Review Q's Week 2 Flashcards
1. anatomy: Histology of blood vessels (1-40) 2. cardiac muscle action potentials physiology (41-70) 3. heart anatomy development part 1 (71-94) 4. heart anatomy part 2 (95-110) 5. antiarrhuthmic drugs (111-140) 6. ECG part 1 (141-161) 7. ECG part 2 (162-177) 8. pathophysiology of arrhythmias (178-197) 9. cardiac arrhythmias (198-end)
Which of the following is thickest in veins?
a. tunica intima
b. tunica media
c. tunica externa
c. tunica externa
Which of the following is thickest in large arteries?
a. tunica intima
b. tunica media
c. tunica externa
b. tunica media
T/F: the tunica media of the aorta is mostly made up of elastic fibers
true
What kind of cells make up the tunica intima?
simple squamous
T/F: the tunica intermedia of capillaries is very thin
false, capillaries have only an endothelium, with no subendothelial layer or other tunics.
(Because capillaries are only one cell layer thick, they only have a tunica intima.)
Which of the following has a tunica media that has more smooth muscles?
a. aorta
b. vena cava
b. vena cava
What two layers make up the tunica intima?
subendothelial layer
+
endothelium
What two layers make up the inner and outer limit of the tunica media (surround it)?
internal elastic lamina
+
external elastic lamina
Which layer of veins makes folds to form valves?
tunica intima
Where are vasa vasorum found?
in arteries and larger veins
(found specifically in the adventitia of the aorta.)
How is the tunica intima separated from the tunica media?
by the internal elastic lamina (IEL), a prominent sheet of elastin.
T/F: elastic fibers are only found in the tunica media
false, elastic fibers are also present in the tunica adventitia (which is bigger in veins)
Why do the large arteries need a blood supply (vasa vasorum)?
Their walls are so thick that the blood they carry cannot diffuse through- they need another source of blood to supply their outer side
What kind of nerves are found in the adventitia, along vasa vasorum? What do they do?
small sympathetic nerves for vasoconstriction.
T/F: Large-sized and middle-sized arteries both have vasa vasorum
false, most middle-sized arteries don’t have a vasa vasorum (the largest of the middle-sized have it)
What separates the tunica media from tunica externa/adventitia?
external elastic laminae
The tunica media of which of the following has more elongated nuclei?
a. Large-sized artery
b. Medium-sized artery
b. Medium-sized artery
(more smooth muscle)
Which of the following allow blood to enter in a pulsatile fashion?
a. thoroughfare channel
b. precapillary sphincters
c. metarterioles
d. postcapillary venules
b. precapillary sphincters
Which of the following lacks any smooth muscle cells.?
a. thoroughfare channel
b. precapillary sphincters
c. metarterioles
d. postcapillary venules
a. thoroughfare channel
Which of the following has the highest diameter?
a. arterioles
b. venules
c. small capillaries
b. venules
T/F: tight junctions between the endothelial cells of the arterioles allow fluid to pass between them to allow diffusion
false, the tight junctions stop the leakage of fluids
Which doesn’t have a tunica intima?
a. arterioles
b. capillaries
c. both
d. neither
d. neither
(Because capillaries are only one cell layer thick, they only have a tunica intima.)
What are pericytes? What do they do?
they’re extra cells in the periphery of blood vessels that proliferate when there’s endothelial damage. They can proliferate to become endothelial cells or smooth muscles of the capillaries.
What are transcytotic vesicles used for?
to transport things through the epithelial cells of the capillaries to the surrounding tissue
Which is most likely found in BM?
a. Fenestrated capillaries
b. Sinusoids
c. Continuous capillaries
b. Sinusoids
Which forces molecules to cross via diffusion/transcytosis?
a. Fenestrated capillaries
b. Sinusoids
c. Continuous capillaries
c. Continuous capillaries
Which is found in the choroid plexus?
a. Fenestrated capillaries
b. Sinusoids
c. Continuous capillaries
a. Fenestrated capillaries
Which of the following are closed by diaphragms?
a. Fenestrated capillaries
b. Sinusoids
c. Continuous capillaries
a. Fenestrated capillaries
Which of the following doesn’t have s continuous external lamina?
a. Fenestrated capillaries
b. Sinusoids
c. Continuous capillaries
b. Sinusoids
(the rest have continuous basement membrane)
Which of the following has the largest diameter?
