Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

B2 > CV Week 2 > Flashcards

CV Week 2 Flashcards

1
Q

_________ is located in the hollow organs of the body and all vasculature except for capillaries and endothelial cells

A

Smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe structures that have smooth muscle

A

trachea and airways, vasculature, bladder, female reproductive organs, epididymis and vas deferences, musculature through GI tract, lymphatic vasculature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

True or false - Because smooth muscle is responsible in a diverse group of organs, it requires a diverse range of regulatory mechanisms to perform specific functions

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In __________, smooth muscle cells all behave independently. Few gap junctions are found in these types of cells because there is no great need to electrically couple.

A

Multi-unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In __________, smooth muscles behave as one unit which is accomplished by having many gap junctions interconnecting cells.

A

Single unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe body structures that contain

a) multiunit smooth muscle cells
b) single unit smooth muscle cells

A

a) airways, vasculature, neural regulation

b) GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

_________ smooth muscle tends to be multiunit, whereas _________ smooth muscle tends to be single-unit

A

Tonically active, rhythmically active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe how ADH regulates smooth muscle

A

ADH is released by posterior pituitary and causes vasoconstriction of smooth muscle (and increased water reabsorption of the kidney)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

_________ cause contraction, proliferation and remodeling of blood vessels

A

Inflammatory mediators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Nitric oxide is an example of ______________. It is produced in the immediate environment of the muscle and causes vasodilation of the blood vessels.

A

Humoral or paracrine signaling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe key differences between smooth muscle and skeletal muscle

A

Myofilaments in skeletal muscle are more highly ordered and produce bands whereas actin and myosin filaments are arranged differently. Smooth muscle contains dense bodies. Smooth muscles also contract more slowly than skeletal muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why do smooth muscle cells contract more slowly than skeletal muscle?

A

Cross bridge attachment.detachment is much slower thus rate of contraction is much slower.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True/False - although smooth muscle cells contract more slowly than skeletal muscle, smooth muscle cells can achieve equivalent (or greater) peak contractions

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does slower cross-bridge cycling in smooth muscle affect energy efficiency?

A

Since cycling of cross-bridges is slower, energy expenditure decreases. This energy efficiency is particularly important to generate sustained contractions over minutes or hours (ie tone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the different types of myogenic activity (intrinsic to the musculature)

A

phasic with tone (anal sphincter), phasic (colon), tonic (some blood vessels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the steps in activating cross-bridge cycling in smooth muscle.

A

1) Myosin binds to actin filament and an inorganic phosphate is released
2) Power stroke where actin gets pulled towards middle of sarcomere
3) Rigor (myosin in low energy form). ADP is released and new ATP binds to myosin head.
4) Myosin unbinds from actin. ATP is hydrolyzed.
5) Cocking of myosin head (myosin in high energy form) and ready to bind again.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe MLCK’s role in cross-bridge cycling

A

MLCK phosphorylates MLC20 (myosin) and facilitates its binding to actin. This facilitates cross-bridge cycling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe MLCP’s role in cross-bridge cycling

A

MLCP dephosphorylates MLC20 and reduces cross-bridge cycling –> muscle relaxation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is MLCP activity regulated by?

A

pathways that in effect regulate Ca++ sensitivity of contractile apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What determines the force and duration of contraction?

A

The balance between myosin phosphorylation and dephosphorylation; therefore, the balance btwn activity of MLCK and MLCP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does Ca++ vary in when there are a) high MLCK levels; b) high MLCP levels

A

a) high MLCK - high Ca++; b) high MLCP - low Ca++

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

_________ (2) are examples of excitatory agonists that cause Ca++ sensitization and thus greater force by inhibiting MLCP

A

Rho Kinase and PKC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

_________ (2) are examples of inhibitory agonists that reduce Ca++ sensitization and thus relax muscle, reducing the force by aggravating MLCP activity

A

cAMP and cAMP dependent mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are three pharmacological agents that are excitatory agonists in regulation of contraction via pharmacochemical coupling?

A

Ach, norepinhephrine, substance P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are two pharmacological agents that are inhibitory agonists in regulation of contraction via pharmacochemical coupling?

A

adenosine, vasoactive inhibitory peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How do ROCK and PKC inhibit MLCP activity and thus stimulate contraction?

A

ROCK phosphorylates MYPT1 subunit of MLCP and PKC via Ca++ and PLC-b mechanism phosphorylates CPI-17,(inhibitory proteins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Smooth muscle cells contains transport proteins and organelle membranes that set and regulate membrane potential, generate excitable events and ___________________

A

Ca++ entry into and removal from the cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Like other excitable cells, the PM has some level of permeability of each ion species present. The dominant membrane permeability in smooth muscle is due to ______________

A

K+ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

RMP is smooth muscle is usually _________ mV

A

-40 to -80

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

_________ couple smooth muscle cells into an electrical syncytium and provide low electrical resistance pathways between cells

A

Gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe the structure of a gap junction.

A

Gap junction is contains numerous CONNEXONS which are channels assembled by six connexin proteins each that form the pore.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Glucose, glutamine, ADP, adenosine, and cAMP all have same ________ through connexins

A

permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What happens to connexons when they are attached to a damaged cell?

A

They close, can be regulated somewhat by Ca++ and pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Name 4 types of K+ channels found in smooth muscle cells

A

voltage-dependent K+ channels (Kv), Ca++ activated K+ channels (BK), 1 transmembrane pore formign loop (Kit, Katp), and 2 transmembrane forming loops (K2p)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Ca++ entry (excitation) tends to be controlled by __________.

A

K+ channels, due to their importance in regulating membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

________ are voltage-independent channels that are important for resting or basal K+ conductance. They contribute to the resting potential of the smooth muscle cells.

A

2 pore K+ channels (K2p)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

High expression of _________ can reduce the tendency for smooth muscle cells to generate action potentials, making the muscle less excitable

A

Voltage-activated K+ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

High abundance of ____________ can lead to rhythmic patterns of activity. These channels are also important for large amplitude hyperpolarizations produced by some inhibitory neurotransmitter as well as some other agonists.

A

Ca++ activated K+ channels (ekg BK)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

____________ are active in negative voltage range and therefore also contribute to a more hyperpolarized cell. They also mediate responses to some inhibitory agonists.

