Topic 5: CVS 2 Flashcards
What sre the 3 branches of aorta at t4 for
Upper limbs, neck and head
Wgat are the 2 branches from brachiocephalic (first division on the right)
Right subclavian and right common carotid artery
What are rhe other 2 beanches
Left common carotid and left subclavian
Where do the common carotid arteries divide into internal and external (producing 4 csrotid arteries)
Level of c3
What id the internal (inner cca) for
Supply to the brain
What is the external for
Supply to neck, face and scalp
Where is the point st c3 called
Carotid sinus
Whst do the subclavian arteries supply
Ipper limbs, thoracic wall, shoulder and neck (both sides)
Where does hesrt muscle het its blood supply
Coronary arteries (right snd lrft)
Where do ca arise
Superior to the cusps of aortic valve from the aotic sinuses
Which aortic sinuses
Left ca from the left (more posterior) aortic sunisband
right (more anterior) aortic sinuses
What drains deoxygenated cardiac blood usually into the coronary sinus then into right atrium
Cardiac beins eg small cardiac vein
What does left ca supply
Left atrium, most left ventricle, some right, anterior part of iv septum
What does jt divide into anteriorly
Circumflex (smaller), left posterior descending/iv branch
What does iv branch go along in anterior
Iv groove
Which vein stemming to coronary sinus is seen on left anterior side
Great cardiac vein
Which cein to coronary sinys is seen on right side
Small Cardiac vein
What does circumflex artery go slong
Left av groove on left border posterior where i
What does it join posterioy
Posterior iv branch (goes down on lrft side)
Hat is the vein on right side which does not go to coronary sinus posteritoly
Anterior vein
Other than small cardiac vein what else is on right side (branch of rca)
Marginal attery ( v small on right botder)
What is it called when somethint branches off the artery but rejoins
Anastomoses
Give example
Anterior elft descending anastomoses with posteror at apex of hesrt
What does right suplly
Right atriuk, most right v, some left v and posterior iv septum
What ca supplies the san in 60% of people
Right ca via an san branch
Where os the posterior iv branch
In the crus of hesrt (xone of ia and iv septum)
Where does sinus deposit deox blood from thr vrins
Inferior wall of right atrium
What does cafdiac muscle sdhere to msde grom collagen dense
Fibrous skeleton
How does the fibrous skeleton support gslve opening
Form 4 fibrous rings and 2 firbous triangles inbeyween the rings to prevent collapse
Which part of the ia and iv septum does fibrous skeleton provude
Membranous
Ofher than precenting valve collapsing what other functions of fibrous skeelton
Electrical batrier between stria and ventricles except at av bundle
Also provide a base for attschment of leaflets and cusps of valves
Is cardiac muscle smooth
No its stritiated
Is cardiac mudcle under voluntary control
No
Does it require stimulstion by ns
No
What mechanisms of contrsction does it have
Sliding filament comtraction betwern thick and thin sarcomere filaments
What allows cardiac muscle to function as a functional syncytium (contract together)
Interconnecting fibres between cells
How is this diff to skeeltal
Skeletal is more linesr ans doesnt have electrical continuity m
What are cardiac cells divided by
Sarcolemma
What is inside each sarcolemma for cells
Intercalated discs and fibrils
What are intercalsted discs for
Seperate sarcoplasm of muscle cells, hold cells together cia tight desmosomes, all electrical excitstion cia gap junctions
What are the 4 electrical tissues of the hesrt
2 nodal tissues (one being san and then avn)
Conductivr fibres
Myocardium
Where is san for pacemaker automstic depolarisation
Posterior of the right atrium (supplied by the rca)
Explain the impulse passing from av node from san
Avn conducting bundles/av bundle
To annulus fibrosus
To ventricle septum (branching to left and right purkinje fibres)
Hoe are the av bundles diff yo the purkinje
Bundles are narrow and slow conducting vs fast conducting which spread impulse at aprx myocardium
Where are purkinje fibres
Subendocardium
Which artery goes from aorta ti the digestive tract
Mesentric artery
What carries blood from gi tract to the liver capillary befs
Portal vein
What artery is the first branch from subclavian srteries to the upper limb eg shoulder/arm pit
Axillary
Name in order below teh axillary in the upper limb
Brachial artery
Radial (outer bone)
Ulnar artery (inner small bone)
What is below the renal arteries
The superior and inferior mesenteric
The subdivision at the pelvic area before leg is what arteries
Common iliac artieries
Which artery supplies blood to bottom part
Femoral artery/ at femur/thigh
