HIPOTHALAMUS & HIPOFISIS

DEVELOPMENT OF PITUITARY (HYPOPHYSIS)

ADENOHYPOPHYSIS RATHKE’S POUCH(P. DISTALIS (THE ROOF OF THE MOUTH) P. TUBERALIS P. INTERMEDIA)

HYPOPHYSIS(PITUITARY)

NEUROHYPOPHYSIS DIVERTICULUM OF (including: DEVELOPING BRAIN NEURAL STALK P. NERVOSA)(Fig. 18.18)

Fig 18.18

THE HYPOTHALAMUS

• IN THE FLOOR AND INFERIOR PARTS OF THE WALLS OF THIRD VENTRICLE

• CONTAINS NEUROSECRETORY CELLS (ENDOCRINE FUNCTION): CLUSTERS OF NEUROSECRETORY CELLS/NUCLEIPRODUCE HORMONES

(RF/IF, oxytocine, ADH/vasopressin)(RF: releasing factor; IF: inhibiting factor; ADH: antidiuretic

hormone)(Fig. 18.5 & 18.6)

Hypothalamus

HYPOTHALAMUS - HYPOPHYSIS- TARGET GLAND

HYPOTHALAMUS RF/IFOXYTOCINE/ADH

ADENOHYPOPHYSIS NEUROHYPOPHYSIS

TROPHIC HORMONES (OXYT./ADH)(TROPHINS)

TARGET GLANDS

HORMONESCELLS/TISSUES CELLS/TISSUES

NEUROHYPOPHYSIS

SUPRAOPTIC ADH NUCLEUS (+ OXYTOCIN)(SON)

NEURONEUROSECRETORY SECRETORY CELLS CELLS (hypothalamus)

PARAVENTRICULAR OXYTOCINNUCLEUS (PVN) (+ADH)

(ADH: antidiuretic hormone/vasopressin)

NEUROHYPOPHYSIS

NEUROSECRETIONNEUROSECRETORY CELL

(Activate)

Substances in the bloodCLUSTERS OF (glucose, peripheral hormones) NEUROSECRETORY CELLS IN THE HYPOTHALAMUS

• ARCUATE NUCLEUS (ARC) (Transported)RF/IF ADENOHYPOPHYSIS

TROPHIC HORMONES Stored (in vesicles)

• SUPRAOPTIC NUCLEUS (SON)ADH (+OXYTOCIN) Released NEUROHYPOPHYSIS (into extracellular space)

• PARAVENTRICULAR NUCLEUS (PVN) Capillaries (fenestrated,

plexus)OXYTOCIN (+ ADH)

(veins)NEUROHYPOPHYSIS Blood

TARGET CELLS

HORMONE SYNTHESIZED

PVN/SON OXYTOCIN

PVN/SON NERVE (Distention of the uterus during labour/delivery OX/ADH Suckling the nipple by the baby)

NEUROHYPOPHYSIS

PREGNANT UTERUS ONSET OF LABOUR

BREAST (MAMMILLARY GLAND) MILK LETDOWN(smooth muscle/myoepithelium)

OOXXYYTTOOCCIINN

(octapeptide)

VASOPRESSIN (ADH) SON/PVN (octapeptide) (OSMORECEPTOR)

COLLECTING TUBULES INCREASED OSMOTIC PRESSURE(kidney) OF THE BLOOD (Haemoconcentration)INCREASED REABSORPTIONOF WATER

CONCENTRATED URINE(in attempt to retain water)

RF/IFADENOHYPOPHYSIS Primary plexus (cords/clumps of endocrine cells) Hypothalamohypophyseal

portal systemTrophic hormone

(Trophin

TARGET GLAND TARGET CELLS/TISSUESHORMONE

STRENOUS WORK(in a hot environment)

HYPOTHALAMUS (ARC)(RF/IF)

