parents?

cells from the umbilical cord and from baby teeth

At metaphase I, homologous chromosomes are connected only at what structures?

chiasmata

Which of the following is not true in regard to crossover?

chiasmata are formed

The first heart sound represents which portion of the cardiac cycle?

closing of the atrioventricular valves

Cardiac muscles differ from skeletal muscles in that they

contain intercalated discs

Cleavage furrow

contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves

During which phase of a twitch in a muscle fiber is tension the greatest?

contraction phase

In a blood pressure measurement of 110/70 the number 70 is the

diastolic pressure

Closer to the heart, arteries would be expected to have a higher percentage of

elastic fibers

Which layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors?

endocardium

Which of the following is not important in preventing backflow of blood?

endocardium

How the extracellular matrix functions

extracellular matrix functions in support and attachment for animal tissues. It also functions in the healing and growth of the tissue

The correct order for the smallest to the largest unit of organization in muscle tissue is

filament, myofibril, muscle fiber, fasicle

Meiosis produces ________ daughter cells.

four haploid

The earliest organ to form and begin function within the developing human is the

heart

Which type of stem cell gives rise to red and white blood cells?

hematopoietic

Slight vasodilation in an arteriole prompts a

huge decrease in resistance

A form of circulatory shock common in young children with severe diarrhea or vomiting is

hypovolemic shock

Which of the following plasma proteins is not produced by the liver?

immunoglobulin

A healthy elastic artery

is compliant

The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer ventricular contraction while no blood is being ejected?

isovolumic contraction

In a healthy young adult what happens to cardiac output when heart rate increases above 160bpm?

it decreases

Which of the following statements about erythropoietin is true?

it facilitates the proliferation and differentiation of the erythrocyte lineage

Smooth muscles differ from skeletal and cardiac muscles in that they

lack myofibrils

The myocardium would be the thickest in the

left ventricle

Autophagy

lysosomal breakdown of a cell's own components

Blood islands are

masses of developing blood vessels and formed elements scattered throughout the embryonic disc

The cardiovascular centers are located in which area of the brain?

medulla oblongata

The part of meiosis that is similar to mitosis is

meiosis II

Of the three germ layers that give rise to all adult tissues and organs which gives rise to the heart?

mesoderm

Which of the following organelles produces large quantities of ATP when both glucose and oxygen are available to the cell?

mitochondria

Drug X blocks ATP regeneration from ADP and phosphate. How will muscle cells respond to this drug?

none of the above

Which portion of the ECG corresponds to repolarization of the atria?

none of the above:atrial repolarization is masked by ventricular depolarization

Which of the following is unique to cardiac muscle cells?

only cardiac muscle is capable of autorhythmicity

What aspect of creatine phosphate allows it to supply energy to the muscles?

phosphate bonds

Which of the formed elements arise from myeloid stem cells?

platelets

Arrange the following terms in order of increasing specialization: oligopotency, pleuripotency, unipotency, multipotency.

pleuripotency, multipotency, oligopotency, unipotency

Which of the following is a function of the rough ER?

production of proteins

Centromere

region of attachment for two sister chromatids

The rough ER has its name due to what associated structures?

ribosomes

Which chamber initially receives blood from th esystemic circuit?

right atrium

The cell membrane of a muscle fiber is called

sarcolemma

Thin and thick filaments are organized into functional units called

sarcomeres

Which cell type helps to repair injured muscle fibers?

satellite cells

An especially leaky type of capillary found in the liver and certain other tissues is called a

sinusoid capillary

Centriole

small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division

Which of the following lists the balbes in the order throught which the blood flows from the vena cava through the heart?

tricuspid, pulmonary semilunar, bicuspid, aoritc semilunar

In relaxed muscle the myosin-binding site on actin is blocked by

tropomyosin

The pulmonary trunk and aorta are derived from which primitive heart structure?

truncus arteriosus

The endothelium is found in the

tunica intima

In the myogenic response

vascular smooth muscle responds to stretch

Ventricular relaxation immediately follows

ventricular repolarization

If a muscle cell of a typical organism has 32 chromosomes, how many chromosomes will be in a gamete of that same organism?

16

The muscles of a professional marathon runner are most likely to have

20 percent fast-twitch muscle fibers and 80 percent slow twitch muscle fibers

A sprinter would experience muscle fatigue sooner than a marathon runner due to

anaerobic metabloism in the muscles of the sprinter

Most blood enters the ventricle during

atrial diastole

Centrosome

cellular structure that organizes microtubules during cell division

Which valve separates the left atrium from the left ventricle?

mitral

The ductus venossu is a shunt that allows

most freshly oxygenated blood to flow into the fetal heart

From which embryonic cell type does muscle tissue develop?

myoblast cells

Muscle that has a striped appearance is described as being

striated

Choose the term that best completes the following analogy: Cytoplasm is to cytosol as a swimming pool containing chlorine and flotation toys is to

the water

Which of the following is a feature common to all three components of the cytoskeleton?

they are all polymers of protein subunits.

Which of the following statements describes smooth muscle cells?

they are resistant to fatigue

Which of the following best describes veins?

thin walled, large lumens, low pressure, have valves

The key components of desmosomes are cadherins and

intermediate filaments

If cardiac muscle cells were prevented from undergoing aerobic metabolism, they ultimately would

stop contracting

Net filtration pressure is calculated by

subtracting the blood colloid osmotic pressure from the capillary hydrostatic pressure

Chiasmata

the structure that forms at the crossover points after genetic material is exchanged

Anaphase

third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell

What structure is most important in forming the tetrads?

synaptonemal complex

Clusters of neruons in the medulla oblongata that regulate blood presure are known collectively as

the cardiovascular center

Hydrostatic pressure is

the pressure exerted by fluid in an enclosed space

What happens to preload when there is venous constriction in the veins?

it increases

Which of the following statements about albumin is true?

it is the most abundant plasma protein

What is a primary function of tumor suppressor genes?

stop certain cells from dividing

Depolarization of the sarcolemma means

the inside of the membrane has become less negative as sodium ion accumulates