Lilly's Chapter 1 PP&WB Flashcards
Right-sided structures lie mostly to
their left-sided counterparts
anterior
Both atrial chambers located mostly to the____of their corresponding ventricles
right
Pericardium function 2
Allow heart to beat without friction
Allow room to expand
Pericardial cavity
Filled with pericardial fluid 5-30ml
3 attachments
Central tendon of diaphragm
•Sternopericardial ligaments
•Vertebropericardial ligaments
*****Endocardium is the ___________and is comprised of
FENP-B
Single layer of endothelial cells Fibroblasts Elastic and collagenous fibers Nerves Purkinje fibers Blood vessels
Right heart receives _______blood from the body (IVC, SVC)and from the _______(________)
deoxygenated; Heart, coronary sinus
**RV pumps blood to __________via_________ which is the only artery with _______blood
the lungs; pulmonary artery; deoxygenated blood
**RV characteristicsIOM 3
Inner wall covered by trabeculae carneae
Outflow tract (conus arteriosus) is smooth for laminar flow
Moderator band : Large trabeculae, Crosses vent. Cavity – Carries component of RBB of the conducting system to the ventricular muscle
RV has ______ papillary muscles and contains the Tricuspid valve
3
**Left heart : LA receives _______blood from the _____via the _________Veins, which is the only veins carrying ________blood
oxygenated; lungs; pulmonary veins;
**LV pumps blood through the ________circulation via _____
Systemic ; aorta
LV characteristics***TA 2
wall? size
Thicker wall 9 – 11 mm ~3x thicker than R. vent.
Aortic Vestibule smooth for laminar flow
LV has ______papillary muscles, contains the _____valve and is the origins of _______and ________ just above
• 2 large papillary muscles
– Mitral Valve
• Origins of RCA & LCA just above Aortic valve cusps
Cardiac Conduction System
SA node–>AVnode–> Bundle of his–>R+ L bundle branches–> Purkinje fibers(subendocardial fibers)
Conduction systemSubendocardial plexus of Purkinje fibers allow_______________before________, this prevents valve_______
papillary muscles to contract before vent. wall
– Prevents valve regurgitation
****Cardiac Innervation(sympathetic )
• Sympathetic fibers from T1-T6 innervate cardiac nerves that terminate in heart and great vessels
***Effect of sympathetic stimulation
HR, Contractility, AVN, PR
Increase HR and Contractility
Decrease AVN Effective Refractory Period
Decrease PR
**Effect of parasympathetic stimulation
HR, Contractility, AVN, PR
Decrease HR and Contractility
Increase AVN effective Refractory Period
Increase PR
**Parasympathetic fibers from_____ innervate
CN X; SA Node, AV Node and Purkinje fibers
Vagal innervation ______and______whereas Sympathetic innervation
Supraventricular and purkinje ; all over
Cardiac Vessels LCA division (AIVCI)
LAD (AIV) (anterior interventricular artery)
Circumflex
Cardiac Vessels RCA division (PM)
PDA (posterior descending) PIV (posterior interventricular artery)
– Marginal
Th blood supply to the SA node is most often derived from the ______in ____% of the population and derived from Circumflex artery in___% of the population. Other 5% from both
RCA;70%; 25%
Posterior Descending and AV nodal arteries arise from the RCA in______of the population. The coronary circulation is termed __________. __% the PDA arises from the Circumflex , resulting in coronary circulation termed. The remaining population PDA is supplied by both the RCA and circumflex, coronary circulation is thermed____
85% of the population; Right dominant; 8% ;Left dominant; 7% Co-dominant
*****Muscle fibers beneath endocardium, particularly _______And________supplied by coronary a. terminal branches or veins.
papillary muscles and left vent. wall
Thebesian
*****A myocyte is an
Individual cardiac muscle cell
****Myofibril is a
Group of sarcomeres
*****Sarcomere
Individual contractile unit of the cell
Line up in cell
The sarcolemma is the
Cell membrane
**A distinct characteristic of cardiac muscle tissue
intercalated disks
Intercalated disks are :
Function
Gap junction complexes
They establish structural and electrical continuity between the myocardial cells
*****The sarcoplasmic reticulum is a
- intracellular membrane network
- Most of the intracellular calcium stored there
- responsible for Ca release and excitation-contraction coupling
*****Action potential
Reversal of electrical potential across a semipermeable membrane cause by conformation changes in selective ion channels.
3 ways
Rhythmic
Conducted appropriately
Coupled to myocardial contraction
*****3 major electrically excitable cell types
- Pacemaker cells found in SA node and AV node
- Specialized conducting cells (purkinje fibers)
- Cardiac myocytes (myocardial syncytium)
Pacemaker cells have _____but no
Automaticity; NMJ
**Pacemaker cells have resting potential of
-60mV
*****Compare to resting potential of vent. Myocytes at
-90mV
*****Unique physiology of Pacemaker cells
SUF
- Slow voltage gated Na+ channels unable to recover so they remain inactivated
- Unique ion channel “pacemaker channel” which allow continuous flow of Na+ until threshold is reached
Depolarization depends on ion transport, gov.d by:
Concentration Gradients
Transmembrane potential
***** Cardiac myocytes have
Fast Na+ ion channels
“Fast Na+ Channels”
- When activated remain open for only a few thousandths of a second, then close
- Inactivated state persists until membrane is repolarized, providing refractory period
Are Fast Na+ channels active on SA/AV nodes?
• Not active on pacemaker cells (SA/AV nodes)
****K+ ion channels
***Inward rectifer channels - open in resting state
allow some K+ to flow out of cell, but overall
negative interior charge slows K+ outflow
• At equilibrium, these forces are balanced and there
is zero net movement of K+
The electrical potential point at which there is zero net movement of K+ across the membrane is known as as “_________”
What is the K+ equilibrium potential is ____mV
Calculated by _______
The potassium equilibrium potential
-91mV
Nernst Equation
**Action potential of cardiac muscles : Phase 4
Na+, Ca2+, Channels closed. Open K+ RECTIFIER CHANNELs keep TMP stable at -90mV
*****Action potential of cardiac muscles : Phase 0
Rapid Na+ influx through open FAST Na+ Channels
*****Action potential of cardiac muscles : Phase 1
Transient K+ channels open and K+ efflux return TMP to 0mV
****Action potential of cardiac muscles : Phase 2 aka ___phase
Plateau phase ; Influx of Ca2+ through L-TYPE Ca2+ channels is electrically balanced by K+ efflux through DELAYED RECTIFIER K+ Channels
Ryanodine receptors: release Ca++ from S.R
*****Action potential of cardiac muscles : Phase 3
Ca2+ channels close but DELAYED RECTIFIER K+ channels remain open and return TMP to -90mV
**Cardiac Depolarization: “Fibrous Skeleton” of the heart
– Fibrous connective tissue that surrounds the AV valves
– Serves as electrical INSULATOR isolates Atria and Ventricles
- AV NOTE IS THE ONLY ELECTRICAL CONDUCTOR TO THE VENTRICLES
Delay at AV node (0.1sec) allows
• atria time to contract before ventricles
_____ node is the only electrical conductor to the Ventricle
AV node
**AV node
serves as electrical “gatekeeper” to limit ventricular stim. during abnormal rapid atrial rhythms
***Electrical AP leads to
Physical contraction
**Myosin
Arranged in thick filaments, globular heads contain MYOSIN ATPASE
*****Actin
Thin filament , a-helix
Tethers myosin to Z-line
Titin (connectin)
***Tropomyosin
Double helix lies between actin filaments and blocks actin&myosin interaction
*****Troponin
Regularly spaced on acting, 3 SUBUNITS
**CALCIUM INDUCED CALCIUM RELEASE
Initial ____________ signal is amplified by ______During what phase
L-type Ca2+ current signal; Calcium induced calcium Release (CICR)
Phase 2 of action potential
*****Ca2+ enters cell via
T-Tubule system
*****Ca2+ triggers _______Receptors on ______ then this membrane dumps_________
Ryanodine receptors; Sarcoplasmic Recticulum ; it stores of Ca2+
Calcium channel Blockers
Bind to which channels
Bind to the L-type calcium channels
**Three Classifications:
Non-Dihydropyridines
benzothiazepines
phenylalkylamines
Dihydropyridiness
**Benzothiazepines Ex (BD)
• dihydropyridines
– nicardipine , amlodipine, nifedipine , nisoldipine, et
– diltiazem
*****Phenylalkylamines (PV)
– verapamil
** dihydropyridines (NNA)
–NNNA
nicardipine , nifedipine , nisoldipine, amlodipine,