STRENOUS WORK INCREASED REABSORPTION OF WATER

HYPOTHALAMIC HORMONES TARGET CELLS

ALDOSTERON & REGULATION OF BLOOD PRESSURE

• THE NEGATIVE FEEDBACK SYSTEM THAT REGULATES THE SECRETION OF ALDOSTERON AND CONTROLS BLOOD PRESSURE

BLOOD VOL. INCREASESTO NORMAL

START

BLOOD VOL. DECREASES

BLOOD PRESSURE DECREASES

KIDNEY RELEASES RENININTO BLOODSTREAM

RENIN CONVERTS ANGIOTENSINOGENINTO ANGIOTENSIN I (AI)

AI PASSES THROUGH LUNGS,IS CONVERTED INTO AII

AII CIRCULATES IN BLOODSTREAM STIMULATES ZONA GRANULOSAOF ADRENAL GLAND TO RELEASE ALDOSTERONE; AII ALSO ACTS AS VASOCONSTRICTOR

BLOOD PRESS. INCREASESTO NORMAL

KIDNEY:INCREASE REABSORPTION OF WATER

(WATER RETENTION)

SODIUM & WATER REABSORPTIONINCREASE BLOOD VOL. IN

ASSOCIATION WITH INCREASED INGESTIONOF SALT & WATER

Oxytocin

ADH

TSH

ACTHGonadotropins:

LH, FSH

Prolactin

GH

FIG 13-4

ADENOHYPOPHYSIS

TROPHIC HORMONES HORMONES ACTING DIRECTLY

(TROPHINS) ON PERIPHERAL TISSUES

Thyroid Stimulating Hormone (TSH) Growth Hormone (GH)/Somatostrophin)

Adrenocorticotropic Hormone (ACTH) Prolactin (Luteotrophic Hormone/LTH)

Follicle Stimulating Hormone (FSH)

Luteinizing Hormone (LH)

PARS INTERMEDIA Melanocyte Stimulating Hormone (MSH)

Pigment formation

HYPOTHALAMUS

• Menggabungkan fungsi-fungsi yang memelihara homeostasis kimia dan suhu

• Berfungsi bersama dengan sistem limbik

• Mengendalikan keluarnya hormon-hormon dari pituitari anterior dan posterior

Figure 11-3: Autonomic control centers in the brain

HYPOTHALAMUS

Mensintesis dan melepaskan hormon-hormon hypophysiotropic :– Thyrotropin-releasing hormone (TRH)– Corticotropin-releasing hormone (CRH)– Gonadotropin-releasing hormone (GnRH)– Growth hormone-releasing hormone (GHRH)– Growth hormone-inhibiting hormone (GHIH)– Prolactin-releasing factor (PRF)– Prolactin-inhibitn hormone (PIH)

HYPOTHALAMUS

• Mensintesis hormon-hormon hypophysiotropic dalam badan sel neuron yang berlokasi dalam hypothalamus

• Membawa hormon turun melalui akson dan tersimpan dalam akhir syaraf (nerve endings)

• Mensekresi hormon-hormon dalam nadi/denyutan (pulses)

HYPOTHALAMUS: Mensekresi Hormon Hypophysiotropic

• Dipengaruhi oleh emosi• Dapat dipengaruhi oleh status metabolik

setiap individu• Dihantarkan ke pituitari anterior melalui

sistem portal hypothalamic-hypophyseal• Biasa memulai tahapan/urutan 3 hormon

Negative Feedback Controls: Long & Short Loop Reflexes

Figure 7-14: Negative feedback loops in the hypothalamicanterior

pituitary pathway

Negative Feedback Controls: Long & Short Loop Reflexes

Figure 7-15: Control pathway for cortisol secretion

Endocrine Control: Three Levels of Integration

Figure 7-13: Hormones of the hypothalamic-anterior pituitary pathway

ANTERIOR PITUITARY

MENSEKRESI HORMON-HORMON TROPIC SECARA PULSATILE

ANTERIOR PITUITARY

ANTERIOR PITUITARY HORMONES

Growth Hormone (GH, Somatotropin): hormon utama yang bertanggung jawab terhadap pengaturan pertumbuhan tubuh, dan penting dalam metabolisme

