Lecture 4 Flashcards
1
Q
What does a hormone-secreting cell do?
A
Secretes hormones; can reach anywhere in your body through blood circulation but only the cells that have that hormone receptor (target cell)
Can have receptor for their own signal (can sense their own hormone)
2
Q
What is a non-target cell?
A
A cell that a hormone can’t bind to
3
Q
What are hormones?
A
One type of chemical signals that enter the blood and activate target cells far from the site of release
4
Q
What are hormones secreted by?
A
Endocrine cells
5
Q
What are hormones that are released by neurons called?
A
Neurohormones (These neurons act as endocrine cells)
6
Q
Based on chemical properties, what are three categories of hormones?
A
Peptides or proteins, steroid hormones, amine hormones
7
Q
Based on chemical properties, what are three categories of hormones?
A
Peptides or proteins, steroid hormones, amine hormones
8
Q
What are peptide or protein hormones?
A
Water-soluble, easily transportable in blood (mixes well with water), receptors are on cell surface (polar–can’t pass lipid membranes easily)
9
Q
What are steroid hormones?
A
Lipid soluble, need carrier proteins in blood (since it can’t mix with water), receptors are mostly intracellular
10
Q
What are amine hormones?
A
Mostly synthesized from amino acid tyrosine, water or lipid soluble–receptors can be intracellular or on surface
11
Q
Where do receptors for water-soluble hormones reside?
A
On the cell surface
12
Q
Where do receptors for lipid-soluble hormones reside?
A
Intracellular; mostly regulate gene expression in nucleus
13
Q
How do receptors for water-soluble hormones induce cellular response?
A
Via second messengers
14
Q
How do receptors for water-soluble hormones induce cellular response?
A
Via second messengers
15
Q
What is the effect of different receptors of a single hormone?
A
Diverse effects
16
Q
What is fight-or-flight response mediated by?
A
Epinephrine
17
Q
What are the effects of epinephrine?
A
Heart beats faster and stronger, blood vessels: more blood to muscle, constriction in skin, kidneys, digestive tract; releases glucose in liver (more energy); releases fatty acids (more energy)
18
Q
What secretes epinephrine?
A
The adrenal gland
19
Q
What secretes epinephrine?
A
The adrenal gland
20
Q
Can endocrine cells exist as individual cells within a tissue? How else might they organize?
A
Yes (e.g., endocrine cells in digestive tract). May organize into secretary organs whose main function is to secrete different hormones (endocrine glands, not organs–e.g., pancreas)
21
Q
What are secretary organs?
A
Endocrine glands that can secrete multiple hormones
22
Q
What’s in the anterior pituitary/what’s it do?
A
Controlled by the hypothalamus, contains many hormones, controls other endocrine glands
23
Q
Posterior pituitary
A
Hypothalamus releases hormones to this. Ex. oxytocin
24
Q
Posterior pituitary
A
Hypothalamus releases hormones to this. Ex. oxytocin
25
What's the pancreas important for?
Energy and homeostasis (e.g., insulin, glucagon)
26
Example of hormone in thyroid gland
Thyroxine
27
Example of hormones in adrenal gland
Cortisol, aldosterone, epinephrine, nonepinephrine
28
Examples of hormones in gonads
Testosterone, estrogen
29
What does white adipose tissue secrete?
Leptin--controls appetite
30
What was the 1st hormone ever discovered?
Secretin from the intestine
31
What is special about Vitamin D?
It acts as a hormone in the skin, not a vitamin
32
What is the central endocrine control?
Hypothalamus, pituitary glands
33
What is the central endocrine control?
Hypothalamus, pituitary glands (nodes of hypothalamus)
34
Posterior pituitary
Hypothalamus releases hormones to this. Ex. oxytocin
| Has no cells that secrete hormones (cells come from hypothalamus)
35
What is the central endocrine control?
Hypothalamus, pituitary glands (nodes of hypothalamus)
36
What is a continuation of the hypothalamus?
Posterior pituitary
37
Where does the hypothalamus release neurohormones via?
The posterior pituitary
38
What is antidiuretic hormone (ADH, vesopressin)?
Increases water retention by the kidneys; not releasing too much urine
39
What is oxytocin?
Promotes bonding, stimulates uterine contractions (childbirth), milk flow, etc.
40
What is oxytocin?
Promotes bonding, stimulates uterine contractions (childbirth), milk flow, etc.
Ex. prairie voles (opposite: mountain voles--less receptors for the hormone)
41
How do things go from hypothalamus to posterior pituitary?
