Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MD1 endocrinologie > L'hypophyse > Flashcards

L'hypophyse Flashcards

1
Q

What’s the difference between the location of the hypothalamus and the pituitary gland?

A

Hypothalamus –> partie du cerveau

Hypophyse –> glande accrochée sous le cerveau

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the main organs targetted by the pituitary gland? (6)

A
  1. Thyroid
  2. Adrenal glands
  3. Ovaries
  4. Testicles
  5. Liver
  6. Breasts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three main levels of hormonal control?

A
  1. Hypothalamus
  2. Pituitary
  3. Target organ (effector)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the purpose of the hypothalamus?

A

Integration center for information within the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is the hypothalamus?

A

Around the third ventricle right above the pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the hypothalamus “control”?

A

Anterior and posterior pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which hormones are secreted by the hypothalamus? (8)

A
  1. CRH
  2. GHRH
  3. Somatostatin
  4. TRH
  5. GnRH (or LHRH)
  6. Dopamine
  7. ADH (vasopressin)
  8. Oyxtocin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which hormones are secreted by the anterior pituitary? (6)

A
  1. ACTH
  2. HGH (or GH)
  3. TSH
  4. LH
  5. FSH
  6. PRL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the main function of the hypothalamus?

A
  1. Stimulates the release of hormones from the anterior pituitary gland
  2. Secretes 2 hormones that inhibit the release of two hormones from the anterior pituitary gland
  3. Produces 2 hormones that are stocked in the posterior pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which hypothalamic hormones stimulate the release of which anterior pituitary hormones? (4:4)

A

CRH –> ACTH

GHRH –> HGH or GH

GnRH –> LH-FSH

TRH –> TSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which two hypothalamic hormones inhibit the release of which two anterior pituitary hormones?

A

Somatostatin -/-> GH

Dopamine -/-> prolactin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two lobes of the pituitary gland and their functions?

A
  1. Anterior pituitary:
    • 2/3 of the pituitary
    • Embryo: provient des cellules ectodermiques
    • PRODUCES hormones
  2. Posterior pituitary:
    • 1/3 of the pituitary
    • Embryo: neurological cells
    • STOCKS hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the selle turcique?

A

saddle-shaped depression in the body of the sphenoid bone of the human skull in which the pituitary gland is located

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Embryology of the pituitary:

A

ectoderme –> Poche de Rathke –> hypophyse antérieur

crête neurale –> hypophyse postérieur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does the hypothalamus communicate with both parts of the pituitary?

A
  1. Anterior: via portal system (venous circulation)
  2. Posterior: not actually separate (embryologically/anatomically) from the hypothalamus, just a continuation of its axons/nerve endings
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the six cell types within the anterior pituitary?

A
  1. Thyréotropes –> TSH and regulated by TRH
  2. Lactotropes –> PRL
  3. Gonadotropes –> LH/FSH and regulated by GnRH
  4. Somatotropes –> HGH and regulated by GHRH
  5. Corticotropes –> ACTH and regulated by CRH
  6. Chromophobes (colourless but job unknown for now)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MRI of the brain and the pituitary:

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which three important nerves are found in the optic chiasma?

A

3, 4, and 6: used for tracking and coordinating eye movement

If there’s a problem with the “sinus caverneux” and these three nerves are affected, it’ll cause diplopia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the name and function of the 3rd cranial nerve?

A

N. occulomoteur

Function: muscles de l’œil sauf grand oblique et droit externe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the name and function of the 4th cranial nerve?

A

N. pathétique/trochléaire

Function: muscles grand oblique de l’œil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the name and function of the 6th cranial nerve?

