ch 11.1- circulatory system

Question 1

right atrium

Answer 1

atrium: Deoxygenated blood flows in
through the upper superior vena cava and the
lower inferior vena cava.

Question 2

right atrium to right ventricle

Answer 2

Blood passes from the
right atrium to the right ventricle through the right
atrioventricular valve (AV or tricuspid valve). The
AV valve is attached to papillary muscles, which
contract to close the valves and prevent backflow
of blood.

Question 3

papilary muscles

Answer 3

AV valve is attached to papillary muscles, which
contract to close the valves and prevent backflow
of blood.

Question 4

AV valve

Answer 4

between the right atrium and ventricle

Question 5

right ventricle

Answer 5

Pumps deoxygenated blood into
the pulmonary artery for pulmonary circulation
through the pulmonary semilunar valve.

Question 6

pulmonary semilunar valve

Answer 6

between the right ventricle and the pulmonary artery

Question 7

when the right ventricle contracts

Answer 7

When
the ventricle contracts, the AV valve closes and the
pulmonary semilunar valve opens. When the
ventricle is relaxed, the AV valve opens to refill the
ventricle, and the pulmonary semilunar valve
closes to prevent backflow from the artery.

Question 8

left atrium

Answer 8

Oxygenated blood from the lungs
flows in through the pulmonary vein. Blood
passes from the left atrium into the left ventricle
through the left AV valve (bicuspid or mitral
valve).

Question 9

left ventricle

Answer 9

Most muscular chamber of the
heart. Pumps oxygenated blood into the aorta for
systemic circulation.

Question 10

pulmonary circulation

Answer 10

moves deoxygenated blood
from heart to the lungs and back in order for it to
become oxygenated. Pathway:

Right atrium → tricuspid valve →
right ventricle → pulmonary semilunar valve →
pulmonary arteries → lung → pulmonary veins → left
atrium

Question 11

systemic circulation

Answer 11

moves oxygenated blood from
the heart throughout the body.

Pathway:
Left atrium → bicuspid / mitral valve → left ventricle → aortic semilunar valve → aorta → body → vena cava → right atrium

Coronary circulation supplies oxygenated blood to
the heart itself for function.

Question 12

cardiommyocytes

Answer 12

(heart muscle cells) have
automaticity, which means they are self-excitable
and able to initiate an action potential without an
external nerve.

Question 13

where is the SA node

Answer 13

upper wall of the rigth atrium

Question 14

SA node

Answer 14

It has the greatest automaticity and
is most likely to reach threshold to stimulate a
heartbeat. It sends a signal to contract both atria
to send blood to the ventricles. It also sends a
signal to the AV node to initiate contraction.

Question 15

AV node location

Answer 15

lower wall of the right atrium

Question 16

function of AV node

Answer 16

add
a brief delay between the contraction of the atria
and the contraction of the ventricles. It also sends
a signal to the bundle of His, located in the
interventricular septum between the ventricles.

Question 17

bundle of His

Answer 17

The bundle of His carries the signal to the
Purkinje fibers, which contract the ventricles.

Question 18

intercalated discs

Answer 18

Signal transduction: The heart has intercalated
discs that connect adjacent heart cells
(cardiomyocytes).

function to
transmit the signal to contract in a coordinated,
rhythmic fashion.

Question 19

what are intercalated discs made of

Answer 19

desmosomes and gap junctions

Question 20

systole

Answer 20

right after the ventricles eject their
blood into the arteries they connect to. Therefore, it
is the phase of the cardiac cycle where blood pressure
is highest in the arteries. The aorta is the blood vessel
that experiences the highest blood pressure.

Question 21

diastole

Answer 21

right after the atria contract to fill the
ventricles. The myocardium is completely relaxed at
this point. Diastole is the phase of the cardiac cycle
where blood pressure is lowest in the arteries.

Question 22

tachycardia

Answer 22

more than 100 bpm

Question 23

bradycardia

Answer 23

less than 60 bpm

Question 24

storke volume

Answer 24

volume of blood pumped
from the heart with each beat. Stroke volume is
calculated by subtracting end-systolic volume from
end-diastolic volume.

Question 25

cardiac output

Answer 25

Cardiac output (CO) is the stroke volume multiplied
by the heart rate. This tells us the volume of blood
being pumped by the heart in one minute.

CO = HR x SV

Question 26

greatest blood presure drop is wehre

Answer 26

from arteries to arterioles

Question 27

veins

Answer 27

Move blood toward the heart. Veins contain
more blood by volume than arteries, but blood
pressure is lowest in veins. Veins contain valves
(aka pocket or venous valves) that help blood
move towards the heart by preventing backflow.
Blood is pushed forward when skeletal muscles
squeeze the veins, not when the heart pumps.

Question 28

plasma

Answer 28

contains water, proteins, nutrients,
hormones, and makes up most of the blood volume. Makes up ~55% of blood volume.

Question 29

white blood cells

Answer 29

are our immune
cells and defend against infection. The most
common white blood cell is the neutrophil.

Question 30

platelets

Answer 30

(thrombocytes) are cytoplasmic cell
fragments that do not have a nucleus; they are responsible for clotting.

Leukocytes and thrombocytes make up
<1% of blood volume.

Question 31

megakaryocytes

Answer 31

Large bone marrow cells
called megakaryocytes are the precursor to platelets. Platelets release factors that help convert fibrinogen into fibrin, which creates a ‘net’ to stop bleeding.

