Flashcards in Endocrine System Deck (75)
What are the primary organs of the endocrine system?
Pituitary gland, hypophysis cerebri
Pineal gland, epiphysis cerebri
What are the secondary endocrine organs?
pacreas, Testes, Ovaries, Kidneys, Stomach, Intestines, Thymus, Heart, Placenta, Adipose Tissue
What are the functions of the endocrine system?
- growth and development
- Internal environment
- Energy production, storage, and utilization
What are the characteristics of the endocrine organs?
- Epithelial origin
- highly vascular
- control or effect mediated by hormones
What is autocrine signalling?
extracellular signal produced by the cell binds to receptors on ITSELF (target sites on same cell)
What is paracrine signalling?
extracellular signal produced by the cell bind to receptors sites on adjacent cells.
What is endocrine signalling?
hormone is secreted into the blood stream by a cell and is then carried via the blood to distant target cells
What can a hormone be? (What are they made of?)
Proteins eg: insulin, glycoproteins, polypeptides
Amino acids eg: T3, T4, catecholamines
Steroids eg: testosterone, estrogen, progesterone
How do hormones travel?
Through the bloodstream to target cells
How do most hormones bind to target cells?
Bind to receptors on the surface of the target cell
How do steroid hormones act on the target cell?
They pass through the plasma membrane of the target cell and bind to the nucleus
What kind of response does a hormone typically give?
Slow sustained responses
What is the hypothalamus?
Portion of the brain that links the nervous system to the endocrine system via the pituitary gland/hypophysis
What do hypothalamic nuclei do?
Control distant cells via hormones through two pathways
- Production of releasing hormones - released into "portal system" to target cells in the adenohypophysis
- hormones axon ally transported and stored in the neurohypophysis, then released in the blood to target distant sites
What is another name for the pituitary gland?
The hypophysis cerebri
What is another name for the posterior pituitary?
What is another name for the anterior pituitary?
What are the developmental origins of the pituitary gland?
Posterior pituitary/Neurohypophysis = neuronectoderm ( from diencephalon)
Anterior pituitary/Adenohypophysis = epithelial (from roof of pharynx)
What are the three portions of the Neurohypophysis?
Pars nervosa (pars posterior)
Infundibular stalk (infundibulum)
Eminentia mediana - small attachment between the hypophysis and infundibulum
What are the three parts of the adenohypophysis?
Pars tube rails
What do the cell bodies of large neurons found in hypothalamus nuclei produce?
Anti diuretic hormone (ADH) and oxytocin
What are herring bodies?
Swellings along the hypothalamic neurons which are the site in which hormones are accumulated.
- storage site for ADH and oxytocin
Where are herring bodies found?
Neurohypophysis (posterior pituitary gland) pars nervosa
What do the axons of the neurohypophysis pars nervosa terminate on?
Which nucleus is associated with ADH?
supraoptic nucleus (SON)
which nucleus is associated with oxytocin?
Paraventricular nucleus (PVN)
What does Antidiuretic hormone do (ADH)
Increases water reabsorption and concentrates urine in the kidneys
What does oxyotcin do?
stimulates contraction of myoepithelial cells for milk let down/release
Which part of the pituitary gland is the glandular part?