E-learning 2 cardiovascular Flashcards
what are the two systems in the heart
pulmonary and systemic
contraction of the ventricles is
systole
relaxation of the ventricles is
diastole
blood leaves the right ventricle through what vessel
the pulmonary trunk
what does the pulmonary trunk divide into
the left and right pulmonary arteries
where does the blood enter after its been oxygenated at the lungs
the left atrium
the thoracic cage protects the contents of the thorax.
what is it made up of
the ribs
costal cartilage
sternum (anteriorly)
thoracic vertebrae (posteriorly)
what is the superior thoracic aperture
the opening at the top of the thoracic cage which is a passage between the thoracic cavity and neck
what is the inferior thoracic aperture
where the diaphragm attached to the thoracic cage
what are the three regions in the thoracic cavity
right pleural cavity
mediastinum
left pleural cavity
what do the right and left pleural cavities contain
the lungs
what is the central compartment of the thoracic cage
mediastinum
what are the two main compartments of the mediastinum
superior mediastinum and the inferior mediastinum
the sternal angle is a horizontal plane between the superior and inferior mediastinum. what number thoracic vertebrae does it divide
T4 and T5
the inferior mediastinum is further subdivided into the
anterior mediastinum, middle mediastinum and posterior mediastinum
the superior mediastinum contains what
the oesophagus
the trachea
the arch of the aorta
superior vena cava
left and right phrenic nerves
vagus nerves
thoracic duct
sympathetic chains
anterior mediastinum consists of
fat and the thymus
middle mediastinum contains the
heart and pericardium
posterior mediastinum contains
the descending aorta
the oesophagus
thoracic duct
azygos systems of veins
what is the azygos system of veins
H shaped configuration of the azygos, hemiazygos and accessory hemiazygos veins.
this system drains the posterior thoracic wall
sympathetic chains are adjacent to what
to the vertebral bodies
what is the thoracic duct
main lymphatic vessel for the return of lymph to the venous system
what is the thymus
a T cell producing lymphoid organ
phrenic nerve
a paired nerve that supplies the diaphragm
what nerve roots does the phrenic nerve come from
C3, C4, C5
what does the vagus nerve (CNX) do
provides the parasympathetic input to the gastrointestinal system and to the heart
the pericardium is a membrane that covers the
heart
it consists of what two layers
an outer fibrous layer
an inner thin serous layer that reflects from the inside of the fibrous sac onto the surface of the heart
serous pericardium has two layers, what are they?
visceral layer (epicardium) - inner layer of the serous pericardium
parietal layer - the outer layer of the serous pericardium which lines the fibrous pericardium
between the double layer is a lubricating fluid which reduces the friction caused when the heart contracts
functions of the pericardium
protection from infection
fixes the heart in the mediastinum and limits its motion (attached to the diaphragm, sternum and tunica adventitia)
lubrication (prevents friction)
prevents rapid overfilling of the heart
what is cardiac tamponade
when blood or fluid accumulates in the pericardium compressing the heart preventing the ventricles from expanding fully and impeding its blood supply
what does pericarditis mean
inflammation of the pericardium
what is pericardiocentesis
a procedure done to remove fluid that has built up in the pericardium
what great vessels are on the right side of the heart
superior vena cava
inferior vena cava
pulmonary trunk
what does the superior vena cava do
brings de-oxygenated blood to the right atrium from the systemic circulation superior to the heart (upper limbs, thorax, head and neck)
what does the inferior vena cava do
brings de oxygenated blood to the right atrium from the systemic circulation inferior to the heart (abdomen, pelvis and lower limbs)
what does the pulmonary trunk do
exits the right ventricle, taking deoxygenated blood to the lungs
what great vessels are on the left side of the heart
pulmonary veins
aorta
what do the pulmonary veins do
these enter the left atrium on the posterior aspect of the heart carrying oxygenated blood from the pulmonary circulation
what are the 4 pulmonary veins
left superior and left inferior pulmonary veins
right superior and left inferior pulmonary veins
what does the aorta do
known as the ascending aorta as it leave the heart, carries high pressure oxygenated blood to the bod in the systemic circulation
what vertebrae level is the base of the heart
T6-9
what intercostal space does the apex of the heart lie between
the 5th
the superior border of the heart reaches as high as which costal cartilage
the 3rd on the right side
the 2nd intercostal space on the left side
the right margin of the heart extends from the ____ costal cartilage to near the ____ costal cartilage
third to sixth
the left margin of the heart descends laterally from the _____ intercostal space to the apex in the ____ intercostal space
second to fifth
layers of the heart:
what is the epicardium
consists of a layer of connective tissue and provides a protective layer over the heart
what is the myocardium
this is the muscular component of the heart wall, it consists of myocytes or cardiac muscle cells