Long neuron cells from hypothalamus extend axons to posterior pituitary --> release neural hormones directly from posterior pituitary
42
What does the hypothalamus have control over?
The anterior pituitary
43
When does the anterior pituitary secrete hormones?
When hypothalamus tells them to (when it releases ___-releasing hormone). Hormones released can control other glands: tropic hormones
44
Where does the anterior pituitary come from?
Gut tissue
45
Examples of hypothalamus/anterior pituitary hormones
Thyrotropin-releasing hormone (TRH) - Thyrotropin (controls thyroid)
Gonadotropin-releasing hormone (GnRH) - gonadotropins (control gonads)
Corticotropin-releasing hormone (CRH) - Corticotropin (control adrenal cortex)
46
Examples of hypothalamus/anterior pituitary hormones
Thyrotropin-releasing hormone (TRH) - Thyrotropin (controls thyroid)
Gonadotropin-releasing hormone (GnRH) - gonadotropins (control gonads)
Corticotropin-releasing hormone (CRH) - Corticotropin (control adrenal cortex)
Growth hormone-releasing hormone (GhRH) - Growth hormone (non-tropic, promotes growth)
47
What is tropic?
Have other endocrine glands as targets
48
What is non-tropic?
Directly stimulates target cells to induce effects
49
What are examples of growth hormone defects?
Gigantism and pituitary dwarfism
50
What controls hormone secretion?
Negative feedback loop
51
What is the process of releasing a hormone?
External or internal conditions -> hypothalamus -> releasing hormone -> anterior pituitary -> tropic hormone -> endocrine gland -> hormone
52
What is the long loop negative feedback for hormone secretion?
Inhibit hypothalamus which inhibits the releasing hormone, thus inhibiting anterior pituitary and the tropic hormone. OR inhibit the anterior pituitary
53
What is the short loop negative feedback for hormone secretion?
Most likely there is too much tropic hormone, so inhibit hypothalamus to stop releasing hormone, which will stop the anterior pituitary
54
What does the thyroid gland produce and store?
Thyroxine and calcitonin
55
What is thyroxine?
A hormone in the thyroid gland that elevates metabolic rate so it's important for development and growth (provides energy for our growth)
56
What does calcitonin stimulate?
Stimulates incorporation of calcium into bone
| In thyroid gland
57
What is the negative feedback regulation of thyroxine?
External or internal conditions -> hypothalamus -> release of TRH (thyrotropin releasing hormone) -> anterior pituitary -> release of TSH (thyro
58
What is the negative feedback regulation of thyroxine?
External or internal conditions -> hypothalamus -> release of TRH (thyrotropin releasing hormone) -> anterior pituitary -> release of TSH (thyrotropin: thyroid stimulating hormone) -> thyroid -> thyroxine
59
What is goiter?
Enlarged thyroid gland. Affects 5% of world's population. Caused by both hyperthyroidism (too much thyroxine) and hypothyroidism (too little thryoxine)
60
What is Grave's disease?
An autoimmune disease (immune system attacks itself), high metabolic rates, feel hot, eyes bulge
61
What is Grave's disease?
An autoimmune disease (immune system attacks itself), high metabolic rates, feel hot, eyes bulge
62
How does hyperthyroidism work in causing goiter?
Excess thyroxine means a higher metabolic rate, more heat generated, high storage of fat under eye. Antibody-binding from Grave's disease activates TSH receptors on thyroid and increases thyroxine. Thyroid remains stimulated and grows bigger
63
How does hyperthyroidism work in causing goiter?
Excess thyroxine means a higher metabolic rate, more heat generated, high storage of fat under eye. Antibody-binding from Grave's disease activates TSH receptors on thyroid and increases thyroxine. Thyroid remains stimulated and grows bigger. TRH and TSH both decrease because of negative feedback.
64
What is Cretinism?
low metabolism, intolerance to cold, physical and mental retardation
65
What is the most common cause of hypothyroidism?
Iodine deficiency --> can't produce functional thyroxine
66
What is needed for thyroxine synthesis?
Iodine-T3 and T4. Majority of thyroxine is T4 but T3 is much more active than T4.
67
How do we solve the iodine deficiency?
Supply salt w/ iodine in countries lacking iodine
68
How does hypothyroidism work in causing goiter?
deficiency in thyroxine from iodine --> negative feedback loop keeps producing more TRH and TSH but the thyroid is still unable to produce thyroxine
69
How does hypothyroidism work in causing goiter?
deficiency in thyroxine from iodine --> negative feedback loop keeps producing more TRH and TSH but the thyroid is still unable to produce thyroxine
70
Where are the adrenal glands located?