A

N. moteur oculaire externe/abducens

Function: muscle droit externe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the axe hypothalamo-hypophyso-thyoïdien?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the axe hypothalmo-hypophyso-gonadique in women?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the axe hypothalmo-hypophyso-gonadique in men?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the axe hypothalamo-hypophyo-surrénalien?
26
What is the circadian cycle?
**Cortisol levels during the day:** * High in the morning * Drops throughout the day * Low at midnight and at the start of the night * Raises again towards the end of the night (this cycle changes depending on your sleep schedule)
27
What is the axe hypothalamo-hypophyso-somatotrope?
28
What hormone inhibits the axe somatotrope?
**Somatostatin**
29
What is the "axe de la prolactine"?
30
What are the three most important things to know about pituitary tumours?
1. Benign 2. Grow slowly 3. Are intrasellar (stay inside the selle turcique)
31
What are the names of the most common benign and malignant pituitary tumours?
Benign --\> adenoma Malignant --\> carcinoma (VERY RARE)
32
How big is a microadenoma?
\< 10 mm
33
How big is a macroadenoma?
≥ 10 mm
34
What are the two main kinds of benign pituitary tumours?
1. **Tumeurs fonctionnelles** (secrétantes): 80% secrètent une ou des hormones 2. **Tumeurs non-fonctionnelles** (non-secrétantes): 20% ne secrètent pas des hormones
35
What do functional tumours secrete?
Prolactin (PRL) --\> 50% ACTH (Cushing) --\> 10-15% HGH (Acromegaly/gigantism) --\> 10-15% TSH (TSHome) --\> Rare LH-FSH --\> Rare
36
What are the most common types of pituitary tumours?
The most frequent: prolactinoma 2nd: non functional
37
What are the two kinds of clinical manifestations of pituitary tumours?
1. Local (neurological) 2. Hormonal (endocrine)
38
What are the main local manifestations of pituitary tumours (neurological)?
* Céphalées (rare except in acromegaly) * Anomalies visuelles: * Hémiansopsie bitemporale * Perte des **champs visuels bitemporaux** * ​Atteinte du chiasma optique * **​​**Diplopie (3,4,6) * Double vision * Atteinte d'un ou des nerfs crâniens par envahissement (sinus caverneux)
39
What are the two kinds of hormonal manifestations caused by pituitary tumours?
1. Surplus hormonal 2. Déficit hormonal
40
What is the difference between a primary/secondary or tertiary illness?
**Organe cible malade:** maladie primaire **Hypophyse/hypothalamus malade:** maladie centrale (2/3)
41
If there's a surplus/deficit in cortisol what is it called?
**Surplus:** Cushing **Déficit:** Insuffisance surrénale
42
If there's a surplus/deficit in T4-T3 what is it called?
**Surplus**: hyperT4 **Déficit**: hypoT4
43
If there's a surplus/deficit in LH-FSH, estrogen, testosterone what is it called?
**Surplus**: pas de syndrome **Déficit**: hypogonadisme
44
What happens to LH and FSH during menopause?
If the hypothalamus or pituitary gland are normal, your LH-FSH levels **SHOULD BE HIGH!** If they're low, that's an issue!
45
If there's a surplus/deficit in HGH what is it called?
**Surplus**: gigantism (in kids), acromegaly (in adults when they're done growing) **Déficit:** déficit en hormone de croissance, déficit somatotrope
46
If there's a surplus/deficit in PRL what is it called?
**Surplus**: hyperprolactinémie **Déficit**: pas de terme
47
What does a surplus of PRL in women cause?
**Chute d'estrogènes qui cause:** * Aménorrhée-galactorrhée (écoulement de lait des mammelons) * Infertility * Osteoporosis
48
What does a surplus of PRL in men cause?
**Chute de testostérone:** * Loss of libido * Erectile dysfunction * Infertility * Osteoporosis * Loss of beard/pubic hair
49
What does a surplus in HGH cause in children/adults?
Children: gigantism Adults: acromegaly