A

Inward rectifiers (Kir)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Ca++ entry is controlled by _______ because these channels set or regulate membrane potential that determines Ca++ entry via __________

A

K+ channels, voltage dependent Ca++ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Depolarization induced activation of ____________ lead to Ca++ entry and contraction of smooth muscle

A

L-type Ca++ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

________ is a Ca++ channel blocker. When added, the muscle relaxes because the __________ have been shut down.

A

Nifedipine, L-type Ca++ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Describe the two ways which Ca++ stimulates cell to depolarize

A

Ca++ activates Cl- to leave the cell –> depolarization and Ca++ activates non-selective cation channels –> depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Describe how Ca++ causes hyperpolarization of the cell

A

Activates BK to transport Ca++ out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Describe Ca++’s role in CICR

A

Ca++ enters cell and stimulates Ca++ induced Ca++ release in sarcoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Describe how depolarization leads to contraction via Ca++ channels

A

depolarization causes an increase in Cav channels opening which increases Ca++ entry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Describe how hyperpolarization leads to decreased contraction via Ca++ channels

A

Decrease in open Cav channels which leads to decreased Ca++ entry and therefore decreased contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

There are three major mechanisms that reduce Ca++ and that relaxation of smooth muscle depends on. What are they?

A

ATP-driven SR Ca++ pump, AT driven PM Ca++ pump, and Na/Ca exchange (NCX, uses Na+ gradient).
The more minor mechanisms are Ca++ binding molecules in cytoplasm and active Ca++ transport in mitochondria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

_______ is a short-acting gas and free radical whose unpaired electrons cause this chemical to be highly chemically reactive

A

Nitric Oxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

The biological actions of nitric oxide are rapidly terminated due to what? This makes this compound short-acting. It must be synthesized on demand.

A

Spontaneous oxidation to NO2 and NO3 resulting in a bio half life of around 3-5 seconds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Nitric oxide is highly ______ so its post-junctional effector proteins are typically within the cell.

A

lipophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

True or false: NO can be synthesized by variety of different cell types

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

The highest levels of nitric oxide in the body are found in the _______

A

neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Describe how nitric oxide inhibits smooth muscle contraction.

A

Vasodilator binds receptor on endothelial cell which activates NOs. NO is produced from Arginine. NO rapidly diffuses across membranes to a smooth muscle cell. It binds guanylyl cyclase which increases cGMP concentration and leads to relaxation of the smooth muscle cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

In the NO pathway, cGMP activates _____________ which then goes on to phosphorylate several proteins important in promoting vasodilation

A

cGMP dependent protein kinase (PKG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How do proteins phosphorylated by PKG promote vasodilation? (3 ways)

A

Proteins inhibit Ca++ release from IP3 receptors; proteins inhibit activation of L-type Ca++ channels; proteins increase Ca++ uptake by SR. These three mechanisms all lead to more highly activated MLCP (Ca++ desensitization)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the lateral leads?

A

I, V5, V6, AVL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the inferior leads?

A

Lead II, Lead III, avF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What are the anterior or septal leads?

A

V1-V4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How would you determine that rhythm is in normal sinus?

A

Upright P wave in inferior leads (lead II, lead III, aVF) [biphasic wave in lead VI - in textbooks]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How would you determine if there is a left axis deviation?

A

R wave in lead I is pointing upward (+) and R wave in lead II is pointing downward (-) (left each other)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How would you determine if there is right axis deviation?

A

R wave in lead I is pointing downward (-) and R wave in lead II is pointing upward (+) (right at each other)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

How long is a normal PR interval?

A

less than 200 msec or 1 big box

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How long is a normal QRS?

A

less than 120 msec or 3 little boxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

How long is a normal QTc?

A

Corrected for heart rate, should be 1/2 of R-R interval, <450 msec or 2.5 big boxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

If there is no correlation between the P wave and QRS and PR interval varies BUT P-P intervals and R-R intervals are consistent, what condition does this indicate?

A

3rd degree heart block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

If the PR interval gets progressively longer until a QRS is dropped, what condition does this indicate?

A

2nd degree heart block, mobitz type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

If the PR interval is consistently longer than 200 msec (one big box), what condition does this indicate?

A

1st degree heart block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

If the PR interval is consistent but a QRS is dropped randomly, what condition does this indicate?

A

2nd degree heart block, mobitz type II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

The ____ is ALWAYS the first downward deflection in the QRS complex. If there is no downward deflection, then it doesn’t exist

A

Q wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Why is a prolonged QTc medically significant?

A

If ventricles attempt to depolarize or contract on top of a Q wave, this leads to serious dysrhythmias such as V-fib and V-tach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What happens in right atrial enlargement?

A

right atrial depolarization lasts longer than normal and its waveform extends to end of left atrial depolarization (uneven double hump with taller 1st hump). P wave is taller than normal although width remains unchanged.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What happens in left atrial enlargement?

A

left atrial depolarization lasts longer. Amplitude is unchanged. Height remains same but duration is longer than 120 msec (3 little boxes). NOTCHED WAVE (“p mitrale”) near peak in lead II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What does an inverted T wave indicate?

A

ischemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What does a spiked T wave indicate?

A

hyperkalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

_______ are wide, random QRS complexes that usually come in early and can be unifocal or multifocal

A

Premature ventricular complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

In _______ every other beat is a PVC whereas in _______ every 3rd beat is a PVC

A

bigeminy, trigeminy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What varies in a sinus arrhythmia?

A

R-R intervals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

In a ____________ the heart beat happens sooner than expected. P waves are present and QRS complex is no different than baseline.

A

premature atrial complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

In _________ there is an irregularly irregular rhythm and ___________ vary without any pattern. There is also an absence of _______ . Atrial HR can run 400-500 bpm.

A

atrial fibrillation, R-R intervals, P waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

In a _________, P wave is often inverted (esp in lead II) but may be under or after QRS and the heart rate is slow.

A

junctional rhythm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What differentiates between high junctional rhythm (stable) and low junctional rhythm (unstable)

A

Narrow QRS suggests stable (high) whereas wide QRS suggests unstable (low)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

In __________ there is a narrow QRS (less than 120 ms or 3 small boxes) and heart rate of over 100 bpm. If there is a wide QRS, what is this called?

A

supraventricular tachycardia; SVT with aberrancy (typical in younger patients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

_________ is a wide complex tachycardia that is typically in older patients with previous myocardial infarction

A

ventricular tachycardia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

In __________, there are no QRS complexes. This represents a chaotic and mechanical cardiac arrest.

A

ventricular fibrillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

A ___________ is can be seen in leads I, II, AVL, V1-V6 and represents a previous MI. In which leads does this deflection not represent pathology?

A

pathological Q wave, not pathology in leads III and AVR.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

______________ is a reentry tachyarrhythmia via accessory pathway.

A

Wolf-Parkinson White

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What accessory pathway is usually seen in WPW?

A

“Bundle of Kent” located between atria and ventricle on side. This electrical signal goes through without delay in AV node and meets the normal signal in ventricular purkinje.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What is diagnostic for WPW?

A

PR less than 125 ms (3 small boxes) and at least one delta wave.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

How does WPW cause tachyarrhythmia (2 ways)

A

Narrow complex - the abnormal signal returns and depolarizes AV node, causing it to fire before the SA node.
Wide complex - abnormal signal hits AV node during its refractory period. Will pass through all the way around and come back to AV node in retrograde fashion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What are common symptoms of WPW?

