Exam 2 Flashcards
(420 cards)
1
Q
How many pairs of cranial nerves are there?
A
12
2
Q
What are cranial nerves I and II connected to?
A
The cerebrum
3
Q
What are cranial nerves III-XII connected to?
A
The brain stem
4
Q
Which portion of the nervous system is the optic nerve considered to be a part of?
A
The central nervous system
5
Q
Which portion of the nervous system are all cranial nerves (other than the optic nerve) a part of?
A
The peripheral nervous system
6
Q
What do the afferent neurons in cranial nerves do?
A
Transmit sensory information to the brain or brain stem.
7
Q
What is cranial nerve II (optic nerve) responsible for? What type of nerve is it?
A
Vision, sensory nerve
8
Q
What does cranial nerve VIII (vestibulocochlear nerve) responsible for?What type of nerve is it?
A
Balance and hearing, sensory nerve
9
Q
What is cranial nerve I (olfactory nerve) responsible for? What type of nerve is it?
A
Smell, sensory nerve
10
Q
Cranial nerves can contain _____, ___________, and ________ neurons that control effector tissues.
A
somatic, parasympathetic, sympathetic
11
Q
What is cranial nerve III (oculomotor nerve) responsible for? What type of nerve is it?
A
Extraocular eye muscle movement, motor nerve
12
Q
What is cranial nerve XII (hypoglossal nerve) responsible for? What type of nerve is ti?
A
Muscles of tongue; motor nerve
13
Q
What does cranial nerve I (olfactory nerve) arise from?
A
The olfactory bulb
14
Q
What does cranial nerve II (optic nerve) arise from?
A
The diencephalon
15
Q
What does cranial nerve III (oculomotor nerve) arise from?
A
The midbrain
16
Q
What does cranial nerve VIII (vestibulocochlear nerve) arise from?
A
The medulla
17
Q
What does cranial nerve X (vagus nerve) arise from?
A
The medulla
18
Q
What does cranial nerve XII (hypoglossal nerve) arise from?
A
The medulla
19
Q
What is the nictitating membrane?
A
A third eyelid, mostly found in birds
20
Q
What does the granula iridica do? Where is it found and in what animal is it most commonly seen in?
A
It reduces glare and increases visual clarity, found in the eye around the pupil, most commonly seen in horses
21
Q
What part of the eye makes a cat’s eye glow?
A
The tapetum lacidum
22
Q
What does the suspensory ligament of the eye do?
A
It connects the ciliary body with the lens, holding it in place.
23
Q
What is the ciliary body of the eye?
A
A circular structure that is an extension of the iris
24
Q
What is the iris of the eye?
A
The colored portion around the pupil
25
What is the pupil of the eye?
The opening at the center of the iris through which light passes
26
What is the lens of the eye?
A curved structure in the eye that bends light and focuses it for the retina (located behind the pupil and iris)
27
What is the cornea of the eye?
The outer layer at the front of the eye
28
What is the aqueous humor of the eye?
The clear liquid inside the front of the eye
29
What is the vitreous humor of the eye?
A clear, colorless fluid that fills the space between the lens and the retina
30
What is the optic disc of the eye?
The round spot on the retina formed by the passage of the axons of the retinal ganglion cells. Where the retina and optic nerve connect.
31
Why is there an optic disc blind spot?
The point where the optic nerves converge to exit the eye (the optic disc). This area of the eye has no light-sensitive cells. This results in a break in the visual field.
32
What is the sclera of the eye?
The white of the eye. A protective covering that wraps over most of the eyeball.
33
What is the retina of the eye?
A layer of photoreceptor cells and glial cells within the eye that captures incoming photons and transmits them along neuronal pathways.
34
What is the choroid of the eye?
The layer of blood vessels and connective tissue between the sclera and the retina.
35
What type of muscle in the iris controls pupil dilation? What is the name of the muscle?
Smooth muscle, ciliary muscle
36
What portion of the nervous system controls pupillary constriction?
The parasympathetic nervous system
37
What muscle (other than smooth) controls pupillary constriction?
Circular muscle
38
What portion of the nervous system controls pupillary dilation?
The sympathetic nervous system
39
What muscle (not smooth) controls pupillary dilation?
Radial muscle
40
What does changes in cornea shape cause?:
Visual impairment
41
What are the components of the retina?
Fibers of the optic nerve, ganglion cells, amacrine cells, bipolar cells, horizontal cells, cone and rod cells (photoreceptor cells), pigment layer, choroid layer, and sclera
42
What do rod cells do?
Provide light vision
43
What are the characteristics of rod cells?
Rhodopsin photopigment absorbs all wavelengths of light, more sensitive but cannot distinguish color, results in shades of gray based on light intensity
44
What do cone cells do?
Provide color vision
45
What are the characteristics of cone cells?
Three types in primates with different scotopsin proteins; scotopsin photopigment can detect red, green, and blue wavelengths
46
How does information from rod and cone cells reach the optic nerve?
Light reduces rod and cone cell neurotransmitter release
47
Where does light hit in the eye for someone who is nearsighted?
Before the retina
48
Where does light hit in the eye for someone who is far sighted?
After the retina
49
How does light hit in the eye for someone who has astigmatism?
The light is scattered on and around the retina
50
What does the vestibular apparatus contribute to?
Sense of balance
51
What portion of the ear are semicircular canals located in?
The vestibular apparatus
52
What do semicircular canals do?
Detect changes in head position and rotational or angular acceleration of the head.
53
Which structures are included in the otolith organs?
The utricle and saccule
54
What do otolith organs do?
Detect changes in head position and linear acceleration of the head
55
What provides positioning information?
Movement of fluid over hair cells
56
What type of receptor are hair cells?
