Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its...
-
Upload
easter-webb -
Category
Documents
-
view
223 -
download
5
Transcript of Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its...
![Page 1: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/1.jpg)
Endo 1.07 The pituitary gland
• Anatomy and histology of the pituitary gland
• Growth hormone and its control
• Actions of growth hormone
• Excess and deficiency of GH
• Causes of pituitary failure
• Micro- and macroadenomas
• Prolactin and prolactinomas
• Arginine vasopressin and its control
• Actions of AVP
• Diabetes insipidus
![Page 2: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/2.jpg)
Embryology of the pituitary gland
![Page 3: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/3.jpg)
![Page 4: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/4.jpg)
Pituitary in pocket of sphenoid bone
Reflection of dura mater allows the entire gland to be surrounded by dura
Thus the arachnoid membrane and CSF cannot enter the sella turcica
![Page 5: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/5.jpg)
![Page 6: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/6.jpg)
Anterior pituitary cells and their hormones
Chromophobes
Cell type
Chromophils
Acidophils Basophils
Growth hormone TSH, ACTH Prolactin LH & FSH
![Page 7: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/7.jpg)
Histology of the pituitary gland
![Page 8: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/8.jpg)
ACTH secreting cells
PRL secreting cells
Immunohistochemical identification of cells
secreting specific adenohypophyseal
hormones
![Page 9: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/9.jpg)
HORMONE SECRETIONS OF THE ANTERIOR PITUITARY GLAND
Hormone % Pituitary cell population
TSH * 3-5%
ACTH * 15-20%
LH/FSH * 10-15%
GH # 40-50%
Prolactin # 10-15%
* Basophil # Acidophil
![Page 10: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/10.jpg)
Growth hormone and prolacin
![Page 11: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/11.jpg)
Actions of growth hormone
![Page 12: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/12.jpg)
MAJOR FACTORS CONTROLLING MAJOR FACTORS CONTROLLING GROWTH HORMONE SECRETIONGROWTH HORMONE SECRETION
STIMULATION INHIBITIONGHRH Somatostatin
Hypoglycaemia Hyperglycaemia
Decreased fatty acids Increased fatty acids
Starvation IGF’s
Exercise/sleep Growth hormone
Stress
Androgens, estrogens Progesterone
-adrenergic agonists -adrenergic
Serotonin Serotonin antagonists
Dopamine agonists Dopamine antagonists
![Page 13: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/13.jpg)
Symptoms of GH deficiencySymptoms of GH deficiency
•Decreased energy levels
•Social isolation
•Lack of positive well being
•Depressed mood
•Increased anxiety
![Page 14: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/14.jpg)
Clinical features of GH Clinical features of GH deficiencydeficiency
• Increased body fat
• Decreased muscle mass
• Decreased bone density
• Increased LDL and decreased HDL cholesterol
• Decreased insulin sensitivity
• Decreased total fluid volume
![Page 15: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/15.jpg)
Insulin induced hypoglycaemia to test for GH deficiency
![Page 16: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/16.jpg)
Treatment of poor growth
• Growth hormone
• Growth hormone releasing hormone
• IGF (growth hormone insensitivity)
• Oxandrolone
![Page 17: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/17.jpg)
Acromegaly
![Page 18: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/18.jpg)
Clinical features of acromegaly
Symptoms
• Carpal tunnel syndrome
• Arthralgia/arthritis
• Excessive sweating
• Angina
• Diurnal drowsiness
• Polydipsia, polyuria
• Renal colic
• Menstrual irregularities
• Impotence
Signs
• Enlarged hands and feet, jaw protusion
• Osteoarthritis
• Greasy skin
• Hypertension
• Cardiomyopathy
• Obstructive sleep apnoea
• Retinopathy, neuropathy
• Renal stones
• Hypogonadism
![Page 19: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/19.jpg)
Oral glucose load to test for GH excess
![Page 20: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/20.jpg)
Causes of pituitary failureDevelopmental abnormalities
Trauma
• Inflammation - viral bacterial or fungal infections
• Infiltrative disease e.g. sarcoidosis
• Tumours of the brain or hypothalamus
• Radiation
• Tumours of the pituitary gland
![Page 21: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/21.jpg)
Pituitary adenomas
Classified by size and hormones they produce
Microadenomas < 1cm diameter
Macroadenomas > 1 cm
30% prolactinomas
15% GH hypersecretion
10% ACTH secreting
10% gonadotrophinomas
< 1% TSH secreting
30% null cell (no hormone)
![Page 22: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/22.jpg)
Chromophobic adenoma
Macroadenomas• Sellar enlargement
• suprasellar damage
• visual loss
• hypopituitarism
• extension into cavernous sinuses
Microadenomas• Tend to present with symptoms of hormonal excess
![Page 23: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/23.jpg)
Treatment of pituitary adenomasTreatment of pituitary adenomas
• Medical
Dopamine agonists e.g. carbergoline/bromocryptine
GH analogue e.g. octreotide
GH receptor antagonists e.g. pegvisomant
• Surgical - transphenoidal surgery • Radiotherapy
![Page 24: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/24.jpg)
![Page 25: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/25.jpg)
Saggital MR scans of a) normal and b) a patient with a craniopharyngioma causing bitemporal hemianopia and
hypopituitarism
![Page 26: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/26.jpg)
including
TRH
Control of prolactin secretion
![Page 27: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/27.jpg)
Causes of Causes of hyperprolactinaemiahyperprolactinaemia
Common ~ 90%
• Dopamine D2 receptor antagonists (antiemetics/neurolepetics)
• Primary hypothyroidism (TRH)
Uncommon ~ 10%
• Pituitary tumour
• ‘Stalk syndrome’ (loss of dopamine)• Macroprolactinaemia (Immunoglobulin binds to
prolactin)
![Page 28: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/28.jpg)
![Page 29: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/29.jpg)
Coronal scans of a patient with a prolactinoma before and after
treatment with cabergoline
![Page 30: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/30.jpg)
Synthesis of arginine
vasopressin and
oxytocin
![Page 31: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/31.jpg)
Actions and control of vasopressin
![Page 32: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/32.jpg)
Increase of vasopressin secretion in response to:
a) % increase in blood volume depletion
b) Increasing plasma osmolality
![Page 33: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/33.jpg)
DIABETES INSIPIDUS
• CENTRAL - Impaired VP synthesis
• NEPHROGENIC - Resistance to VP
Lithium
CLINICAL TEST - 8h water deprivation/
saline load
SYMPTOMS - Polyuria/thirst
![Page 34: Endo 1.07 The pituitary gland Anatomy and histology of the pituitary gland Growth hormone and its control Actions of growth hormone Excess and deficiency.](https://reader035.fdocuments.us/reader035/viewer/2022062519/56649e295503460f94b16d30/html5/thumbnails/34.jpg)
Tests for central and nephrogenic diabetes
insipidus
Changes in plasma osmolality (A) and urine osmolality (B) after 8 hours water deprivation and after an intramuscular injection of a long-acting synthetic vasopressin analogue, desmopressin
AVP response to an infusion of 3-5% sodium chloride