Endocrine And Reproductive ✔️ Flashcards
(136 cards)
1
Q
What is the primary function of endocrine organs?
A
To secrete hormones into the bloodstream to regulate various bodily functions.
2
Q
What properties are shared by all endocrine glands?
A
- Secrete chemical substances known as hormones
- Secrete hormones directly into the blood, not through ducts
- Regulate specific body functions
3
Q
What bodily functions are regulated by hormones to maintain homeostasis?
A
Body fluids, electrolytes, glucose, cellular metabolism, growth, and the wake-sleep cycle.
4
Q
What does “double duty” refer to in endocrine physiology?
A
Endocrine organs share functions with another system such as the nervous, immune, digestive, or reproductive systems.
5
Q
Which organs are examples of endocrine structures that share functions with other systems?
A
• Nervous system: Hypothalamus and posterior pituitary gland
• Immune system: Thymus
• Digestive system: Pancreas
• Reproductive system: Ovaries and testes
6
Q
How are hormones classified according to composition?
A
- Monoamines (e.g., adrenaline)
- Peptide & protein hormones (e.g., secretin, insulin)
- Lipid and cholesterol-derived hormones (e.g., prostaglandins, testosterone)
7
Q
Adrenaline is an example of which hormone composition type?
A
Monoamine hormone
8
Q
Secretin and insulin are examples of which hormone composition type?
A
Peptide and protein hormones
9
Q
Prostaglandins and testosterone are examples of which hormone composition type?
A
Lipid and cholesterol-derived hormones
10
Q
Which hormone/chemical messenger was the first to be discovered and by whom?
A
Secretin
discovered in 1902 by Bayliss and Starling.
11
Q
Where is secretin produced and what is its primary function?
A
Produced in S-cells of the duodenum to regulate the pH of the duodenum
12
Q
What does secretin regulate in the stomach and pancreas?
A
• Gastric acid secretion
• Pancreatic bicarbonate secretion
(to regulate the pH of the duodenum)
13
Q
How does secretin contribute to osmoregulation?
A
By regulating vasopressin secretion from the posterior pituitary
14
Q
What effect does secretin have on pancreatic ducts?
A
Increases pancreatic bicarbonate (HCO₃⁻) secretion.
15
Q
What effect does secretin have on the bile ducts?
A
Increases bile duct bicarbonate (HCO₃⁻) secretion
16
Q
How does secretin affect gastric emptying and acid secretion?
A
It delays gastric emptying and reduces acid secretion.
17
Q
What renal effect does secretin have?
A
Increases renal bicarbonate (HCO₃⁻) secretion.
18
Q
How does secretin affect heart function?
A
Increases heart contractility.
19
Q
What is secretin’s role in vasopressin regulation?
A
It increases vasopressin release
20
Q
What vascular effect does secretin have?
A
Causes vasodilation
21
Q
True or false
secretin helps regulate thirst and satiety
A
True
22
Q
True or False:
The hypothalamus links the nervous system to the endocrine system.
A
True
23
Q
What functions are controlled by the hypothalamus?
A
Body temperature
Appetite
Thirst
Wake/sleep cycles
24
Q
True or False:
The hypothalamus disrupts homeostasis.
A
False
It maintains it
25
Where are vasopressin and oxytocin synthesized?
Hypothalamus
26
Where are vasopressin and oxytocin transported after synthesis?
To the posterior pituitary
27
True or False:
Like the anterior pituitary hormones, the Posterior pituitary hormones (vasopressin and oxytocin) release are regulated by hypothalamic releasing hormones
FALSE
They are released in response to direct physiological signals, not releasing hormones (UNLIKE the anterior pituitary hormones)
28
What triggers the release of posterior pituitary hormones?
Specific physiological signals like high plasma osmolarity or parturition (giving birth).
29
How are vasopressin and oxytocin administered clinically?
Intravenously (I.V.)
30
True or False:
Vasopressin and oxytocin have long half-lives.
False
they have very SHORT half-lives
31
What are the main actions of vasopressin (ADH)?
• Vasopressor effect (causes vasoconstriction to raise blood pressure)
• Antidiuretic effect (inhibits water release to promote retention)
32
What condition is treated with vasopressin?
Diabetes insipidus (DI)
33
What causes diabetes insipidus?