Mechanoreceptors
57
How is information transmitted from the ear to the brain?
Through the vestibulocochlear nerve (VIII) to the cerebellum.
58
What are the hairs of hair cells in the ear called?
Kinocilium and stereocilia
59
What connects to hair cells in the ear?
Vestibular nerve fibers
60
What are the bands between stereocilium called?
Tip links
61
What are the steps of depolarization of hair cells in semicircular canals?
1) Tip links stretch and open channels when stereocilia bend towards tallest member.
2) K+ enters hair cell, depolarizing it.
3) Depolarization opens voltage gated Ca^2+ channels.
4) Ca^2+ entry causes greater release of neurotransmitter.
5) More neurotransmitters leads to higher rate of action potential.
62
What are the steps of hyperpolarization of hair cells in semicircular canals?
1) Tip links slacken and close when stereocilia bend away from the tallest member.
2) No K+ enters cell, hyperpolarizing it.
3) Ca^2+ channels close
4) No neurotransmitter is released .
5) No action potentials occur.
63
What do otoliths do?
Provide weight to fluid overlaying hair cells.
64
What structures are included in the otolithic membrane?
Otoliths and a gelatinous layer
65
What is the tympanic membrane?
The eardrum
66
Where is the tympanic membrane found?
The middle ear of mammals
67
What does the tympanic membrane do?
Vibrates in response to sound waves and provides sound intensity and pitch information.
68
What is intensity?
Loudness
69
What does intensity depend on?
Wave amplitudes
70
What is pitch?
Tone
71
What does pitch depend on?
Wave frequency
72
What is ultrasound frequency? How far does it travel?
High frequency; 20,000 Hz; travels short distances
73
What is infrasound frequency? How far does it travel
Low frequency; 20 Hz; travels through land and water over long distances
74
What animal can hear ultrasound frequency?
Bats
75
What animals can hear infrasound frequency?
Whales and elephants
76
What are ossicles?
Three small bones in mammals that transfer vibrations from the tympanic membrane to the cochlea oval window.
77
What is the ossicle order?
Tympanic membrane ---> malleus ---> incus ---> stapes ---> oval window
78
How many ossicles are found in reptiles, tailless amphibians, and birds?
One
79
What is the ossicle in reptiles, tailless amphibians, and birds called?
Columella
80
What is the cochlea?
A coiled tubular system with three fluid filled compartments
81
What is the upper compartment of the cochlea called?
Scala vestibuli
82
What is the middle compartment of the cochlea called?
Scala media or cochlear duct
83
What is the lower compartment of the cochlea called?
Scala tympani
84
What is the organ of corti?
Thousands of hair cells arranged in four parallel rows found on top of the basilar membrane in the cochlear duct.
85
What is the organ of corti responsible for?
A sense of hearing
86
How does the organ of corti work?
Inner row of hair cells transform cochlear vibrations into action potentials that are then transmitted to the brain temporal lobe by cranial nerve VIII.
87
What is the oval window?
A membrane covering the entrance to the cochlea in the inner ear.
88
What is the round window?
One of the two openings into the cochlea from the middle ear. Serves to decompress acoustic energy that enters the cochlea.
89
What is the malleus?
A hammer-shaped bone that connects to the tympanic membrane.
90
What is the incus?
Anvil-shaped bone that connects to the malleus and the stapes.
91
What is the stapes?
Stirrup-shaped (smallest bone in the body) bone that connects to the incus and the oval window.
92
What is the cochlear duct/ scala media?
A fluid-filled, spiral-shaped cavity found in the inner ear.
93
What is the basilar membrane?
The main mechanical element of the inner ear. It separates incoming sounds into its component frequencies that activate different cochlear regions.
94
What is the tectorial membrane?
A highly hydrated matrix above hair cells in the cochlea. Plays a vital role in stimulation of hair cells.
95
How are oval window vibrations transmitted?
Through fluid (perilymph) within the scala vestibuli and then the scala media (cochlear duct) over the organ of corti.
96
How are different pitches perceived?
Different sound wave frequencies cause peak vibrations at different positions along the basilar membrane.
97
How is sound intensity perceived?
Greater sound wave amplitudes cause greater basilar membrane movement.
98
What part of the brain turns sounds into coherent and meaningful sounds?
The cerebrum temporal lobe
99
How do the basilar membrane and tectorial membrane interact?
The stereocilia of the basilar membrane contact the overlying tectorial membrane. The hairs are bent when the basilar membrane is deflected in relation to the tectorial membrane. The bending of the hair cell opens mechanically gates channels.
100
What are gustatory cells?
A type of chemoreceptor found in the tongue taste buds that prove a sense of taste.
101
How many gustatory cells are there per taste bud?
About 50
102
How is the sense of taste created?
Food molecules bind to receptors in gustatory cells that trigger cell action potentials. Action potential are sent via cranial nerve VII and X to the cerebrum parietal and temporal lobes and the hypothalamus.
103
What tastes can gustatory cells sense?
Bitter, sweet, sour, or salty foods.
104
What does food bind to on gustatory cells?
Channels or 7TMDR
105
What are olfactory neurons?
A type of chemoreceptor found in the nasal cavity (believed to be the only type of neuron in mammals to undergo mitosis during adult life)
106
A specific type of ______ for each odor molecule.
neuron
107
How many different smells can the human olfactory system distinguish?
1 trillion
108
What is the pathway in when smells reach the brain?
1. Odor present
2. Nostrils
3. Respiratory epithelium in the nasal passage
4. Olfactory epithelium
5. Olfactory bulb
6. Brain
109
What is the passageway in which pheromones reach the brain?
