Hypothalamus and hypophysis cerebri

Three reproductive processes controlled by the hypothalamus

1. Gametogenesis 2. Menstrual cycle 3. Secondary sexual characteristics

What are the parts of the hypophysis cerebri?

1. Andenohypophysis - Pars tuberalis, pars intermedia and pars distalis (anterior) 2. Neurohypophysis - Median eminance, infundibular stem, pars nervosa (posterior)

Seven efferents of the hypothalamus

1. Anterior and medial dorsal nuclei of the thalamus 2. Amygdaloid nuclei 3. Hippocampus 4. Reticular formation of the brain stem 5. Autonomic nuclei of the brain stem and spinal cord 6. Tubero-infundibular tract from the arcuate nucleus to the median eminance and infundibular stem of the pituitary gland 7. Hypothalamo-hypophysial tract from the supraoptic and paraventricular nuclei to the posterior lobe of the pituitary gland

What nuclei (part) of the hypothalamus does the following: 1. Endocrine 2. Autonomic nervous system 3. Temperature regulation 4. Regulation of food and water intake

1. Arcuate nucleus through the tuberoinfundibular tract 2. Cranial - parasympathetic, Caudal - Sympathetic 3. Cranial - sweating & vasodilation, Caudal - shivering & vasoconstriction 4. Medially - satiety, Laterally - hunger and thirst

Cells that make up the adenohypophysis

1. Chromophobes - these are minimally staining and are precursors to chromophils. They are produce every little or no hormones 2. Chromophils - Hormone producing cells. It includes basophophils and acidophils. Basophils stain blue/blue purple and acidophils appear red/orange.

What four structures does the neurohypophysis contain?

1. Non-myelinated nerve fibers: These are fibers arising from the hypothalamo-hypophysial tract. They carry vasopressin and oxytocin. 2. Herring bodies - these are the neurosecretory terminals of the axons 3. Pituicytes: Neuroglial cells that support the axons 4. Venous sinusoids

Two neurohypophysial hormones synthesized by the hypothalamus

1. Oxytocin 2. Vasopressin

Ten endocrine organs of the body

1. Pituitary gland 2. Thyroid gland 3. Parathyroid 4. Suprarenal 5. Pineal gland6. Islets of Langerhans of the pancreas 7. Ovaries 8. Testis 9. Kidneys 10. Placenta

Seven parts of the hypothalamus

1. Preoption 2. Supraoptic 3. Tuberal 4. Mamillary 5. Medially the Perventricular and 6. Intermediate, and 7. Lateral region

What are the nine nuclei of the hypothalamus?

1. Supraoptic 2. Paraventricular 3. Acruate 4. Lateral 5. Dorsomedal 6. Ventromedial 7. Posterior, 8. Medial, 9. Lateral mamillary nuclei

Five afferents of the hypothalamus

1. Thalamic anterior and medial dorsal nuclei 2. Amygdaloid nucleus via the stria terminalis 3. Reticular formation of the brain ste, 4. Hippocampus via the column of the fornix 5. Frontal cortex

Developmental abnormality of the adenohypophysis

Remnants of the connection between Ruthke's pouch and the hypothalamus can form turmors called craniopharyngiomas

Four types of basophils

Secrete glycoprotein hormones 1. Corticotropes - adrenocorticotropic hormone 2. Thyrotropes -thyroid stimulating hormone 3. Gonadotropes - FSH and LH 4. Melanotropes - melanocyte stimulating hormone

What are the superior, inferior, anterior, posterior and lateral relations of the hypophysis cerebri?

Superior - Optic chiasm, tuber cinerium, diaphragma sellae, infundibular recess of the third ventricle Inferior - Sphenoid bone and sphenoidal air sinus Anterior - Tuberculum sellae and the anterior intercavernous sinus Posterior - Dorsum sellae and posterior cavernous sinus Lateral - Cavernous sinus and its contents

Superior, inferior, anterior and posterior extent of the hypothalamus

Superior - hypothalamic sulcus, Inferior - with structures forming the floor of the third ventricle, Anterior - lamina terminalis, Posterior - vertical line drawn behind the mamillary body

Blood supply of the pituitary gland

Arterial supply 1. Superior hypophysial artery - median eminence and infundibular stem of the neurohypophysis 2. Inferior hypophysial aretery - pars nervosa (posterior) - the above are from the internal carotid artery 3. Hypothalamo-hypophysial portal vessels - these arise from capillaries in the median eminence and infundibular stem Venous drainage into the cavernous sinus

Clinical correlates: What do the following result in? Tumor compressing the optic chiasma leads to ---> Pressure over the hypothalamus ---> Damage to the posterior lobe ---> Acidophil adenoma ---> Basophil adeoma --->

Bitemporal hemianopia Hypothalamic syndrome Diabetes insipidus Giganitism, acromegaly Cushing's syndrome

What separates the medial and lateral parts of the hypothalamus?

Column of the fornix

Development of the adenohypophysis

Develops from Rathke's pouch - Rathke's pouch is ectodermal diverticulum (an outpouching of a hallow cavity) appearing from the roof of the stomodeum - It then seperates form the stomodeum - Lies on top of the downgrowth from the forebrain vesicle (diencephalon) - Posterior wall remains thin and forms the pars intermedia

Development of the neurohypophysis

Develops from the diencephalon - A downgrowth from the forebrain vesicle forms - The downgrowth rests on the back of the Ruthke's pouch - The growth stays in contact with the hypothalamus and develops into the pas posterior, infundibular stem and median eminence

What are the weight, transverse and anteroposterior measurements of the pituitary gland?

It weights 500mg and measures 12mm transversely and 8mm anteroposteriorly

Relation of the hypothalamus to the lateral ventricle

Makes up the floor and lateral wall

In what is the pituitary gland situated?

The sella turcica on the body of the sphenoid bone

Two types of acidophils

These cells secrete polypeptide hormones 1. Somatotropes - growth hormone 2. Mammotropes - prolactin