Lecture 10 - Heart and Great Vessels Flashcards
what are the four main components of cardiovascular system?
- the heart (pump)
- arteries and veins (conducting vessels)
- capillaries (sites for exchange with the tissues)
- lymphatic vessels (drainage system)
what are the three main functions of the cardiovascular system?
1) maintain homeostasis
2) transport
3) regulation of body temperature
what are the four main types of transport carried out by the cardiovascular system?
1) metabolites and waste
2) hormones and signalling molecules
3) dissolved gases (O2 and CO2)
4) immune and inflammatory cells
what are the two circuits of the cardiovascular system?
- pulmonary circuit to the lungs
- systemic circuit to the rest of the body
the heart resides in the _____, a central region of the _____ within the rib cage and bounded on the left and right by the ______
mediastinum, thorax, lungs
contains the heart, esophagus, trachea, thymus gland, and large blood vessels
mediastinum
are the lungs a part of the mediastinum?
no
forms a tough, fibrous protective sack for the heart
pericardium
what are the two layers of the pericardium?
parietal pericardium and fibrous pericardium
layer of the pericardium made of tough CT and does not stretch
fibrous pericardium
layer of the pericardium made of smooth, flat epithelia that secretes fluid and reduces friction
parietal (serous) pericardium
what are the three layers of the heart wall?
epicardium, myocardium, and endocardium
layer of the heart wall made of smooth epithelium that secretes fluid and interacts with parietal pericardium to reduce friction
epicardium
layer of the heart wall made of unique cardiac cell tissue with varying thickness
myocardium
layer of the heart wall made of smooth epithelia which prevents blood clotting
endocardium
where is the apex of the heart?
tips of the ventricles (pointy part)
where is the base of the heart?
where most of the vessels connect to the heart
collects blood from the lower part of the body
inferior vena cava
collects blood from the upper part of the body
superior vena cava
receives deoxygenated blood from superior and inferior vena cava
right atrium
the walls of the right atrium are made of a unique type of muscle called
pectinate muscle
blood enters the right atrium through here (blood comes from the heart’s own blood supply)
coronary sinus
area of the right atrium which can stretch to allow for more blood to enter (also has pectinate muscle)
atrial appendage (auricle)
how thick are the walls of the right atrium?
not very
what is the purpose of the heart valves?
prevent blood backflow
attach leaflets of the atrioventricular valves to the papillary muscles
chordae tendinae
how do atrioventricular valves work?
when ventricles contract, blood gets under the cusps and pushes them up and closed
what is the is function of the papillary muscles and chordae tendinae?
prevents valves from flapping back into the atrium (keeps it at a horizontal)
where is the tricuspid valve located?
between the right atrium and right ventricle
how many leaflets or cusps does the semilunar valve have?
three
how do the semilunar valves work?
when blood falls back, blood fills the sinuses and leaflets are pushed closed
divides into the right and left pulmonary artery
pulmonary trunk
where is the pulmnoary valve located?
between the right ventricle and pulmonary trunk
brings oxygenated blood back to the heart
pulmonary veins
carries deoxygenated blood away from the heart
pulmonary arteries
how many pulmonary arteries are there?
two
how many pulmonary veins are there?
four
the walls of the left atrium are made up of:
a smooth portion and a portion with pectinate muscle
which valve separates the left atrium from the left ventricle?
mitral (bicuspid) valve
how many leaflets does the mitral valve have?
two
when the ventricles are relaxed, blood can ______, and contraction of the atria ______
continuously drip inside the ventricles, pushes the last bit inside
when the left ventricle contracts, the bicuspid valve closes and blood passes through the:
aortic valve
what are the two semilunar valves?
pulmonary and aortic valves
as blood falls back in the aortic valve and fills the sinuses, a little spills into the:
coronary arteries
should meet in the middle when the semilunar valves close
nodule
what is special about all four valves in the heart?
they all align in the same horizontal plane
walls that separate the right and left sides of the heart
cardiac septa
what are the two types of cardiac septa?
interatrial septa and interventricular septa
why is the musculature for the left ventricle thicker than the right?
because more force is needed to push blood to the body
what are coronary vessels?
the vascular supply to the heart tissue
where is the right coronary artery located?
in the coronary sulcus between the right atrium and ventricle
where is the circumflex branch of the left coronary artery located?
in the coronary sulcus
where is the anterior interventricular artery located?
runs along the anterior interventricular septum (feeds conduction system)
where is the posterior interventricular artery located?
in posterior interventricular sulcus
the coronary sinus collects _____ from the heart tissue and delivers it to the _____
deoxygenated blood, right atrium
true or false: the conduction system in the heart is made up of nerve tissue
false, conductive cells are sepcialized myocardial cells optimized for spontaneous depolarization and transmission of electrical signals
what is the function of gap junctions present between cardiac myocytes?
allow ion flow to synchronize muscle contraction and transmit electrical signal
make up 99% of the myocardium and are responsible for contraction of the heart
contractile cells
collection of conductive cells which fire at the fastest rate in the heart (makes them the pacemaker)
sinoatrial (SA) node
the gatekeeper cells of the heart, pauses to allow the atria to contract before telling the ventricles to contract
atrioventricular (AV) node
line of conductive cells which tells left atrium to contract at the same time as the right atrium
Bachmann’s bundle
what is the path of the conductive system through the heart?
SA node –> internodal tract/bachmann’s bundle –> AV node –> bundle of His –> left and right bundle branch –> Purkinjie fibers
what are the five main steps of the cardiac cycle?
1) atrial systole begins
2) atrial systole ends and atrial diastole begins
3) ventricular systole
4) ventricular diastole - early
5) ventricular diastole - late
what is the “lub” sound of the heart?
the AV valves closing
what is the “dub” sound of the heart?
semilunar valves closing
by placing a stethoscope at specific areas of the chest, the sounds of the individual valves can be:
amplified
what is the purpose of an electrocardiogram (ECG/EKG)?
an assessment of electrical activity of the heart
how many vessels are associated with the arch of the aorta?
3
the vessels that stem from the arch of the aorta feed the:
head and upper limbs
what are the three branches that stem from the aortic arch?
- brachiocephalic trunk
- left common carotid artery
- left subclavian artery
the brachiocephalic trunk separates into:
the right common carotid artery and the right subclavian artery