1. Pheromones present
2. The moth of the vomeronasal channel
3. Vomeronasal organ (Jacobson's organ)
4. Impulse transmitted
5. Olfactory bulb
6. Brain
110
Where do olfactory neurons synapse?
On mitral cells in olfactory glomeruli
111
What are olfactory glomeruli?
"Smell collection centers" where neurons for a specific odor molecule converge on mitral cells
112
Olfactory neuron action potential ________ with concentration of an odor molecule and _______ are released within glomerus on mitral cell.
increase, neurotransmitters
113
What do mitral cells do?
Send sensory information to cerebrum temporal lobe.
114
What is the vomeronasal organ (VNO)?
An addition sense organ in mammals and reptiles. Causes reproductive and social behaviors by reception of pheromones.
115
Where is sensory information from the vomeronasal organ sent?
The hypothalamus (region of the brain that controls reproduction)
116
What is the flehming response?
Animal opening of VNO to receive pheromones
117
What is the endocrine system?
A system of glands or tissues that secrete hormones into the blood and regulate animal homeostasis and physiology.
118
What is endocrinology?
The study of endocrine glands, their secretion of hormone into the blood, and the effects of endocrine hormones on tissues.
119
What is the rate of change in animal physiology for the endocrine system compared to the nervous system?
The endocrine system provides a slower rate of change - typically seconds, days, or weeks.
120
The endocrine system allows the animal to undergo necessary physiological changes for _______, _________, and response to _______.
growth, reproduction, stress
121
List examples of animal endocrine glands:
Pineal, hypothalamus, pituitary, parathyroid, thyroid, thymus, heart, liver, stomach, adrenal gland, pancreas, duodenum, kidney, adipose tissue, skin, ovaries, and placenta
122
What are the functions of the endocrine system?
1. maintain animal temperature
2. food, water, and mineral seeking and satiety
3. water, ion, and pH balance
4. digestion, metabolism, and growth
5. behavior and stress response
6. biological rhythms
7. reproduction
123
What is compensatory hypertrophy?
An increase in the size of an organ to compensate for the activity of the other lost organ.
124
What was the first endocrine experiment and the first documentation of a successful organ transplant?
Arnold Bethold's cockerel experiment
125
What cells do endocrine hormones influence?
Cells with receptors for the specific hormone
126
What is hormone half life?
The time it takes for half of a hormone concentration in blood to disappear.
127
What causes hormone half life?
Hormone metabolism
128
What the types of hormone secretion?
Basal or tonic, sustained, and episodic.
129
What is basal or tonic hormone secretion?
The hormone is secrete in low constant concentrations
130
What is sustained hormone secretion?
The hormone is secreted in high constant concentrations
131
What is episodic hormone secretion?
The hormone is secreted in pulses or episodes
132
When is episodic hormone secretion common?
Common for neuroendocrine hormones, pulses are related to neuron action potentials
133
Where are endocrine hormones metabolized?
In the liver, kidneys, or lungs
134
What is often collected to measure animal hormone concentrations?
Blood, urine, or feces.
135
What is negative feedback?
When the hormone reduces or turns off its own production
136
What is positive feedback?
When the hormone tends to increase its own production
137
When does positive feedback occur?
When rapid or drastic change is needed
138
Can positive feedback be sustained for long periods of time?
No
139
What is an example of positive feedback?
Parturition
140
What are major regulators of the endocrine system?
The hypothalamus and the pituitary gland
141
What does the pituitary gland consist of?
Two distinct glands- the anterior and posterior pituitary
142
What are hypothalamic nuclei?
Groups of nerve cell bodies that respond to specific sensory information and release neuroendocrine hormones into the anterior or posterior pituitary.
143
List the hypothalamic nuclei?
1. Ventromedial nuclei (VMN)
2. Arcuate nuclei (ARC)
3. Anterior hypothalamic area (AHA)
4. Preoptic nuclei (PON)
5. Suprachiasmatic nuclei (SCN)
6. Paraventricular nuclei (PVN)
7. Supraoptic nuclei (SON
144
How does the anterior pituitary develop?
From oral tissue
145
How does the posterior pituitary develop?
From brain/neural tissue
146
What major hormones does the posterior pituitary produce?
Oxytocin and vasopressin
147
What does oxytocin do?
Stimulates milk ejection and uterine contractions in females.
148
What does vasopressin do?
Contributes to animal water retention and regulates blood pressure.
149
Is oxytocin an amino acid, a peptide, or a protein?
A peptide (8 amino acids)
150
How does vasopressin effect the nephrons in kidneys?
It increases the permeability of distal and collecting tubules to water.
151
How does vasopressin effect arterioles throughout the body?
It causes vasoconstriction.
152
What is the Ferguson reflex?
Contraction of muscle in the uterus for parturition.
153
What is the milk let-down reflex?
Contraction of smooth muscle in mammary glands for milk ejection.
154
What does oxytocin control in both males and females?
Animal behavior including mate choice and pair bonding, trust, mothering abilities, and orgasms.
155
What are the steps of the Ferguson reflex?
1. Fetus presses on cervix
2. Sensory neurons in cervix send information to the hypothalamus
3. Oxytocin is released from posterior pituitary
4. Oxytocin stimulates uterine smooth muscle contraction
5. Fetus presses on cervix more vigorously - contributes to labor and parturition.
156
What is oxytocin used for by doctors?
Labor induction
157
What are the steps of the milk let-down reflex?
1. Stimulation of neurons within the mammary gland during nursing.
2. Information sent to the hypothalamus
3. Oxytocin is released from the posterior pituitary
4. Oxytocin stimulates contraction of myoepithelial cells surrounding glandular cells
5. Milk is transported into mammary gland ducts and cistern.
158
Is vasopressin an amino acid, a peptide, or a protein?
