Endocrine System Flashcards
Be able to compare and contrast a simple neural reflex vs. neuroendocrine reflex.
Both-work through afferent neurons taking signals to the spinal cord then to target tissue:
-Simple-target tissue is directly innervated
-Neuroendocrine-release of neurohormone acts on distant cells
Define “hormone” (classical understanding)
Chemical substances produced by ductless glands and secreted into the blood supply to affect a tissue distant from the gland.
Define “hormone” (current understanding)
Hormones can be produced by single cells as well.
May not enter the bloodstream or target distant cells.
Be able to list and describe the 5 types (6 given) of hormone modes of transmission.
-Epicrine
-Paracrine
-Endocrine
-Exocrine
-Neurocrine
-Autocrine
Epicrine
Hormones pass through gap junctions of adjacent cells without entering extracellular fluid
Paracrine
Hormones diffuse through interstitial fluid
Endocrine
Hormones are delivered via the bloodstream
Exocrine
Chemical substance is secreted to exterior of the body or into the digestive tract
Neurocrine
-Hormones pass through synaptic clefts between neurons as do neurotransmitters
-Hormones can also be synthesized in a neuron and secreted directly into the blood from the axon
Autocrine
Hormone is produced by a cell and acts on itself
Be able to list the 4 biochemical categories of hormones.
-Amines
-Peptides
-Steroids
-Prostaglandins
Amines
-Thyroid hormones
-Adrenal catecholamines
Peptides
-Growth hormone (GH)
-Prolactin (PRL)
-Luteinizing hormone (LH)
Steroids
-Estradiol (E2)
-Testosterone (T)
-Cortisol
-Progesterone
Prostaglandins
PGF2
Know some examples of pharmaceuticals that are administered to animals to control reproduction (names and what they mimic).
-Cystorelin & Factrel
-ECP
-Folltropin-V
Cystorelin & Factrel
Affects Gonadotropin releasing hormone (GnRH)
ECP
Affects estradiol
Folltropin-V
Affects Follicle stimulating hormone (FSH)
Know the “borders” of the hypothalamus in the brain.
-Anteriorly by the optic chiasma
-Posteriorly by the mammillary bodies
-Dorsally by the thalamus
-Ventrally by the sphenoid bone
Know what the Sella Turcica is.
-The bony recess at the base of the brain
-Space created by the sphenoid bone
Surge Center
-Releases Gonadotropin releasing hormone (GnRH)
-MALES DO NOT HAVE ONE
Tonic Center
Releases Gonadotropin releasing hormone (GnRH)
Be able to provide one example of a releasing hormone that comes from the hypothalamic neurons.
Gonadotropin releasing hormone (GnRH)
Know the embryonic origin of the anterior vs. posterior pituitary gland.
-Posterior pituitary: Originates from the diencephalon (from the brain)
-Anterior pituitary: Originates from Rathke’s pouch (roof of the mouth)
Hypothalamic regulation of the anterior pituitary.
-Hypothalamo-Hypophyseal Portal System
~Vein draining in the hypothalamus breaks up into a capillary bed within the anterior pituitary.
~Route by which releasing factors from the hypothalamus travel to cause release of hormones from the anterior pituitary
Hypothalamic regulation of the posterior pituitary.
-Action potentials generated by the need for each of the stored hormones
-causes release of the substance into the blood supply.
-Neurons from specific nuclei extend into the posterior lobe where neurohormones are released into a simple arteriovenous capillary plexus.
Be able to list the hormones synthesized/secreted by the posterior pituitary.
-ADH
-Oxytocin
Know the embryonic origin of the anterior vs. posterior pituitary gland.
-Posterior pituitary: Originates from the diencephalon (from the brain)
-Anterior pituitary: Originates from Rathke’s pouch (roof of the mouth)
Know what the Hypothalamo-Hypophyseal Portal System is and how it is involved in the release of hormones from the anterior pituitary
-The portal system is a complex of blood vessels within the stalk region
-The portal system carries hypothalamic hormones specifically to the anterior pituitary without dilution in the systemic blood: Allows rapid response and Little dilution of peptide hormones (peptide hormones have short half life)
Know the 3 parts of the anterior pituitary gland.
-Pars distalis
-Pars intermedia: melanocyte stimulating hormone
-Pars tuberalis
Know the 5 cell types of the principal part of the anterior pituitary and the hormone(s) synthesized/secreted by each.
-Somatotropes: Growth hormone (GH)
-Corticotropes: Corticotropin releasing hormone
-Mammotropes: Prolactin (PRL)
-Thyrotropes: Thyroid stimulating hormone (TSH)
-Gonadotropes: Follicle stimulating hormone (FSH)
and Luteinizing hormone (LH)
