DAT bio Chapter 11, circulatory system Flashcards
No circulatory system
use simple diffusion
to distribute nutrients. Includes bacteria,
protista, fungi, invertebrate animals.
Open circulatory system –
– pumps fluid called
hemolymph into sinuses or hemocoel.
Includes some mollusca, arthropoda,
Echinodermata.
Closed circulatory system
Use a pumping
heart to move blood through vessels. Includes
annelida (earthworms)
Most chordates (eukaryotic vertebrates within kingdom Animalia) have what kind of a system
closed circulatory system
● 2-chambered hearts is composed of?
atrium and ventricle-(fish)
Deoxygenated blood fills the heart and is pumped
to the gills for oxygen exchange.
3-chambered hearts is composed of?
(2 atriums and 1 ventricle)-amphibians and reptiles which are poikilothermic chordates.
Ventricles are stronger than atria T.F
True
4-chambered hearts is composed of
2 atriums and 2 ventricles- birds and humans. which are homeothermic chordates
Flow of blood through heart
Step 1
Right atrium
Deoxygenated blood is returned
here from the upper superior vena cava and
the lower inferior vena cava. Blood passes
through the right atrioventricular valve (AV
valve, or tricuspid valve) to the right
ventricle. AV valve is attached to papillary
muscles, which contract to close the AV valves
and prevent backflow of blood.
Flow of blood through heart
Step 2
Right ventricle
Pumps deoxygenated blood
through the pulmonary semilunar valve to the
pulmonary artery. Blood enters pulmonary
circulation. When the ventricle contracts, the
AV valve is closed and the pulmonary
semilunar valve is open. When the ventricle
relaxes, the AV valve is open to refill the
ventricle, and the pulmonary semilunar valve
closes to prevent the backflow of blood.
Flow of blood through heart
Step 3
left atrium
Oxygenated blood is returned
here from the lungs from the pulmonary vein.
Blood passes through the left AV valve (or
bicuspid, or mitral valve) to the left ventricle.
Flow of blood through heart
Step 4
left ventricle
– Most muscular chamber of
the heart. Pumps oxygenated blood into the
aorta and systemic circulation.
What is pulmonary circulation?
moves deoxygenated
blood from heart to the lungs and back in order
for it to become oxygenated.
Pathway for pulmonary circulation
Right atrium → tricuspid valve →
right ventricle → pulmonary semilunar valve →
pulmonary arteries → lung → pulmonary veins → left
atrium
What is systemic circulation
moves oxygenated blood
from the heart throughout the body.
systemic circulation pathway
Left atrium → bicuspid / mitral valve → left
ventricle → aortic semilunar valve → aorta → body
→ vena cava → right atrium
- The SA node (pacemaker)
- location
- function
1) located in the
upper wall of the right atrium
2) initiates the cardiac cycle.
3) 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.
Which part of the cardiac cycle has the most automaticity? (are self-excitable
and able to initiate an action potential without an
external nerve.)
SA node
most likely to reach
threshold to stimulate a heartbeat.
The AV node
- location
- function
1) lower wall of the
right atrium.
2) function of the AV node is to
add a brief delay between the contraction of
the atria and the contraction of the ventricles.
What kind of signal is sent by the AV node?
also sends a signal to the bundle of His,
located in the interventricular septum
between the ventricles. The bundle of His
carries the signal to the Purkinje fibers, which
contract the ventricles.
When does Systole happen?
occurs 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.
When does diastole happen?
occurs 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.
Heart beat sound is described as
lub dub
Lub stands for
The atria are relaxed, while the
ventricles are contracting. The noise
comes from the AV valves snapping shut
as the ventricles contract.
Dub stands for
The atria are contracting, while the
ventricles are relaxing. The noise comes
from the semilunar valves snapping
shut.
Systole happens ____ the lub-dub sounds.
Diastole occurs between the dub and ___ lub
sound.
between
next
What is Signal transduction
The heart has intercalated discs that connect
adjacent heart cells (cardiomyocytes). Intercalated
discs are made of desmosomes and gap junctions
and function to transmit the signal to contract in a
coordinated, rhythmic fashion.
What is heart rate
is how fast the heart beats.
Tachycardia is greater than 100 beats per minute,
bradycardia is less than 60 beats per minute.
What is Stroke volume (SV)
the volume of blood
pumped from the heart with each beat. Stroke
volume is calculated by subtracting end-systolic
volume from end-diastolic volume.
What is Cardiac output (CO)
stroke volume
multiplied by the heart rate. This tells us the
volume of blood being pumped by the heart in 1
minute.
What is Total peripheral resistance (TPR) is
the total
amount of resistance that blood faces when
flowing through the vasculature of the body.
Vasoconstriction increases TPR, while vasodilation
decreases TPR.
What is Systolic blood pressure
the highest pressure in
your arteries when your ventricles contract. This is
the top number in a blood pressure reading.
