1.2 Anatomy and Develop of Hypothal Pit and Pineal Flashcards
What week does the forebrain divide into 2 parts? what parts?
5th week, Telencephalon and Diencephalon
What 4 parts does the Diencephalon divide into?
Thalamus, subthalamus, hypothalamus, epithalamus
What area of the diencephalon gives rise to the hypothalamus?
Neuroblasts from the intermediate zone of the diencephalic (lateral) walls of the 3rd ventricle.
What is the tuber cinereum exposed to?
the subarachnoid space
what is the median eminence surrounded by?
The circle of willis
What is the floor of the optic recess of the 3rd ventricle?
the optic chiasm
The lateral and median saggittal zones of the hypothal are named so in relation to what structure?
lateral and medial to the fornix.
Medial Preoptic nucleus (preoptic region)
Regulates release of gonadotropic hormones from anterior pituitary.
Lateral Preoptic Nucleus (preoptic region)
Sleep, Damage/lesion leads to insomnia
Suprachiasmatic Nucleus (supraoptic/Anterior region)
Circadian rhythm, connected to reticular formation & corpus striatum. Direct input from retina.
Anterior hypothalamic Nucleus (supraoptic)
Temperture regulation, stimulates parasympathetic NS. Lesion/Damage will cause hyperthermia.
Paraventricular Nucleus (supraoptic)
Connected to post pitvia neural tracts. Neurosecretory neurons: Synthesize & secrete oxytocin. Contraction of uterine & mammary smooth m - Parturition & milk ejection
Supraoptic nuc (supraoptic)
Connected to posterior pituitary via neural tracts. Neurosecretory neurons: Synthesize & secrete ADH/vasopressin to Increase reabsorption of water in kidney->decrease production of urine. Lesion causes diabetes insipidus.
Dorsomedial nuc (Tuberal region)
Fight or Flight
Ventromedial Nucleus (tuberal region)
Satiety center. Inhibits urge to eat. Damage or destruction can cause hyperphagia, obesity, rage
Arcuate (Infundibular) Nucleus (tuberal region)
Within tuber cinereum/median eminence. Hypothalamic releasing factors. Contains dopaminergic neurons.
Lateral Tuberal Nuclei (tuberal region)
doesnt do much… :)
Tuberomammillary Nucleus (tuberal region)
Source of histamineric fibers project to cerebral cortex and thalamus. Participate in sleep-wake cycle.
Lateral Hypothalamic Nucleus (tuberal region)
Hunger/feeding center. Induces eating. Leasion here causes starvation & emaciation. Within anterior, tuberal, & posterior regions
Posterior hypothalamic nuc (mamillary (posterior)region)
Thermal regulation-produce and conserve heat. Stimulates sympathetic NS. Lesion leads to inability to thermoregulate.
Mamillary body (mamillary (posterior)region)
Memory. Input from hippocampal formation, dorsal & ventral tegmental nuclei, & raphe nuclei.
What does the posterior pit arise off?
Bud from floor of diencephalon, grows downward, attachment is infundibular stalk and have large secretory neurons called Pars nervosa.
Where are hormones of the posterior pit stored and released into?
Stored in Herring bodies in the axons of pars nervosa and released into inferior hypophyseal a.
Where does the anterior pit arise from?
From ectoderm of developing oral cavity. Hypophyseal diverticulum-Projects from roof of stomodeum (primordial oral cavity). Stalk regresses. Forms hypophyseal (Rathke) pouch. Anterior wall thickens, reducing pouch’s lumen to small fissure. Specialized glandular epithelium
What are the three parts of the ant pit?
Pars Tuberalis, Pars Intermedia, (75%)Pars Distalis
What are the 2 types of cells of the pineal gland and what does the pineal gland release?
Produce melatonin: Diurnal rhythm related to light & darkness. Jet lag can affect melatonin secretion.