What 3 layers do all blood vessels have except capillaries
Tunica intima (inner) Tunica media (middle) Tunica adventitia (outer)
What is initma
Single endothelial layer connected to connecticr tissue. It allows to be battier to pkasma proteins etc
What is media
Smooth musclr layer vsrying in elastin and collagen thickness (for elasticity and contractile power)
What is adventitia and role
Connrctive tissue sheath which tethers vessels loosely in place
What does the advetitia have in latge arteries
Small blood cessles (vaso vasorum) which penetrste the media for hetter blood supply
What else can latge arteries contain
Nociceptice sensory fibres snd sumpathetic plexi
What vlood cessels are the most richbin elastin media and gicr examples
Elastic arteries ef aorta and PA and iliac arteries
What is their diamter
1-2 cm
What forms the diastolic bp in elastic arteries
Recoil back after expanding in systole
What are the second latgest vessles and examples
Muscular/conduit arteries eg radial, coronary, cerebral
Diameter
0.1-1cm
Is their media thicker than elastin arteries
Yes and They have a samller lumen sue to more smooth muscle (less elastin)
Why do they have more muscle in media
To prefent collapsing eg at corners like elbows so radial needs muscle
What do they lack
Elastin and collagen
What are they innervwted by
Ans
What is their role
Limitation of vlood loss
Which vessels reg blood flow to limbs
Arterioles
Diameter
Third largest at below 0.1cm
Do they havr a latge lumen
No, small limen for resistance
What are differences between proximal and distal (closer to capillaries)
Proximal is innerveted by sns as have much more smooth muscle
Distal has less smooth muscle and isnt innervated (too floee to capillsries)
What sre wide shunt vessles called which bypass capillary beds
Arteriovenous anastomoses
Where are the only av anastomoses and why
Nasal and skin mucosa
In nose to warm air
Skin for temp reg
What are they innervated by
Sns
What are anastomoses
Connection between 2 bessels
Dimater of cenules vs veins
Venules = 0.05-0.2 cm vs veins 0.2 cm or smaller
Do they have a thin or thick tunica media with sm and collagen
V thin (larger lumen)
What do the intima have in limbs if veins
Valves
Why do veins have low resistance
Many of them and latger lumen than artieries/arterioles
What are they called capacitance vessels
Carry 2/3 of blood
Why is it imporant veins are innervsted by sns for contrsction
Allows smooth muscle contraction which displaces blood resergoir to the tissues
What is the white disc called in fentre of thorax which has the ooesphoagus and ivc in it
Central tendon
What is the diamter of single endothelial capillaries
Below 0.007 cm (even smaller than venules at 0.05-0.1
Are capillaries smaller than arteriovenous anastomoses
Yes. Theyre around same as venules
Why does coronary arteries fill only in relaxation
In contraction sl valves of aorta open and block the ca but they close during relaxation so backflow goes to ca
Which branch is from the crus
Right ca posterior iv branch
What does the circumflex anastomose with
The posterior iv branch of rca
Which vein doesn’t drain back to coronary sinus but directly to right atrium
The anterior cardiac vein on right side
What are the veins on the posterior
The middle in the posterior iv groove then the posterior vein on the left side
What is myocardial ischaemia
When there is a block and lack of oxygen gets to the ca and causes pain in chest
What does myocardial ischemia lead to
Infarction which is dead tissue due to lack of oxygen eg blockage becomes severe
What does infarction cause to do with san that needs defibrillator
Fibrillation means lack of rhythm
How is it treated
Ischemia is via a healthier lifestyle
Infarction needs clot bursting agent or defibrillator
What holds cardiac cells together even if separated by intercalated discs and also what allows electrical impulse sent to all
Desmososmes
Gap junctions allow electrical impulses sent
What else separates cells other than intercalated discs
The sarcolemma around fibrils
Which area of heart isn’t insulated by the fibrous skeleton allowing crossover of electrical impulse from atria to ventricle
Av bundle
How are cardiac cells diff
They aren’t interconnected functional synctium, they are electrically separate and linear
Where does impulses go from avn
Down av bundle down annulus fibrosum (insulated) then down where it bifurcates to left and right of ventricle (purkinje fibres)
Are purkinje fast or slow conducting
Fast and conduct impulse spreading across ventricular myocardium
Which component in media does veins not have a lot of
Elastin
What does vasa vasorum supple to large arteries
With blood supply at the adventitia and outer media
