PITUITARY GLAND HYPOTHALAMUS Anatomical Relations Pituitary Sella Turcica
- Slides: 46
PITUITARY GLAND HYPOTHALAMUS
Anatomical Relations • • • Pituitary Sella Turcica Optic Chiasm Median Eminence Mamillary Body Cavernous Sinus (not visible)
Subdivisions of the Pituitary (Hypophysis) • Adenohypophysis (Anterior Pituitary) – Pars Distalis – Pars Intermedia – Pars Tuberalis • Neurohypophysis (Posterior Pituitary) – Pars Nervosa – Infundibular Stalk
Adenohypophysis
Pars Distalis
Cells: • Acidophils – Somatotroph – Lactotroph • Basophils – Gonadotrophs – Thyrotrophs • Corticotrophs (can’t distinguish) • Chromophobes
Hormones • Prolactin/Growth Hormone Family – Prolactin – Growth Hormone • Glycoprotein Family – Thyroid Stimulating Hormone (TSH) – Gonadotropins: • Follicle Stimulating Hormone (FSH) • Luteinizing Hormone (LH) • Pro-opiomelanocortin Family – ACTH
Prohormones • Many small hormones, especially peptide hormones, are synthesized as part of a larger peptide. • The large peptide is called a prohormone • The active hormone is cut of the larger prohormone by an enzyme. • The prohormone generally is not active.
POMC
Pars Intermedia • MSH – Pro-opiomelanocortin Family – Alpha – Beta • Also in Hypothalamus – Involved in regulating metabolism and appetite
Pars Tuberalis
Hypothalamus
Hypothalamo-hypophyseal Portal System • Superior hypophyseal artery • Portal Vessels • Capillary Bed of Pars Distalis
Hypothalamic Releasing Hormones • • • Thyrotropin Releasing Hormone (TRH) Corticotropin Releasing Hormone (CRH) Gonadotropin Releasing Hormone (Gn. RH) Growth Hormone Releasing Hormone (GRH) Somatostatin (GIH) Prolactin Inhibiting Hormone (PIH)
Feedback Control of Anterior Pituitary • Long Loop • Short Loop • Ultrashort Loop • Amplitude • Frequency
Pathologies • Hypersecretion • Hyposecretion • Classification – Primary (Pituitary’s Target Gland) – Secondary (Pituitary) – Tertiary (Hypothalamus) • Pituitary adenomas
Growth Hormone (GH)
Chemistry • • Single chain protein, 191 amino acids MW 21, 500 2 -disulfide bridges Synthesized as part of a larger protein, pre. GH (MW 28, 000)
Function • Stimulate Secretion of Insulin-like Growth Factor 1 (IGF-1) • Increase linear growth • Increase protein synthesis • Decrease protein catabolism • Increase lipid catabolism • Decrease carbohydrate uptake and utilization
GHRH Control of Secretion: Somatostatin (GHIH) Stimulates • GRH Inhibits the Secretion of GH – Neural regulation • • Diurnal Rhythms Deep Sleep Stress Exercise – Metabolic control • Blood Glucose • Blood Fatty Acids • Blood Amino Acids • Somatostatin Secretion of GH
Feedback • GH--Short Loop • IGFs--Long Loop • Metabolic control – Blood Glucose – Blood Fatty Acids – Blood Amino Acids • Neural regulation – – Diurnal Rhythms Deep Sleep Stress Exercise
Long-Loop Diurnal Feedback Rhythms Exercise Sleep Regulation Stress GH Short-Loop Somatostatin Feedback Hypothalamus Serum: Glucose Lipids Amino Acids GRH Ant. Pituitary IGF 1 Liver IGF 1 GH Serum: Glu. Lipids Amino Acids Other Target Tissues
Pathologies
Hypersecretion
Gigantism
Acromegaly
Glucose Intolerance • A form of Diabetes • Caused by Hyperglycemia • Leads to Type II Diabetes
Hyposecretion
Dwarfism
Prolactin (PRL) • Chemistry • Function: • Control of Secretion
Control of PRL Baby Suckles Nipple Baby Weaned Sensory Impulses to Hypothalamus Milk Production Dopamine Secretion Prolactin
Adrenocorticotropic Hormone (ACTH) • • Chemistry Biosynthesis Function Control of Secretion
Control of ACTH Stress Sleep Hypothalamus CRH Ant. Pituitary ACTH Adrenal Cortex Glucocorticoids
Thyroid Stimulating Hormone (TSH) • Chemistry – Glycoprotein – 2 Chains • Function – Stimulate production of thyroid hormone (T 4 & T 3)
Control of TSH Hypothalamus TRH Anterior Pituitary TSH Thyroid T 4 & T 3 T 4
Gonadotropins • Follicle Stimulating Hormone (FSH) • Luteinizing Hormone (LH) • Chemistry – Glycoprotein • Function – Stimulate function of the reproductive tract
Gonadotropin Control Hypothalamus Gn. RH (FSH Only) Ant. Pituitary FSH LH Gonad Inhibin E 2 & P or T
Posterior Pituitary Pars Nervosa
Anatomical Structure • An extension of the hypothalamus • Pituicytes • Axons • Supraoptic n. – ADH • Paraventricular n. – Oxytocin
Hormones
Antidiuretic Hormone (ADH, Vasopressin) • Supraoptic nucleus • Chemistry • Receptors – V 1 – V 2
Function: • Vasoconstriction – Increase Blood Pressure • Increase permeability of collecting tubule to H 2 O
Blood Pressure Control of ADH Blood Pressure Vasoconstriction Blood Vessels Supraoptic Nucleus Blood Osmolality Posterior Pituitary ADH H 2 O Absorption Kidney, Collecting Duct
Diabetes insipidis
Oxytocin (Pitocin) • Paraventricular nucleus • Chemistry • Receptors – Phosphatidylinositol pathway • Function – Increases frequency and duration of uterine smooth muscle contraction – Stimulates milk “let down. ”
Positive Feedback Delivery Shuts Control of Oxytocin Loop Shut-Off Suckling On Nipple Off Positive When Child. Loop is Full Feedback Unknown? Hypothalamus Labor Contractions Milk Let-Down Post. Pituitary Mammary Myoepithelial Cells Oxytocin Uterine Smooth Muscle
- Pituitary gland anatomical relations
- Endocrine system function
- Sella turcica
- Sellar cavity
- Cribriform plate
- Hyposecretion of prolactin
- Hypothalamus hormones
- Endocrine gland hormone
- Thyoid gland
- Pituitary gland and pineal gland spiritual
- Pituitary gland division
- What is the name
- Pituitary gland
- Hypersecretion of prolactin
- Embryonic origin of pituitary gland
- Triple 'f' of gland for flight, fright and fight is
- Pituitary gland hormones
- Hypophyseal fossa and pituitary gland
- Putery gland
- Circulação
- Histology of pituitary gland
- Pituitary gland disorders
- Follicular epithelium
- Brainstem glioma
- Exocrine glands function
- Diaphragma sellae
- Pituitary gland thyroid
- Hormoni hidrosolubili
- Pituitary venous drainage
- Colloid anatomy
- Where is kidney pain felt diagram
- Hypophyseal fossa and pituitary gland
- Anterior pituitary
- Pituitary gland function
- Hormones secreted by adenohypophysis
- Pateys stylomandibular tunnel
- Adrenal gland relation
- Nidus parotideus
- Meteofax
- Equazione paraboloide ellittico
- Giovanni sella
- Disequazioni due variabili
- Simb mtb
- Matematika derivate
- Empty sella
- Employee relations in public relations
- Hypothalamus