Which of the following is NOT a subdivision of the hypothalamus?

A) Lateral Hypothalamic Areas

B) Medial Forebrain Bundle

C) Periventricular zone

D) Intermediate zone

E) Cerebral Cortex

What is the anterior boundary of the hypothalamus?

A) Mammillary body

B) Optic chiasma

C) Anterior commissure

D) Tuber cinereum

E) Thalamus

What do lymphoid follicles in the thyroid contain?

Germinal centers.

Which part of the brain is the hypothalamus located in?

A) Hindbrain

B) Midbrain

C) Forebrain

D) Cerebellum

E) Brainstem

Which structure is located inferiorly to the hypothalamus?

A) Thalamus

B) Mammillary body

C) Subthalamus

D) Structures in the floor of the 3rd ventricle

E) Cerebral cortex

Which endocrine glands are affected by hypopituitarism?

The adrenal glands, thyroid, testes, or ovaries.

How is the hypothalamus subdivided?

Divided by the Fornix.

What is the size of the hypothalamus compared to?

A) The size of a walnut

B) The size of a pea

C) The size of an almond

D) The size of a grape

E) The size of a grain of rice

What is the size of the pituitary gland compared to?

A) The size of a walnut

B) The size of a pea

C) The size of an almond

D) The size of a grape

E) The size of a grain of rice

Which of the following is NOT a subdivision of the hypothalamus?

A) Anterior region

B) Posterior region

C) Lateral region

D) Medial region

E) Cerebellar region

What is the primary function of the hypothalamus?

A) Coordination of voluntary movements

B) Regulation of autonomic functions and homeostasis

C) Processing visual information

D) Control of balance and posture

E) Memory storage and retrieval

What is the primary blood supply to the pituitary gland?

A) Carotid artery

B) Vertebral artery

C) Hypophyseal portal system

D) Subclavian artery

E) Aorta

What structure divides the hypothalamus into two lateral areas?

A) Fornix

B) 3rd ventricle

C) Internal Capsule

D) Medial Forebrain Bundle

E) Periventricular zone

What is the primary function of the hypothalamic nuclei?

A) To regulate blood pressure

B) To process visual information

C) To control various physiological functions

D) To facilitate motor coordination

E) To store memories

How are the hypothalamic nuclei grouped?

A) By size

B) By color

C) By regional distribution and function

D) By shape

E) By age

Which zone of the Medial Forebrain Bundle is described as thin?

A) Lateral zone

B) Intermediate zone

C) Periventricular zone

D) Lateral Hypothalamic Area

E) Medial zone

What is the weight range of the thyroid gland?

25 - 40 grams.

What is the approximate volume of the hypothalamus in adult humans?

A) 10 cm^3

B) 4 cm^3

C) 1 cm^3

D) 8 cm^3

E) 6 cm^3

What percentage of the total weight of the adult human brain does the hypothalamus represent?

A) 0.1%

B) 0.3%

C) 1%

D) 0.5%

E) 2%

Which structure is located directly above the hypothalamus?

A) Cerebellum

B) Brainstem

C) Thalamus

D) Corpus callosum

E) Pineal gland

From which part of the brain does the hypothalamus develop?

From a swelling in the diencephalon.

From which part of the diencephalon is the hypothalamus formed?

A) Dorsal part

B) Lateral part

C) Ventral part

D) Rostral part

E) Caudal part

What is the location of the supraoptic region?

It lies above the optic chiasma.

What is a common consequence of iodine deficiency?

Hypothyroidism.

What substances are transported in the infundibular stalk?

Neurosecretory substances called releasing and releasing inhibitory factors/hormones.

Which nuclei are found in the supraoptic region?

Supraoptic Nuclei, Suprachiasmatic Nuclei, Anterior Hypothalamic Nuclei, Paraventricular Nuclei, and Periventricular Nuclei.

What theory explains the regulation of body weight in the hypothalamus?

Set Point Theory.

What autoimmune disease destroys thyroid cells?

Hashimoto’s Thyroiditis.

Where are hormones like TSH, FSH, LH, ACTH, GH, and PRL stored?

In the anterior lobe of the pituitary gland.

Which are the most prominent nuclei in the supraoptic region?

Supraoptic and Paraventricular Nuclei.

What is the primary source of blood supply to the hypothalamus?

Via the Circle of Willis.