A

unexplained syncope and palpitations infrequently. Normal risk not high except if there’s abnormal pathways.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Drugs such as digoxin, Beta-blockers, verapanil, and adenosine will make WPW worse. Why?

A

Work mainly on AV node not on accessory pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What drug and surgical treatments are used for WPW?

A

Procanamide and Amiodarone. Surgical catheter ablation to damage accessory pathway.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What are the most common congenital defects?

A

Heart followed by genital/urinary tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Describe the pathway of cardiac progenitor cells to the mesoderm

A

Cardiac progenitor cells form in epiblast then migrate in cranial –> caudal order through the primitive streak to the SPHLANCNIC LATERAL PLATE MESODERM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Where do prospective myoblasts and hemangioblats reside?

A

in the SPHLANCNIC MESODERM in front of the neural plate and on each side of th emebryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

In formation of the heart tube, angiogenic cell clusters initially coalesce to form ______________

A

right and left endocardial tubes [ endothelial heart tubes ]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

After the embryo folds ________ and __________, the endocardial tubes fuse via ________ to form the heart tube

A

cardiocaudally, laterally, programmed cell death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Describe the four layers of the primitive heart from inside to outside

A

endocardium, cardiac jelly, myocardium, epicardium (outside covering of the tube)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

The cardiac jelly is a thick, acellular material made by ____________

A

myocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

In the epicardium, _______ migrates from the septum transversum to form the ____________

A

mesothelium, coronary arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

On day 18, the endocardial tubes and dorsal aortae are formed between what two layers?

A

endoderm and sphlancnic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

On day 22, the embryo is in the __________ and fusion occurs only the ______ region of the horseshoe shaped heart tube

A

8 somite stage, caudal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What structures rise from the crescent portion of the horseshoe shaped heart tube?

A

outflow tract and most of ventricular region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

In 22-day embryo, _____________ drain the yolk sac

A

vitelline veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

In 22-day embryo, __________ carry O2 from the placenta

A

umbilical veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

In 22-day embryo, _______________ drain body wall and head

A

common cardinal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

True or false: The inflow and outflow tracts are connected to the heart tube before any cardiac folding takes place

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Around day 23, the _______ begins to form from a series of expansions, constrictions and fold

A

cardiac loop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

What are the four initial dilations of the heart tube?

A

sinus venosus, primitive atrium, primitive ventricle, bulbus cordis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

What two features of the heart does the cardiac loop create?

A

1) normal position of heart chambers; 2) changes a single circuit system into an asymmetrical circuit system with pulmonary and systemic circulations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

At day 24, remodeling of the _______ begins with a shift to the right of venous return

A

sinus venosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

What does the right vitelline vein give rise to?

A

inferior vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

What does the right anterior cardinal vein give rise to?

A

superior vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

What does the left sinus horn give rise to?

A

coronary sinus and oblique vein of the left atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

The right sinus horn blends into the right posterior wall of the right atrium to become the smooth area _____________

A

sinus venarum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

What three vessels open into sinus venarum?

A

THINK RIGHT ATRIUM. Inferior vena cava, superior vena cava, coronary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

The sinus venarum contains the ___________ which act as conducting fiber tract from SA node to AV node

A

crista terminalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

_________ are found in the cardiac jelly where they are described as “swellings”

A

endocardial cushions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

What germ tissue are endocardial cushions derived from?

A

sphlancnic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

The sphlancnic mesoderm (endocardial cushions) and __________ in the conotruncal area play a role in formation of the _____________

A

neural crest cells, septa and valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

Endocardial cushions are important because they play a role in __________

A

cardiac defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

The primitive atrium is partitioned between the right and left _________

A

endocardial cushions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

During partitioning of the primitive atrium, a thin membranous septum called the __________ because the right and left endocardial cushions

A

septum primum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

After the formation of the septum primum, programmed cell death forms the ________

A

ostium secundium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

What is the role of the ostium secundium?

A

Maintains the right to left shunt bypassing the pulmonary circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

What thick muscular septum forms to the right of the septum primum?

A

Septum secundum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

The ________ forms in the septum secundum which maintains the right to left shunt

A

Foramen ovale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

When does the foramen ovale close?

A

immediately after birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

At birth, closure of the foramen ovale is functiona. Describe what this means in terms of atrial pressure.

A

At birth, there is a decrease in right atrial P from occlusion of placental circulation and increase in left atrial pressure due to increased pulmonary venous return (USING LUNGS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

When does the anatomical closure of the foramen ovale occur? What two structures fuse?

A

Occurs at 3 months, septum primum and septum secundum fuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

Incomplete anatomical fusion of septum primum and septum secundum causes ____________. This is present in 25% of the population and clinically usually of no importance.

A

probe patency of foramen ovale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Defects in the ________ cause the most clinically significant atrial septal defects and are prevalent in females to males in a _____ ratio

A

ostium secundum, 2:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

The cor triloculare biventriculare is also known as the _______

A

common atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

What four heart defects do endocardial cushions play a role in?

A

atrial septal defect, ventricular septal defect, transposition of the great vessels, tetralogy of fallot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Conotruncial cushions, which also contain neural crest cells, play a role in both heart and _________ defects

A

craniofacial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

During partitioning of the atrioventricular canal, what do the four endocardial cushions form(3)

A

septum , bicuspid valve, tricuspid valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

During partitioning of the atrioventricular canal, what can go wrong (2)

A

persistent common atrioventricular canal and abnormal division of the canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

The truncoconal septa form from _________ that migrate from the hindbrain through pharyngeal arches ___, 4, and 6 and then invade the truncus arteriosus to form the septa.

A

neural crest cells, 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

During the fifth week, _____ ridges/swellings appear and go on to form the ________________ which divides the truncus into the aortic and pulmonary channels

A

truncal, aorticopulmonary septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

After formation of the truncal swellings, _____ swellings also form which give rise to the _________________

A

conal, outflow tracts of right and left ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

_________ contribute to both swellings to form connective tissue and smooth muscle of aorticopulmonary system

A

neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

During partitioning of the truncus arteriosus and the bulbus cordis, _______ lines up the correct outflow tract with the correct ventricle

A

spiraling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

During partitioning of the truncus arteriosus and bulbus cordis, If neural crest cells were to be experimentally removed or blocked during their migration this would lead to ___________

A

persistent truncus arteriosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

If there is no aorticopulmonary septum formed, then there will be ________

A

persistent truncus arteriosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

If the aorticopulmonary septum does not spiral there will be ____________

A

transposition of the great vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

If the aorticopulmonary septum is misaligned there will be ___________

A

tetralogy of fallot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

Persistent truncus arteriosus is normally accompanied by __________

A

ventricular septal defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

In persistent truncus arteriosus, which great vessel gets more blood flow and why?

A

The pulmonary artery section receives more blood flow than the aorta section due to decreased pressure in the lungs compared to systemic circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

Describe the basic pathology of persistent truncus arteriosus.

A

In persistent truncus arteriosus, the great vessels do not separate and there is a VSD. Deoxygenated and oxygenated blood mix and go into body and lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

In persistent truncus arteriosus, since the pulmonary artery section receives more blood than aorta, what happens that leads to pulmonary HTN?

A

Too much blood in the lungs leads to fluid build up which makes it difficult to breathe. Blood vessels to the lungs become damaged. This makes it harder to pump blood into the lungs over time due to pulmonary HTN that develops.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

Due to pulmonary HTN, more blood starts to go into the body then the lungs eventually in persistent truncus arteriosus. What occurs as a result?

A

Cyanosis worsens as blood with lower O2 travels to the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

How is persistent truncus arteriosus treated?

A

corrective surgery needed within 6 months of life - closure of VSD and separation of great vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

Infants with transposition of the great vessels can only survive after birth if they have one of which 3 defects?

A

patent ductus arteriosus, atrial septal defect, ventral septal defect - allows intermixing of the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

If these defects are not present, how can they be surgically induced?

A

Cardiac catheterization (balloon atrial septostomy) may create large hole in the atrial septum or a patent ductus arteriosus can be clinically induced to remain open allowing blood flow btwn pulmonary artery and aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

Describe the basic pathology of transposition of the great vessels.

A

The great vessels are switched so the aorta is connected to the right ventricle and the pulmonary trunk is connected to the left ventricle - therefore oxygenated blood going to lungs and deoxygenated blood going to systemic circulation - NOT COMPATIBLE WITH LIFE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

During the arterial switch procedure, what remains attached to the aorta?

A

coronary arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

Transposition of the great vessels is usually accompanied by an _____________

A

atrioseptal defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

______________ the most common cyanotic heart defect

A

teratology of fallot

160
Q

Describe the basic pathology of teratology of fallot

A

The outflow tract openings fail to align with the ventricles. Right ventricular outflow (pulmonary artery) is blocked which causes pulmonary stenosis and an overriding aorta. A ventricular septal defect accompanies.

161
Q

The ventricular septal defect and pulmonary stenosis in TOF leads to high pressure in the ___________ which results in ____________

A

right ventricle, right ventricular hypertrophy

162
Q

In extreme situations, right ventricular outflow tract is completely blocked, which leads to teratology of fallot and _________

A

pulmonary artesia

163
Q

Children with teratology of fallot are at risk of having what kinds of spells??

A

Hypercyanotic spells due to spasm of infindibular region (below pulm vave) and/or sudden increased pulmonary vascular resistance which produces a sudden decrease in amount of blood getting to lungs.

164
Q

What kind of shunt develops in teratology of fallot? How does this lead to acidosis?

A

Right to left shunt which means more deoxygenated blood is going into systemic circulation. This further increases pulmonary vascular resistance which leads to acidosis.

165
Q

Older children learn to prevent or alleviate symptoms by squatting. What is squatting believes to do?

A

Squatting kinks the large arteries in the lower extremities which increases systemic vascular resistance and forces more blood across the pulmonary outflow tract.

166
Q

What are the four components of teratology of fallot? Which is the primary problem?

A

Ventricular septal defect (VSD), pulmonary stenosis, overriding aorta, thickening of the right ventricle. VSD is primary problem.

167
Q

During partitioning of the primitive ventricle, where does the muscular ventricular septum develop?

A

midline on floor of primitive ventricle

168
Q

The __________ is located between the free edge of the muscular interventricular septum and fused AV cushions

A

interventricular foramen

169
Q

Closure of the interventricular foramen via completion of the conus septum and outgrowth of tissue from the inferior endocardial cushion leads to formation of the ____________

A

membranous interventricular septum

170
Q

In other words, membranous interventricular septum is formed when the proliferation of right and left ____________ combined with proliferation of inferior (AV) endocardial cushion closes the interventricular foramen.

A

right and left bulbar ridges (conus cushions)

171
Q

_____ are the most common cardiac congenital defects, occurring in about 30% of cases

A

ventricular septal defects

172
Q

What is the most common cause of ventricular septal defect?

A

membranous IV septum does not form

173
Q

Single or multiple perforations in the ______________ can also cause ventricular septal defects

A

muscular interventricular septum

174
Q

Describe the two mechanisms of no shunt (acyanotic) congenital heart defects

A

(1) anomaly of aortic arches, (2) coarctation of aorta

175
Q

Describe three types of anomalies of aortic arches

A

right arch of aorta, double arch of aorta, retro-esophageal right subclavian artery

176
Q

Describe the three mechanisms of left to right shunt (acyanotic) congenital heart defects

A

persistent ductus arteriosus, interatrial septal defects, interventricular septal defects

177
Q

Describe the three mechanisms of right to left shunt (cyanotic) congenital heart defects

A

(1) complete transposition of the great vessels, (2) truncus arteriosus communis (persistent), (3) teratology of fallot

178
Q

The smooth portion of the left atrium houses the _______________

A

pulmonary veins

179
Q

Remodeling of the vascular system generally occurs from ______ to ________ tracts

A

inflow, outflow

180
Q

For the inflow tract, above the diaphragm, remodeling begins with a shift to right of venous return. This leads to formation of what 5 structures?

A

IVC, SVC, coronary sinus, oblique vein of left atrium, sinus venarum

181
Q

For the inflow tract, below the diaphragm, the vitelline system gives rise to what structures? (3)

A

liver sinusoids (incl ductus venosus), the portal system (portal vein, SMV, IMV) and a portion of the inferior vena cava.

182
Q

For the inflow tract, below the diaphragm, what occurs to the right and left umbilical veins?

A

The right umbilical vein disappear and the left umbilical veins anastomoses with the ductus venosus in the liver.

183
Q

Anastomosis of the left umbilical vein with the ductus venosus in the liver results in what?

A

Shunting of oxygenated placenta blood into inferior vena cava and right side of heart

184
Q

The _________ form a portal system that drains the blood from the foregut, midgut, and upper part of anorectal canal

A

right and left vitelline veins

185
Q

For the outflow tract, ventrally, the aortic arch arteries rise from the _________ through expansion of cranial end of the __________

A

aortic sac, truncus arteriosus

186
Q

Dorsally, the aortic arches connect to left and right ______

A

dorsal aortae

187
Q

What develops from aortic arches 3,4, and 6 (and R and L dorsal aortae)?

A

adult arterial system, ASYMMETRICAL arches

188
Q

Aortic arch 6 remains on left side and goes on to form what?

A

pulmonary vessels and ductus arteriosus

189
Q

What can maintain a patent ductus arteriosus if clinically indicated?

A

exogenous prostaglandins

190
Q

Small pactent ductus arteriosuses can be closed via what?

A

prostaglandin inhibitors such as indomethacin or ibuprofen

191
Q

What two main reasons necessitate closure of PDA?

A

(1) large size of ductus –> large volume of blood going into lungs can lead to overload –> heart enlargement then failure; (2) avoid risk of developing endocarditis

192
Q

Development of endocarditis in ____ of patients with PDA will lead to an increased mortality of 50%

A

1/8

193
Q

In fetal circulation, well oxygenated blood returns from the placenta via the ________

A

umbilical vein

194
Q

In fetal circulation, what two pathways does blood travel in from placenta?

A

1/2 of blood passes through hepatic sinusoids whereas other half bypasses the liver and goes through the ductus venosus into the inferior vena cava

195
Q

What are the two right to left shunts in fetal circulation?

A

(1) blood from right atrium goes through foramen ovale into left atrium; (2) the small amount of blood from right ventricles that enters the pulmonary trunk passes through ductus arteriosus into the aorta.

196
Q

In fetal circulation, blood flows from right to left atria via foramen ovale and then into the ascending aorta. What tissues are best oxygenated this way?

A

head, neck, upper limbs

197
Q

How is blood in placental circulation re-oxygenated?

A

Blood is returned via umbilical arteries to the placenta

198
Q

At birth, what three shunts cease to function?

A

foramen ovale (interatrial), ductus arteriosus (inter great vessel) and ductus venosus (bypass lungs)

199
Q

What causes the foramen ovale to close upon birth?

A

Aeration of the lungs provides a dramatic fall in vascular resistance. An increase in pulmonary blood flow leads to increased L atrial pressure above that in R atrium which closes foramen ovale.

200
Q

Upon birth, what happens to the ductus arteriosus and ductus venosus?

A

constriction

201
Q

What are the remnants of umbilical arteries upon birth?

A

internal iliac arteries and media umbilical ligaments

202
Q

What are the remnants of the umbilical vein upon birth?

A

ligamentum teres of liver

203
Q

What are the remnants of ductus venosus upon birth?

A

ligamenetum venosum

204
Q

What are the remnants of the foramen ovale upon birth?

A

Fossa ovalis (becomes obliterated?)

205
Q

Circulation is a __________ that features a branching pattern and blood flows through serial and parallel paths

A

closed circuit

206
Q

True/False -In all cases blood flows through 2 capillary beds in series

A

false, sometimes blood flows through a single capillary bed and sometimes it flows through an arrangement of parallel and series paths

207
Q

What pathway does blood from the right to the left heart take?

A

It can only take a single pathway, across a single capillary bed in the lungs.

208
Q

Sometimes, in the normal human body, some deoxygenated blood (which should have gone to right heart) mixes with oxygenated blood bound to ______________

A

systemic arteries

209
Q

_________ transport blood under high pressure, have rapid pulsatile blood flow and are densely innervated. These vessels have a strong muscular wall.

A

arteries

210
Q

________ are the smallest branches of arteries.

A

Arterioles

211
Q

Arterioles are major ______________ of whole peripheral circulation and have a ________ layer

A

resistance vessels, thick smooth muscle

212
Q

Arterioles are ________ innervated and have a _________ layer

A

very densely, endothelial cell

213
Q

Arterioles regulate blood flow to ________

A

capillary beds

214
Q

Arterioles are considered “_______________” due to having the biggest P drop

A

stopcocks of circulation

215
Q

In arterioles, how is basal tone established?

A

smooth muscle is partially contracted under normal conditions

216
Q

True/False: Arterioles are the most significant point of control over peripheral resistance to flow

A

True

217
Q

True/False: Arterioles outnumber any other type of artery

A

True

218
Q

True/False: Arterioles are less muscular in proportion to their diameter

A

FALSE - arterioles are more muscular in proportion to their diameter

219
Q

Arterioles are highly capable of changing their ______

A

radius

220
Q

How is blood flow to the capillaries controlled?

A

via vasoconstriction and vasodilation

221
Q

What is the difference between skeletal muscle and vascular smooth muscle in terms of tone?

A

Vascular smooth muscle has some tone without needing neural input.

222
Q

The basal tone seen in smooth muscle comes from _________ and ________ factors

A

intrinsic, local

223
Q

All types of smooth muscle cells exhibit _________ channels which are typically _______ which are activated by the cell’s membrane potential

A

voltage-dependent Ca++, L-type Ca++ channels

224
Q

Cells that sit negative to ________ must be depolarized in order to be activated by L-type Ca++ channels

A

-60mV

225
Q

Cells that are positive of -60mV have some ______ activation of L-type channels and therefore ______ Ca++ entry

A

tonic x2

226
Q

True/False: Capillaries have smooth muscle

A

FALSE - CAPILLARIES DO NOT HAVE SMOOTH MUSCLE

227
Q

Describe the features of capillary walls.

A

Very thin walls consisting of a single layer of endothelium permeable to small molecular substances.

228
Q

Name three features of capillaries.

A

1) major exchange vessels, 2) largest total cross-sectional area, 3) low flow velocity

229
Q

__________ are small vessels with thin walls that collect blood from capillaries and also participate in exchange

A

venules

230
Q

What happens when blood enters venules from capillaries?

A

total cross-sectional area diminishes and thus the velocity of blood flow increases

231
Q

Venules progressively merge to form larger _____ which transport blood _________

A

veins, back to heart

232
Q

Veins are major ________ vessels and a major ______ reservoir.

A

capacitance (major collection and storage site for blood), controllable

233
Q

Describe three features of veins

A

1) thin but muscular walls, 2) under low pressure, 3) densely innervated

234
Q

About _____ of entire blood volume of body is in systemic circulation and about _____ is in heart and lungs

A

85, 15%

235
Q

Describe the distribution of the blood in circulation

A

65% in veins, 13% in arteries, 7% in arterioles and capillaries

236
Q

_________ is the total area of all vessels added together at each _____ in the circulatory stem

A

cross-sectional area, level

237
Q

Blood velocity is measured in a __________ at each ______ in the circulatory system

A

single vessel, level

238
Q

_________ markedly affects blood velocity

A

vessel radius/diameter

239
Q

The highest velocity is found in the _____ which also has the lowest cross-sectional area

A

aorta

240
Q

The lowest velocity is found in the _______ which has the highest cross-sectional area

A

capillaries

241
Q

Veins have ____ velocity and ____ area

A

higher, lower

242
Q

True/False: Capillaries have 1000x the cross sectional area of aorta

A

true

243
Q

What is the formula for velocity of blood flow?