Thyroid-stimulating Hormone (TSH): menstimulasi sekresi hormon thyroid & pertumbuhan kelenjar thyroid

Adrenocorticotropic Hormone (ACTH): menstimulasi sekresi kortisol oleh korteks adrenal & memacu pertumbuhan korteks adrenal

ANTERIOR PITUITARY

Follicle-stimulating Hormone (FSH): Wanita: menstimulasi pertumbuhan dan perkembangan folikel ovarium, memacu sekresi estrogen oleh ovarium. Pria: dibutuhkan untuk produksi sperma

Luteinizing Hormone (LH): Wanita: bertanggung jawab untuk ovulasi, pembentukan corpus luteum dalam ovarium, dan pengaturan sekresi ovarium pada hormon seks wanita. Pria: menstimulasi sel dalam testes untuk mensekresi testosterone

Prolactin: Wanita: menstimulasi perkembangan payudara dan produksi susu. Pria: berperan dalam fungsi testicular

ANTERIOR PITUITARY

Mensintesis berbagai hormon pituitari anterior pituitary oleh berbagai macam populasi sel.Corticotropes - ACTH

Lactortropes - Prolactin

Somatotropes - GH

Thyrotropes - Thyrotropin

Gonadotropes - FSH, LH

• Stimulasi Hypothalamic – dari CNS • Stimulasi Pituitary–dari hypothalamic trophic Hs• Stimulasi kelenjar Endocrine –dari pituitary trophic

Hs

Pengaturan Endokrin: Three Levels of Integration

Pathologies: Over or Under Production

Figure 7-19: Negative feedback by exogenous cortisol

Pathologies: Due to Receptors

Figure 7-20: Primary and secondary hypersecretion of cortisol

POSTERIOR PITUITARY

Terdiri atas akhiran akson dari badan sel dalam hypothalamus (supraoptic dan paraventricular)

Axons melintas dari hypothalamus menuju ke posterior pituitary melalui traktus hypothalamohypophysial

Hormon-hormon Posterior pituitary disintesis dalam badan sel dalam neuron dalam nukleus supraoptic dan paraventricular

POSTERIOR PITUITARY

Hormon-hormon yang disintesis dalam hypothalamus ditransportasi turun sepanjang akson menuju ke akhiran pada posterior pituitary

Hormon-hormon disimpan dalam vesikel-vesikel dalam posterior pituitary sampai dengan dilepaskan ke dalam sirkulasi

Principal Hormones: Vasopressin & Oxytocin

Figure 7-12: Synthesis, storage, and release of posterior pituitary hormones

POSTERIOR PITUITARY

Oxytocin:

Disintesis sebagai hormon prekursor: prepro-oxyphysin

Bekerja utamanya pada payudara dan uterus

Meningkatkan kontraksi otot polos Vas Deferens

POSTERIOR PITUITARY

Vasopressin

Osmolalitas plasma dimonitor olehosmoreceptors dalam hipothalamus

Peningkatan osmolalitas plasma menstimulasi sekresi vasopressin

Perubahan sedikit saja di atas tekanan osmotik plasma normal ( 285 mosm/kg) menstimulasi dilepaskannya vasopressin

POSTERIOR PITUITARY

Sekresi vasopressin juga distimulasi oleh:

1. Penurunan volume darah yang banyak

2. Penurunan tekanan darah

POSTERIOR PITUITARY

Kerja Vasopression :

Menurunkan ekskresi air oleh ginjal (V2 receptors)

Constricts blood vessels (V1 receptors)

Meningkatkan hormon adrenocorticortropin (V1B receptors)

Summary of the Endocrine System

Figure 7-2-3: ANATOMY SUMMARY: Hormones

Summary of the Endocrine System

Figure 7-2-2: ANATOMY SUMMARY: Hormones