What evidence supports the Set Point Theory?

Neurons respond consistently to glucose, free fatty acids, and insulin levels.

What structures are included in the tuberal region of the hypothalamus?

Infundibulum, tuber cinereum, and the area around it.

What are Hurthle Cells?

Oncocytic cells found in cancerous or benign thyroid nodules.

What is the medial boundary of the hypothalamus?

Cavity of the 3rd ventricle.

What is hypopituitarism?

A condition characterized by underactivity of the pituitary gland affecting hormonal production.

What is the largest endocrine organ in the human body?

The thyroid gland.

What are the two parts of origin for the hypothalamus and pituitary gland?

1. Ectodermal outpocketing of the stomodeum. 2. Downward extension of diencephalon.

What are the two largest tracts that carry fibers to and from the mammillary nuclei?

Fornix and Mammillothalamic Tract.

What hormones do the supraoptic and paraventricular nuclei secrete?

Vasopressin (ADH), Oxytocin, and Corticotropin-releasing Hormone.

Which arteries provide blood supply to the preoptic area of the hypothalamus?

Anteromedial Branches from the Anterior Cerebral Artery and Anterior Communicating Artery.

What is the role of the arcuate nucleus in the hypothalamus?

It controls hunger and satiety through a reciprocal relationship.

Which nuclei are found in the tuberal region?

Dorsomedial Nuclei, Ventromedial Nuclei, Arcuate/Infundibular Nuclei, and Premammillary Nuclei.

What structure lies laterally to the hypothalamus?

Internal Capsule.

What is a characteristic feature of Hurthle Cells?

Grainy, polygonal, and strongly stained thyrocyte cytoplasm.

What are pituicytes?

The most numerous cells of the neurohypophysis.

What is the function of the Stria Terminalis?

It serves as an afferent pathway to the hypothalamus from the amygdala.

What is the approximate weight of the hypothalamus?

About 5 grams.

What is the pars tuberalis?

A superior circumferential extension of pars distalis that encircles the posterior pituitary gland.

From where are pituicytes derived?

They are derived from the floor of the diencephalon.

What are the two zones of the Medial Forebrain Bundle?

Periventricular (thin) zone and Intermediate (thick) zone.

How does the hypothalamus control the anterior lobe of the pituitary gland?

Through the Tubero-hypophyseal (Tuberoinfundibular) Tract.

What percentage of adenohypophyseal cells are TSH cells?

Less than 5%.

What is the shape and size of TSH cells?

Medium sized and angulated or elongate.

What do follicular cells (thyrocytes) line?

The follicles of the thyroid gland.

What is the percentage of adenohypophyseal cells that are corticotroph cells?

15-20%.

What is the origin of the adenohypophysis?

It originates from the ectodermal out-pocketing of the primitive oral cavity called Rathke’s pouch.

When are Lactotroph cells fully recognized?

At 23 weeks GA.

What is the significance of the hypothalamus in the brain?

It plays a crucial role in various functions including hormone regulation.

What type of meninges investment does the pituitary gland lack?

Leptomeningeal investment.

Are the supraoptic and paraventricular nuclei large or small?

Both are not large but easily recognized.

What is the Medial Forebrain Bundle?

An ill-defined bundle of unmyelinated and thinly myelinated axons that courses through the lateral hypothalamic area.

What connects the two lobes of the thyroid gland?

An isthmus.

What is a potential effect of tumors in the anterior pituitary?

They can produce excessive amounts of hormones, overstimulating other endocrine glands.

What do the hypothalamic arteries anastomose with?

The capillary plexus of the pituitary gland.

What are the two components of the preoptic nucleus?

Medial Preoptic Nucleus and Lateral Preoptic Nucleus.

What is the direction used to describe the regional distribution of hypothalamic nuclei?

From rostral to caudal (or antero-posterior direction).

What is neurosecretion in the context of the hypothalamus?

The process where neurons in some hypothalamic nuclei produce active peptides that discharge to neighboring capillaries.

What connects the pituitary gland to the hypothalamus?

The infundibulum of the pituitary stalk.

From which part of the diencephalon is the hypothalamus formed?

The most ventral part.

Which hormone is secreted in the supraoptic nuclei?

Vasopressin (ADH).

What is the dorsal border of the hypothalamus?

Hypothalamus sulcus.

What is the larger, distal part of the anterior lobe of the pituitary gland called?