A reduction in or insensitivity to vasopressin
34
What are the risks of vasopressin intoxication?
Water intoxication and hyponatremia
35
What are the two main physiological roles of oxytocin?
Stimulates uterine contraction (during labor) AND causes milk ejection.
36
What are the two main physiological roles of oxytocin?
Stimulates uterine contraction (during labor) AND causes milk ejection.
37
What are rare adverse effects of oxytocin?
Uterine rupture
Hypertension
Water retention
Fetal death
38
What regulates the hypothalamic-pituitary axis?
Neuropeptides (releasing or inhibiting hormones)
39
What is the role of hypothalamic releasing hormones in clinical practice?
They are used for diagnostic purposes
40
How are anterior pituitary hormones administered?
• Intramuscular (IM)
• Subcutaneous (SC)
• Intravenous (IV)
41
True or False:
Anterior pituitary hormones can be taken orally.
False
they are proteins and would be broken down by digestive enzymes.
(So only IM, SC, and IV)
42
What stimulates the release of growth hormone (GH) from the anterior pituitary?
Growth hormone-releasing hormone (GHRH) from the hypothalamus.
43
What inhibits GH secretion?
Somatostatin
44
When are GH levels highest? And in what manner is it released ?
During sleep
and it is released in a PULSATILE manner.
45
What are the main physiological effects of GH?
• Stimulates normal growth
• Stimulates hepatic production of IGF (Insulin-like Growth Factor)
• Stimulates uptake of amino acids and protein synthesis
46
What condition results from a lack of GHRH, and what is the treatment?
Pituitary dwarfism
treated with somatropin.
47
What results from excessive GH production in children and adults?
What is used as treatment?
Children: Gigantism
Adults: Acromegaly
Bromocriptine or somatostatin
48
What is the function of the liver in the growth hormone pathway?
It responds to GH by producing insulin-like growth factors (IGFs).
49
What hypothalamic hormone stimulates ACTH release from the anterior pituitary?
Corticotropin-releasing hormone (CRH).
50
What organ is the target of ACTH?
The adrenal cortex.
51
What are the three main hormone categories secreted by the adrenal cortex?
• Mineralocorticoids
• Glucocorticoids
• Androgens
52
Example and function of mineralocorticoids?
Example: Aldosterone
Function: Regulate water and electrolyte balance
53
Example and function of glucocorticoids?
Example: Cortisol
Function: Metabolic, anti-inflammatory, and immunosuppressive effects
54
Function of adrenal androgens?
Function: Contribute to the development of secondary sex characteristics and libido
55
What hormones are secreted by the adrenal medulla?
Adrenaline and noradrenaline
56
What are the three zones of the adrenal cortex (from outermost to innermost)?
• Zona Glomerulosa
• Zona Fasciculata
• Zona Reticularis
(Hint: GFR)
57
What hormone class is secreted by the zona glomerulosa?
Mineralocorticoids (e.g., aldosterone and corticosterone)
58
What hormone class is secreted by the zona fasciculata?
Glucocorticoids (e.g., cortisol and cortisone)
59
What hormone class is secreted by the zona reticularis?
Androgens (e.g., estrogens and testosterone)
60
What diagnostic role does CRH play?
It helps differentiate Cushing syndrome from ectopic ACTH-producing cells.
61
What two conditions are distinguished in diagnosis involving ACTH levels?
Addison’s disease vs. secondary adrenal insufficiency
62
How is ACTH released throughout the day?
In pulses, with an overriding diurnal rhythm—peaks in the morning and is lowest in the evening
63
What stimulates ACTH release, and what inhibits it?
• Stimulates: Stress (fight-or-flight)
• Inhibits: Cortisol (negative feedback)
64
What is the target organ of ACTH?
The adrenal cortex
65
What hormone does the anterior pituitary release in response to CRH?
Adrenocorticotropic hormone (ACTH)
66
What type of feedback does cortisol exert on the HPA axis?
Long negative feedback to the hypothalamus.
67
What hormone exerts short negative feedback in the HPA axis?
ACTH : it feeds back on the hypothalamus
68
What type of feedback does cortisol exert on the HPA axis?
Long negative feedback to the hypothalamus.
69
____________ is a deficiency in corticosteroid production due to primary adrenal insufficiency
Addison’s disease
70
What are common symptoms of Addison’s disease?
