phys final - cardio, resp, thermoregulation Flashcards
1
Q
the greatest blood pressure decrease occurs as blood flows through ___
A
arterioles
2
Q
BP of static circulation when the heart is not pumping blood; typically 7 mm Hg
A
mean circulatory filling pressure
3
Q
pressure difference b/w mean aortic pressure and mean venae cavae pressure; typically 95 mm Hg
A
systemic perfusion pressure
4
Q
pressure between pulmonary artery and pulmonary veins; typically 8 mm Hg
A
pulmonary perfusion pressure
5
Q
which type of BP represents the potential energy to move blood
A
aortic BP
6
Q
pressure energy is used up through friction, which is converted to __
A
heat
7
Q
the pressure difference between the aorta and venae cavae is maintained by
A
the pumping of blood by the heart
8
Q
___ are more compliant than arteries; blood volume reservoirs
A
veins
9
Q
perfusion pressure divided by blood flow; regulates blood flow in tissues, organs, etc
A
resistance
10
Q
resistance of a tube is defined by ___ law
A
poiseuille’s law
11
Q
why is the resistance of a single arteriole greater than the resistance of a capillary network
A
the capillary network has a greater diameter
12
Q
vascular resistance of an organ is primarily determined by
A
diameter of its arterioles
13
Q
how does vasoconstriction affect arteriole resistance to blood flow (inc or dec)
A
increases
14
Q
how does vasodilation affect arteriole resistance to blood flow (inc or dec)
A
decreases
15
Q
what are the only three potential causes of increased mean aortic blood pressure
A
increased cardiac output (CO)
increased TPR
both
16
Q
how does hypertension affect CO, BP and TPR
A
normal CO
inc BP
inc TPR
17
Q
how does severe hemorrhage or dehydration affect CO, BP and TPR
A
dec CO
dec BP
inc TPR
18
Q
why does vasoconstriction occur in arterioles of kidneys, splanchnic circulation and resting skeletal muscle when an animal is experiencing low BP
A
minimizes the fall in arterial pressure
19
Q
how does vigorous exercise affect CO, BP, TPR
A
CO inc
TPR dec
BP negligibly changed
20
Q
pulmonary perfusion pressure difference divided by cardiac output
A
pulmonary vascular resistance
21
Q
pressures in the aorta and pulmonary artery during each cardiac ejection
A
systolic arterial pressure
22
Q
minimal pressures in the aorta and pulmonary artery before each new cardiac ejection
A
diastolic arterial pressure
23
Q
amplitude of the pressure pulsations in an artery
A
pulse pressure
24
Q
what conditions will cause an inc in pulse pressure
A
stroke volume inc
HR dec
aortic compliance dec
25
how does PDA and aortic regurgitation affect aortic and pulse pressure
aortic systolic pressure inc
aortic diastolic pressure dec
aortic pulse pressure inc
26
aorta and large arteries are described as ___ vessels
elastic
27
dispensability and ability to return to the original shape after the distending force or pressure is removed
elasticity
28
measure of how much force or pressure is required to achieve distension
compliance
29
arterioles are described as ___ vessels
muscular
30
contraction of ___ can reduce or stop the flow of blood in individual capillaries
precapillary sphincters
31
veins are described as ___ and ___ vessels
compliant and reservoir
32
most widespread type of capillary in the body
continuous
33
three ways of exchange through continuous capillaries are
diffusion - lipid soluble substances
pores - H2O and small lipid-insoluble
transcytosis - plasma proteins
34
the blood brain barrier is made of ___ capillaries
continuous
35
discontinuous (sinusoid) capillaries have large pores in between endothelial cells which allow
large plasma proteins to pass through
36
how do sinusoid capillaries contribute to detoxification
large pores allow toxins bound to plasma proteins to get into the liver
37
where are sinusoid capillaries found
liver
spleen
bone marrow
38
capillaries with holes through endothelial cells, rather than between
fenestrated capillaries
39
where are fenestrated capillaries found
sites of high fluid exchange
GIT
endocrine glands
kidneys
40
excess interstitial fluid and its plasma proteins are removed from the interstitial space through ___
lymph flow
41
what conditions cause an inc in capillary hydrostatic pressure
inc arterial BP
dec arteriolar resistance
backing up of venous blood
42
what condition causes an inc in interstitial hydrostatic pressure