Pars distalis.

What is unique about the tissue composition of the adenohypophysis compared to the neurohypophysis?

The adenohypophysis appears very cellular compared to the neurohypophysis.

What areas are supplied by the Posteromedial Branches from the Posterior Communicating Artery?

Tuberal nuclei, Mammillary nuclei, and Caudal portion of lateral hypothalamic nuclei.

Which artery supplies the posterior nuclei of the hypothalamus?

Thalamoperforating Branches from the Posterior Cerebral Artery.

What physiological functions does the hypothalamus play a role in?

Appetite control, sleep regulation, and behavioral traits like depression and pleasure.

What is the primary source of venous drainage for the hypothalamus?

The Internal Jugular Vein.

What is the volume of neural tissue that makes up the hypothalamus?

4 cm³.

Which sinus drains venous blood from the cavernous sinus?

Superior and Inferior Petrosal Sinuses.

When does the thyroid begin to function?

At the end of the third month of gestation.

What is the size of the pituitary gland?

The size of a pea.

What type of cells are corticotroph cells?

Basophilic cells that secrete Adrenocorticotropic Hormones (ACTH).

What is neurosecretion in the hypothalamus?

The process where neurons produce active peptides that discharge to neighboring capillaries.

What structures form the posterior and superior border of the hypothalamus?

Midbrain tegmentum and mammillary bodies.

What are the relations of the hypothalamus?

Connections with other brain structures.

What structures are located inferiorly to the hypothalamus?

Structures in the floor of the 3rd ventricle, including tuber cinereum, infundibulum, and mammillary body.

What does the pars intermedia contain?

Basophils (corticotrophs), chromophobes, and numerous colloid-filled cysts.

What is the role of the hypothalamus in relation to the posterior lobe of the pituitary gland?

It controls the posterior lobe (Neurohypophysis) through three tracts.

What are the three tracts that connect the hypothalamus to the posterior lobe of the pituitary gland?

Paraventriculohypophyseal Tract, Supraopticohypophyseal Tract, and Hypothalamohypophyseal Tract.

Where is the hypothalamus located in relation to the thalamus?

Inferior to the thalamus, forming the lateral/lower walls and floor of the third ventricle.

What is the pars intermedia?

A small intermediate portion between the anterior and posterior portions of the gland, a remnant of the hypophyseal pouch of Rathke.

What is the primary component of the posterior lobe (neurohypophysis)?

Pars nervosa, which contains approximately 100,000 unmyelinated neurons.

What are the main components of the hypothalamus module?

Anatomy, Embryology, Boundaries, Relations, Functions, Subdivisions.

What is the anatomical term for the pituitary gland?

Hypophysis cerebri.

Where is the pituitary gland located?

At the base of the brain in the middle cranial fossa.

Where is the hypothalamus located in relation to the thalamus?

Below the thalamus, separated by the hypothalamic sulcus of Monro.

When do Somatotroph cells appear during gestational age?

At 8-9 weeks GA.

What do C-cells (parafollicular cells) secrete?

Calcitonin.

What is the weight of the pituitary gland?

0.5 grams.

What are the three parts of the adenohypophysis?

Pars distalis, pars intermedia, and pars tuberalis.

What is the significance of the infradiaphragmatic hypophysial cistern?

It is formed by the reflection of leptomeninges and explains the higher incidence of meningiomas in the suprasellar surface.

What is another name for the arcuate nucleus?

Infundibular or periventricular nucleus.

How does the hypothalamus influence the adenohypophysis?

By secreting releasing or release-inhibiting factors (Releasing Hormones).

What forms an arterial ring around the upper part of the infundibulum stalk?

Hypothalamic branches of the Superior Hypophyseal Artery.

How long can the thyroid gland supply hormones without additional synthesis?

Up to 3 months.

From which embryonic layer does the thyroid gland originate?

Foregut endoderm.

What percentage of the total weight of the adult human brain does the hypothalamus represent?

0.3% (0.03g).

What is the size comparison of the hypothalamus?

The size of an almond.

Why is the hypothalamus described as the 'Head of Ganglion of the Autonomic Nervous System'?

Because stimulation of the hypothalamus produces autonomic responses.

What is the function of the hypophyseal portal system?

It allows vascular anastomoses of the adenohypophysis, neurohypophysis, and hypothalamus.