• Muscular weakness
• Low blood pressure
• Depression
• Anorexia
• Weight loss
• Hypoglycemia
71
What are common symptoms of Addison’s disease?
• Muscular weakness
• Low blood pressure
• Depression
• Anorexia
• Weight loss
• Hypoglycemia
72
How is Addison’s disease treated?
With corticosteroid replacement therapy (e.g., prednisone).
73
What causes Cushing’s syndrome?
Excess of glucocorticoids (too much cortisol)
74
What are the hallmark signs of Cushing’s syndrome
• Weight gain
• Moon face
• Muscle wasting
• Poor wound healing
• Osteoporosis
(Just read picture for more clinical features)
75
____________ is an endocrine disorder caused by excess cortisol from any source, while ___________ is a specific form caused by a pituitary tumor.
• Cushing’s syndrome
• Cushing’s disease
76
What hypothalamic hormone stimulates TSH release from the anterior pituitary?
TRH (Thyrotropin-Releasing Hormone)
77
What gland is the target of TSH?
The thyroid gland
78
What is the primary function of T3 and T4?
Stimulate normal growth and development by maintaining tissue metabolism for normal function.
79
What are symptoms of hyperthyroidism (thyrotoxicosis)?
• Tachycardia
• Body wasting
• Protrusion of the eyeballs
• Heat intolerance
• Cardiac arrhythmia
80
How is hyperthyroidism treated?
With radioiodine, surgery, or medical therapy
81
What are symptoms of hypothyroidism?
• Bradycardia
• Sensitivity to cold
• Weight gain
• Fatigue
• Mental and physical slowing
• In children: mental retardation and dwarfism
82
What are the consequences of untreated hypothyroidism in children?
It can cause mental retardation and dwarfism due to impaired physical and mental development.
83
What is the treatment for hypothyroidism?
Thyroxine (T4)
84
What are the two main thyroid hormones?
• Triiodothyronine (T3)
• Thyroxine (T4)
85
What stimulates TRH release from the hypothalamus?
Cold, stress, and trauma
86
What hormone negatively regulates TSH release?
Somatostatin
(T3 too)
87
What feedback effect do T3 and T4 have on the anterior pituitary?
Negative feedback — they inhibit TSH secretion.
88
Hypothyroidism or Hyperthyroidism?
Hypothyroidism
89
Hypothyroidism or Hyperthyroidism?
Hyperthyroidism
90
What is the role of pulsatile GnRH secretion?
It is essential for the release of FSH and LH from the pituitary gland.
91
What effect does continuous administration of GnRH have?
It inhibits gonadotropin (FSH and LH) release.
92
What are the target organs of FSH and LH in females?
The ovaries
93
What hormones are produced in females as a result of FSH and LH stimulation?
Estrogen and progesterone
94
What is the target organ of LH in males and what hormone does it stimulate?
The testes; it stimulates testosterone production.
95
What cell type does FSH act on in the male reproductive system?
Sertoli cells
96
What is the function of Sertoli cells in response to FSH?
Support spermatogenesis
97
What cell type does LH act on in the male reproductive system?
Interstitial cells (Leydig cells)
98
What do interstitial cells produce in response to LH?
Testosterone
99
What hormones stimulate follicle maturation in the ovary?
FSH and LH
100
What ovarian structure primarily secretes estrogen?
The growing follicle (GF)
101
What structure secretes progesterone after ovulation?
The corpus luteum (CL)
102
How does estrogen in contraceptives suppress follicle development?
By inhibiting FSH secretion through negative feedback.
103
What are two effects of progesterone in contraceptives?
• Inhibits LH secretion, preventing ovulation
• Makes cervical mucus less suitable for sperm
104
How do estrogen and progestogen work together to prevent pregnancy?
They alter the endometrial environment to prevent implantation.
105
What are common unwanted side effects of the combined oral contraceptive pill?
• Weight gain (due to fluid retention and/or anabolic effect)
• Mild nausea, flushing, dizziness, depression, or irritability
• Skin changes (acne or increased pigmentation)
• Amenorrhea or variable return of menstruation after stopping the pill
106
What are serious adverse effects or contraindications of the combined pill?
• Increased risk of cardiovascular disease (e.g., venous thromboembolism, myocardial infarction, stroke)
• Familial history of breast cancer
107
What is the primary function of prolactin?