accumulation of interstitial fluid (swelling and edema)
43
what condition causes an inc in capillary oncotic pressure
hyperproteinemia
44
what conditions cause an inc in interstitial oncotic pressure
inc rate of transcytosis
tissue inflammation
45
what conditions cause excessive filtration of fluid out of capillaries
inc in venous BP
hypoproteinemia
physical injury or allergic reaction
46
an inc in venous BP can be caused by:
1. application of too tight dressings on an extremity
2. severe pulmonic stenosis
3. ____
failure of LV or RV
47
what chemicals, released during an injury or Ag reaction, inc the permeability of capillaries to plasma proteins
histamine
bradykinin
48
extrinsic mechanisms predominately control the arteriolar resistance of organs that can withstand temporary blood flow reductions including
kidneys
splanchnic organs
resting skeletal muscle
49
intrinsic mechanisms control the arteriolar resistance of critical organs including
brain
heart
working skeletal muscle
50
2 examples of intrinsic mechanisms that control arteriolar resistance
histamine
exercise
51
effect of oxygen on arterioles
vasoconstriction - systemic
vasodilation - pulmonary
52
effect of CO2 on systemic arterioles
vasodilation
53
effect of K+ ions on systemic arterioles
vasodilation
54
effect of adenosine on systemic arterioles
vasodilation
55
effect of lactic acid on systemic arterioles
vasodilation
56
effect of endothelin-1 (ET-1) on local (paracrine) vessels
vasoconstriction
contraction of vascular sm. muscles
dec blood flow
57
nitric oxide (NO) is stimulated by
inc in blood flow velocity past the endothelium
58
effect of NO on local vessels
vasodilation
relaxes sm. muscle
inc blood flow
59
effect of thromboxane A2 (TXA2) on local vessels
vasoconstriction
platelet aggregation
60
effect of prostacyclin (PGI2) on local vessels
vasodilation
bleeding
61
effect of histamine on local vessels
vasodilation
62
effect of bradykinin on local vessels
vasodilation
63
histamine and bradykinin stimulate the formation of
nitric oxide
64
source of bradykinin
globulins in blood or tissue fluid
65
source of ET1, NO, PGI2
endothelial cells
66
an increase in tissue blood flow in response to increased metabolic rate
active hyperemia
67
a temporary increase above normal in blood flow to the tissue after a period when blood flow was restricted
reactive hyperemia
68
relative constancy of blood flow in an organ despite changes in perfusion pressure
autoregulation
69
true or false: the same metabolic mechanism responsible for active and reactive hyperemia control autoregulation
true
70
why must most of the blood needed to support the LV be delivered during ventricular diastole
mechanical compression during ventricular systole reduces the blood flow to the left coronary vessels
71
animals with coronary artery disease will develop ___ because ____ develops during exercise
exercise intolerance;
ventricular ischemia
72
pulmonary vessels have (greater or lesser) compliance, due to less intravascular pressure
greater
73
when a endotracheal tube is placed in an animal, what can cause the pulmonary vessels to become compressed
abnormal elevation in airway pressure
74
by which two ways does the ANS regulate the cardiovascular system
1. release norepinephrine and acetylcholine
2. release epinephrine and norepinephrine from the adrenal medullar
75
which neurotransmitter do sympathetic neurons release to regulate the CV system
norepinephrine
76
which neurotransmitter do parasympathetic neurons release to regulate the CV system
acetylcholine
77
receptors for epinephrine and norepinephrine
a-adrenergic (a1, a2)
b-adrenergic (b1, b2, b3)
78
receptors for acetylcholine
muscarinic cholinergic (M2, M3)
nictotinic cholinergic
79
effect of activating a-adrenergic receptor in arterioles/veins
vasoconstriction/venoconstriction
80
which receptor causes decreased blood flow to the organs, increase total peripheral resistance and increased arterial BP when activated
a-adrenergic receptors in the arterioles
81
which receptor displaces venous blood toward the heart, increases central venous pressure, RV preload and stroke volume when activated
a-adrenergic in veins of abdominal organs
82
which receptor causes an increased pacemaker rate, faster speed of conduction, decreased refractory period, and quicker stronger contractions when activated