50
How can a hormonal deficit be caused by a tumour?
A tumour that squishes the pituitary gland causing damage and cellular destruction * Usually it's a macroadenoma (\> 10 mm otherwise it's probably too small)
51
What can a hormonal deficit in TSH, LH-FSH, or ADH cause?
TSH --\> hypoT4 LH-FSH --\> hypogonadism, amenorrhea, delayed puberty ADH --\> insipid diabetes
52
What investigation is typically done to diagnose pituitary tumours?
**Histoire/examen physique:** * recherche de sx et signes en lien avec: problèmes neurologiques, surplus/déficit hormonal * examen des champs visuels
53
What kind of imagery is done to find pituitary tumours?
**MRI of pituitary gland** * MUST SPECIFY PITUITARY otherwise, slices are too big
54
What is the difference between a static and dynamic blood test?
Static is a normal blood test but dynamic is done with hormonal suppression/stimulation
55
How to investigate if you're looking for a hormonal surplus?
Suppression test --\> try to lower levels
56
How to investigate if you're looking for a hormonal deficit?
Stimulation test --\> try to increase levels
57
How to investigate if you think it's a PRL surplus?
Static testing to look at PRL levels and this level orients the dx (more PRL usually means a bigger tumour) ## Footnote **NO DYNAMIC TEST AVAILABLE**
58
How to investigate if you think it's an HGH surplus?
**Static test:** * No useful for dx but very useful for followup **Dynamic test:** * Suppression test (hyperglycémie orale provoquée) * Normally a surcharge in sugar should cause a decrease in GH (\<0.4 ug/L) but this won't happen if you have gigantism or acromegaly
59
How to test for a PRL deficit?
Static testing only, no stimulation test available
60
How to test for an HGH deficit?
Static testing isn't very useful Stimulation test with arginine or hypoglycemia which should increase to normal levels when stimulated
61
Static testing 1/2
62
Static testing 2/2
63
Dynamic testing available:
64
What forms of treatment are available for pituitary tumours? (3)
1. Surgery 2. Medical treatment (Rx) 3. Radiotherapy: if chx or rx doesn't work
65
Surgery for pituitary tumour treatment:
Should be used first for all tumours EXCEPT for ones that secrete PRL Resection by the trans-sphenoid route (through nose to brain)
66
Why isnt the first line tx for prolactinomas surgery?
They respond VERY well to medication to surgery usually isn't necessary
67
What are the indications for surgery for a pituitary tumour?
1. If it is functional (secretes except PRL) 2. If if causes "syndromes chiasmiques" --\> perte de champs visuels 3. Growing +++ in young patients
68
What 3 kinds of Rx are available to treat pituitary tumours?
1. Agonistes de la dopamine 2. Analogues de la somatostatin 3. hGH receptor blocker
69
What do dopamine agonists do and how do they work?
Dopamine inhibits PRL release Therefore they're used to tx prolactinomas
70
How do somatostatin analogues work and what do they do?
Somatostatin inhibits HGH release Used to treat HGH releasing hormone (ex: acromegaly, gigantism)
71
How do GH receptor blockers work and what do they do?
Used to treat hormones that produce GH if surgery doesn't completely work
72
What are the three most common dopamine agonists?
1. Bromocriptine (Parlodel) 2. Carbergoline (Dostinex) 3. Quinagoline (Norprolac)
73
What are the three most common somatostatin agonists?
1. Octréotide (Sandostatin) 2. Lanréotide (Somatuline) 3. Pasiréotide (Signifor)
74
What is the main hGH receptor blocker called?
Pegvisomant (Somavert)
75
How should prolactinomas be treated?
**First, treat with dopamine agonists** If they don't work, look into surgical options but this is very rare
76
How are HGH producing tumours treated?
**First, surgery!** Then somatostatin analogues if levels stay elevated or it comes back and then HGH blocker if necessary
77