120/80 → 120 mmHg is the systolic pressure.
Diastolic blood pressure
is the pressure in your
arteries while the heart is relaxing between beats.
This is the bottom number in a blood pressure
reading.
120/80 → 80 mmHg is the diastolic
pressure.
Mean arterial pressure (MAP)
the average
arterial pressure during one complete cardiac
cycle. It is calculated by multiplying your cardiac
output by your total peripheral resistance.
MAP = CO x TPR MAP = (HR x SV) x TP
Vessels transport ____ to and from the heart in a
closed circulatory system. Arteries move blood
____ from the heart, while veins move blood
____ the heart.
Blood
away
towards
Does arteries or veins have higher blood pressure and why
Arteries
due to the hydrostatic pressure from the heart.
Arteries branch off into smaller arteries called what
arterioles (This is where we see the greatest drop
of blood pressure.)
Arterioles branch further into what?
capillaries
Capillaries are
vessels that are 1 cell thick and diffuse gas and nutrients to the interstitial fluid.
(Note: even though arterioles see the
greatest drop in BP, they are not where BP is
lowest. BP is lowest in the veins) T/F
T
Functions of capilaries
collect waste and CO2 and enter a
venule, which then connects to a vein, which
brings the blood back to the heart. Blood moves
back to the heart by a series of valves within the
veins that prevents backflow of blood. Skeletal
muscles squeeze the veins to push the blood
forward, it is not the pumping of the heart that
moves blood through the veins.
Veins contain more blood by volume than arteries
and have the lowest blood pressure of all vessels.
T/F
What is plasma made out of
contains water, proteins, nutrients,
hormones, and makes up most of the blood
volume. Makes up ~55% of blood volume.
White blood cells (leukocytes)
are our
immune cells and defend against infection.
The most common white blood cell is the
neutrophil.
Platelets (thrombocytes)
function
cell fragments
that do not have a nucleus, they are
responsible for clotting. Platelets release factors that help
convert fibrinogen into fibrin, which creates a
‘net’ to stop bleeding. Many of the clotting
factors are synthesized with Vitamin K, a
deficiency in Vitamin K will lead to increased
bleeding.
precursor of platelets in large bone marrow cells
megakaryocytes
how much of leukocytes and thrombocytes make up of blood volume?
less than 1 percent
Red blood cells (erythrocytes)
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. Makes up ~45%
of blood volume.
Red blood cells have ____ on their surfaces
antigens
What are antigens made of and their function
little sugars and protien that mark our blood as a certian type.
Type a blood has what antigen
A antigen
Type b blood has what antigen
B antigen
Type AB blood has what antigen
both A and B antigen
Type O blood has what antigen
neither A or B antigen
Another surface protein besides antigen called
Rhesus factor (Rh)
Two types of RH
+ and -
If a donor is Rh(+) , they cannot
donate to someone who is Rh(-), because the
donor has antigens on the surface of the blood
cell. T/F
True
What is a universal donar?
(blood donor who can donate
to anyone) is O (-).
O blood type has neither A nor
B surface antigens, and O (-) blood also does not
have an Rh surface antigen. This means there are
no blood cell surface antigens that would stimulate
immune clearance by someone receiving the O (-)
blood.
What is universal acceptor?
AB (+). Because an AB (+)
person has both A and B cell surface antigens, as
well as an Rh surface antigen, they can receive any
blood type and not mount an immune response.
Any blood cell surface antigen they receive would
be something their blood cells already have.
Where does fetus gets their oxygen and nutrients?
from the placenta through the umbilical cord which gets its oxygen from the mother
Because the
fetus gets its oxygen through the placenta, the
blood in its heart does not need to go to the
pulmonary system (to the lung) – it is not exposed to air.
Instead, what happens?
the oxygenated blood in the right atrium
goes directly to the left atrium through a hole in
the heart called foramen ovale.
How is the waste and carbon dioxide removed from the fetus?
removed from the right ventricle to the umbilical cord
The mothers and the fetus blood mixes in the placenta T/F
False. does not mix
Placenta provides an exchange of _____ and _____ across a barrier
gas and nutrients
Erythroblastosis Fetalis
A concept that is occasionally tested is 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.
Where does Nutrient and gas exchange occur
level of the capillaries
Hydrostatic pressure does what
pushes fluid out of the capillaries on the arteiral end into interstitial space
Oncotic pressure, does what
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 what remaining fluid
lymph which consists of interstitial fluid,
bacteria, fats, and proteins.
The lymphatic
capillaries _____ together to form larger vessels
that travel to the heart.
merge
lymph
is filtered through____ which are centers
for the immune response system to eliminate
infections.
lymph nodes
lymph
is filtered through lymph nodes, which are centers
for the immune response system to eliminate
infections. T/F
True
How is backflow of lymph prevented?
system of valves that prevents backflow of blood