b1 adrenergic
83
which receptor increases HR, stroke volume and cardiac output
b1 adrenergic
84
which sympathetic receptor causes vasodilation
b2 adrenergic
85
which receptor increases coronary and skeletal muscle blood flow
b2 adrenergic
86
where are b1 adrenergic receptors located
heart - all cardiac muscle cells
87
where are b2 adrenergic receptors located
arterioles - coronary and skeletal muscle
88
which receptor decreases pacemaker rate, slows speed of conduction, increases refractory period, causes slower contractions when activated
M2 cholinergic - of heart cells
89
which receptor inhibits norepinephrine release from sympathetic neurons when activated
M2cholinergic - of sympathetic nerve endings at ventricular muscle cells
90
which receptor decreases HR and cardiac output
M2 cholinergic - of heart cells
91
which receptor decreases magnitude of sympathetic effects of ventricular muscle cells
M2 cholinergic - of ventricular muscle cells
92
which parasympathetic receptor causes vasodilation, which is mediated by nitric oxide
M3 cholinergic
93
in which location do M3 cholinergic receptors increase coronary blood flow
coronary arterioles
94
in which location to M3 cholinergic receptors cause engorgement and erection
genital arterioles
95
in which location do M3 cholinergic receptors increase muscle blood flow in anticipation of exercise
skeletal muscle arterioles
96
the four neural-hormonal mechanisms that regulated BP and blood volume to ensure adequate blood flow are:
1. arterial baroreceptor reflex
2. atrial volume receptor reflex
3. defense alarm reaction
4. ______
vasovagal syncope
97
via the arterial baroreceptor reflex, afferent impulses are sent to the CNS to reflexively alter ____ and _____ in noncritical organs to keep BP at a set point
cardiac output and vascular resistance
98
the 2 types of baroreceptors
aortic arch baroreceptors
carotid sinus baroreceptors
99
what do arterial baroreceptors sense
arterial pressure changes
100
afferent nerves of the carotid sinus baroreceptors join which cranial nerve
glossopharyngeal (ninth)
101
afferent nerves of the aortic arch baroreceptors join which cranial nerve
vagus (tenth)
102
what causes the baroreceptors to initiates APs
systolic ejections from the heart
103
how do baroreceptors signal an increase in arterial pressure
by increasing their AP frequency
104
when the arterial baroreceptor reflex responds to decreased BP, it will stimulate and ___ in sympathetic activity
increase
105
to counteract the dec BP, the increased sympathetic activity of the baroreceptor reflex will cause ____ of the arteriolar smooth muscles, leading to an increase in ____
contraction (vasoconstriction);
total peripheral resistance (TPR)
106
to counteract the dec BP, the increased sympathetic activity of the baroreceptor reflex will cause increased ____ and decreased _____ of the myocardium; this leads to an increased cardiac output
contractility;
systolic duration
107
to counteract the dec BP, the increased sympathetic activity of the baroreceptor reflex will stimulate the SA node to increase the ____; this leads to an increased cardiac output
HR
108
what are the 2 limitations of the baroreceptor reflex
1. does not reverse BP disturbances, only minimizes their effects
2. has little influence on longterm BP
109
locations of the atrial volume receptors
walls of LA, RA and pulmonary veins
110
atrial volume receptors are activated by
stretch
111
in response to low blood volume, the atria volume receptor reflex increases sympathetic activity on the kidney to increase ____ and decrease ____
inc renin release;
dec Na excretion
112
in response to low blood volume, the atria volume receptor reflex increases sympathetic activity on the pituitary to increase ___ and ___
inc ADH release and thirst
113
in response to low blood volume, the increased ADH release and inc thirst causes an increase in ___ and decrease in ___
inc water intake;
dec urine flow
114
psychogenic responses are triggered by
sensory stimuli
115
2 important psychogenic responses
1. defense alarm reaction (fight or flight)
2. vasovagal syncope (playing dead)
116
intrinsic HR of a dog
about 140 bpm
117
cardiovascular effects of the defense alarm reaction include:
1. inc HR and SV
2. vasoconstriction in noncritical organs
3. vasodilation in coronary vessels and working skeletal m.
4. _____
inc BP - reset baroreceptor reflex so as to not oppose increased BP
118
during the defense alarm reaction, the cardiovascular effects are enhanced by which two circulating hormones
ADH
angiotensin II
119
cardiovascular effects of the vasovagal syncope include:
1. dec BP
2. dec sympathetic activity, inc parasympathetic
3. vasodilation in noncritical organs
4. ____
dec in TPR, HR and CO
120
true or false: the baroreceptor reflex is reset to compensate the BP change of vasovagal syncope
false - emotional state overrides the baroreceptor reflex and the compensatory reflex is not observed
121
fainting during vasovagal syncope is caused by
dec BP leading to inadequate cerebral blood flow
122
potential causes of heart failure include:
- ischemia
- myocarditis
- toxins
- drug effects
- _____
electrolyte imbalances
123
consequences of left heart failure without compensation:
1. dec LV stroke volume
2. dec LV output
3. _____
4. severe exercise intolerance or death
dec mean arterial BP (MAP)
124
2 mechanisms for compensating left heart failure
starling's mechanism
arterial baroreflex
125
during starling's mechanism of compensation, the RV maintains a higher stroke volume than the LV, this results in:
1. inc LA pressure
2. ____
3. inc LV end diastolic volume - a partial correction of the low stroke volume
inc LV preload
126
complications of heart failure include:
1. exercise intolerance
2. _____
3. persistent inc in blood volume
edema
127
during LV failure, blood dams up in the pulmonary vessels, leading to
pulmonary edema
hypoxemia
pleural effusion
128
during RV failure, blood dams up in systemic vessels, leading to
edema in extremities and abdomen
129
a persistent increase in blood volume causes
inc BP
130
a common treatment for increased blood volume is
diuretics - reduce salt and H2O retention, dec BP
131
with persistent heart failure, pulmonary edema can cause
cardiac hypoxia
132
with persistent heart failure, vasoconstriction in kidneys can cause tissue ischemia leading to
kidney failure and uremia
133
with persistent heart failure, vasoconstriction of intestinal mucosa can cause tissue ischemia leading to
inc permeability of intestinal mucosa, bacteremia, and septic shock
134
where does is the majority of blood lost from during hemorrhage
veins - blood reservoirs
135
at what point is hemorrhage fatal without compensation
40% hemorrhage
136
what 2 mechanisms act as immediate compensations for hemorrhage
arterial baroreceptor reflex
atrial volume receptor reflex
137
effects after compensation for hemorrhage
MAP 10% below normal
SV 20% below normal
CO 20% below normal
138
hemorrhage causes hydrostatic pressure to fall below normal, therefore ____ is favored
reabsorption of interstitial fluid back into the capillaries
139
water reabsorption to compensate for hemorrhage does not contain ___ and ___
plasma proteins and blood cells
140
the final steps for compensation from hemorrhage is the
restoration of lost plasma cells and blood cells
141
within several days, plasma proteins are synthesized in the ____ to compensate from hemorrhage
liver
142
within several weeks, blood cells are produced by the ____ to compensate from hemorrhage
bone marrow
143
how does gravity affect the CV system
increases distending pressure in the dependent vessels (those below the heart)
distends dependent veins
144
what occurs when an animal transitions from lying down to standing up
decrease in central blood volume and central venous pressure
145
exercising muscle has increased ___ and decreased ___
inc metabolic products
dec local oxygen
146
increased blood flow to exercising muscle is known as
active hyperemia
147
effects of active hyperemia on exercising muscle
deliver more O2
remove some accumulated metabolic products
148
a psychogenic effect where the CNS inc sympathetic activity (and decreased parasympathetic activity) to the heart and blood vessels in preparation for exercise
central command
149
activation of specialized receptors in muscles and joints by an increase in muscular work to increase sympathetic and decrease parasympathetic activity
exercise reflex
150
autonomic adjustments for exercise
central command and exercise reflex
151
effects of muscle pump on CV system
inc ventricular preload
inc stroke volume
inc CO
152
effects of respiratory pump on CV system:
1. inc venous return
2. inc central venous volume
3. _____
inc ventricular preload
153
the nostrils, nasal cavities, pharynx, larynx, trachea, bronchi and bronchioles are part of the ____; they are responsible for humidifying, warming and filtering the air before it reaches the gas exchange region
conducting zone
154
the respiratory bronchioles, alveolar ducts and alveolar sacs are part of the ___; they are where gas exchage occurs
respiratory zone
155
what are the mucosa covered turbinate bones which warm and humidify the inhaled air, while cooling the arterial blood that supplies the brain; they include the dorsal, middle and ventral meatus airway passages
conchae
156
____ prevents aspiration of food into the trachea
epiglottis
157
the organ of phonation is located in
larynx
(syrinx in birds)
158
site of insertion of an ET tube
glottis
159
during inspiration, abductor muscles contract to prevent the upper airways from closing; in horses, laryngeal neuropathy prevents the abductor muscles on the L side from contracting, this causes the horse to make a ____ sound
roaring
160
what is the purpose of the cartilaginous rings of the trachea
prevent airway from collapsing
161
volume of the conducting zones
anatomic dead space
162
ventilated but not perfused alveoli, no gas exchange
alveolar dead space
163
the sum of anatomic and alveolar dead spaces
physiologic dead space
164
part of an ET tube that extends beyond the respiratory system
equipment dead space
- important to choose the right size tube
165
total volume of air breathed per minute
minute ventilation
166
sum of air volume that enters the perfused alveoli and the volume that remains in the physiologic dead space
tidal volume (VT)
167
as oxygen demands increase, the animal can inc ___ and ___ to compensate
inc VT
inc respiratory frequency
168
fresh air available for gas exchange
alveolar ventilation
169
cattle and horses have a (greater or lesser) dead space/tidal volume ratio than dogs
greater
170
what happens to the alveolar pressure when the lungs expand during inhalation
alveolar pressure dec; becomes lower than atm pressure
171
when might abdominal or internal intercostal muscles participate in the respiratory cycle
during exercise or some disease states
172
how do the diaphragm and external intercostals move during inspiration
diaphragm contracts, moves caudal
external intercostals contract
173
type of breathing: pronounced abdominal movements
abdominal
174
type of breathing: pronounced rib movements
costal
175
complementary breathing cycles include accessory movements such as
yawning
sigh
176
normal quiet breathing
eupnea
177
difficult breathing
dyspnea
178
increased depth, frequency or both
hyperpnea
179
rapid shallow breathing
polypnea
180
cessation of breathing
apnea
181
excessive rapidity of breathing
tachypnea
182
abnormal slowness of breathing
bradypnea
183
crackles can be heard if there is
edema
exudate within airways
184
wheezes can be heard if there is
airway narrowing
185
air that can be inspired after inhaling the tidal volume; forced inspiration
inspiratory reserve volume
186
air that can still be expired after the tidal volume; forced expiration
expiratory reserve volume
187
air that remains in the lungs after the most forceful expiration
residual volume
188
an open connection b/w the pleural space and the outside air or alveoli
pneumothorax
189
pneumothorax can cause
lung collapse
mediastinum displacement
death from asphyxia
190
the interpleural pressure is (positive or negative)
negative
191
under normal conditions, airways are held open because of ___
transpulmonary pressure difference
192
lung compliance depends on:
1. elasticity of the tissues in the lung and thoracic cage
2. ____
surface tension in the alveoli
193
less pressure is necessary to maintain a given volume during deflation than during inflation
pressure-volume hysteresis
194
disease conditions that lower the lung compliance include:
1. fibrosis
2. edema
3. pneumothorax
4. ____
lack of surfactant
195
produced by alveolar cells type II; essential to maintain a high lung compliance; is amphipathic
surfactant
196
force that impedes airflow along the respiratory tract
resistance
197
the resistance in the trachea and bronchi is (higher or lower) than in the bronchioles
higher
198
how does volume affect resistance
as volume inc, airway dilates and R dec
199
sympathetic innervation: circulating epinephrine acts on beta 2 adrenergic receptors to ___ the airways
dilate
200
parasympathetic innervation: which nerve controls Ach for bronchoconstriction
vagus
201
how does NO affect airways
dilator
202
how do the inflammatory mediators histamine and leukotrienes affect airways
constrictors
203
the first site of edema fluid accumulation
extra-alveolar vessels
204
how is resistance and alveolar capillaries affected when total lung capacity (TLC) is reached
resistance inc
alveolar capillaries flattened
205
the main source of vascular resistance in pulmonary circulation
capillaries
206
in quadrupeds, where is blood perfusion greatest
caudodorsal regions of the lungs
207
on the pulmonary circulation, a1 receptors cause (constriction or dilation)
vasoconstriction
208
on the pulmonary circulation, b2 receptors cause (constriction or dilation)
vasodilation
209
the thicker vascular muscle of cows and pigs allows them to have
greater vascular response to hypoxia
210
occurs in response to disease conditions where PO2 is reduced; causes low blood flow to poorly ventilated regions of the lung
hypoxic pulmonary vasoconstriction
211
collapsed alveoli leading to reduced blood flow
atelectasis
212
disease condition in cattle at high altitude; hypoxic vasoconstriction causes R side heart failure
brisket disease
213
heartworm disease can cause ___ due to blocking the flow of the R heart, increasing the pulmonary arterial pressure
RV hypertrophy