what is the endocardium
this layer of epithelium and connective tissue lines the heart and covers the heart valves
the difference between cardiac and skeletal muscle is that cardiac muscle cells form a highly branched interconnecting network of fibres which allows the heart to operate as a functional syncytium. what does syncytium mean
an electrical stimulus to any one part of the heart can cause contraction of the whole myocardium
what seperates the adjacent sarcoplams
interclated discs
intercalated discs allow the electrical excitation to pass between cells through
gap junctions
what is the fibrous skeleton of the heart
structure that the cardiac muscle is anchored to
the support is provuded by dense
collagen
the networks of collagen forms four fibrous rings that surround the
valve openings and two fibrous trigones
the fibrous skeleton serves multiple purposes
- prevents the valve openings from collapsing or distending
- provides a base for attachment for the leaflets and cusps of valves
- forms an electrical barrier between the atria and ventricles, preventing the from contracting together
the atria are separated by the
interatrial (IA) septum
the ventricles are divided by the
interventricular (IV) septum
internal structures of the atria:
what is the atrioventricular orifice (right)
the aperture in which blood flows from the right atrium to the right ventricle. the tricuspid valve is positioned here
what is the atrioventricular (AV) node
the electrical relay station between the atria and ventricles. it is located in the posteroinferior region of the interatrial septum near the opening of the coronary sinus
crista terminalis
it is the origin of the pectinate muscles. the sulcus terminalis acts as a surface making for internal crista terminalis
fossa ovalis
an embryological remnant of the foramen ovale. the foramen ovale is a hole between the two atria in a foetal heart
opening of the coronary sinus
the coronary sinus is the main cardiac vein. it is where the deoxygenated blood brained from the heart itself returns to the hearts circulation
pectinate muscles
pectinate means comb like
these are parallel ridges in the wall of the atrium
right auricle
the is also known as the right atrial appendage
it is a muscular pouch that acts to increase the capacity of the atrium
sinoatrial node
the pacemaker of the heart.
located in the posterior wall of the right atrium, inferolateral to the opening of the superior vena cava along the superior part of the crista terminalis
sulcus terminalis
a shallow depression marking the point of fusion between the venous part of the right atrium and the true right atrium. the crista terminalis sits of the internal surface on this structure
what are papillary muscles
extensions of the muscle of the ventricular wall
papillary muscles are attached to the valves by the
chordae tendineae
during systole the papilary muscles…
contract
this prevents the valves from
inverting when theres high pressure
structures of the ventricles:
atrioventricular valve has how many cusps (right side)
3 (tricuspid)
atrioventricular valve has how many cusps (left side)
two (bicuspid) , can also be referred to as the mitral valve
what is the conus arteriosus
the anterosuperior region of the right ventricle from which the pulmonary trunk arises
what is the interventricular groove
the groove or sulcus on the external surface of the heart which marks the division between the two ventricles
what is the interventricular septum
the wall between the left and right ventricles
what is the moderator band
a thick muscular structure that arises from the interventricular septum and ends at the right anterior papillary muscle. it acts as as shortcut for electric impulses from the right bundle tract
what are the semilunar valves
valves between the ventricles and the great vessels
where is the aortic valve
between the left ventricle and the aorta
where is the pulmonary valve
between the right ventricle and pulmonary artery
how many cusps do semilunar valves have
3
from the AV node where do the impulses pass along
AV bundle of His, through the fibrous skeleton and down the interventricular septum
what does it then split into
the left and right bundle branches
the bundles terminate at an extensive network of fibres called the
purkinje fibres
where do coronary arteries arise from
superior to the cusps of the aortic valve
the right coronary artery arises from the
right aortic sinus (and vice versa)
where does the left coronary artery supply
left atrium
most of left ventricle
some of right ventricle
anterior part of the IV septum
the SA node in 40% of the population
what does the left coronary artery divide into
the anterior interventricular branch and the smaller circumflex branch
where does the right coronary artery supply blood to
right atrium
most of the right ventricle
some of the left ventricle
posterior IV septum
the SA node in 60% of the population
the right coronary artery gives off a sinoatrial node branch that supplies the SA node in 60% of the population, the other 40% gets blood supplied to the SA node by the
circumflex branch
what other branches does the RCA give off
the marginal branch and the posterior interventricular branch
a network of cardiac veins drains deoxygenate blood from the heart tissue and deposits it in what? and where does this drain into?