How are ACTH and TSH producing tumours treated?
**Always surgery first!**
78
How are LH-FSH secreting tumours treated?
Surgery only if they are causing problems (+++ sx) cause usually an increase has no/little clinical manifestations
79
How are non-functional tumours treated (no secretion)?
**Only treated if it's growing +++ or has a neurological impact,** otherwise tx w/ Rx not chx and chx if +++ impact of Rx not working
80
What is PRL and what does it do?
Polypeptide hormone that comes from lactotropic cells Role: * Mature breasts during pregnancy * Production of breast milk and oxytocin is necessary for It to be secreted * It is physiologically increased during pregnancy and when breast feeding
81
How are PRL levels controlled?
Under hypothalamic control Inhibited by dopamine * passes from the hypothalamus to pituitary through the venous portal system (through the tige) **BUT** **Levels can be increased by hypoT4 as an increase in TRH can stimulate PRL**
82
What is the "effet de tige"?
An increase in PRL caused by a tumour (usually macroadenoma) compressing the tige as there is no longer any dopamine inhibiting PRL release * LARGE tumour with relatively low (still increased) PRL levels
83
Effet de tige vs prolactinoma:
Effet de tige: * PRL \< 100ug/L: usually quite a big tumour found on MRI Prolactinoma: * PRL \>\> 100ug/L but can be lower if tumour is small * **PRL levels and size of tumour are correlated**
84
What happens to PRL levels in primary hypothyroidism?
The pituitary is normal... there's an inherent problem with the thyroid * Increased TRH levels to try to stimulate thyroid will cause a small increase in PRL * **when the hypothyroidism is treated... PRL levels will return to normal!**
85
What are the most common clinical manifestations of hyperprolactinemia?
Too much PRL --\> hypogonadism so most sx are associated with that: * Aménorrhée * Gallactorhée (rare in men, more common in women who have been pregnant/have breastfed before) * Gynécomastie * Ostéoporose * Infertilité * Perte de libido * Problème érectile
86
What are 5 physiological causes of hyperprolactinemia?
1. Grossese 2. Allaitement 3. Sommeil 4. Nourriture 5. Stress
87
What are 7 "pathological causes" of hyperprolactinemia?
1. Prolactinoma 2. Compression du tige hypophysaire 3. Médication 4. HypoT4 primaire 5. Lésion thoracique/stimulation locale (brain associates this with suckling) 6. Insuffisance rénale chronique (PRL can't be eliminated) 7. Idiopathique
88
What kinds of Rx can cause hyperprolactinemia?
1. Antipsychotics 2. Antidepressants 3. Morphine BUT levels usually still \< 100 ug/L
89
What is HGH/GH and what does it do and how does it work?
Polypeptide hormone secreted by somatotropic cells in the pituitary Typically low amount in circulation: * **Pulsatile secretion** * Peak with: meals, exercise, sleep * Max levels during puberty and from there keep decreasing
90
What are the main roles of GH?
* Growth (dim = nainisme, inc = gigantism/acromegaly) * Protein metabolism * Lipid metabolism * Glucose metabolism (important cause acromegaly can cause Db due to a decrease of glucose uptake and increase of gluconeogenesis --\> tx acromegaly = Db goes away)
91
How does GH work?
Indirect action via somatomedins in the liver * small proteins produced by liver when stimulated by GH * the most common is somatomedin C (IGF-1)
92
How is GH controlled?
Stimulated by GHRH (hypothalamus --\> pituitary) Inhibited by somatostatin **also stimulated by:** * hypoglycemia/jeûne * stress * sleep * meals rich in arginine **also inhibited by:** * hyperglycemia * lack of emotional support/love * obesity
93
How to investigate hyperGH?
**Static**: IGF-1 measure **Dynamic**: hyperglycémie orale provoquée
94
How to investigate hypoGH?
**Static**: measure IGF-1 levels (not that useful) Dynamic: stimulation testing * Test à l'arginine: better test * Stress à l'insuline (induce hypoglycemia)
95
Which three pathologies are associated with altered GH levels?
**Deficit**: growth retardation **Surplus**: gigantism and acromegaly
96
What usually causes acromegaly?
Usually cause by a pituitary tumour (usually a macroadenoma) but dx is usually quite late in disease progression
97
What are the most common clinical manifestations of acromegaly?
**Local manifestations (due to compression):** * Headaches * Visual problems (diplopia, hémianospie bitemporale) **Hormonal deficit (autres axes) due to compression:** * hypofonction hypophysaire (déficit en LH-FSH, TSH, et ACTH) **Surplus in GH:** * Hypertrophy of extremities (hands, feet, jaw (usually only bottom), nose, ears, larynx (deepen voice) * Arthrosis * Soft tissues (hypertrophy of skin and sub-cue tissues, hyperhidrosis, intestinal polyps) * Visceromegaly (ex: megacolon (non-toxic), cardiomyopathy/valvulopathy/arrhythmias) * Metabolic effects (diabetes/glucose intolerance)
98
How to investigate for acromegaly? (4 main things)
**Static testing:** * IGF-1 levels * HGH levels --\> cannot be used to establish dx **Dynamic testing: suppression** * hyperglycémie orale provoquée (normally should cause HGH \< 0.4ug/L) **Imagery**: pituitary MRI Finally, **evaluation of the other axes** to look for hormonal deficits caused by the tumour (compression)
99
How to treat an adenoma that secretes HGH?
1. Trans-sphenoid resection 2. Medical tx if surplus still present after chx * Somatostatin analogues * Dopamine agonists * HGH receptor blockers 3. Radiotherapy but really only used in RARE cases
100
How to treat returning/persistent acromegaly?
**Tx with somatostatin agonist** * somatostatin lowers levels but has a quite short half-life * therefore agonists with a longer half-life are used to help lower levels for longer periods of time
101
What is an "insuffisance hypophysaire" causing a deficit of all hormones called?
Panhypopituitarism
102
What can cause pituitary insufficiency?
**Tumours**: adenomas, craniopharyngiomas **Congenital reasons:** natural deficit in 1+ hormones **Vascular**: infarctus de l'hypophyse, Syndrome de Sheehan **Rx**: immunotherapies used for cancer tx * (ex: Ipilimumab and Nivolumab) **Granulomatous causes:** tuberculosis, sarcoidosis, histiocytosis **Mechanical damage**: chx, radiotx, trauma
103
What is Sheehan Syndrome?
a condition that affects **women who lose a life-threatening amount of blood in childbirth** or who have severe low blood pressure during or after childbirth, which can deprive the body of oxygen. * **This lack of oxygen that causes damage to the pituitary gland is known as Sheehan's syndrome** * This Is permanent, cannot recover from this and will cause need for long-term hormonal replacement therapy
104
What changes the clinical presentation of pituitary insufficiency?
Déficit hypophysaire Installation rapide vs lente (années) Durant l'enfance vs adulte
105
What are the clinical manifestations of a pituitary insufficiency that causes a deficit in LH-TSH?
**Hypogonadism:** * Delayed puberty * Aménorrhée * Infertilité * Perte de libido * Dysfonction érectile * Perte de poils-barbe * Dim. masse musculaire * Ostéoporose
106
What are the clinical manifestations of a pituitary insufficiency that causes a deficit in GH?
* Delayed growth * Loss of muscle mass * Increased fat % * Osteoporosis
107
What are the clinical manifestations of a pituitary insufficiency that causes a deficit in PRL?
Absence of breastmilk production after birth
108
What are the clinical manifestations of a pituitary insufficiency that causes a deficit in TSH?
**HypoT4:** * Fatigue * Chills * Constipation * Dry skin * Depression
109
What are the clinical manifestations of a pituitary insufficiency that causes a deficit in ACTH?
**"Déficience surrénalienne":** * Fatigue * Weight loss * Anorexia * N/V * Abdominal pain * Arthralgia/myalgia * Orthostatisme: ensemble de troubles observés chez certains sujets dans la station debout
110
How do you investigate suspected pituitary insuffiency?
MRI of pituitary Biochemical testing: * Static * Dynamic: stimulation testing depending on hormones * HGH: arginine/insulin * Cortisol: insulin stress test (not ideal for pituitary... used more for primary adrenal insufficiency)
111
How to treat pituitary insufficiency?
Hormonal replacement therapy depending on hormones missing: * ACTH: hydrocortisone (Cortef) * TSH: Levothyroxine sodium (Synthroid) * LH-FSH: * Women: estrogen + progesterone if premenopausal * Men: testosterone * HGH: take HGH * PRL: no replacement therapy available
112
What is oxytocin?
Hormone produced by the hypothalamus stored in the neurohypophysis/posterior pituitary Stimulates: (+ feedback) * Contraction of uterus while giving birth * Expulsion of breast milk when feeding **No pathologies associated with it**
113
What is vasopressin?
Another name for ADH Hormone used to maintain volume of circulating extracellular fluid/seric osmolality Stocked in the posterior pituitary, but synthesized in the hypothalamus
114
What are the three main roles of ADH?
1. Reabsoption of water in collector tubules 2. Maintain VCE 3. Maintain seric osmolality
115
Which pathologies are associated with a deficit and surplus of ADH?
Deficit: DI (insipid diabetes) Surplus: SIADH (syndrome inapproprié de sécrétion d'ADH)
116
What are the 6 most common causes of SIADH?
1. Rx 2. HypoT4 3. Insuffisance surrénalienne 4. Pathologie cérébrale (tumeur, ACV, infection, hémorragie...) 5. Pathologie pulmonaire (tumeur, pneumonie ...) 6. Chx majeure
117
How is SIADH dx?
Hyponatremia (surplus of water not loss of Na) Osm sérique diminuée Osm urinaire \> 100 mOsm/kg * **Osm urinaire \> sérique** **Make sure to exclude:** * HypoT4 --\> tx with L-thyroxine * Insuff. surrénalienne --\> tx with hydrocortisone
118
How to treat SIADH?
You have to treat the **cause,** not the **symptom**! You can also use water restriction to tx (800-1500ml of liquid/24hrs)
119
What is diabetes insipidus?
Deficit in ADH causing +++ water loss because the kidneys cannot concentrate the urine
120
What are the two "forms" of diabetes insipidus?
1. Central: deficit in ADH 2. Nephrogenic: kidneys resistant to ADH
121
What are the main causes of central diabetes insipidus?
1. Pituitary: * post-chx * metastasis * cranial trauma 2. Hypothalamus: * tumour 3. Tige hypophysaire: * trauma * tumour * chx 4. Idiopathic:
122
What are the main causes of nephrogenic diabetes insipidus? (4)
* Congenital/familial * Rx (lithium +++) * Hypercalcemia * Pregnancy
123
What are the most common clinical manifestations of diabetes insipidus?
Polyuria/nycturia Polydipsia Dehydration
124
What tests are used to investigate diabetes insipidus?
Static: * hypernatremia * seric osm increased (due to dim. water reabsorption) * urinary osm decreased (+++ water) Dynamic: * dehydration test if partial diabetes insipidus
125
How to treat diabetes insipidus?
**Drink when you're thirsty (always keep water next to patient)** DDAVP = desmopressin * man-made form of ADH and is used to replace a low level of ADH * give at nighttime before bed... but can also be given during the day
126
What to do if you have a pituitary insufficiency with low thyroid levels AND low cortisol levels?
ALWAYS TREAT CORTISOL FIRST! **C before T** Treating the thyroid first can cause an increase in cortisol metabolism and lower levels even more which is VERY VERY dangerous * can cause choc surrénalien

MD1 endocrinologie (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions