Exam 2 Flashcards
(309 cards)
1
Q
Which of the following lipoproteins is responsible for delivering cholesterol to tissues?
A. Chylomicrons
B. VLDLs
C. LDLs
D. HDLs
A
C.LDLs
2
Q
In addition to there being an optimal total cholesterol count, the goal is often to achieve the lowest possible _______ count and the highest possible _______ count
A. LDL///HDL
B. HDL///LDL
C. HDL///triglyceride
D. Triglyceride///LDL
A
A. LDL///HDL
3
Q
Lipoproteins that contain the greatest proportion of ______ tend to be greatest in density.
A.Triglycerides
B.Phospholipids
C.Protein
D.Cholesterol
A
C.Protein
4
Q
Cells of which organ are responsible for taking up the greatest amount of LDLs from circulation via the receptor-dependent mechanism/pathway.
A.Adipose tissue
B.Adrenal cortex
C.Liver
D.Ovaries/testes
A
C.Liver
5
Q
Which of the following lipoproteins is responsible for delivering triglycerides to tissues?
A.Chylomicrons
B.VLDLs
C.LDLs
D.HDLs
A
A.Chylomicrons
6
Q
During exercise which of the following factors contributes to the increase in perfusion of active muscle?
A. Local decrease in CO2 production by active muscle
B. Local decrease in O2 consumption by active muscle
C. Increased arteriolar resistance to flow (locally supplying muscle)
D. Relaxation of precapillary sphincters (locally supplying muscle)
E. All of the above
A
D. Relaxation of precapillary sphincters (locally supplying muscle)
7
Q
Imagine that you are treating a burn patient and his blood work shows a decreased serum albumin level. The inflammation and exposed burn wounds have led to an excessive loss of albumin. You also notice that he is suffering from generalized pitting edema. Which of the following statements best explains the edema based on the above information regarding this patient?
A. Increased capillary blood pressure increases bulk flow out of capillaries and into interstitial space
B. Decreased capillary blood pressure increases bulk flow out of capillaries and into interstitial space
C. Increased interstitial hydrostatic pressure increases bulk flow out of capillaries and into interstitial space
D. Decreased plasma osmotic (colloid oncotic) pressure increases bulk flow out of capillaries and into interstitial space
E. Increased plasma osmotic (colloid oncotic) pressure increases bulk flow out of capillaries and into interstitial space
A
D. Decreased plasma osmotic (colloid oncotic) pressure increases bulk flow out of capillaries and into interstitial space
8
Q
Why is the baroreflex considered only a short term strategy for regulating Mean Arterial Blood Pressure?
A.Because drops in blood pressure sensed by the aortic and carotid baroreceptors cannot lead to an increase in Angiotensin II which is necessary to increase plasma volume
B.Because the aortic and carotid baroreceptors adapt to sustained changes in blood pressure
C.Because renal baroreceptors are more efficient at adjusting heart rate in response to sustained changes in blood pressure.
D.All of the above
A
B. Because the aortic and carotid baroreceptors adapt to sustained changes in blood pressure
9
Q
Endothelial-derived relaxing factor (EDRF) is
A.Adenosine
B.Nitric Acid
C.Norepinephrine
D.Endothelin
A
B.Nitric Acid
10
Q
The direction of the action potential movement through the conduction system of the heart for each cardiac cycle is normally
A.SA node—bundle of His—Purkinje fibers—AV node
B.SA node—AV node—bundle of His—Purkinje fibers
C.AV node—SA node—bundle of His—Purkinje fibers
D.AV node—bundle of His—SA node—Purkinje fibers
E.Bundle of His—AV node—Purkinje fibers—SA node
A
B.SA node—AV node—bundle of His—Purkinje fibers
11
Q
Which of the following would cause an increase in Mean Arterial Pressure (either directly or indirectly)?
A.Increased ventricular filling B.Increased venous return C.Increased heart rate D.Increased arteriolar vasoconstriction E.All of the above
A
E.All of the above
12
Q
Which of the following is not a factor that either enhances or contributes to maintaining venous return of blood to the heart?
A.High compliance of the venous system
B.Skeletal muscle contraction
C.cardiac suction
D.Venous valves
A
A.High compliance of the venous system
13
Q
Which two pressures promote the bulk flow movement of fluid into the capillary?
A.Plasma oncotic pressure and interstitial-fluid oncotic pressure
B.Capillary blood pressure and interstitial-fluid oncotic pressure
C.Interstitial-fluid hydrostatic pressure and interstitial-fluid oncotic pressure
D.Interstitial-fluid hydrostatic pressure and capillary blood pressure
E.Interstitial-fluid hydrostatic pressure and plasma oncotic pressure
A
E.Interstitial-fluid hydrostatic pressure and plasma oncotic pressure
14
Q
Which of the following conditions can cause vasodilation of systemic arterioles?
A. High O2 concentrations B. High pH C. Low CO2 concentrations D. High CO2 concentrations E. All of the above
A
D.High CO2 concentrations
15
Q
There are many factors that can damage the endothelial lining of blood vessels throughout the body including smoking, dislipidemia, uncontrolled diabetes, and hypertension. Patients with endothelial damage (and dysfunction) to the coronary arteries that perfuse the heart are at higher risk for cardiac ischemia (i.e. O2 deprivation). Why?
A. Because there is impaired endothelial sensitivity to local concentrations of O2, CO2, pH, and adenosine
B. Because there is impaired endothelial release of Nitric Oxide
C. Because local tissue perfusion is not being matched to metabolic need
D. All of the above
A
D.All of the above
16
Q
TM is a 56 year old male who presents to your office for the first time. He tells you that his previous provider diagnosed him with aortic stenosis a few years ago. When you auscultate his chest, you hear a murmur during:
A. Diastole
B. Systole
C. In between S1 and S2
D. B & C
A
D. B & C
17
Q
Mrs. M presents to your clinic symptomatic for left-sided heart failure (means the left ventricle is having trouble pumping blood). What symptoms might Mrs. M present with?