the coronary sinus
drains directly into the right atrium
what causes a heart attack (myocardial infarction)
when a coronary artery becomes blocked or severely restricted (myocardium becomes ischaemic)
VASCULAR SYSTEM:
what vessels emerge from the heart
great vessels
great vessels split into smaller and smaller
arteries
even narrower high resistance vessels are called
arterioles
arterioles branch into a huge number of
capilaries
capillaries is the primary site of
diffusion of nutrient and waste products between the blood and the tissues
capillaries converge to form
venules
venules converge into
veins
veins end up at the
vena cava which return blood to the right atrium and the pulmonary veins which return blood to the left atrium
the wall of blood vessels contain
tunica intima (inner most layer)
tunica media (middle layer)
tunica adventitia (outer layer)
the intima consists of a single sheet of
endothelial cells resting on a thin layer of connective tissue
the intima layer is mechanically weak however the endothelium is the main barrier to the
plasma proteins and secretes many vasoactive products
the media consists of a layer of
smooth muscle of varying thickness in a matrix of elastin and collagen
the adventitia is a connective tissue sheath with no distinct outer border its main role is to
tether vessels loosely in place
in large arteries the adventitia contains a small blood vessel network called the
vasa vasorum
the vasa vasorum is responsible for
nourishing the media
in larger arteries the vessel also penetrate the outer tunica media
what are the main resistance vessels because of their narrow lumen and large numbers
arterioles
what do capillary walls consist of
single layer of endothelial cells
arteriovenous anastomosis
found in the skin and nasal mucosa
wide shunt vessel which bypass the capillary beds
veins and venules
thin tunica media composed of smooth muscle and collagen
thin walls means they are easily distended and often collapse
aorta divided into four parts
ascending
arch
descending / thoracic
abdominal
what branches off the ascending aorta
the left and right coronary arteries branch from the ascending aorta and supply the heart
what levels is the aortic arch
T4/T5
aortic arch branches into
1st - brachiocephalic trunk which divides into the right subclavian artery and the right common carotid artery
the arch of the aorta then gives off the left common carotid artery and the left subclavian artery
what do the common carotid arteries divide into and at what level
they divide into the internal and external carotis arteries at level of C3
the exteral carotid artery is the major blood supple to the
neck, face scalp and its respective side
the internal carotid artery is the major blood supply to the
brain on its respective side
subclavian arteries supplys blood to the
arm, thoracic wall, shoulder and neck of its respective side
what arteries do the subclavian arteries become
the axillary and then the brachial artery in the upper limb
descending / thoracic aorta sits left of the vertebral column in the thorax it gives off branches that supply blood to the…
structures of the thorax e.g the oesophagus, lungs, thoracic wall muscles, pericardium and the superior surface of the diaphragm
when does the descending aorta become the abdominal aorta
as it passed through the aortic hiatus of the diaphragm at the vertebral level of T12
abdominal aorta
gives off many branches which supply blood to structures of the abdomen, pelvis and lower limb
the abdominal aorta splits into which arteries that travel towards the pelvis and lower limb
two common iliac arteries
what is the first unpaired branch of the abdominal aorta
the coeliac trunk
where does the coeliac trunk supply blood to
stomach, liver, gallbladder, pancreas and spleen
where does the coeliac trunk come off the abdominal aorta
at the verterbral level of T12
what is the second unpaired branch of the abdominal aorta
the superior mesenteric artery
where does the mesenteric artery supply blood to
midgut structure of the abdomen including most of the small intestine and proximal portion of the large intestine
where does the mesenteric artery come off the abdominal aorta
vertebral level of L1
which paired branches come off the abdominal aorta and supply the kidneys
the renal arteries
where do they renal arteries come off the abdominal aorta
vertebral level of L1/L2
what is the third unpaired branch off the abdominal aorta
the inferior mesenteric artery
where does the inferior mesenteric artery supply blood to
the hindgut structures which is the distal portion of the large intestine
where does the inferior mesenteric artery come off the abdominal aorta
vertebral level of L3
where do the common iliac arteries form the bifurcation (split into two) of the abdominal aorta
at the vertebral level of L4
the common iliac artery on each side will split into what arteries
an internal and an external iliac artery
the internal iliac artery supplies structures of the
pelvic cavity and perineum
external iliac artery continues as the femoral artery and supplies the
lower limb on the respective side
superior vena cava:
the internal jugular vein drains most of the
head and ncek
the subclavian vein drains the
upper limb
the internal jugular and the subclavian veins join togther to form what vein
brachiocephalic vein on each side of the body
these brachiocephalic veins join togther to form the
superior vena cava
azygos system which drains the posterior thoracic wall also drains into…
the superior vena cava
inferior vena cava is formed of the
common iliac veins
the common iliac veins drain structure of the
lower limb and pelvis
the main tributaries (veins that branch into the inferior vena cava) of the inferior vena cava include
renal, lumbar (lower back) and hepatic (liver) veins
what is the portal venous system
a collection of veins which drains into the liver before draining into the IVC.
where do these veins originate from
the digestive organs within the abdomen
therefore the blood contains what
nutrients and waste that has been absorbed along the GI tract
the liver then does what within this blood
filters and metabolises these substances.
the filtered blood then returns to the heart via the hepatic veins and the IVC