a. Fenestrated capillaries
b. Sinusoids
c. Continuous capillaries
b. Sinusoids
Which acts as a valve in veins?
a. tunica intima
b. tunica media
c. tunica externa
a. tunica intima
Which has more pericytes?
a. Postcapillary venules
b. Large collecting venules
b. Large collecting venules
Which is thin in small and medium-sized veins?
a. tunica intima
b. tunica media
c. tunica externa
a. tunica intima
Which is thin in large-sized veins?
a. tunica intima
b. tunica media
c. tunica externa
b. tunica media
How do you differentiate between normal versus lymphatic capillaries
lymphatic capillaries don’t have blood cells (usually)
Which are bigger, endothelial cells of blood vessels OR endothelial cells of lymphatic vessels?
endothelial cells of lymphatic vessels
How are the spaces between the endothelial cells formed?
they’re anchored by anchoring filaments (made up of elastin and endothelium)
Which of the following depolarizes?
a. sheath cells
b. glomus cells
b. glomus cells
(What induces the depolarization? low oxygen, high carbon dioxide, low pH)
What information do glomus cells rely to the brain? Through which nerve does this occur?
Changes in the CO2, O2, and H+ concentrations
via glossopharyngeal nerve
Where are baroreceptor-sensory nerve terminals located?
in the tunica adventitia
What is the primary pacemaker of the heart? Why?
the SA node is the primary pacemaker because it depolarizes at a more rapid pace than the others (60-100bpm)
What’s the intrinsic rate of the AV node?
40 to 55 beats/min
What’s the intrinsic rate of Tawara branches & Purkynje?
25 to 40 beats/min
Which results from ventricular repolarization?
a. P wave
b. T wave
c. QRS complex
b. T wave
Which results from ventricular depolarization?
a. P wave
b. T wave
c. QRS complex
c. QRS complex
What’s the electrical connection that links the atria and ventricles?
the AV node and AV bundle
What is the last place to be activated in the heart?
posterobasal areas of the ventricles (the outflow tracts)
Where does depolarization first take place?
a. endocardium
b. myocardium
c. epicardium
a. endocardium
Which results from artrial depolarization?
a. P wave
b. T wave
c. QRS complex
a. P wave
Where does repolarization first take place?
a. endocardium
b. myocardium
c. epicardium
c. epicardium
Action potentials last shorter in which of the following? Why?
a. endocardium
b. myocardium
c. epicardium
c. epicardium
they have stronger Ito current (outward potassium current) which acts to repolarize
Describe the ion flow in stage 2. What causes the plateau
Ca influx is balancing K efflux
Does this represent the AP in the antiarrhythmic cells or the AP in cardiac muscle?
In cardiac muscle
During stage 4, what is the cell permeable to?
Na and K (more to Na; as stage four continues the K movement decreases)
How does the positive chronotropic effect work?
opens more HCN-channels and L-type calcium channels to make the depolarization more rapid (so we reach threshold faster-> heart rate increases)
Explain how Parasympathetic stimulation causes a slower heart rate. What mechanisms are used?
reduces iHCN and iCa2+ channels (these channels act to depolarize)
opening of the acetylcholine regulated K+-channels (these channels hyperpolarize)
At which stage can another AP form?
At the latter part of stage 3, deformed AP can be generated with stronger than normal stimuli
(relative refractory period is end of stage 3)
Describe the action potential that occurred in stage 3
They’re abnormal (upstroke is slower, amplitude is lower, duration is shorter)
The sodium channels aren’t fully activated, but the calcium channels are fully activated.
Explain cardiovascular syncope
Fear causes a strong activation of the vagus nerve, which hyperpolarizes the AV node. Due to this hyperpolarization, the threshold cannot be reached.
T/F: the smaller the radius, the more vulnerable the nodal cell is to conduction block (AV block)
true
Why is the AV-node delay important?
ensures that the ventricles are relaxed at the time of atrial contraction and permits optimal ventricular filling during the atrial contraction
What does negative dromotropic intervention cause?
a. increases speed of conduction
b. decreases speed of conduction
b. decreases speed of conduction
What determines absolute refractory period?