Question 32

clotting factors

Answer 32

Many of the clotting factors are synthesized with Vitamin K, a deficiency in Vitamin K will lead to increased bleeding. Platelets
are also immune cells that function in the innateimmunity.

Question 33

red blood cells

Answer 33

Red blood cells (erythrocytes) are responsible
for transporting oxygen attached to hemoglobin.
Mature red blood cells are anucleate (they don’t
have a nucleus) in order to maximize the amount
of space they have to carry hemoglobin and
oxygen, making them very flexible. Makes up
~45% of blood volume.

Question 34

blood clotting

Answer 34

A mechanism that protects our blood
vessels from damage. When a tear in our blood
vessels occurs, the blood clotting cascade then
‘plugs’ the tear, sealing any vessel leaks

The blood clotting cascade is an example of a positive
feedback mechanism. Damaged tissues release a
signal that attracts platelets to the site → each platelet
will then release a signal to attract more platelets → a
clot is formed. The steps to this process are as follows:

Question 35

blood clotting steps

Answer 35

1. Tissue damage: Damaged tissue tears blood
   vessel walls, exposing their collagen.
2. Platelet activation: Exposed collagen triggers
   platelet activation. Platelets will adhere and
   aggregate at the site of the tear, forming a
   platelet plug.
3. Clotting factors release: Activated platelets
   release clotting factors that convert prothrombin
   (inactive precursor) → thrombin (active form).
4. Formation of clot: Activated thrombin converts
   fibrinogen (inactive precursor) → fibrin (active
   form). Fibrin strands polymerize with other fibrin
   strands, and attach platelets to form a blood clot
   (hemostatic plug).

Question 36

antigens on RBCs

Answer 36

These antigens are little sugars and proteins
that mark our blood as a certain type.

Question 37

agglutination

Answer 37

happens when the wrong blood type is given to someone

clumping of antibodies of that blood type

Question 38

umbilical vein

Answer 38

carries oxygenated blood from the
placenta to the fetal heart,

Question 39

umbilical artery

Answer 39

carries deoxygenated blood from the fetal heart back
to the placenta.

Question 40

fetal lung and liver

Answer 40

nonfunctional
and filled with fluid. To compensate, fetal circulation
has:

Question 41

ductus venosus

Answer 41

A duct (tunnel) that connects the
umbilical vein to the inferior vena cava. Blood
that passes through the ductus venosus bypasses
the nonfunctional fetal liver.

The ductus
venosus connects two veins (umbilical vein to vena
cava).

Question 42

foramen ovale

Answer 42

A hole that allows blood in the
right atrium to flow into the left atrium. Recall
that the right ventricle pumps to the lungs, which
are nonfunctional in the fetus. Blood that passes
through the foramen ovale bypasses pulmonary
circulation.

Question 43

ductus arteriosus

Answer 43

A duct that connects the
pulmonary artery to the aorta. Blood pumped
by the right ventricle into the pulmonary artery
can bypass the lungs by moving through the
ductus arteriosus.

The ductus arteriosus connects two
arteries (pulmonary artery to aorta).

Question 44

Wastes and CO2

from the fetus are removed via

Answer 44

the
umbilical artery in the umbilical cord. Nutrients and
gas exchange across a barrier to prevent mixing of
fetal and maternal blood in the placenta.

Question 45

erythroblastosis fetalis

Answer 45

If the mother has Rh (-)
blood type and the fetus has Rh (+) blood, during
labor, the fetal Rh (+) blood will enter the mother’s
system, and she will develop anti-Rh antibodies. This
will not pose a problem in the first pregnancy, but if
the mother becomes pregnant again with another Rh
(+) fetus, the mother’s anti-Rh antibodies will attack
the fetus, because antibodies are small enough to
cross the placental barrier.

Question 46

lymphatic system

Answer 46

subsystem of the
circulatory system that regulates fluid levels and
produces immune cells. Its components are lymph
nodes, lymph vessels, adenoids (lymphatic tissue),
the spleen, and the thymus.

Question 47

nutrients and gas exchange occur at the level of

Answer 47

capillaries. Hydrostatic pressure pushes fluid out of
the capillaries on the arterial end into interstitial
space. Oncotic pressure, a type of osmotic pressure,
brings fluid back into the capillaries at the venule end.
However, not all the fluid is reabsorbed from the
interstitial space into the venule. Lymphatic capillaries
collect the remaining fluid, called lymph, which
consists of interstitial fluid, bacteria, fats, and
proteins.

Question 48

lymphatic capillaries

Answer 48

The lymphatic capillaries merge together to form
larger vessels that travel to the heart. Along the way,
the lymph is filtered through lymph nodes, which are
centers for the immune response system to eliminate
infections.

Question 49

lymph vessels

Answer 49

have no pressure (like veins), but the
constriction of skeletal muscle, in conjunction with the
smooth muscle present in the lymphatic vessel walls
allows for the propulsion of lymph via peristalsis. This
allows fluid to move towards the heart, and backflow
of fluid is prevented with a system of valves, similar to
veins.

Question 50

lymph volume

Answer 50

Solute concentration influences lymph volume. If
there is an increased amount of proteins (e.g.,
albumin) within the blood vessels, water will flow into
these vessels, reducing the amount of water left in the
interstitial fluid and decreasing lymph volume.