What structures define the anterior border of the hypothalamus?

Anterior commissure, optic chiasm, lamina terminalis.

What is the hypophyseal portal system associated with?

Blood supply of the pituitary gland.

What are herring bodies?

Bulging segments of unmyelinated axons containing secretory products.

From where does the Tubero-hypophyseal Tract arise?

The tuberal region, mainly from the arcuate nucleus.

What is the role of the portal venules in the pars tuberalis?

They are part of the hypophyseal portal system.

What is the structure of pituicytes?

Elongated, uni- or bipolar cells that display prolongation of cytoplasm into one or more processes.

What connects the thyroid to the tongue?

The thyroglossal duct.

Which nuclei secrete Vasopressin (ADH)?

Supraoptic nuclei.

Where is Oxytocin secreted from?

Paraventricular nuclei.

What are the two types of cells found in the Pars distalis?

Chromophils and Chromophobes.

What types of connections do the hypothalamic nuclei have?

Efferent and afferent connections that bring nuclei into contact with CNS structures.

What separates the anterior lobe from the optic chiasma?

Diaphragma sellae.

What do the axons from the paraventriculo-hypophyseal tract join to form?

The Supraoptico-hypophyseal Tract.

What is stored in the colloid of thyroid follicles?

T3 and T4 hormones.

What part of the pituitary gland is formed from the hypophyseal pouch of Rathke?

Adenohypophysis.

What structures are located anteriorly to the hypothalamus?

Anterior commissure, lamina terminalis, and optic chiasma.

What is the Tubero-hypophyseal Tract primarily associated with?

The anterior lobe of the pituitary gland (Adenohypophysis).

What is the primary function of the pars distalis?

It accounts for 75% of the gland and contains important endocrine cells.

Which neurons are associated with the supraoptic and paraventricular nuclei?

Magnocellular neurons.

What type of tumors are most commonly found in the anterior pituitary?

Benign tumors.

What is the role of the posterior nucleus in the hypothalamus?

It plays a role in thermoregulation.

What is the name of the bundle that divides the medial hypothalamus?

Medial Forebrain Bundle (MFB).

Where is the preoptic nucleus located?

Adjacent to the Lamina Terminalis.

What hormones do TSH cells secrete?

Thyroid stimulating hormones (TSH).

When are oxytocin and vasopressin detectable in the pars nervosa?

23 weeks.

What is the Paraventriculo-hypophyseal Tract formed by?

Axons of the paraventricular nucleus and axons from the supraoptic nucleus.

What hormones do Acidophils secrete?

Growth hormones (GH) and Prolactin (PRL).

What are the major parts of the brain reviewed in the module?

Forebrain, Midbrain, Hindbrain.

What is the function of the neurohypophysis?

Transfer of hormonal substances from neurosecretory granules to the intravascular space.

How is the adenohypophysis connected to the hypothalamus?

Via the tuberoinfundibular tract, where axonal processes of parvocellular neurons project into the median eminence.

What hormones do Gonadotroph cells secrete?

Follicle stimulating hormones (FSH) and luteinizing hormones (LH).

What substances are transported by the Tubero-hypophyseal Tract?

Releasing and releasing inhibitory factors/hormones (TSH, FSH, LH, ACTH, GH, PRL).

What type of neurons are found in the tuberoinfundibular tract?

Parvicellular neurons.

What is another name for the anterior pituitary gland?

Pars distalis.

What is the relationship between pituicytes and neurosecretory fibers?

Pituicytes are closely associated with neurosecretory fibers.

What is unique about the mammillary nucleus compared to other hypothalamic nuclei?

It is not closely related to autonomic and endocrine functions but plays a role in memory.

What can persist as remnants of the thyroglossal duct?

Thyroglossal cyst or thyroglossal fistula.

How are the hypothalamic nuclei categorized?

According to regional distribution and their different functions.

What are Chromophils?

Secretory cells that store hormones in cytoplasmic granules.

What are the two subtypes of Chromophils?

Acidophils and Basophils.

What characterizes the fiber tracts and connections of the hypothalamus?

They are extensive and complex, with some organized into definite bundles and others being diffuse and difficult to trace.

What are the two origins of the pituitary gland?

Somatoectodermal protrusion and neuroectodermal protrusion.

What are the boundaries of the hypothalamus in the anteroposterior direction?