A

velocity is equal to blood flow divided by cross sectional area

244
Q

Describe the relationship between velocity, blood flow and cross-sectional area

A

Velocity is proportional to blood flow and inversely proportional to cross-sectional area

245
Q

Describe the three reasons why blood velocity decreases from aorta to capillaries

A

1) greater distance means more friction to reduce speed, 2) smaller radii of arterioles and capillaries offers more resistance, 3) farther from heart, total cross sectional area becomes greater and greater

246
Q

Describe fluctuation of the arterial pressure in regards to pulsatile heart pumping

A

The arterial pressure in aorta is high because heart is pumping constantly. However, it is higher in the systolic phase than diastolic phase.

247
Q

__________ is the force exerted by the blood against any unit area of the vessel wall

A

blood pressure

248
Q

As blood flows through systemic circulation, pressure decreases progressively because of the _________

A

resistance to blood flow

249
Q

Intravascular pressure stretches blood vessels in proportion to their _________

A

compliance

250
Q

Largest decrease in pressure occurs across the _________ because they are the site of highest resistance

A

arterioles

251
Q

What is pulse pressure?

A

the difference between peak arterial pressure of systole and peak arterial pressure of diastole

252
Q

How is pulse pressure dampened over the course of the arterial tree? (2)

A

1) compliance of arterial walls, 2) resistance to flow as vessel diameter becomes smaller.

253
Q

Due to the hydraulic filter effect, the flow through capillaries will be ________ thoughout the cardiac cycle

A

continuous

254
Q

What is compliance?

A

the elasticity of vessel walls

255
Q

True/false: Capillary blood flow is non-pulsatile

A

True - due to increasing dampening by vessel compliance and functional resistance of small arteries and arterioles

256
Q

In Grave’s disease, in addition to hyperthyroidism and elevated basal metabolism, what changes are seen in arterioles?

A

Arteriolar vasodilation and reduced arteriolar resistance - causes a dampening effect on pulsatile arterial pressure which diminishes it. Pulsatile flow observed in capillaries of nail beds.

257
Q

_________ is the lowest arterial pressure during the cardiac cycle

A

Diastolic P

258
Q

The most important determinant of pulse pressure is __________

A

stroke volume.

259
Q

The arterial pulse P gives valuable clues about a person’s pulse pressure, unless what?

A

arterial compliance is not normal

260
Q

Describe the arterial pulse pressures and stroke volumes found in those with severe CHF and severe hemorrhage

A

small arterial pulse pressures because their stroke volumes are abnormally small

261
Q

Describe the arterial pulse pressure and stroke volume found in those with aortic regurgitation

A

large stroke volume, increased arterial pulse P

262
Q

Describe the stroke volumes in trained atheletes

A

Have high stroke volumes at rest because their HRs are usually low due to prolonged ventricular filling times

263
Q

What are the two factors that dampens pulse P over the course of arterial wall tree?

A

compliance and resistance to flow as vessel diameter becomes smaller

264
Q

______________ is the avg arterial pressure with respect to time

A

mean arterial pressure (MAP)

265
Q

What is the formula for MAP?

A

=1/3 pulse pressure + diastole P; or (1/3 systolic-diastolic) + diastolic; or 1/3 systole + 2/3 diastolic

266
Q

Describe why venous P tends to be low.

A

Veins have a high capacitance and can hold large volumes of blood and lower pressure.

267
Q

True/False: atrial pressure is even lower than venous pressure

A

true

268
Q

Atrial pressure can be estimated by the __________ [approximately equal]

A

pulmonary wedge pressure

269
Q

True/false: Absolute pressure drives blood flow

A

FALSE - pressure gradient - blood flows from high P to low P

270
Q

___________ is the quantity of the blood that passes a given point in circulation in a given period of time

A

blood flow

271
Q

What is the formula for blood flow

A

Blood flow is equal to the pressure gradient divided by resistance. Also can be mean arterial pressure / resistance

272
Q

Blood flows when?

A

pressure exceeds resistance

273
Q

_____________ is the total quantity of blood that can be stored in a given portion of the circulation for each mmHg pressure rise

A

compliance

274
Q

What is the formula for compliance/capacitance?

A

Compliance is equal to the volume divided by the pressure

275
Q

True/False: Capacitance is much greater in arteries than veins

A

FALSE, much greater in veins

276
Q

Capacitance/compliance is determined in large part by the relative proportion of __________ to __________ in the vessel wall

A

elastin fibers, smooth muscle and collagen

277
Q

True/False: Aging decreases compliance

A

true. As a person ages, the arteries become stiffer and less distensible.

278
Q

Artherosclerosis results from the deposition of tough, rigid _______ inside the vessel wall and around the atheroma. This increases stiffness and decreases the elasticity of the artery wall.

A

collagen

279
Q

________ is the force that impedes blood through the system

A

resistance

280
Q

What factors change the resistance of blood vessels? (3)

A

blood viscosity, blood vessel length, radius of the vessel

281
Q

How is resistance in blood vessels calculated?

A

resistance is equal to 8blood viscosity * blood vessel length divided by piradius^4 (R = 8nl/pi*r^4)

282
Q

What blood cells/proteins elevates blood viscosity the most? In that regard, what conditions elevate blood viscosity?

A

RBC count and albumin, polycythemia and dehydration

283
Q

What decreases blood viscosity?

A

anemia and hypoproteinema –> increased blood flow

284
Q

What declines with distance in terms of blood vessels?

A

pressure and flow

285
Q

What is the most powerful influence over blood flow?

A

vessel radius - only significant way of controlled resistance - marked affects blood velocity

286
Q

________ are changes in vessel radius

A

vasoreflexes

287
Q

Smooth muscle in which blood vessel layer contracts during vasoconstriction?

A

tunica media

288
Q

What is the major determinant of resistance in blood vessels and why?

A

Changes in the radius of vessels because the viscosity of blood or length of blood vessel cannot be easily changed from moment to moment

289
Q

What is the relationship between blood flow and radius of vessel?

A

Blood flow is proportional to the 4th power of radius and therefore small changes in vessel radius cause large changes in flow (ml/min)

290
Q

Inhibition of sympathetic activity ______ blood vessels and _____ blood flow whereas very strong sympathetic activity _____ blood vessels and _____ blood flow

A

dilates, increases, constricts, decreases (sometimes down to 0 despite high arterial P)

291
Q

An increase in arterial pressure would cause what in regards to blood flow? Why?

A

a proportional increase in blood flow.

292
Q

Why is blood flow at arterial pressure of 100mmHg usually 4-6X as a great as blood flow at 50 mmHg instead of 2X?

A

There is an effect of increased pressure on increased vascular diameter. Increase in arterial pressure increases the force that pushes blood through the vessel but also distends the vessels at the same time which decreases vascular resistance

293
Q

What is the largest proportion of resistance contributed to?

a) arteries
b) arterioles
c) capillaries

A

arterioles

294
Q

Describe blood flow and pressure for blood vessels in series.

A

Each blood vessel in series receives same total blood flow and as blood flows through the series of blood vessels, pressure decreases.

295
Q

True or false: For a given system, total resistance is less than the resistance of any of the individual arteries.

A

TRUE

296
Q

What is the equation for total resistance in parallel?

A

1/Rtot = 1/Ra + 1 Rb.. 1/Rh

297
Q

Describe blood flow and pressure for blood vessels in parallel

A

Each artery in parallel receives a fraction of total blood flow. In each parallel artery, the pressure is the same.

298
Q

Where is series resistance found?

A

Illustrated by the arrangements of blood vessels within a given organ

299
Q

Where is parallel resistance found?

A

illustrated by systemic circulation (arteries branching off aorta)

300
Q

The ___________ is the complete resistance that blood encounters as it flows from arterial to venous side of circulation

A

total peripheral resistance

301
Q

The ______ is the resistance that blood encounters as it flows from capillaries back to the heart

A

venous resistance

302
Q

__________ is fluid’s resistance to flow, “thickness,” or internal friction of the fluid

A

viscosity

303
Q

What are the three factors that influence blood viscosity?

A

hematocrit, temperature, flow rate

304
Q

What change in the following would cause blood viscosity to increase?
A) hematocrit
B) temperature
C) flow rate

A

A) increase in hematocrit, B) decrease in temperature, C) flow rate decrease (non-newtonian flow)

305
Q

Blood behaves as a non-newtonian fluid which means that its viscosity changes as a function of _________

A

shear rate (velocity)

306
Q

TRUE/FALSE: When blood moves quickly as in peak systole, it is thicker whereas when blood moves slowly during end-disastole, it is thinner.

A

FALSE - faster=thinner. RBC’s are sticky and aggregate at slower speeds.

307
Q

What is polycythemia vera and how does it affect blood viscosity?

A

Polycythemia vera is a condition where there is increased RBC production from the bone marrow. This would increase blood viscosity (increased hematocrit).

308
Q

How does whole body hypothermia during surgery affect blood viscosity?

A

It increases blood viscosity and increases resistance to flow due to decrease in temperature

309
Q

How is blood viscosity affected during circulatory shock?

A

There is very low flow in the microcirculation causing increased cell to cell and protein to celll adhesive interactions –> increased viscosity

310
Q

When laminar flow occurs, where is velocity of flow greatest?

A

Greatest in center of the vessel than toward the outer edges. FLOWS IN LAYERS, FASTER IN CENTER.

311
Q

True or false: Flow is always proportional to driving P.

A

FALSE - only under laminar flow conditions

312
Q

Where is velocity of flow lowest in laminar/streamline flow?

A

At vessel wall

313
Q

__________ occurs when red blood cells move toward the center of the blood vessel in response to increased flow rate. This lowers apparent viscosity of blood.

A

Axial streaming

314
Q

In _______ flow the blood flows in all directions in the vessel. Where are the fastest velocities found?

A

turbulent flow, fastest velocities not necessarily in the middle of the stream

315
Q

True/False: Once a critical velocity is reached, turbulent flow results and then flow does not increase proportionally with rises in pressure

A

True

316
Q

How is the critical velocity leading to turbulent flow defined?

A

Via Reynolds number (Ng). Ng = Vdp/n [ mean velocity * tube diameter * fluid density ] / fluid viscosity

317
Q

What are the major factors that increase Reynold’s number (and therefore turbulence)

A

Decreased blood viscosity; increased blood velocity

318
Q

How does lymphatic circulation differ from cardiovascular circulation?

A

lymphatic circulation is open, there is no pump and there is excess extracellular fluid and debris

319
Q

__________ plays a role in blood pressure control and coagulation of blood

A

endothelium

320
Q

How do endothelial cells affect blood pressure?

A

release angiotensin converting enzyme

321
Q

How are the lymphatic and cardiovascular systems similar?

A

There is progressive branching to transport

322
Q

What are the the main functions of the lymphatic system?

A

transport and homeostasis

323
Q

Veins drain ___________ and transport to the heart

A

capillaries and capillary beds

324
Q

What are the three layers of blood vessels?

A

tunica intima, tunica media, tunica adventitia

325
Q

The __________ is the innermost layer of the blood vessel that contains the lumen

A

tunica intima

326
Q

What is the tunica intima composed of?

A

simple squamous epithelium

327
Q

What is secreted by the tunica intima?

A

collagen and laminin for ECM, NO for vasodilation, enzymes such as angiotensin converting enzyme (ACE)

328
Q

True/False: The tunica intima is very metabolically active and plays a major role in homeostasis

A

True

329
Q

What enters via the tunica intima?

A

water, electrolytes, O2, CO2

330
Q

The ________ of the tunica intima is a cellular interface between epithelium and connective tissue made of glycoproteins and collagen

A

basal lamina

331
Q

The __________ of the tunica intima is loose CT scattered with smooth muscle cells

A

subendothelial connective tissue

332
Q

The _________ is a fenestrated sheet of elastin that allows diffusion of nutrients from endothelium to pass through and form gap junctions with smooth muscle cells in tunica media

A

internal elastic lamina

333
Q

What is the main component of the tunica media?

A

Smooth muscle - allows for constriction or dilation

334
Q

In the tunica media, the composition of elastin and collagen varies based on what?

A

function of the artery

335
Q

In what vessels is the tunica media NOT found?

A

Not found in capillaries or post capillary venules

336
Q

Describe structures/cells found on smaller and larger vessels in regards to the tunica media.

A

Smaller vessels have cells called pericytes; larger vessels have external elastic lamina

337
Q

Where do smooth muscle cells start in the tunica media?

A

Start at the internal elastic lamina

338
Q

The outermost layer of blood vessels is called ___________ and contains fibroblasts, collagen, elastic fibers that blend into the surrounding connective tissue

A

tunica adventitia

339
Q

What two structures are contained on the tunica adventitia (important for blood flow)

A

vasa vasorum (the vessels of the vessels) and nerves (send signals to vessel to constrict or relax)

340
Q

True/False: Nerves penetrate through all layers of the blood vessel

A

FALSE, only on outside, gap junctions relay info

341
Q

When nerves in the tunica adventitia are stimulated what do they release? Describe the action

A

Noreepinephrine, diffuses through external elastic lamina and causes depolarization and contraction of outermost smooth muscle cells. Gap junctions propagate through layers of the tunica media.

342
Q

When stimulated by sympathetic discharge, most blood vessels constrict. What are the exceptions?

A

skeletal muscle arteries dilate

343
Q

True/False: In all elastic and muscular arteries, the vaso vasorum supplies with nutrients and O2 via diffusion

A

FALSE, only in small vessels, in larger vessels there are capillary beds to the tunica media

344
Q

What are the three types of arteries?