A. Edema in the lower extremities
B. SOB
C. Unsteady gait
D. None of the above
A
B. SOB
18
Q
Which one of the following statements about stress is FALSE?
A. Exposure to intermittent stress is beneficial for overall health
B. Stress can come in many forms including the physiological and psychosocial
C. Exposure to intermittent stress is harmful for overall health
D. Adaptation to one form of stress can increase one’s capacity to tolerate other forms of stress.
A
C. Exposure to intermittent stress is harmful for overall health
19
Q
In which of the following stages of the General Adaptation Syndrome does the degree of activation of the stress response decline despite the presence of the stressful stimulus?
A.Alarm
B.Resistance
C.Exhaustion
D.None of the above
A
B.Resistance
20
Q
Activation of the amygdala suggests:
A.an intensely pleasurable experience
B.a mildly pleasurable experience
C.an intensely frightening experience
D.a mildly uncomfortable experience
A
C.an intensely frightening experience
21
Q
In what part of the brain are real or perceived stressors interpreted/evaluated?
A.Prefrontal cortex
B.olfactory bulb
C.hippocampus
D.hypothalamus
A
A.Prefrontal cortex
22
Q
Which structure within the limbic system of the brain represents the “link” between your “thinking and feeling brain” and stimulation of the sympathetic nervous system and the adrenal cortex?
A.Prefrontal cortex
B.olfactory bulb
C.hippocampus
D.hypothalamus
A
D.hypothalamus
23
Q
Parasympathetic postganglionic fibers
A. Are on average much longer in length than sympathetic postganglionic fibers
B. Arise from the ganglion chain located along either side of the spinal cord
C. Branch out from the celiac or hypogastric gangliaAre on average much longer in length than sympathetic postganglionic fibers
D. Are cholinergic
E. Secrete norepinephrineAre on average much longer in length than sympathetic postganglionic fibers
A
D. Are cholinergic
24
Q
Nicotinic Acetylcholine receptors
A. Respond to acetylcholine released from both sympathetic and parasympathetic preganglionic fibers
B. Are found primarily in the heart
C. Bind with norepiniphrine released from sympathetic preganglionic receptors
D. Bind with acetylcholine released from parasympathetic postganglionic fibers.
A
A. Respond to acetylcholine released from both sympathetic and parasympathetic preganglionic fibers
25
Disruption of which one of the following cranial nerves will most effect parasympathetic control over visceral function?
A.IX
B.VII
C.X
D.II
C.X
26
Epinephrine is a ____________ hormone released from the ___________.
A.Parasympathetic, adrenal medulla
B.Sympathetic, adrenal cortex
C.Sympathetic, adrenal medulla
D.Parasympathetic, adrenal cortex
C.Sympathetic, adrenal medulla
27
Which of the following synapses involves muscarinic Acetylcholine receptors?
A.Synapses in the sympathetic chain ganglion
B.The synapse between the axon terminals of the vagus nerve and the heart
C.Synapses in the hypogastric plexus
D.The synapses between parasympathetic preganglionic neurons and postganglionic neurons
B. The synapse between the axon terminals of the vagus nerve and the heart
28
What is a lipoprotein?
Lipoproteins are special fat-carrying proteins
29
What are the 5 types of lipoproteins and how are they classified?
1) Chylomicrons
2) Very-low density lipoproteins (VLDL)
3) Intermediate-density lipoproteins (IDL)
4) Low-density lipoproteins (LDL)
5) High-density lipoproteins (HDL)
classified by density
30
What is an LDL? What purpose does it serve?
LDL is a type of lipoprotein that is 50% cholesterol. Their purpose is to circulate in your bloodstream and deliver cholesterol to your cells/tissues.
31
Why are LDLs considered the “bad” cholesterol?
LDLs are “bad” because they represent an excess of cholesterol in the system (too much, like levels over 200, can cause plaque formation, occlusion, etc.)
32
What are the 3 possible routes of elimination for LDLs in circulation?
- receptor-mediated uptake
- reverse cholesterol transport
- scavenger pathway
33
What is the receptor-mediated uptake route of elimination for LDLs in circulation?
primary pathway used by the liver (also used by the adrenal cortex, testes, and ovaries)
- in this method, receptors on tissue membranes uptake cholesterol in order to synthesize hormones etc.
34
What is the reverse cholesterol transport route of elimination for LDLs in circulation?
this is considered the “good” pathway - HDLs bind to the LDLs that are in circulation and get them returned to the liver
35
What is the scavenger pathway route of elimination for LDLs in circulation?
- this way is damaging to the body
LDLs interact with reactive oxygen species in circulation and become “oxidized” and very reactive, so they damage the lining of blood vessels
—> this leads to inflammatory response (release of cytokines, monocytes become macrohpages) and LDLs get consumed/removed by the macrophages in circulation
36
What is the LDL receptor? What role does it play in influencing circulating LDL levels?
The LDL receptor is usually located on organ tissue and allows the circulating LDL to bind and be internalized by that tissue and for the tissue to utilize the cholesterol carried by the LDL molecule
The majority of LDL receptors (75%) are found on the liver—the liver primarily uses cholesterol to produce bile salts
37
What is HDL? Where does it come from? What role does it play in regulating circulating lipid levels?
HDL is part of our reverse cholesterol transport pathway (the “Good pathway”) - it’s the molecule that brings LDLs back to the liver
38
What are the possible causes for “primary hypercholesterolemia”?
Potential cause: often genetic, such as defective synthesis of apoproteins, lack of LDL receptors, defective LDL receptors, defective HLD enzymes
39
“Cheerios” claims to reduce cholesterol levels if eaten daily for at least a few weeks. By what mechanism is this accomplished?
Cheerios have Oat bran which is a water soluble fiber
increasing water soluble fiber in your diet forms gooey substance in your intestines which will bind to bile salts and cause the bile salts to be excreted
when the bile salts are excreted, the liver makes more bile salts by taking up more LDLs from circulation, thereby reducing cholesterol levels (preventing the recycling of bile salts from your GI tract)
40
How do Statins work?
by blocking the HMG CoA reductase inhibitors
41
What is HMG CoA reductase?
the enzyme thats used by the liver to synthesize cholesterol
42
By what mechanism do the “Statin” class drugs lower cholesterol?
Statins work by blocking the HMG CoA reductase inhibitors so that the liver can't synthesize cholesterol
43
What is the myelin sheath in the PNS made up of?
Schwann cells
44
What is the myelin sheath in the CNS made up of?
Oligiodendrocyte
45
What purpose does the myelin sheath serve?
Insulates the axon, which (1) ensures that the action potential goes from A to B and (2) increases the speed of the transmission
46
Review the 5 events involved in the synaptic transmission at the Neuromuscular junction.
1. Action potential arrives at the junction
2. Influx of Calcium into the cell
3. Excitatory: Sodium channels open
4. Inhibitory: Potassium floats out which causes it to hyperpolarize
5. Neurotransmitters are either eaten up or diffused away
47
What is a “cranial nerve”?
Cranial nerve = nerves coming out of the cranium, 12 pairs (know all of them - some are motor and sensory, some are just sensory, some are just motor)
48
What is the most important cranial nerve
10 Vagus nerve (major part of the PSNS), send and receive signals from structures in the face/neck (except for Vagus)
49
What is a “spinal nerve”?
Spinal nerve = 31 pairs, both sensory and motor with one exception (C1 which is JUST MOTOR)
50
What nerve fibers come through the dorsal route and how?
sensory nerve fibers coming in (afferent)
51
What nerve fibers come through the ventral route and how?
motor fibers coming out (efferent)
52
What neurotransmitter is used in all of the synapses in the Celiac Ganglion?
Acetylcholine (binds to nicotinic)
53
Where are you likely to find muscarinic acetylcholine receptors?
PSNS - at the second synapse - will be located on target cells/organs
54
Stress is defined as
a state of tension that can lead to disruption or that threatens homeostasis
55
What are the 3 components of the General Adaptation Syndrome that was developed by Hans Selye?
- alarm reaction
- a stage of resistance
- stage of exhaustion
56
What is the function of the frontal lobe?
“limbic cortex” (prefrontal cortex)
judgement, insight, motivation, mood,
emotional reactions
57
What is the function of the Hippocampus?
declarative memory – short Term memory
58
What is the function of the Amygdala?
critical to coordinated responses to
Stress (especially with emotional content).
Integrates behavioral reactions involving
Survival.
Conditioned emotional responses,
Stimulation of amygdala can produce a rage
Reaction.
59
What is the function of the Hypothalamus?
- primary output for limbic System
- connected to anterior pituitary hormone
- Output and sympathetic NS
- regulates Body temperature, appeptite, and sexual Responses
60
2 of the most important healthy stressors:
- demanding mental activity (i.e. learning - “uncomfortable”)
- demanding physical activity
61
stress is a problem if it is ___ or ____
it is acute and overwhelming OR persistent and unrelenting
62
Alarm reaction:
a stress response is mobilized as a result of exposure to stress
63
Stage of resistance:
upon repeated exposure to the stressor, your body adapts and you become resistant to that stressor
64
third stage (exhaustion) is when stress becomes
maladaptive - stress response comes back, and all of a sudden the stress response creates a worsening
65
negative physiological stress example=
cold
66
all forms of stress are
triggered the same way and get processed the same way
67
limbic system:
collection of structures that are highly interconnected and are the “emotional brain” - feeling and reacting
68
prefrontal cortex:
“thinking” part of the brain - it makes important observations that are then sent to the limbic system to be evaluated for emotional content (ex. judgments, insight, motivation, mood, emotional reactions)
69
if you take an animal and specifically stimulate the amygdala, you’ll see a ___ response
rage
70
when triggered by the thinking/feeling/reacting part of your brain, the hypothalamus ___
stimulates the stress response/output
| the olfactory bulb (smell)
71
stress is a ___ response
SNS
global, rapid response:
- increase in HR
- bronchodilation (taking in more oxygen)
- increased perfusion to skeletal muscles
- liver enervation which increases glycogen breakdown and blood glucose levels
72
the long-lived stress response is when the adrenal medulla releases
epinephrine (adrenaline)
73
what are the 6 main effects of raised cortisol levels during the stress response
1. vasoconstriction, BP rises
2. liver - increases blood glucose
3. causes kidneys to retain calcium (for muscle contraction)
4. sodium retention (for muscle contraction)
5. increased excitability of the brain (mental acuity)
6. suppression of immune function (supposedly temporary) in order to mobilize energy elsewhere
74
in the alarm phase, our ability to resist stress is at
a low point
75
Hyperlipidemia is a major risk factor for the development of
atherosclerosis
76
Three types of lipids found in the body:
Triglycerides
Phospholipids
Cholesterol
77
Because triglycerides and cholesterol are insoluble in plasma they are
encapsulated by
special fat-carrying proteins called lipoproteins
78
What gives a lipoprotein a greater density is
protein content
79
The more protein in a lipoprotein, the higher in
density
80
Chylomicrons are mostly
triglycerides
81
LDLs are mostly
cholesterol
82
HDLs are mostly
protein
83
LDLs are lipoproteins that deliver ___ to tissue
cholesterol
84
Chylomicrons are lipoproteins that deliver ___ to tissue
triglycerides
85
HDLs do NOT deliver lipids to cells, instead their primary function is to
regulate the amount of LDLs in circulation
86
What do the apoproteins on the shell of the lipoprotein do?
act as identifying markers for the lipoproteins and determine their metabolic fate
87
Note that at the phospholipid layer at the shell of the lipoprotein, there's a hydrophobic/water-soluble head and fat soluble tails. Which way do each face?
Heads face the plasma
Tails face the inside of the cell
88
cholesterol and triglycerides are consumed in ___ and absorbed by the ___
food
intestines
89
when chylomicrons get into circulation, they will go to what 3 places?
1. adipose tissue in skeletal muscle
2. to the liver, which will produce HDLs and VLDLs
3. while in circulation, some chylomicrons along with VLDLs from the liver will convert to IDLs and LDLs
90
cholesterol is part of the ____ for all cells in our body
plasma membrane
91
What organ is the biggest consumer of LDLs, and why?
liver is the biggest consumer of LDLs (70%) and uses the cholesterol in the LDLs to produce bile
92
all of the ___ glands need cholesterol
endocrine glands that produce steroid hormones (testes, adrenal cortex, ovaries)
93
most common pharmacological intervention to reduce cholesterol is the use of
statins
94
Hyperlipidemia or dyslipidemia is
the presence of elevated levels of certain
| lipoproteins in the blood stream (namely LDLs )
95
Primary hypercholesterolemia
elevated levels of cholesterol (namely LDLs)
that develops independent of other health problems or lifestyle behaviors.
Ex. often genetic – defective synthesis of apoproteins, lack of LDL receptors, defective receptors, etc
96
total cholesterol =
HDLs and LDLs
97
Secondary hypercholesterolemia is associated with
lifestyle and behavior
Ex. obesity, high-caloric intake, diabetes mellitus ETC
98
muscosal/epithelial cells that line the intestines take dietary cholesterol and triglycerides and form
chylomicrons -- so they can be absorbed/enter the bloodstream
99
Three Types of Hormones
- Peptide and Protein hormones (water soluble)
- Amino Acid Derived hormones (water soluble)
- Steroids Hormones (fat soluble)
100
Hormone (particular) Binding Proteins are used in hormones like
Thyroid hormones
Steroid hormones
IGFs
GH
101
3 purposes of hormone binding proteins:
(1) Allows for transport of lipid soluble hormones
(2) Provides blood with a reservoir of hormone, minimizing minute-to-minute fluctuations in hormone concentration
(3) Extends the half-life of the hormone in circulation
102
Hormones that bind to plasma proteins tend to be ones whose actions are more
long-term
like those involved in inducing the synthesis of new proteins in target tissues
103
Of the three classes of hormones, which is entirely fat-soluble?
Steroids
104
2 specific forms of the same hormone that is not a steroid hormone but is also fat soluble?
Thyroid (T3 and T4)
105
Thyroid hormone controls
basal metabolic rate
106
Net hormone effect is proportional to
the plasma concentration of that hormone
107
Free, biologically active hormone means that
has to be able to bind to its receptor, and be biologically active to have its desired physiological effect
108
Some hormones are releases in ___, others in ___
pulses
diurnal (24 hour cycle)
109
Steady state of hormone levels is determined by what 3 rates?
rate of secretion
rate of binding/unbinding
rate of removal from the blood
110
what time of day is cortisol peak?
just upon or before waking in the morning - part of what helps to transition you from sleep to wakefulness
111
What is the SCN and where in the brain is it located?
part of the brain that is spontaneously active around the 24 hour cycle
right above where your optic nerves cross (optic chiasm)
112
What are 2 hormones released in pulses?
GNRH/LH
Oxytocin
113
Central endocrine glands are part of the
CNS
114
How is the hypothalamus connected to the pituitary gland?
the connecting stalk
115
What is the hypothalamus composed of?
neuronal cells (many are neurosecretory cells)
116
What are the 2 parts of the pituitary gland?
anterior lobe and posterior lobe
117
2 hormones that the hypothalamus releases from the posterior pituitary
1. vasopressin (ADH - antidiuretic hormone)
note this is a vasoconstrictor
2. oxytocin
important role in labor, breastfeeding
social bonding, parental bonding
118
Hormone 3 is what acts on the
target tissue
119
How is the control of hormonal secretion a negative feedback loop?
because hormone 3 (and 2) provides negative feedback to the glands above it to ultimately control the levels of hormone 3
120
if TRH is high and TSH is high, but T3 and T4 is low, the problem is at the
thyroid gland
121
most important hormone signal is the
third hormone signal (will have the most influence over what the proceeding hormones do)
122
high TSH SHOULD produce high
t3 and t4
123
Adrenal medulla:
part of (and controlled by) the sympathetic nervous system, releases epinephrine and a little bit of norepinephrine
124
Adrenal cortex:
endocrine gland that produces steroid hormones
125
all steroid hormones are synthesized from
cholesterol
126
3 categories/layers of steroid hormones that the adrenal complex produces
1. glucocorticoids
2. mineralcorticoids
3. sex hormones
127
glucocorticoids are similar in structure to
mineralocorticoids
128
what are glucocorticoids
stress hormones that elevate blood glucose
129
corticosterum, cortisol, cortisone are all
glucocorticoids
130
what are mineralcorticoids?
this causes sodium retention and potassium loss
aldosterone (only one)
131
what are some examples of sex hormones?
progesterone
different forms of estrogen
masculinizing hormones (testosterone, DHEA)
132
What are the 4 steps of cortisol production?
1. Hypothalamus releases CRH
2. CRH acts on anterior pituitary for it to release ACTH
3. ACTH acts on adrenal cortex to increase production of cortisol
4. Cortisol provides negative feedback at the level of the hypothalamus and anterior pituitary again
133
baseline cortisol is produced in a
diurnal pattern
peak level: just before waking
lowest: right before bed
134
cortisol-related reactions are meant to be
SHORT LIVED
135
Gap Junctions are
very large ion channels that connect to separate excitable cells
136
When are Gap Junctions critical?
with action potential moving through the HEART
become important when we want cells firing actions together, or when we want to have coordination between cells
137
what are the 2 main Catecholamines?
epinephrine, norepinephrine
138
What are Neuroactive peptides?
neuromodulators, will change the relationship between the post-synaptic cell and the neurotransmitter
139
the vast MAJORITY of SYNAPSES are ___ in nature
chemical
| electrical synapses are faster than chemical
140
Hypothalamus is both a ___ and ___ structure
neuronal AND endocrine structure
141
cerebellum regulates
motor movements, extremely important in LEARNED motor movements (example of writing your signature over and over the same way without thinking about it)
142
Where do cranial nerves sit?
at base of brain, where neuronal axons come out
143
What are the entirely sensory cranial nerves?
I – olfactory (smell),
II optic; vision,
VIII (vestibulocochlear – hearing)
144
What are the Purely motor cranial nerves?
```
III oculomotor
IV trochlear
VI abducens ocular movements,
XI accessory
XII hypoglossal – move tongue left and right
```
145
mixed function cranial nerves
V- trigeminal touch different sections of face and see if you can feel, jaw muscles for chewing are working properly
VII – facial = facial expressions, taste
IX – glossopharyngeal nerve (posterior for sensory function) muscles of tongue
X – Vagus nerve – PSNS
146
Where are the preganglionic cell bodies in the SNS located?
Lateral horn of spinal cord (T1-T3)
147
Where are the preganglionic cell bodies in the PSNS located?
midbrain, medulla (arising out of CN 3, 7, 9, 10) and lateral horn of the spinal cord
148
What is (are) the primary difference (s) between a hormone and a neurotransmitter?
Hormone: longer duration, slower, distance effects, travel longer distances, released by endocrine gland – transported to target organ Via blood stream
Neurotransmitter: released in synaptic cleft – short distance and affects adjacent cell and acts very quickly
149
Of the three main categories of hormones (peptide, amino acid-derived, and steroid) which are water-soluble and which are lipid-soluble?
Peptide and amino acid derived = WATER
Steroid and thyroid – LIPID
150
What are hormone-binding proteins and what purposes do they serve?
Albumin bus = generic
allows for transport of lipid soluble hormones
Provides blood with a reservoir of hormones minimizing minute to minute fluctuations in concentration
Extends the ½ life of the hormone in circulation (increases length in bloodstream)
151
Where are Oxytocin and Vasopressin synthesized? From where are they released?
synthesized in SCN
released from POSTERIOR pituitary
152
What are the primary physiological effects of thyroid hormone?
controls metabolism
Up-regulation of Na K pumps is going to increase metabolic function of cell or tissue type and cause us to burn more energy
Increases gene expression
Up-regulates production of proteins that increase metabolism
153
What are the two major zones of the adrenal glands? How do they differ?
Adrenal cortex – secrete corticosteroids
Adrenal medulla – SNS – epinephrine and norepinephrine
154
What is the only layer of the adrenal cortex that can produce aldosterone?
zona glomerulosa
155
What is the difference between mineral-corticoids and gluco-corticoids? Where are they respectively synthesized?
Mineralocorticoids = glomerulosa
Na+ retention and K+ excretion
Ex. Aldosterone
Glucocorticoids = all three layers of adrenal cortex
they Elevate blood glucose, amino acids, and fatty acids
Maintaining levels of energy in blood stream
156
Describe the primary physiological effects of cortisol
Priority is to mobilize energy:
1. Increase blood glucose
(Increase glycogenolysis, increase glyconeogenesis, decrease glucose)
2. Increase blood amino acids (Protein degradation)
3. Increase blood fatty acids (Lipolysis)
157
What is the location of the postganglionic cell bodies in the SNS?
paravertebral ganglia: sympathetic chain ganglia
OR
prevertebral ganglia: celiac ganglia, hypogastric plexus
158
What is the location of the postganglionic cell bodies in the PSNS?
scattered plexi close to or on the target organ
ex: cardiac plexus on aortic arch
159
Length of preganglionic fibers: SNS vs PSNS
SNS: short
PSNS: long
160
Length of postganglionic fibers: SNS vs PSNS
SNS: long
PSNS: short
161
What happens in the first synapse in the SNS?
acetylcholine binds to nicotinic ACH receptors
162
What happens in the first synapse in the PSNS?
acetylcholine binds to nicotinic ACH receptors
163
What happens in the second synapse in the SNS?
norepinephrine binds to alpha 1, beta 1 or beta 2 receptors on target cell
164
What happens in the second synapse in the PSNS?
acetylcholine binds to muscarinic ACH receptors on target cell
165
What happens in the endocrine arm of the SNS?
adrenal medulla releases epinephrine which binds to beta receptors
166
What happens in the endocrine arm of the PSNS?
GI hormones regulate digestive function
167
Pulmonary veins and systemic arteries carry what kind of blood?
oxygen rich
168
Pulmonary arteries and systemic veins carry what kind of blood?
oxygen poor
169
There are two types of specialized cardiac cells related to Autorhythmicity
1) Contractile muscle cells 99%
| 2) Autorhythmic cells 1%
170
SA node runs at about ___ action potentials/min
70-80
171
Cardiac Output is
Volume of blood ejected from each ventricle per minute
= Heart Rate (HR) X Stroke Volume (SV)
= 70 beats/min X 70ml/beat
= about 5 liters/min
172
Cardiac Reserve =
Max CO – resting CO
173
There are two mechanisms involved in altering stroke volume:
(1) Intrinsic control – increased filling
| 2) Extrinsic control – effects sympathetic stimulation to the heart (ionotropic
174
The arteries are designed to perform two major duties:
1) Fast transport from the heart to tissues (large diameter vessels)
2) Store pressure and provide driving force for flow when heart is resting (elastic walls)
175
MAP =
diastolic pressure + 1/3 pulse pressure
176
Local/intrinsic factors that control Vasoconstriction Or Vasodilation of Arterioles
Chemical:
1) Local metabolic changes*** MOST IMPORTANT
2) Histamine release
Physical
1) Local application of heat or cold
2) Myogenic response to stretch
177
Arteriole vasoconstriction is caused by local metabolic changes which include
Endothelin
increased Oxygen (O2)
decreased Carbon dioxide (CO2)
decreased Acidity
decreased Adenosine
178
Arteriole vasodilation is caused by local metabolic changes which include
EDRF
Nitric Oxide
decreased Oxygen (O2)
increased Carbon dioxide (CO2)
increased Acidity
increased Adenosine
179
Sympathetic nerve fibers supply arteriole smooth muscle everywhere but the
brain
180
Increased SNS activity causes generalized ___ of the arterioles
vasoconstriction
181
Decreased SNS activity causes generalized ___ of the arterioles
vasodilation
182
Total peripheral resistance (TPR) is most influenced by
Arteriolar resistance
183
Capillaries are
The sites for exchange of all material between blood and tissues
184
Blood velocity ___ through capillary beds
slows
185
Venous Capacity:
Volume of blood that the veins can accommodate
186
Venous Return:
Volume of blood entering each atria from the venous vessels
187
5 main factors that influence Venous Return:
1) Sympathetically induced venous vasoconstriction
2) Skeletal muscle activity
3) Effects of venous valves
4) Respiratory activity
5) Cardiac suction
188
___ is the main driving force in supplying blood to tissue
MAP
189
What happens when MAP is too low vs. too high?
Too low – inadequate perfusion
Too High – increased workload on heart
190
Control systems for MAP can be divided into two categories:
1) Short-term regulation: Baroreceptor reflex
| 2) Long term regulation: Renal influences in Plasma volume
191
____ is the site of blood oxygenation
pulmonary capillaries
192
oxygen delivery occurs in the
systemic capillaries
193
arteries = always sending blood ___ from the heart
away
194
veins = always sending blood ___ the heart
towards
195
while the entire blood volume circulates through the heart, it can’t get to any of that oxygen - oxygenation of the heart itself happens through a special circulatory route called the
coronary vessels - set of coronary arteries and veins that perfuses the cardiac muscle itself
196
PATH of blood movement through the heart
from the systemic veins to the inferior vena cava to superior vena cava, draining lower body and upper body, enters right atrium passes through right AV valve into right ventricle
from RV into pulmonary valve and arteries, into the lungs, comes back to heart through pulmonary veins on either side - enters left atrium through left AV valve into left ventricle then through aortic valve into the aorta
197
there are valves between ___ and ___, and between ___ and ___
atria and ventricles, and between ventricles and arteries
198
no valves between
veins and atria
199
features that set cardiac muscle apart include:
- uniquely “branched” arrangement of the individual cells
- cardiac muscle is striated (has lines that represent where the contractile proteins are lining up within the cell)
- intercalated discs connect cardiac muscle cells from end to end both physically and electrically
200
“pacemaker potential” makes autorthymic cells
SPONTANEOUSLY active (this means it’s self-triggering, you don’t need a “triggering event”)
201
First event that starts a cardiac cycle =
firing of the SA node
| causes depolarization of both atria and triggers P wave
202
before the SA node fires, atrial pressure is ___ than ventricular pressure
greater
203
the stage before the SA node fires is called
PASSIVE VENTRICULAR FILLING
this happens IN BETWEEN cardiac cycles (aka THROUGHOUT DIASTOLE)
204
PR interval =
time in between the firing of the P wave and the QRS interval
this is equal to the AV nodal delay
205
QRS complex =
depolarization of the ventricles —> quickly leads to contraction of the ventricles
(once the AV node fires and passes the action potential to the bundle of HIS and purkinje fibers)
206
the volume in the ventricles at the end of diastole/beginning of ventricular contraction is called
end diastolic volume
this represents the extent of ventricular filling
207
the purpose of ventricular contraction is to pump blood into the
arteries (pulmonary artery and aorta)
208
in order to open the aortic valve, the left ventricle has to
build up enough pressure to EXCEED the pressure in the aorta
209
all of the valves are ___ during isovolumetric contraction
closed
210
as blood enters the aorta, it expands the
aortic wall and causes aortic pressure to rise as well
211
average BP is around 120/80. the diastolic arterial blood pressure of 80 represents the _____, and 120 represents the ____
resting pressure in the arterial system
peak systolic pressure
212
end systolic volume represents
the relative “empty” phase of the ventricles
213
Stroke volume:
volume of blood ejected by each ventricle during a cardiac cycle
VERY IMPORTANT because this is the volume of blood given to all of systemic circulation
214
T phase begins ___ ventricular systole ends
before
215
when ventricular pressure falls below aortic pressure, we have the
closure of the aortic valve
216
2nd heart sound is caused by the
closure of the aortic and pulmonary valves
217
when the ventricular pressure (red line) falls below the green line (atrial pressure), only then will
the AV valves open up again
218
what happened to aortic pressure when we closed the aortic valve?
we got a little bump called the dichroic notch
219
the reverberation of pressure when the aortic valve closes is called the
dichroic notch
220
most of the filling of the ventricles during diastole (resting phase) is actually being done
passively
221
first step of the cardiac cycle
Action potential spreads to AV valve and depolarizes ventricles
222
you get the closure of those AV valves as
ventricular pressure exceeds atrial pressure (red goes above green)
223
you get that first heart sound when
the AV valves shut
224
as the ventricular pressure rises during isovolumetric contraction, all the valves stay
closed
225
when ventricular pressure (red) exceeds aortic pressure (purple), the aortic valve
opens
226
Pulmonary artery has only pressure range of ___ and is ___ compared to right side
7-10
very small
227
pulmonary circulation is very ___ pressure
low
228
CO truly is the measure of
cardiac function
229
resting CO is more than enough to
maintain metabolic needs at rest
230
To increase Cardiac Output, increase
HR or SV or Both
231
Stroke volume formula
EDV – ESV
232
Cardiac reserve is a measure of how
healthy and fit we are
elite athletes will have a tremendous cardiac reserve
233
Activity intolerance would be an appropriate nursing diagnosis for someone who
had a max CO that was closer to resting CO
234
Pacemaker of the heart is the
SA node
naturally around 70-90bpm
235
Parasympathetic enervation of the heart is through the
vagus nerves
236
When Acetylcholine is released onto muscarinic receptors, it causes what relating to the heart?
reduction of heart rate
237
lengthening AV node delay (time between atrial and ventricular contraction) maximizes
ventricular filling (and thereby maximizes stroke volume)
238
Sympathetic shortening of the AV nodal delay occurs when ___ binds to ___
Norepinephrine binds to Beta 1 receptors on the SA and AV node cells —>
Beta 1 receptors in the heart increase heart rate AND contractility
239
Patients who are on beta blockers often have quite a ___ heart rate
low (50-60), will feel really tired
240
if you increase filling of the heart (ie stretching the heart muscle), you increase
contractility
241
the stretching that happens to cardiac muscle during greater filling enhances the force of contraction -- this is called the
length-tension relationship
242
for skeletal muscle, the resting length represents the
optimal length for generation of force
- for bicep, thats when the elbow is at 90 degrees
243
in the heart, resting length of cardiac muscle is ____ than optimal
SMALLER/SHORTER
244
"The more you fill the heart, the higher the end diastolic volume and the greater the Stroke volume" - what is this relationship called?
Frank Starling Relationship
245
resistance to flow will be proportional to
diameter/radius of the vessel
246
small increases in radius produce
huge drops in resistance and huge increases in flow
247
What 2 things affect arteriole resistance:
viscosity of blood is directly related to HCT (the proportion of cells to plasma)
diameter of the vessel
248
systemic arteries are the first vessels that receive
fully oxygenated blood
249
arteries do stretch but will ____ rebound after being stretched
very quickly
250
when the ventricles are relaxing, the artery recoil provides
the perfusion pressure
251
pressure in the arteries vacillates between ____ pressure and ____ pressure
resting pressure (the pressure in the arteries as a result of cardiac diastole/cardiac rest)
and peak systolic pressure (generated from cardiac systole)
252
MAP represents perfusion pressure to organs during ____ times of the cardiac cycle
ALL
253
cuff pressure is ____ than systolic pressure in order to cut off the blow flow
higher
254
2 functions of arterioles
1. they variably distribute CO based on current demands of the organ. This percentage changes based on metabolic demands of organ.
2. They can regulate arterial BP
255
Arterioles all have a Normal resting diameter, which is determined by
normal “arteriole TONE”
256
arteriole tone is produced by
baseline elastic properties of muscle tissues and baseline sympathetic activity/input
257
Generally speaking, non-active people have higher ___ arteriole tone
sympathetic
258
heating an area causes
vasodilation
259
cooling will cause
vasoconstriction
260
Myogenic Response to stretch is
short lived constriction in response to an increased flow to the area
this is a transient change when there is an increased BF to area—vessels stretch- rebound recoil
261
Histamine is an inflammatory mediator and a VERY strong
vasodilator
262
LOCAL control of BP example
when metabolic activity of tissue is low, you’ll have elevated 02 levels, reduced C02, low tissue acidity, and free adenosine is low —> the endothelium senses this and releases vasoconstrictor called “ENDOTHELIN” to act on smooth muscle and cause constriction
263
when metabolic activity is high, you’ll have
low levels of O2, inc in c02, inc in acidity and adenosine, and when endothelium receives this it releases nitric oxide (Gas) to dilate vessels
264
SNS nerve fibers enervates entire vasculatry except for
capillaries
265
increased SNS activity leads to
generalized vasoconstriction
266
so when SNS activation is high in the body, the arterioles constrict, which elevates ___ and ___
TPR and MAP
267
when SNS activity is low, the arterioles dilate, which lowers ___ and ___
TPR and MAP
268
arterioles are the gates to
perfusion of the organ
269
epinephrine has a little more preference for___receptors, whereas norepinephrine has a little more preference for ____ receptors
beta 2
alpha 1
270
Vasopressin and Angiontensin II are both involved in regulation of ___ and ___
regulation of TBW, plasma volume
both are vasoconstrictors, so they have an Influence on BP also
271
the diameter of the capillary is actually slightly less than a ___
RBC
272
plasma proteins (albumin), RBCs, WBCs cannot get through
pores
273
lipid-soluble substances pass through ____ and Small, water-soluble substances can pass through ___
endothelial cells
pores
274
capillary beds sit between
arterioles and venuoles
275
Meta-Arterioles
fast, freeway like vessels allow from blood to go from arterioles into venules
276
collections of smooth muscle called the Pre-capillary sphincter control
the perfusion through capillary beds
277
when pre-capillary sphincter is constricted, blood moves through ____; when sphincter relaxed, blood flows through ____.
meta-arterioles
capillaries
278
capillary blood flow
distribution of fluid across the capillaries that is a completely passive process
279
most of the time, blood flow back to the heart from the veins is running ____ gravity
against
280
TPF is highly dependent on what 2 things?
- the status of arterioles
| - Viscosity of blood: ratio of RBC to plasma (hematocrit)
281
ratio of RBC to plasma is
hematocrit
282
Degree of PS activity impacts
HR, CO, MAP
283
Degree of Symp activity impacts:
HR, SV, and arteriole radius
284
Long term control of blood pressure is done by
controlling blood volume (job of the renal system)
285
short term Baroreceptor reflex causes
changes in BP that are predominantly caused by changes in body position
286
Baroreceptors and chemoreceptors are present in 2 key places:
1) aortic Arch
| 2) carotid sinus
287
In which of the vessels in the vascular tree does blood velocity slow down? What purpose (s) does this serve?
Blood velocity slows down in the CAPILLARIES.
Their purpose is to deliver oxygen and nutrients to our tissues - the blood slows down to allow for proper exchange.
288
John gets on a stationary bike in an exercise physiology lab. Strapped to his left thigh is a device that can measure blood flow to a specific region of quadricep muscle tissue. John starts to peddle vigorously and after a few minutes of this rigorous exercise the blood flow gauge reads a three-fold increase in quadricep perfusion. Explain at least two mechanisms that have contributed to this increase in muscle perfusion.
1. Decreased oxygen
2. Increase in acidity - stemming from the CO2 increasing
3. Increased adenosine
289
If a patient had an alteration in his second heart sound (ex. the sound was muffled or involved an abnormal whistle), this would most likely indicate a problem with what structure in the heart?
S2 murmur indicates either stenosis (hardened valves) or prolapse of the aortic valves
290
What are the only times during the cardiac cycle that ventricular volume is not changing?
During isovolumetric ventricular contraction and isovolumetric ventricular relaxation
291
A patient with hypertension has a systolic blood pressure of 140mmHg and a diastolic blood pressure of 95mmHg. How high must left ventricular pressure reach in order to end isovolumetric contraction in this patient (give a number value)?
Left ventricular pressure has to reach 95 mm Hg
This is the point where the aortic valves open (aka ventricular pressure - red line - must exceed/go above aortic pressure - purple line)
292
What is the purpose of the AV nodal delay?
the AV nodal delay allows for the ventricles to fill completely before it contracts (maximizing the end diastolic volume of the ventricle)
293
Describe all the electrical and mechanical events of the cardiac cycle that correspond in time with the QRS complex (and just after, 30-40 msec, the QRS complex) on the EKG?
MECHANICAL: mitral valve closes —> isometric contraction —> ventricular pressure exceeds aortic pressure —> aortic valve opens
ELECTRICAL: depolarization of the ventricles and the depolarization of the atria
294
If you were to cut off all parasympathetic and sympathetic innervation to the heart, what would heart rate be? Explain why?
It’ll rely solely on the SA node - beating at 70-80
295
Consider the extensive branching of the arterioles leading to many small capillary vessels. What factor influencing the rate of diffusion is being maximized?
Surface area
296
Which valves close during the second heart sound?
aortic and pulmonic
297
What is happening in terms of aortic vs. ventricular pressure at the second heart sound?
Ventricular pressure is lower than aortic pressure (this causes aortic valves to shut)
298
What is happening electrically in terms of the EKG at the second heart sound?
T wave (represents repolarization of the ventricles)
299
When you are taking a blood pressure, what does each tapping sound represent?
The blood flowing through those arteries, when the arteries expand (heart beating and then pushing blood through the arterial system)
300
What factors control precapillary sphincter tone?
Metabolic activity and metabolic need
301
What factors control arteriolar diameter?
```
INTRINSIC
Chemical:
1. Local metabolic changes*** MOST IMPORTANT
2. Histamine release
Physical:
1) Local application of heat or cold
2) Myogenic response to stretch
```
Extrinsic: neuronal PSNS and SNS, also hormonal vasopressin and angiotensin
302
Describe in detail (including valves) the path that blood takes as it enters the heart from the Vena cava until its final entrance into the Aorta.
Blood enters either superior or inferior vena cava, going into right atrium,
then passes through tricuspid valve into right ventricle, projected through pulmonic valve — goes to lungs, gets oxygenated —
oxygenated blood returns to left side of heart via pulmonary veins, left atrium, mitral valve, then goes into the left ventricle
pumped out through aortic valve to the brain, rest of your body and extremities, then returns via the venous circulation back to the right side of the heart
303
Consider the gap junctions located in the intercalated disks of cardiac muscle. Think about some consequences of selective blockade of those junctions.
Gap junctions allow for free flow of cytoplasm - electric coupling - this is essential for synchronized cardiac contraction
304
Why is the Sinoatrial node considered the pacemaker of the heart? What area of the heart would become the pacemaker if the SA node stopped functioning?
SA node is the pacemaker because it defines the baseline heart rate if you don’t include hormonal effects on the heart.
If the SA node stopped working, the heart rate would be 40-60 because that’s the rate of the AV node.
305
Consider the EKG. If you were to look at a series heart cycles on an EKG, the distance between which two waveforms would decrease if heart rate increased?
The distance between R to R waves would decrease, as would the TP interval - any 2 wave forms that are the same from one cardiac cycle to the next will shorten if the heart rate increases
306
Describe the pressure differences during Isovolumetric contraction between the ventricles and the atria
ventricular pressure is higher
307
Describe the pressure differences during Isovolumetric contraction between the ventricles and the arteries
pressure of the arteries will be higher
308
What is the required change that allows the ventricles to move from Isovolumetric contraction to the ejection phase?
Ventricular pressure has to exceed aortic pressure (red line above purple line)
309
Consider all the pressures and forces involved in Capillary Bulk Flow. Explain two alterations in those forces that could result in edema.
Edema could be caused by:
- Increased interstitial oncotic pressure (draws fluid out)
- Increased capillary blood pressure
- Decreased capillary oncotic pressure