214
disease in racehorses in which pulmonary hypertension causes blood vessels to dilate and eventually rupture
exercise induced pulmonary hemorrhage
215
the peribronchial plexus is formed by the bronchial circulation (broncho-esophageal and right apical bronchial arteries), it divides into subepithelial vascular plexus and vasa vasorum, what is the function of the subepithelial vascular plexus
warming of inhaled air
216
the peribronchial plexus is formed by the bronchial circulation (broncho-esophageal and right apical bronchial arteries), it divides into subepithelial vascular plexus and vasa vasorum, what is the function of the vasa vasorum
nourishment
217
what is the bronchial circulation's response to hypoxia
vasodilation
218
when the pulmonary arterial supply is inadequate, such as in the case of obstruction, ____ will supply the lungs
bronchial vessels
219
alveolar gas composition and exchange is determined by
PO2
PCO2
220
PO2 is essential for
O2 movement in/out of blood
221
PO2 values change due to changes in __ and ___
atmospheric pressure
presence of water vapor
222
if CO2 production inc, what must also inc to keep PCO2 constant
alveolar ventilation
223
causes of hypoxemia include:
1. alveolar hypoventilation
2. diffusion impairment
3. low ventilation to perfusion ratio
4. intense exercise in elite athletes
5. _____
right to left shunts
224
CO2 has higher solubility than O2, therefore CO2 diffuses (faster or slower) than O2
faster
225
how does exercise affect perfusion rates
increases
- inc surface area for diffusion
226
what is the driving force for gas diffusion
difference in partial pressures b/w the alveoli and capillary blood
227
why does edema, inflammation and fibrosis cause diffusion impairments leading to hypoxemia
thicken membrane reducing surface area
228
how is the blood O2 level during exercise
low
229
what condition occurs when the pneumonic region receives no blood flow resulting in lower oxygen tension in blood returning to systemic arteries for delivery to tissues; treatment with O2 does not help
right to left shunt
230
factors that shift the Hb dissociation curve to the right (lowers affinity)
dec pH
high PCO2
inc in 2,3-BPG
inc in temp
231
the change in color of Hb from bright red to bluish red as it loses O2
cyanosis
232
Hb affinity for CO is (higher or lower) than O2
higher
- carboxyhemoglobin
- carbon monoxide poisoning
233
how much the respiratory muscles are working is monitored by
proprioceptors
234
what kind of signal do peripheral chemoreceptors, central chemoreceptors and joint/muscle receptors send
stimulatory
235
what kind of signal do pulmonary stretch receptors and airway irritant receptors send
inhibitory
236
where is the central pattern generator located
pons and medulla
237
what type of receptor is myelinated and participates in the hering-bruer reflex that prevents lungs from over-inflating; located in sm muscle in trachea and main bronchi
slow adapting pulmonary stretch receptors
238
what type of receptor is myelinated and rapid adapting and is stimulated by irritants to produce cough, bronchoconstriction, and mucus secretion tachypnea; located among epithelial cells from the nasopharynx to bronchi
irritant receptors
239
what type of receptor is unmyelinated, C fibers located next to capillaries in the interstitium and walls of airways
J receptors
240
what type of receptors are located in the diaphragm and intercostal muscles
muscle spindle and tendon organs
241
central chemoreceptors detect PCO2 and H+ changes in the ___ and ___
CSF and brain ECF
242
peripheral chemoreceptors in the carotid and aortic bodies detect changes in
pH
PaCO2
PaO2
243
in birds, what is the correct order of flow of:
air capillaries, blood capillaries, infundibulum
infundibulum
air capillaries
blood capillaries
244
skin cell that produces keratin, is the major structural protein of the epidermis and contributes to the epidermal water barrier
keratinocytes
245
where is the epidermal water barrier located
b/w stratum granulosum and corneum
246
skin cell located in the stratum basale which protects the skin against UV irradiation
melanocytes
247
what amino acid starts the synthesis of melanin
tyrosine
248
merkel's corpuscle has what type of receptor
mechanoreceptor
249
cells of the dermis incl:
1. fibroblasts
2. macrophages
3. leukocytes
4. ____
mast cells
250
which gland lubricates the skin, provides water impermeability and inhibits bacterial growth
sebaceous
251
sebaceous glands are stimulated by
testosterone
252
which type of sweat gland is common in primates, open into pores, and is not associated with the hair follicle
eccrine glands
253
which type of sweat gland is common in domestic animals, opens into a hair follicle and has an odiferous secretion
apocrine glands
254
how does brown adipose tissue produce heat
uncoupling the ETC
255
where in the brain are the feeback control mechanisms for body temp regulation located
hypothalamus
256
___ produced by preoptic anterior hypothalamic area causes a rise in the thermoregulatory set point, leading to a fever
PGE2 - prostaglandin E2