Extends from the lamina terminalis to the posterior of the mammillary body.

Which hormone is secreted in the paraventricular nucleus?

Oxytocin.

Which nuclei are located laterally to the hypothalamus?

Subthalamic nuclei.

What distinguishes Thyrotroph cells?

They secrete thyroid-stimulating hormone (TSH).

Where do the axons of the magnocellular nuclei terminate?

In the pars nervosa.

Where is the thyroid gland located?

On the anterior aspect of the neck, anterior and inferior to the larynx.

What vision problems can large tumors in the anterior pituitary cause?

Pressure on the optic nerves leading to vision problems.

What guides the descent of the thyroid gland?

The tractus thyroglossus.

What is an example of a tumor that can overstimulate other endocrine glands?

Prolactinomas.

When do the thyroid lobes form during development?

By the 7th week of gestation.

From which region does the Tubero-hypophyseal Tract arise?

From the tuberal region, mainly from the arcuate nucleus.

What are follicles in the thyroid gland?

Hollow structures that store colloidal material.

What is the size of the pineal gland?

The size of a grain of rice.

How does the venous drainage of the posterior pituitary lobe occur?

Through short and long portal veins that join the pars distalis capillary bed and the inferior hypophyseal vein draining directly to the cavernous sinus.

What is the role of Lactotroph cells?

To secrete prolactin (PRL).

What role does calcitonin play in the body?

It is involved with calcium metabolism.

What type of capillaries are found in the neurohypophysis?

Fenestrated capillaries derived from the inferior hypophyseal artery.

What forms the sellar diaphragm?

Dura proper covers the lateral aspects of the cavernous sinuses and forms the sellar diaphragm.

What is Grave’s disease?

An autoimmune disorder that leads to hyperthyroidism.

Which hormones are regulated by the hypothalamus?

Growth hormone, ACTH, thyrotropin, and gonadotropins (FSH and LH).

How does the hypothalamus connect to the pituitary gland?

Via a stalk.

What type of neuronal structure is found in the hypothalamus?

Ill-defined neuronal nucleus and clusters of nuclei.

What connects the posterior and anterior pituitary gland to the hypothalamus?

Infundibular stalk.

What is the rostrocaudal extent of the hypothalamus?

About 10 mm.

What arteries supply the pituitary gland?

Superior hypophyseal artery and inferior hypophyseal artery.

What is the Hypothalamo-hypophyseal Tract formed by?

Both the Paraventriculo-hypophyseal and Supraoptico-hypophyseal tracts.

What is the precursor for active thyroid hormones?

Thyroglobulins.

What is the function of the pituitary gland?

It influences the activities of many other endocrine glands and organ systems.

What structure is located posteriorly to the hypothalamus?

Subthalamus.

When do Gonadotroph cells develop?

At 12-15 weeks GA.

What are the two main tracts of the hypothalamohypophyseal secretory system?

Supraopticohypophyseal and paraventricularhypophyseal tracts.

What are the two lateral areas of the hypothalamus called?

Lateral Hypothalamic Areas (LHA).

What happens to some colloids in Hashimoto’s Thyroiditis?

They become atrophied or empty.

What structures are included in the mammillary region of the hypothalamus?

Mammillary bodies, posterior nucleus, and mammillary nucleus.

At what week are oxytocin and vasopressin detectable in the supraoptic and paraventricular nuclei?

19 weeks.

What type of cells contribute to the parafollicular cells of the thyroid?

Neural crest cells.

What is the anatomical position of the thyroid gland in relation to the vertebrae?

Opposite C5 - T1 vertebra.

At what level are the inferior borders of the thyroid gland located?

Level of the 6th tracheal cartilage.

What is the primary function of Somatotroph cells?

To secrete growth hormones (GH).

What are the subdivisions of the hypothalamic nuclei?

4 Regions.

What are pituicytes?

Glial cells that resemble astrocytes and provide support to axons of neurosecretory cells.

What type of cells primarily make up the adenohypophysis?

Glandular epithelial cells of the secretory portion derived from the pharyngeal epithelium.

What is unique about the blood-brain barrier (BBB) in the hypothalamus?

The BBB is not present in the hypothalamus, posterior pituitary, and choroid plexus; they are circumventricular organs.

What types of cells are primarily found in the pars tuberalis?

Gonadotrophs, intermixed with a few corticotrophs and thyrotrophs.