Peptide (8 amino acids)
159
What are the names of some hormones that are the same as vasopressin?
Anti-diuretic hormone (ADH), Arginine vasopressin (AVP) in humans and other animals, Lysine vasopressin (LVP) in pigs
160
How does AVP control blood pressure through arterioles?
AVP binds to receptors (V1R) on smooth muscle cells around arteries causing vasoconstriction, arterial resistance, and elevated blood pressure.
161
How does AVP increase water retention?
AVP binds V2R in kidney, increases aquaporin activity, increases animal water retention and reduces urine volume.
162
What does increased water retention cause?
Increased blood volume and blood pressure.
163
What is central diabetes insipidus?
When the body cannot properly balance fluid levels due to damage of the pituitary gland or hypothalamus from surgery, a tumor, head injury, or illness.
164
What is a cause for diabetes insipidus?
A mutation on the vasopressin gene.
165
What is polydipsia?
Excessive drinking
166
What is polyuria?
Excessive urination
167
What does the hypothalamic-hypophyseal (HH) blood portal system do?
Allows small quantities of neuroendocrine hormone to act on cells in the anterior pituitary before they are diluted by general circulation.
168
What are acidophils?
Lactotropes and somatotropes
169
What are basophils?
Gonadotropes or thyrotropes
170
What are chromophobes?
Corticotropes
171
What do neurons in the hypothalamus do?
Secrete releasing and inhibiting neuroendocrine hormones into portal system
172
What type of cells in the anterior pituitary secrete anterior pituitary hormones into general blood circulation?
Trope cells
173
What does prolactin do?
Stimulates mammary gland growth and production of milk factors in alveolus, particularly milk proteins casein and lactalbumin.
174
What is prolactin produced by?
Lactotrope cells in the anterior pituitary.
175
Prolactin is under constant _________ __________ by _______ from hypothalamus arcuate nucleus (ARC).
negative regulation, dopamine
176
What does nursing trigger?
Mechanoreceptors in teats and reduces dopamine release from hypothalamus, increasing release of prolactin from anterior pituitary.
177
What do mammary alveolus have?
PRL receptors
178
What do mammary alveolus cells do?
Synthesize and secrete milk proteins in response to PRL
179
What is prolactinoma?
The most common type of pituitary tumor. Causes hyperprolactinemia or excessive prolactin secretion.
180
What does hyperprolactinemia do?
Can cause infertility in females and males. In males it can lead to erectile dysfunction and low libido.
181
What is galactorrhea?
Abnormal mammary secretions, can occur in males.
182
What is used as a form of treatment for various prolactin disorders?
Dopamine agonists
183
What other animal tissues can produce PRL?
Skin, tumors/cancers, and sweat glands.
184
What other biological functions have been found to use prolactin?
Female reproduction, sodium and water balance, metabolism, and behavior.
185
______ causes emperor penguins that have lost young to steal young from other mothers.
Prolactin
186
What do somatotropes do?
Secrete growth hormone (GH) (aka somatotropin) from the anterior pituitary
187
What is the most abundant anterior pituitary trope cell type?
Somatotropes
188
What stimulates GH secretion?
Neuroendocrine hormone growth hormone releasing hormone (GHRH)
189
Where are GHRH neurons found?
Within hypothalamus arcuate nucleus (ARC)
190
What is GH secretion inhibited by?
Neuroendocrine hormone growth hormone inhibitory hormone (GHIH) (aka somatostatin)
191
Where are GHIH neurons found?
Within hypothalamus periventricular nucleus (PVN)
192
What does GH effect?
Various tissues, particularly the liver, skeletal muscle, adipose tissue, bone, and cartilage (osteoblasts/chondrocytes)
193
What are the effects of GH related to metabolism?
Causes liver to release glucose and lipolysis of adipose tissue to release triglycerides into the blood for energy. Occurs during animal fasting, exercise, and hibernation.
194
What type of action is the effect of GH in relation to metabolism?
Acute or immediate actions
195
What are the effects of GH in relation to growth?
Increases chondrocyte and osteoblast activity, resulting in bone growth. Increases skeletal muscle fiber synthesis and hypertrophy.
196
What type of action is the effect of GH in relation to growth.
Chronic or long-term actions
197
What does GH stimulate the production of in target tissues?
IGF-1 and IGF-2
198
What are GH actions mediated by?
GH or IGF-1/IGF-2
199
_____ has negative feedback on secretion of GH from anterior pituitary and GHRH from hypothalamus. ___ also has negative feedback on GHRH.
IGF-1, GH
200
____ and ____ increase chondrocyte and osteoblast activity, increasing longitudinal bone growth.
GH, IGF-1
201
What is gigantism?
High levels of circulating GH and IGF-1 as a child that results in abnormal bone lengthening. Typically caused by pituitary tumors.
202
What is acromegaly?
High levels of circulating G and IGF-1 during middle age that increases bone diameter.
203
What is laron syndrome?
Insensitivity to GH, resulting in abnormal short stature. Typically caused by recessive mutation of the GH receptor (GHR) gene.
204
Who was the world's tallest man?
Robert Wadlow
205
Who was an example of acromegaly in the slides?
Maurice Tillet
206
Who was an example of laron syndrome in the slides?
Norman Apolo Ramirez
207
What is growth hormone receptor deficiency associated with?
Major reduction of pro-aging signaling, cancer, and diabetes in humans.
208
What mutation do miniature brahman cattle have?
A mutation in the GH gene.
209
What is a major determinant of small size in dogs?
A single IGF-1 allele.
210
What did early therapies for growth deficiency in children use? What were the side effects?
Pituitary extracts from human cadavers. Side effects included a prion disease called Creutzfeld-Jakob disease.
211
What occurred in regards to GH deficiency in children in 1985?
Genetech began producing recombinant human GH that was produced by the FDA for use in children with growth deficiency. Marketed as protropin.
212
What was used as a treatment to increase milk production in cattle?
In 1937, pituitary extracts. In1994, recombinant bovine growth hormone (bGH or BST). Increases milk production by about 10 lbs/day
213
What are AquAdvantage Salmon?
Salmon with transgenic GH. Fist transgenic animal approved for human consumption in the US.
214
What is different about AquAdvanatage Salmon?
They have a GH gene from a closely related species (chinook) and a gene promotor from another type of fish that allows production of the chinook GH from all tissues year around. Reduced market tie from 3 years to 18 months.
215
Anterior pituitary secretion of GH in Atlantic salmon is _______.
Seasonal
216
What is the time to market for AquaAdvantage salmon?
18 months
217
What is the intent behind AquaAdvantage salmon?
To reduce hunting of wild salmon and increase food availability.
218
What do corticotropes secret from the anterior pituitary?
Adrenocorticotropic hormone (ACTH)
219
What is the secretion of adrenocorticotropic hormone (ACTH) stimulated by?
The neuroendocrine hormone corticotropin releasing hormone (CRH)
220
Where are CRH neurons found?
Within hypothalamus periventricular nuclei (PVN)
221
ACTH stimulates adrenal gland _______ production.
cortisol
222
What do adrenal glands consist of?
An outer cortex and inner medulla region.
223
Where are adrenal glands located?
Cranial to the kidneys
224
What three classes of steroids does the adrenal gland produce?
Mineralocorticoids, glucocorticoids, and androgens
225
What is the most important mineralocorticoid to know?
Aldosterone
226
What is the most important glucocorticoid to know?
Cortisol
227
The adrenal medulla is composed of ________ cells that make ___________ and ____________.
Chromaffin, epinephrine, norepinephrine
228
Adrenal cortex _____ _________ cells have ____ receptors and synthesize ________ in response to ____.
zona fasciculata, ACTH, cortisol, ACTH
229
What located of the adrenal cortex are mineralocorticoids located in?
Zona glomerulosa
230
What location of the adrenal cortex are glucocorticoids located in?
Zona fasciculata
231
What location of the adrenal cortex are androgens located in?
Zona reticularis
232
What is the outermost layer of the adrenal gland called?
A connective tissue capsule
233
List the layers of the adrenal cortex in order of outermost to innermost.
Zona glomerulosa, zona fasciculata, zona reticularis
234
When are CRH an ACTH released?
During stress, fasting, and in the morning hours
235
ACTH stimulates the adrenal cortex ____ ________ cells to produce ______.
zona fasciculata, cortisol
236
What are cortisol receptors (glucocorticoid receptors)?
Steroid nuclear receptors
237
Where are cortisol receptors (glucocorticoid receptors) found?
In the liver, adipose tissue, skeletal muscle, and immune cells.
238
Cortisol receptors regulate ____ _________ and are considered a __________ factor.
gene transcription, transcription
239
What are the functions of cortisol?
Increase animal blood glucose concentrations during stress and fasting, increase lipolysis in adipose tissue and proteolysis in skeletal muscle, block some immune processes, block some reproductive processes, reduce digestive tract activity, and fetal cortisol helps initiate parturition and promote fetal lung development.
240
How does cortisol increase blood glucose concentrations?
By increasing glucose synthesis (gluconeogenesis) and release from the liver.
241
Why does cortisol increase lipolysis and proteolysis (break down of protein)?
It frees triglycerides and amino acids as additional sources of energy.
242
What do thyrotropes produce from the anterior pituitary?
Thyroid stimulating hormone (TSH)
243
What is TSH secretion stimulated by?
Thyrotropin releasing hormone (TRH)
244
Where are TRH neurons found?
Within hypothalamus periventricular nuclei (PVN)
245
Where is the thyroid gland located?
Next to the trachea
246
TSH stimulates the thyroid gland ________ cells to produce thyroid hormones __ and __.
principle, T3, T4
247
What is the most active thyroid hormone?
T3
248
What enzyme converts T4 into T3?
5' 3' deiodinase
249
Where does T3 bind and what does it regulate?
To a nuclear receptor inside the target cell, regulates gene transcription
250
T3 and T4 have _________ feedback on TRH in hypothalamus and TSH in pituitary.
negative
251
Where are T3 and T4 synthesized?
On thyroglobulin
252
What is thyroglobulin?
A large protein in the thyroid follicle colloid
253
What does T3 and T4 synthesis require?
Iodine
254
What are the functions of thyroid hormones?
Increase animal metabolic activity and thermogenesis, contributes to CNS development in fetus, and increases receptors for many other hormone (including GH) and promotes animal growth.
255
What is hypothyroidism?
An under active thyroid gland. A reduction or loss of thyroid hormone production.
256
What are the symptoms of hypothyroidism?
Sensitivity to cold, adiposity (fat accumulation), depression, and impaired memory.
257
What is the #1 cause of hypothyroidism?
Iodine deficiency
258
What is a goiter?
An abnormal enlargement of the thyroid gland?
259
What causes goiters?
No iodine = no T3 and T4 = no negative feedback on TRH/TSH. Excessive TSH causes thyroid gland growth.
260
What is Hashimoto's thyroiditis?
An autoimmune disease where the immune system attacks. thyroglobulin, causing inflammation and swelling of the thyroid gland.
261
T4 and T3 are important for fetal _____ development.
brain
262
In humans, the fetus depends on the mother's thyroid hormone the first __ weeks of gestation for brain development.
12
263
What is the most common and preventable cause of child mental issues in the world?
Maternal iodine deficiency and hypothyroidism
264
What is animal systemic blood calcium sensed by?
Parathyroid gland chief cells and thyroid gland C cells.
265
What does a decrease in blood calcium cause?
Causes chief cells to release PTH which then increases bone osteoclast activity and release of calcium and phosphate from animal bone.
266
What is PTH?
Parathyroid hormone
267
What does PTH cause in kidneys and why?
Increases vitamin D production in kidney which helps to increase dietary calcium absorption from the digestive tract.
268
What does an increase in blood calcium concentration cause?
Causes C cells in thyroid gland to release calcitonin, which inhibits osteoclast activity.
269
What is nutritional hyperparathyroidism?
Reduced calcium in diet or reduced calcium absorption from digestive tract, leading to an increase in blood PTH and bone degeneration.
270
How big is a blue whale heart (length, width, height, and weight)?
5ft long, 4ft wide, 5ft tall, and over 400 lbs (640 times bigger than a human heart)
271
How often does a blue whale heart beat?
6 bpm
272
What are the aspects of the cardiovascular system?
The heart and blood vessels or vasculature
273
What factors are transported within blood?
water; solutes or ions; glucose, triglycerides, and amino acids; large proteins; endocrine hormones; cells/cellular material; gases, oxygen; and carbon dioxide; heat
274
Where is the animal heart located?
In the pericardial cavity, located in an area called the mediastinum
275
What is the visceral pericardium?
The inside connective tissue of the pericardium, touching the heart.
276
What is the pericardial cavity?
The space between the visceral pericardium and the parietal pericardium.
277
What is the parietal pericardium?
The outside lining of the pericardium, away from the heart.
278
What is the function of the right pump of the heart?
It collects oxygen depleted blood from tissues and pumps it to the lungs
279
What is the function of the left pump of the heart?
It collects oxygen-rich blood from the lungs and pumps it to body tissues.
280
What does the atrium do?
Collects blood entering the heart
281
What does the ventricle do?
Forces blood out of the heart.
282
What is the function of the superior vena cava?
Returns blood from the head and upper limbs
283
What are the functions of the right pulmonary veins?
Return blood from the right lung
284
What is the function of the inferior vena cava?
Returns blood from the lower body and legs
285
What are the functions of the left pulmonary veins?
Return blood from the left lung
286
What do arteries do?
Carry blood away from the heart
287
Blood leaving the right side of heart exits the _____ _______ through the __________ ______ into the lungs and is low in oxygen.
right ventricle, pulmonary artery
288
Blood leaving the left side of the heart exits the ___ _______ through the ____ and is high in oxygen.
left ventricle, aorta
289
What do veins do?
Carry blood to the heart
290
Blood entering the right side of the heart enters the ____ _____ from the ___ ___ and it low in oxygen.
right atrium, vena cava
291
Blood entering the left side of the heart enters the ___ _____ from the _______ ____ and is high in oxygen.
left atrium, pulmonary veins
292
What do the left and right AV valves do?
Ensure blood flow from atria into ventricles
293
Aortic and pulmonary ________ valves ensure flow from ventricles into arteries.
semilunar
294
Why doesn't blood entering the atrium not flow back into veins?
Pressure in the atrium is not much greater than venous pressure.
295
What type of valve is the right AV valve?
Tricuspid
296
What type of valve is the left AV valve?
Bicuspid/ mitral
297
What structures prevent eversion of AV valves?
Chordae tendineae and valve leaflets
298
When pressure is greater behind the valve, it _____. When pressure is greater in front of the valve, it ______.
opens, closes
299
Where is the myocardium located?
Between the endocardium and the visceral pericardium
300
What does the myocardium consist of?
Myocardiocytes arranged in a spiral pattern
301
Why do myocardiocytes arrange in a spiral pattern?
When they contract, they "wring" blood from the apex to the base where the major arteries exit
302
What do intercalated discs contain?
Desmosomes and gap junctions
303
What is the purpose of gap junctions in myocardiocytes?
They allow the spread of action potential between myocardiocytes throughout the myocardium.
304
What are action potentials initiated by in the heart?
Pacemaker cells
305
What are pacemaker cells?
A special conductivity cell found in the cardiac muscle, generate spontaneous action potentials that spread throughout myocardiocyte gap junctions
306
What is systole?
Heart contraction, heart blood ejection
307
What is diastole?
Heat relaxation, heart blood filling
308
Where are pacemaker cells located?
In the sinoatrial node (SA) and the atrioventricular node (AV)
309
How do pacemaker cells initiate action potentials?
They do not have a resting membrane potential, and they slowly depolarize until reaching threshold.
310
What does full pacemaker action potential anvolve?
The opening of a voltage gated calcium channel, allowing calcium to enter the cell.
311
How is heart rate modified?
Autonomic neurons synapse on SA node and modify pacemaker cell activity
312
What is the AV node?
Secondary group of pacemaker cells activated by the SA node and located in the heart septum
313
What is the function of the AV node?
To help transmit action potentials between atria and ventricles
314
The AV node has a _____ rate of depolarization.
slower
315
What does a slower depolarization in the AV node allow for?
It allows the atria to completely contract and fill ventricle with blood before the next depolarization.
316
What is the Common Bundle or Bundle of His?
Pacemaker cells located in the heart septum that transmit action potential from the AV node into purkinje fibers.
317
What are purkinje fibers?
Elongated myocardial cells that form branches and rapidly propagate action potentials throughout the ventricle myocardium.
318
Heart __________ is followed by heart ________.
conductivity, contraction
319
Describe action potential in myocardiocytes.
Have a delay in reestablishment in resting membrane potential. Near peak of action potential, voltage gated calcium channels open letting more positive charge into the cell.
320
What is the importance of the delay in action potentials in myocardiocytes?
It creates a delay between heart contractions so that tetany doe not occur.
321
What is used to detect the electrical conductivity generated by cardiac muscle?
Electrocardiogram (ECG or EKG)
322
What is arrhythmia?
Abnormal heart electrical activity, abnormal heart rate and rhythm
323
What is atrial fibrillation (Afib)?
An irregular and often rapid heart rhythm
324
What is the P wave?
Atrial depolarization
325
What is the QRS complex?
Ventricular depolarization
326
What is the T wave?
Ventricular repolarization
327
What is the PR segment?
AV nodal delay, time it takes for electrical conductivity to move between atria and ventricles.
328
What is the ST segment?
The time between ventricle depolarization and repolarization, when ventricular contraction occurs.
329
What is the TP interval?
Passive ventricular filling, all chambers at rest.
330
What is the cardiac cycle?
One complete cycle of heart contraction
331
Which lasts the longest, systole or diastole?
Diastole
332
What are the steps of blood flow during the cardiac cycle?
1. Passive filling during ventricular and atrial diastole.
2. Atrial contraction
3. Isovolumetric ventricular contraction
4. Ventricular ejection
5. Isovolumetric ventricular relaxation
333
What is used to detect heart sounds?
A phonocardiogram
334
What are the "lub" and "dub" sounds of the heart created by?
Shutting of the AV (LUB or heart sound S or S1) and semilunar (DUB or S2) valves during systole.
335
What is the pause between heart sounds?
Diastole
336
What is a heart murmur?
An abnormal heart sound that typically results from abnormal heart valve function.
337
What are innocent heart murmurs?
Heart murmurs that are common in young but disappear in adulthood.
338
What happens during diastole?
AV valves are open and aortic and pulmonary valves are closed. Blood flows from the vena cava and pulmonary veins into atria and into ventricles by passive filling.
339
What happens at the end of diastole?
Ventricular filling of blood is completed.
340
What is the volume of blood in ventricles after diastole filling called?
End-diastolic volume
341
What happens at the beginning of systole?
SA nodes fire, atria depolarize (P wave) and contract, increasing atrial pressure. Impulse passes through AV node and bundle of His, depolarizing ventricles (QRS complex). Ventricles contract, increasing ventricular pressure and AV nodes close.
342
What happens during systole?
Both AV and semilunar valves are closed, and ventricles continue to contract. Ventricular pressure rapidly build but volume doesn't change. When ventricular pressure exceeds pulmonary artery and aorta pressure, pulmonary and aortic semilunar valves open. Blood is forced into pulmonary artery and aorta and ventricular volume decreases rapidly.
343
What happens at the end of systole?
Ventricular emptying is completed.
344
What is the volume of blood remaining in ventricles at the end of systole called?
End-systolic volume
345
What is the stroke volume?
The volume of blood pumped out of the ventricles.
346
What happens during early diastole?
Ventricles repolarize (T wave), ventricular pressure falls below arterial blood pressure and aortic and pulmonary semilunar valves close (ventricular repolarization). Ventricular pressure continues to fall (isovolumetric ventricular relaxation).
347
What is heart rate?
The number of cardiac cycles per minutes.
348
What is cardiac output?
The volume of blood ejected or pumped by the heart per minute.
349
What is cardiac output equal to?
Heart rate x stroke volume
350
What is cardiac output influenced by?
Animal activity, autonomic nervous system, animal size, body temperature, and animal age.
351
What is heart rate controlled by?
A balance between the parasympathetic and sympathetic nervous system
352
What is the parasympathetic nervous system's effect on the heart?
ACh decreases heart rate through decreased SA node activity and increased AV node delay
353
What is the sympathetic nervous system's effect on the heart?
NE and E increases heart rate through increased SA node activity and decreased nodal delay.
354
How does NE and E increase SV?
They contract smooth muscle around veins, forcing more blood back into the right side of the heart. They also increase myocardiocyte contraction, squeezing more blood into the ventricle. This results in greater EDV and greater SV.
355
How is SV controlled intrinsically?
The more that myocardiocytes are stretched at EDV, the stronger they contract and the greater the SV.
356
Why do myocardiocytes contract more strongly when stretched?
The stretching of myocardiocytes results in increased tension and causes thick and thin myofilaments to be closer resulting in more cross bridge interactions.
357
What is preload?
The potential force generated within the ventricle wall due to cardiac stretch.
358
What is the purpose of preload?
It increases the contraction capacity of the cardiac muscle, allowing for greater blood ejection from the ventricle when a larger volume is present.
359
What does preload depend on?
Ventricular filling and EDV
360
What is afterload?
The force against which the heart must contract to eject blood out of the semilunar valves, particularly the aortic valve.
361
What does afterload depend on?
Arterial blood pressure
362
Why is preload so important?
It allows the two sides of the heart equilibrate and eject an equal volume of blood.
363
What is blood pressure important for?
Providing tissues with blood, oxygen, and nutrients; overcoming gravity and driving blood to the brain; providing proper blood flow to the heart; and providing blood filter pressure on the kidneys.
364
What major factors influence blood pressure?
Cardiac output, blood vessel radius, and animal blood volume.
365
What are the blood vessels of pulmonary and systemic circulation?
Arteries, arterials, capillaries, venules, and veins
366
How many layers do arteries and veins have?
3
367
What is the tunica intima?
Simple squamous epithelium, connective tissues (inner layer)
368
What do large arteries have?
An internal elastic layer and an external elastic layer
369
What is the tunica media?
Smooth muscle (thicker in arteries and arterioles) and elastic fibers
370
What is the tunica externa?
Connective tissue, callogen fibers
371
What is the purpose of arteries?
Provide rapid passage of blood from heart to tissues
372
What happens to arteries during systole and diastole?
They expand during systole and recoil during diastole (because if a thick external elastic membrane)
373
Maximal pressure exerted on the arteries during systole averages ___ mmHg in humans.
120
374
Minimal arteriole pressure during diastole averages __ mmHg in humans.
80
375
What does a blood pressure of 120/80 mmHg mean?
The pressure on arteries during systole is 120 mmHg and the pressure on arteries during diastole is 80 mmHg.
376
What is mean arterial pressure (MAP)?
Average of blood pressure generated during a single cardiac cycle. Measure of the driving force of blood through the cardiovascular system.
377
How is MAP calculated?
Systole pressure + (2 x diastole pressure)/3
378
Why is it important for blood pressure to stay below a certain point?
It would overwork the heart and create vessel damage.
379
What is constantly modified to correct for changes in MAP?
Arteriole total peripheral resistance (TPR)
380
What is the importance of arterioles?
Regulate MAP by controlling total peripheral vascular resistance (TPR) or the resistance of blood flow
381
What are vasoconstriction and vasodilation caused by?
Smooth muscle contraction or relaxation in arterioles
382
What does smooth muscle in veins maintain?
Vasular tone
383
What are the characteristics of smooth muscle found in arterioles?
Myogenic activity and persistent sympathetic stimulation.
384
Flow gets ____ and resistance gets _____ as the arterioles move alway from the heart.
higher, lower
385
What is vessel stretch?
A type of autoregulation that causes increased myogenic activity and vasoconstriction.
386
How do gases and low metabolic changes effect arteriole radius?
Smooth muscle relaxation triggered by reduced oxygen or increased carbon dioxide levels in surrounding tissues.
387
How does temperature effect arteriole radius?
Heat generated by active tissues causes vasodilation.
388
What local vasoactive molecules effect arteriole radius?
nitric oxide, prostaglanidins, and more
389
What immune cell causes vasodilation?
Histamine
390
The ___________ nervous system provides most extrinsic control of arteriole radius.
sympathetic
391
How does NE cause vasoconstriction?
It binds to alpha-adrenergic receptors on smooth muscle.
392
How does NE and E cause vasoconstriction?
NE and E from adrenal medulla become endocrine hormones and bind alpha-adrenergic receptors on smooth muscle.
393
Reduced sympathetic activity contributes to _______.
vasodilation
394
E has greater affinity for _____ ________ receptors.
beta2-adrenergic receptors
395
Where are beta2-adrenergic receptors found?
In heart and skeletal muscle arteriole smooth muscle cells.
396
E _______ blood flow to organs (apha1 and vasoconstriction) and ________ blood flow to heart muscle (beta2 and vasodilation) during _______ animal activity or stress.
reduces, increase, increased
397
What is the importance of capillaries?
They function to increase diffusion between blood and tissues.
398
Capillaries have a high ________ ____ and low _____ _______.
surface area, blood pressure
399
What are capillaries comprised of?
A single layer of simple squamous epithelial cells.
400
_____ between capillary endothelial cells provide permeability for filtration.
Pores
401
How do oxygen and carbon dioxide diffuse through the endothelial cells of capillaries?
Down concentration gradients
402
How do plasma, water, small water-soluble molecules, glucose, and amino acids diffuse through the epithelial cells of capillaries?
Through pores between epithelial cells
403
What can contribute to colloid osmotic pressure?
Large plasma proteins that cannot leave capillary.
404
How are large proteins hormones transported through capillaries?
Through the endothelial cells
405
What can reduced plasma proteins result in?
Edema or fluid accumulation in the interstitial space and tissues
406
What is ultrafiltration?
Movement of water and small molecules into interstitial space around cells
407
What is reabsorption?
Movement of water back into the capillary.
408
What is the importance of the venous system?
It serves as a low pressure blood reservoir and returns blood to the heart/
409
Veins have _____ elasticity and smooth muscle but have a _____ radius and distend to accommodate large volumes of blood.
little, large
410
What is blood returned to the heart by?
Driving pressure of the cardiac cycle, sympathetic activity, one-way venous valves, skeletal muscle pump and respiratory pumps, and cardiac suction during diastole.
411
What does MAP depend on?
Total peripheral vascular resistance (TPR) and cardiac output (CO)
412
What is blood oxygen, carbon dioxide, and MAP monitored by?
Mechanoreceptors and chemoreceptors
413
What are arterial baroreceptors?
A type of mechanoreceptor on the carotid arteries and aorta that sense chances in MAP and signal to the cardiovascular control center in the medulla (baroreflex activation)
414
________ __________ in carotid and aortic arteries sense changes in oxygen concentrations and signal to the cardiovascular and respiratory centers in the medulla.
Peripheral chemoreceptors
415
Baroreceptor action potential ______ with increased MAP and _______ with reduced MAP.
increase, decrease
416
What does information sent to the cardiovascular control center and sympathetic and parasympathetic nervous system fine tune to influence MAP?
HR, SV, and TPR
417
What is effected by low MAP in the heart atria?
Low pressure baroreceptors
418
What do low pressure baroreceptors do?
Activate sympathetic neurons extending to the kidneys. Reduces sodium and water loss by reducing kidney blood filtration. Activated the Renin-Angiotensin-Aldosterone system. Increases animal water retention, blood volume, and MAP over time.
419
What is released by heart atria myocardiocytes in response to increased blood volume?
Atrial natriuretic peptides (ANPs)
420
What do ANPs do?
Travel through blood and increase kidney excretion of sodium and water in urine. They also inhibit the Renin-Angiotensin-Aldosterone system.