The refractory period lasts as long as the inactivation gates are closed
What does the conduction speed of the AV node depend on?
diameter of node
the amplitude
Which of the following does hyperkalemia cause?
a. increases speed of conduction
b. decreases speed of conduction
b. decreases speed of conduction
(Negative dromotropic intervention)
Conduction velocity is called
dromotropy
How do Sympathetic stimulation & catecholamine speed up dromotropy?
phosphorylation of Ca-channels and HCN channels
Which of the following use the sympathomimetic effect to change dromotropy?
a. hyperkaliemia
b. thyroxine
c. ischemia
d. inflammation
b. thyroxine
(sensitizes sympathetic receptors)
How does hyperkaliemia effect dromotropy? HOW?
decrease it by inactivating calcium channels (-> inhibit AP generation and block conduction)
How does Parasympathetic stimulation slow down the conduction velocity?
hyperpolarization via opening of acetylcholine regulated K-channels
The heart tube is derived from what structure?
angioblastic cords
Initially, before the three folds occur, the heart tube is in which relation to the pericardial cavity?
a. dorsal
b. ventral
b. ventral
(becomes dorsal after the folds)
What gives rise to the pericardium?
mesoderm
(also gives rise to the heart)
Whats the origin of heart muscles?
cardiac jelly
What structure develops to become the ascending aorta and the pulmonary trunks?
truncus arteriosus
What allows communication between the primordial atrium and ventricle?
atrioventricular canal
Which early structure is absorbed and becomes the right atrium (smooth part of R atrium)?
sinus venosus
What two things does the sinoatrial valve separate?
sinus venosus and primordial atrium
During the folding of the heart tube, which structure is dorsal?
a. atria
b. ventricles
a. atria
Where does the septum perimum grow towards?
fused endocardial cushions
foramen primum allows the communication between what two structures?
the right and left atrium
Which end of the heart tube is located dorsally?
a. atrial end
b. venous end
b. out flow end
b. venous end
(its the tail end and is the inflow region)
Which structure splits the atrioventricular canal into right and left sections?
endocardial cushions that grow towards each other and fuse to form “fused endocardial cushion”
After birth, increased blood return from the lungs closes foramen ovale. Which is true about this mechanism?
a. the blood pressure pushes the upper limb of the septum primum
b. the blood pressure pushes the lower limb of the septum primum
c. the blood pressure pushes the upper limb of the septum secundum
d. the blood pressure pushes the lower limb of the septum secundum
b. the blood pressure pushes the lower limb of the septum primum
T/F: foramen secondum is formed due to perforations in septum secondum
false, it’s formed due to perforations in septum primum
Which of the following veins bring blood from the body of the embryo?
a. Umbilical vein
b. Viteline veins
c. Cardinal veins
c. Cardinal veins
What’s the origin of the smooth part of right vs smooth part of left atrium
Right= Sinus venarum
Left= pulmonary vein
What’s the origin of the rough part of right vs smooth part of left atrium
Both develop from the primordial atrium
Which of the following veins bring blood from the yolk sac?
a. Umbilical vein
b. Viteline veins
c. Cardinal veins
b. Viteline veins
(Umbilical vein brings from placenta)
What’s the most common type of congenital heart disease?
Ostium secundum types of septal defects
What type of defect is located in the superior part of the interatrial septum?
sinus venosus defect
What occurs if both the septum primum and septum secundum fail to develop?
The interatrial septum is absent and a common atrium is formed
How does AV canal/ AV septal defect occur?
Endocardial cushions fail to fuse with each other
How does the patent foramen primum defect occur?
Failure of fusion of septum primum with endocardial cushions
What are the three things that fuse together to form the membranous part of the interventricular septum?
left bulbar ridge
+
right bulbar ridge
+
downward projection of the endocardial cushion
Both the right and left ventricles have smooth outflow parts. Where are these regions derived from?
Bulbus cordis
right ventricle = conus arteriosus / Infundibulum
left ventricle = aortic vestibule
The ascending aorta and pulmonary trunk develop from…
trucus arterious
Which of the following is used to bypass the liver in fetal circulation?
a. ductus venosus
b. foramen ovale
c. ductus arteriosus
a. ductus venosus
(the rest are used to bypass the pulmonary circulation)
Which of the following forms ligamentum teres after birth?
a. ductus venosus
b. foramen ovale
c. ductus arteriosus
d. umbilical veins
d. umbilical veins
After birth what do these structures develop into?
ductus venosus
ductus arteriosus
ductus venosus-> ligamentum venosum
ductus arteriosus-> ligamentum arteriosum
What will the incomplete closure of interventricular foramen cause?
membrane ventricular septal defects