Endocrine System Anatomy Lectures 1 & 2 PDF

The Endocrine System Anatomy Lectures 1 & 2 Hypothalamus & pituitary gland & pineal body Dr. Mohamed Fathi Ass. Professor of Anatomy & Embryology By the end of these lectures you must know: Overview of endocrine system. Anatomical features of hypothalamus...

The Endocrine System Anatomy Lectures 1 & 2 Hypothalamus & pituitary gland & pineal body Dr. Mohamed Fathi Ass. Professor of Anatomy & Embryology By the end of these lectures you must know: Overview of endocrine system. Anatomical features of hypothalamus and its development. Anatomical features of pituitary gland. Histology of pituitary gland. Development of pituitary gland. Pineal gland (Anatomy, histology & function).  An Overview of the Endocrine System * The endocrine system is a group of specialized organs and body tissues that produce, store and secrete chemical substances known as hormones which regulate growth, metabolism and sexual development and function. * The endocrine system is made up of several endocrine glands: 1. The hypothalamus, pituitary gland (hypophysis cerebri) & the pineal gland. 2. The thyroid gland, the parathyroid glands & the thymus gland. 3. The suprarenal glands & the islets of Langerhans of the pancreas. 4. The testes of the male, the ovaries of the female, and the placenta (if present).  An Overview of the Endocrine System * The endocrine glands differ from the exocrine glands in that they are ductless glands. Their secretions (hormones) are released directly into the blood stream and may affect one or several organs throughout the body. * Hormones are chemical messengers created by the body. They transfer information from one set of cells to another to coordinate the functions of different parts of the body.  The Hypothalamus The hypothalamus is a small part in the brain ( part of diencephalon), located inferior to the thalamus, in the lower central part of the brain. Functions: H 1. Regulation of satiety, metabolism & body temperature. 2. Secretion of hormones that stimulate or suppress the release of the hormones of the pituitary gland.  The Hypothalamus Many of these hormones are releasing hormones, which are secreted into an artery (the hypophyseal portal system) that carries them directly to the pituitary gland. In the pituitary gland, these releasing hormones signal secretion of H stimulating hormones. 3. The activities of the endocrine system and the autonomic nervous system on the target organ (the specific structure acted on by a hormone) are integrated and coordinated by the hypothalamus.  HYPOTHALAMUS Extent Ant: lamina terminalis  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus.  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus. Inf: – floor of 3rd ventricle  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus. Inf: – floor of 3rd ventricle – interpeduncular fossa  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus. Inf: – floor of 3rd ventricle – interpeduncular fossa 3 parts (anteroposteriorly)  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus. Inf: – floor of 3rd ventricle – interpeduncular fossa 3 parts (anteroposteriorly) Optic part  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus. Inf: – floor of 3rd ventricle – interpeduncular fossa 3 parts (anteroposteriorly) Optic part Tuberal part  HYPOTHALAMUS Extent Ant: lamina terminalis Post: plane post to mammillary bodies Sup: hypothalamic sulcus. Inf: – floor of 3rd ventricle – interpeduncular fossa 3 parts (anteroposteriorly) Optic part Tuberal part Mammillary part 3 zones 3 zones column of fornix traversing 3 zones column of fornix traversing lat zone 3 zones column of fornix traversing lat zone med zone 3 zones column of fornix traversing lat zone med zone – periventricular zone 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone important nuclei 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone important nuclei supraoptic 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone important nuclei supraoptic paraventricular NOT peri 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone important nuclei supraoptic paraventricular arcuate 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone important nuclei supraoptic paraventricular arcuate mammillary 3 zones column of fornix traversing lat zone med zone – periventricular zone – intermediate zone important nuclei supraoptic paraventricular arcuate mammillary suprachiasmatic Connections Connections 1. Cortical 1 2. Limbic 3 5 2 3. Retinal 4 4. Lower centers 5. Pituitary Connections 1. Cortical visceral & olfactory areas autonomic response (past experience) 2. Limbic 3. Retinal 4. Lower centers 5. Pituitary Connections 1. Cortical visceral & olfactory areas autonomic response (past experience) 2. Limbic Hippocampus via fornix (Papez circuit)  memory consolidation 3. Retinal 4. Lower centers 5. Pituitary Connections 1. Cortical visceral & olfactory areas autonomic response (past experience) 2. Limbic Hippocampus via fornix (Papez circuit)  memory consolidation Amygdala & Septal areas emotions  autonomic reactions 3. Retinal 4. Lower centers 5. Pituitary Connections 1. Cortical visceral & olfactory areas autonomic response (past experience) 2. Limbic Hippocampus via fornix (Papez circuit)  memory consolidation Amygdala & Septal areas emotions  autonomic reactions 3. Retinal light suprachiasmatic nc biological clock 4. Lower centers 5. Pituitary Connections 1. Cortical visceral & olfactory areas autonomic response (past experience) 2. Limbic Hippocampus via fornix (Papez circuit)  memory consolidation Amygdala & Septal areas emotions  autonomic reactions 3. Retinal light suprachiasmatic nc biological clock 4. Lower centers – Ascending Visceral (general & taste) sensations Somatic (temp. - nipple - genitalia) 5. Pituitary Connections 1. Cortical visceral & olfactory areas autonomic response (past experience) 2. Limbic Hippocampus via fornix (Papez circuit)  memory consolidation Amygdala & Septal areas emotions  autonomic reactions 3. Retinal light suprachiasmatic nc biological clock 4. Lower centers – Ascending Visceral (general & taste) Somatic (temp. - nipple - genitalia) – Descending Cranial (III, VII, IX, X) Spinal (via reticulospinal T.)  – LHCs  symp & parasymp – AHCs  Shivering 5-Pituitary  Nervous connection with post lobe (Hypothalamo-hypophyseal tract) Vascular connection with ant lobe (Hypothalamo-hypophyseal portal circulation) portal = sinusoid veins  Nervous connection with post lobe (Hypothalamo-hypophyseal tract) – Supraoptic nc  vasopressin Vascular connection with ant lobe (Hypothalamo-hypophyseal portal circulation)  Nervous connection with post lobe (Hypothalamo-hypophyseal tract) – Supraoptic nc  vasopressin – Paraventricular nc  oxytocin Vascular connection with ant lobe (Hypothalamo-hypophyseal portal circulation) Blood supply of hypothalamus: Arterial supply : Posteromedial group of Posterior cerebral artery ( one of the central brs of circle of willis.