Stimulation and maintenance of lactation (milk production).
108
Besides milk production, what other function does prolactin serve in breast tissue?
It promotes proliferation and differentiation of mammary tissue.
109
What are common symptoms of hyperprolactinemia?
• Galactorrhea
• Hypogonadism
110
What is the treatment for hyperprolactinemia?
Dopamine D2 agonists, such as bromocriptine
111
What neurotransmitter inhibits prolactin secretion from the anterior pituitary?
Dopamine (via D2 receptors)
112
What hormone does GHRH stimulate from the anterior pituitary, and what is its main effect?
• Stimulates: Growth Hormone (Somatotropin)
• Effect: Regulates growth via IGF-1 from the liver
113
What is the effect of somatostatin on the anterior pituitary, and what does this regulate?
• Inhibits: Growth Hormone release
• Effect: Regulates growth
114
TRH stimulates which hormone, and what is its downstream effect?
• Stimulates: Thyroid Stimulating Hormone (TSH)
• Effect: TSH stimulates T₃ and T₄ release from the thyroid gland
115
CRH leads to the release of which hormone, and what is the primary effect?
• Stimulates: ACTH (Adrenocorticotropic hormone)
• Effect: ACTH stimulates adrenal cortical hormone release (mainly cortisol)
116
What does prolactin releasing factor stimulate, and what is its effect?
• Stimulates: Prolactin
• Effect: Promotes mammary tissue development and milk production
117
What hormone from the hypothalamus inhibits prolactin release, and what is the effect?x
• Hormone: Dopamine (also called Prolactin Inhibiting Hormone, PIH)
• Effect: Inhibits milk production
118
What hormone does GnRH stimulate, and what are the effects of these hormones?
• Stimulates: FSH and LH
• Effect:
• FSH: Stimulates ovum growth in females, gametogenesis in males
• LH: Stimulates sex hormone production
119
Which pancreatic cells secrete insulin, and what triggers its release?
• Secreted by: Beta cells
• Trigger: High blood glucose (mainly)
120
Which pancreatic cells secrete glucagon, and what triggers its release?
• Secreted by: Alpha cells
• Trigger: Low blood glucose
121
What is the metabolic role of insulin?
Acts as a fuel storage hormone, promoting growth and differentiation.
122
What is the metabolic role of glucagon?
Acts as a fuel mobilizing hormone
123
________ is a chronic metabolic disorder characterized by hyperglycaemia.
Diabetes mellitus
124
What causes Type 1 diabetes and how is it treated?
• Cause: Absolute deficiency of insulin
• Treatment: Insulin therapy
125
What characterizes Type 2 diabetes?
A relative deficiency of insulin due to reduced sensitivity to its action (insulin resistance)
126
What class of drug is metformin, and what are its two main actions?
• Class: Biguanide
• Actions: Reduces insulin resistance and reduces hepatic glucose production (gluconeogenesis)
127
What are two notable effects of metformin?
(Helpful and adverse)
• Helpful effect: Weight loss in obese patients
• Adverse effect: Lactic acidosis—use caution in chronic kidney disease (CKD)
128
What is the mechanism of action of sulfonylureas like glibenclamide?
They stimulate insulin production.
(Oral hypoglycemic drugs)
129
What is a major side effect of sulfonylureas?
Hypoglycemia
130
What are incretins?
Hormones released from the gut that enhance insulin secretion in response to glucose and regulate appetite, gastric emptying, and glucagon secretion.
131
Where are incretins released from?
The gut
132
List the effects of incretins on metabolism.
• Potentiate insulin secretion in a glucose-dependent manner
• Slow gastric emptying
• Decrease food intake and increase satiety
• Decrease postprandial glucagon secretion
• Promote beta cell proliferation
• Reduce weight gain and postprandial hyperglycemia
133
What are GLP-1 agonists used for, and name two examples.
• Used to treat type 2 diabetes as adjunct therapy when control fails
• Examples: exendin-4, liraglutide (injectable)
134
What is a major adverse effect of GLP-1 agonists?
Pancreatitis
135
Incretins are contraindicated in patients with what history?
Known or family history of thyroid carcinomas
136
What does the incretin effect demonstrate?
That oral (or intestinal) glucose triggers a stronger insulin response than IV glucose due to incretin hormone release.