On top of kidneys like little pets
71
What two glands make up the adrenal glands?
Cortex and medulla
72
What is the cortex controlled by?
Corticotropin
73
What is the medulla controlled by?
CNS
74
What hormones are in the cortex?
Cortisol, aldosterone, sex steroids
75
What is cortisol?
mediates metabolic responses to stress; inhibits immune system (suppressed when someone else is more important); long-lasting effect on body
76
What is aldosterone?
Salt water balance (salt retention, water retention--kidneys)
77
Where is the cortex located?
In the external party of the adrenal gland
78
Where is the medulla located?
In the internal part of the adrenal gland; neurotissue/neuronal tissue
79
Which hormones are in the medulla?
Epinephrine (mainly) and norepinephrine -- fight or flight response
80
What is norepinephrine
Noradrenaline. More secreted from neurons (sympathetic division of autonomic nervous system)
81
What are the Islets of Langerhans?
clusters of endocrine cells in the pancreas that produce three different hormones
82
What cells are located in the islets?
Beta cells, alpha cells, delta cells
83
What cells are located in the islets?
Beta cells, alpha cells, delta cells
84
What do beta cells produce?
Insulin for glucose uptake
85
What do alpha cells produce?
Glucagon to stimulate the liver to convert glycogen (storage of glucose) to glucose
86
What is glycogen?
storage of glucose
87
What do delta cells produce?
Somatostatin-inhibits release of both insulin and glucagon
88
What do delta cells produce?
Somatostatin--inhibits release of both insulin and glucagon
89
How does insulin work in glucose metabolism?
GLUT4 which is the glucose transporter is not normally available on the membrane -- glucose binds with insulin receptor on membrane -- triggers long series of events until GLUT4 on membrane -- GLUT4 can pick up glucose
90
What happens if the blood glucose drops below normal?
Stimulates pancreas to secrete glucagon -> increases circulating glucagon -> breakdown of glycogen in liver -> release of glucose to blood -> blood glucose level rises
91
What is glucagon?
Stimulates liver to release glucose from glycogen (glucose storage)
92
What happens if the blood glucose rises above normal?
Stimulates pancrease to secrete insulin -> increase in circulating insulin -> uptake of glucose by cells -> metabolic energy production, fat synthesis, glycogen synthesis -> blood glucose level drops
93
What happens if the blood glucose rises above normal?
Stimulates pancreas to secrete insulin -> increase in circulating insulin -> uptake of glucose by cells -> metabolic energy production, fat synthesis, glycogen synthesis -> blood glucose level drops
94
What happens if the blood glucose rises above normal?
Stimulates pancreas to secrete insulin -> increase in circulating insulin -> uptake of glucose by cells -> metabolic energy production, fat synthesis, glycogen synthesis -> blood glucose level drops
95
What is diabetes mellitus?
High blood and urine glucose (too much sugar)
96
What are some symptoms of diabetes mellitus?
Increased urine output, dehydration, weakness (no fuel), lethargy (proteins burn out), body wasting (use fat storage, protein for energy)
97
What are some complications of diabetes?
Heart disease, stroke, hypertension, kidney disease, blindness, nervous disorders, amputation, etc.
98
How was diabetes originally diagnosed in India?
Urine-put out for ants or doctors would taste it
99
What is Type I (Juvenile onset) diabetes?
Beta cell dysfunction --> lack of insulin
100
What happens when blood glucose level is high for someone with Type I diabetes?
Stimulates pancreas to secrete insulin -> can't increase insulin -> can't uptake glucose -> can't have metabolic energy production etc -> blood glucose level does not drop
101
What happens when blood glucose level is high for someone with Type II diabetes?
stimulates pancreas to secrete insulin -> increase in circulating insulin -> can't uptake glucose by cells -> no metabolic energy production, etc. -> blood glucose level does not drop
102
What is Type II (Adult onset) diabetes?
Insulin responsiveness deficiency (no response to insulin)
103
What is the percentage of diabetes that is type II?
more than 80%
104
What is pancreas burnout?
High glucose levels stimulates pancreas to create more insulin -> gets exhausted, very tired -> pancreas burnout in later stages where the body can't produce insulin (like type I)
105
What is pancreas burnout?
For type II. High glucose levels stimulates pancreas to create more insulin -> gets exhausted, very tired -> pancreas burnout in later stages where the body can't produce insulin (like type I)
106
Who discovered insulin?
Frederick Banting and Charles Best, student of Banting. Won Nobel Prize. Found by dog's pancreas (insulin produced to help humans)
107
Who discovered insulin?
Frederick Banting and Charles Best, student of Banting. Won Nobel Prize. Found by dog's pancreas (insulin produced to help humans)
108
```
In the disease diabetes mellitus, a lack of insulin prevents:
A. The excretion of glucose
B. Glucose breakdown
C. Glucose uptake by cells
D. Conversion of glucose to glycogen
E. Glucose synthesis
```
C
109
What are male hormones generally called?
Androgens
110
What is the dominant form of male hormone?
Testosterone
111
What does testosterone do?
Muscle and bone growth (muscular, taller, lower voice), male characteristics, aggressive
112
What are female hormones?
Estrogen and progesterone
113
What is the dominant form of estrogen?
Estradiol
114
What is estradiol?
dominant form of estrogen; female characteristics --breasts, curvy, more fat and less muscle
Synthesized from testosterone by aromatase (an enzyme)
115
How does testosterone regulation work in males?
Hypothalamus -> GnRH (gonadotropin releasing hormone) -> anterior pituitary -> Luteinizing hormone (LH) -> testes -> testosterone
Long loop goes to anterior or hypothalamus. Short loop goes from LH to hypothalamus
116
What happens if there is too much testosterone (overuse of steroids) in males?
Long loop--less GnRH, LH. Thus less sperm produced (testes) and less fertility with too much testosterone
117
What happens if there is too much testosterone (overuse of steroids) in females?
Long loop--less GnRH, LH, FSH. Ovary is inhibited and estrogen and other female hormones won't be produced (less female characteristics).
118
What hormone is important for testosterone in males?
LH
119
What hormone is important for regulating ovaries in females?
LH and FSH (follicle stimulating hormone)
120
What hormone is important for regulating ovaries in females?
LH and FSH (follicle stimulating hormone)
121
What does sexual reproduction involve and why is it important?
Involves shuffling of genetic information; increases genetic material for survival
122
What are the three fundamental steps of sexual reproduction?
Gametogenesis, mating, and fertilization
123
What is gametogenesis?
Making gametes
124
What is mating?
Getting gametes together
125
What is fertilization?
Fusing gametes
126
What is gametogenesis?
Making gametes (produces cells needed for reproduction)
127
What is fertilization?
Fusing gametes
128
What are gametes?
Cells specialized for production
129
What are the 2 gametes?
Female egg and male sperm
130
Haploid
For each gene/chromosome, we have 2 copies of each gene. Gametes are haploid--only 1 copy
131
Where does gametogenesis occur?
In gonads
132
What are the 2 gonads?
Testes, ovaries
133
What are the 2 gonads?
Testes, ovaries
134
What are the two parts to the human reproductive system?
Primary sex organs and accessory sex organs
135
What are primary sex organs and what do they do?
Gonads: testes and ovaries. Produce gametes and secrete hormones
136
What are accessory sex organs?
External genitalia (penis and vagina) and glands, tubules, and ducts
137
What does vas deferens do?
Transports sperm to ejaculatory duct
138
What do glands do for the male reproductive system?
Secrete semen components
139
What is semen for?
Provide nutrients, facilitate sperm movements, etc.
140
What does the sperm join to in the end and from where?
From ejaculatory duct to the urethra
141
What is the epididymis?
Stores sperm (hat on top of testes)
142
What do testes do?
Generate sperm
143
What do testes do?
Generate sperm
144
What is the regulation of the male reproductive system?
Hypothalamus --> GnRH --> Anterior pituitary --> LH or FSH --> Leydig cells or Sertoli cells -> testosterone or spermatogenesis -> reproductive tract and other organs or STOPS
Testosterone--negative feedback loop
145
What is the regulation of the male reproductive system?
Hypothalamus --> GnRH --> Anterior pituitary --> LH or FSH --> Leydig cells or Sertoli cells -> testosterone or spermatogenesis -> reproductive tract and other organs or STOPS
Testosterone--negative feedback loop
146
Which of the following treatments would not help a patient with advanced prostate cancer?
A. Blocking Luteinizing Hormones
B. Remove testes
C. Blocking gonadotropin-releasing hormone
D. Blocking the action of testosterone
E. Cutting vas deferens associated with testis
E because testosterone goes everywhere through the blood
147
Which of the following treatments would not help a patient with advanced prostate cancer?
A. Blocking Luteinizing Hormones
B. Remove testes
C. Blocking gonadotropin-releasing hormone
D. Blocking the action of testosterone
E. Cutting vas deferens associated with testis
E because testosterone goes everywhere through the blood
148
How does one get prostate cancer?
Prostate gland growth stimulated by testosterone
149
How does one get prostate cancer?
Prostate gland growth stimulated by testosterone
150
What does the fimbria do?
Swoops up the egg from the ovary like a mop or Venus fly trap
151
What does the ovary do?
Produce eggs and hormones, ovulates the egg
152
What is the endometrium (REMEMBER!)
the lining of the uterus
153
What is the endometrium (REMEMBER!)
the lining of the uterus
Endo: in
Metrium: ..
154
What is the uterus for?
Fetus growth
155
How do sperm and egg meet?
Sperm has flagella to move and must move its way up to the oviduct and meet halfway
156
What is an oviduct (Fallopian tube)?
Kind of like an esophagus --squeezes the egg. Cilia inside helps egg move a little bit
157
What happens in the Ovarian cycle?
Produces eggs and hormones
158
What happens in the uterine or menstrual cycle?
Prepares the uterus endometrium for fertilized egg
159
What is the average length of 1 cycle in a women's reproductive system?
28 days
160
What events occur in the ovarian cycle?
oocyte maturation (1) --> developing follicle (7) --> ovulation (14) --> corpus luteum (21) --> developing oocyte (28)
161
What is a developing follicle?
Vesicle that contains egg, also produces hormone (mainly estrogen)
162
What happens at ovulation?
Egg is matured: released from ovaries
163
What is the corpus luteum?
Remaining part of follicle; important for secreting hormones estrogen and progesterone; degrades by day 28
164
What happens in the uterine cycle?
gets thinner from day 1 to day 3 or 4 (bleeding and sloughing-menstruation) --> rapid growth of endometrium (highly proliferated and vascularized endometrium) --> doesn't stop growing at day 14 --> a week or so after, it stops growing (allows time for the egg to be fertilized) --> no egg then plateaus and stops growing
165
How does ovarian and uterine cycles hormone regulation work?
Hypothalamus --> GnRH --> anterior pituitary --> LH/FSH --> ovary --> estrogen and progesterone --> uterus
166
How does ovarian and uterine cycles hormone regulation work?
Hypothalamus --> GnRH --> anterior pituitary --> LH/FSH --> ovary --> estrogen and progesterone --> uterus
Regulates estrogen and progesterone through anterior and hypothalamus.
167
What are the hormonal changes accompanying the cycles for LH, FSH, estrogen, and progesterone for females?
LH: peaks right before ovulation
FSH: higher than LH at day 1, peaks a little right before ovulation
estrogen: peaks before day 14
progesterone: peaks after ovulation; if fertilized egg arrives, it will start increasing. No fertilized egg--> reduce progesterone
168
What are the hormonal changes accompanying the cycles for LH, FSH, estrogen, and progesterone for females?
LH: peaks right before ovulation
FSH: higher than LH at day 1, peaks a little right before ovulation
estrogen: peaks before day 14
progesterone: peaks after ovulation; if fertilized egg arrives, it will start increasing. No fertilized egg--> reduce progesterone
169
What is fertilization?
union of sperm and egg
170
What does union of sperm and egg create?
a single cell called a zygote
171
What does a zygote develop into?
an embryo
172
What is a mammal egg surrounded by?
the cumulus
173
What is the cumulus?
A gelatinous matrix that sperm must get through to get to an egg
174
What is the zona pellucida?
a glycoprotein envelope beneath the cumulus --sperm recognition. Has a protein that recognizes only human sperm
175
What is the zona pellucida?
a glycoprotein envelope beneath the cumulus --sperm recognition. Has a protein that recognizes only human sperm. If you remove this, you can have a human hamster fertilization but it won't grow
176
what is the ovum?
the egg
177
what is in vitro fertilization and who discovered it?
inserting the egg and sperm from pipettes. Robert Edwards, Nobel Prize
178
what is in vitro fertilization and who discovered it?
inserting the egg and sperm from pipettes. Robert Edwards, Nobel Prize
179
```
Which of the following hormones will decline immediately after a surgery that removes both ovaries?
A. Luteinizing hormone
B. Gonadotropin releasing hormone
C. Follicle stimulating hormone
D. Estrogen
E. All of the above
```
D