A

muscular, elastic, arterioles

345
Q

______ arteries are the biggest blood vessels and are involved in conduction of the blood from the heart.

A

Elastic arteries

346
Q

The tunica media of the elastic arteries contain ______ fenestrated layers of elastin and allow vessels to stretch and _____ when alternating with smooth muscle cells which accommodates and propels the large bolus of blood from left ventricle

A

40-70, recoil

347
Q

In the elastic arteries, what allows for movement and distention?

A

loose fibroelastic tissue in adventitia

348
Q

Name some elastic arteries

A

pulmonary trunk, aorta, common carotid, subclavian, common iliacs

349
Q

The ________ arteries are the distributing arteries and most named arteries. They include a prominent elastic lamina and external elastic lamina.

A

muscular

350
Q

In muscular arteries, there are ______ layers that are connected via _____ to allow for propagation of nerve signals

A

4-40, gap junctions

351
Q

What feature of muscular arteries allows neurotransmitters to pass?

A

clear external elastic lamina

352
Q

The ______ are the terminal arteries where internal elastic lamina is poorly defined. There is no need for vasa vasorum in these vessels.

A

Arterioles

353
Q

True/false: In arterioles, the tunica adventitia can be easily differentiated from connective tissue

A

FALSE - other layers can be differentiated though

354
Q

What are the main differences between arteries and veins?

A

Veins are larger, arteries have a thicker tunica media, arteries maintain their round shape in sections and usually won’t contain blood cells

355
Q

______ are thin walled vessels with a single endothelial layer on a basal lamina

A

capillaries

356
Q

True/False: Capillaries do not contain a tunica media or adventitia

A

TRUE

357
Q

True/False Capillaries are involved in temperature control

A

TRUE

358
Q

How do smooth muscle cells appear on slides?

A

will appear spindle shaped but on cross section will appear round

359
Q

What are the three types of capillaries?

A

continuous, fenestrated, sinusoidal

360
Q

In continuous capillaries, endothelial cells are connected via _______. These capillaries participate in ________ of amino acids and glucose

A

tight junctions, carrier-mediated transport

361
Q

Where are continuous capillaries found?

A

nervous, muscle and connective tissue. modified in brain to limit passage of molecules.

362
Q

In fenestrated capillaries, there are thin openings called ______ that cover pores in endothelial cell walls. These allow more leak.

A

diaphragm

363
Q

Where are fenestrated capillaries found?

A

pancreas, intestines, and endocrine glands. Found in glomeruli of kidney but with no diaphragms.

364
Q

In sinusoidal capillaries there is a _______ endothelial wall and basal lamina which allows several blood cells to go through at once. They also have _____ that conform to structure in which they are located.

A

discontinuous; irregular channels

365
Q

Where are sinusoidal capillaries found?

A

spleen, liver, bone marrow, lymphoid organs

366
Q

True/False: Veins are more numerous than arteries, larger than corresponding arteries and contain 70% more blood volume

A

TRUE

367
Q

True/false: Venule walls are more permeable than capillary walls

A

True

368
Q

True/false: Veins have less vasa vasorum than arteries

A

FALSE - have more bc blood in circulation has less O2

369
Q

What is the preferred site for white blood cell migration?

A

venules (lots in lymph nodes)

370
Q

True/false: In large veins, the tunica adventitia is more developed that that of tunica media

A

True - tunica media is much less prominent in veins

371
Q

True/false: Valves are found in all veins

A

FALSE -found in large and medium veins

372
Q

True/false: Smooth muscle is found in all veins

A

FALSE - only those above >1mm

373
Q

The ________ is made up of endothelial cells overlying connective tissue and fibroblasts and smoooth muscle cells in the heart

A

endocardium

374
Q

The endothelium in the endocardium is continuous with the tunica intima of _______

A

great vessels

375
Q

The subendocardial layer of loose connective tissue in the endocardium contains what three things?

A

nerves, blood vessels, purkinje fibers

376
Q

The ______ contains heart muscle that is specialized for conduction. It is also important for endocrine functions, structure, and contraction

A

myocardium

377
Q

Specialized cardiac muscle cells called ______ travel superficially in the myocardium

A

purkinje fibers

378
Q

Describe the pathway of electrical impulse through the heart

A

SA node –> AV node –> Bundle of His –> Right and Left bundle branches –> Purkinje Fibers

379
Q

What hormone actions are secreted from the myocardium?

A

Hormones that control BP, fluid and electrolytes

380
Q

Myocardial cells are attached to the _________

A

fibrous skeleton

381
Q

The ________ is also the visceral layer of the pericardium. It is the innermost layer of the pericardium and the outer surface of the heard.

A

Epicardium

382
Q

_______ is the passage of blood cells through intact walls of capillaries, typically accompanies inflammation

A

diapedesis

383
Q

What are the two main jobs of the lymphatic system?

A

transport fluid away from tissues and to serve an immune function

384
Q

Describe the flow through the lymph system?

A

Lymphatic capillaries –> lymphatic vessels that drain regionally –> lymph nodes where it is filtered –> lymphatic ducts

385
Q

Describe the differences in the lymph system in comparison to the CV system.

A

There is a thin walled endothelial layer but there are overlapping endothelial cells without tight junctions. Discontinuous basal lamina. Numerous valves in vessels. Lumens are larger than veins. Only largest vessels have smooth muscle cells. Ill-defined boundaries between three layers. Vessels similar to vasa vasorum.

386
Q

The subendocardial connective tissue in heart is analogus to _____

A

tunica intima

387
Q

________ are places where veins and arteries come together and allow in certain circumstances bypass of the capillary bed

A

arterial-venous anastomoses

388
Q

What is Bernaud’s sign? What are the causes?

A

Bernaud’s sign is when digits turn white in cold weather. Can be related to autoimmune disorders and sometimes idopathic. Typically no ischemia.

389
Q

What is the difference between cardiac and skeletal muscle?

A

Cardiac muscle has branching fibers, central nuclei and intercalated discs. Do not perfectly line up.

390
Q

During lymph node circulation, afferent lymphatic vessels pierce the lymph node and open into the _______ and penetrate the cortex.

A

subcapsular sinus

391
Q

After the lymph node cortex has been penetrated, _________ continue into the medulla as branching medullary sinuses surrounded by medullary cords

A

Paratrabecular sinuses

392
Q

In the medulla, subcortical sinuses are confluent with medullary sinuses and penetrate the capsule to join the ___________

A

efferent lymphatic vessel

393
Q

Where are B and T cells located in the lymph nodes?

A

B cells are contained in the lymphatic nodules (have a germinal center) and T cells are in the deep or inner cortex

394
Q

What cells do the medullary cords contain?

A

macrophages and plasma cells

395
Q

True/False: If sentinel nodes are negative for disease, likely that other nodes are negative as well

A

True

B2 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions