Endocrine Ch 17 Flashcards
What are the endocrine glands?
Pituitary, thyroid, parathyroid, adrenal, pineal, thymus
What two organs produce both hormones and exocrine products?
Pancreas
Gonads
What are endocrine, exocrine, and neuroendocrine organs?
Endocrine-ductless glands/dump hormone directly into capillaries
Exocrine- non hormonal substances routed to membrane surface by duct
Neuro-hypothalamus controls pituitary gland hormones
Differentiate autocrines and paracrines.
Auto- chemicals that exert effects on same cell that secrete
Para-locally acting chemicals that affect cells other than those secreting (blood clotting chems)
What are three types of hormones?
Amino acid based (proteins)
Steroid (cholesterol/lipid)
Eicosanoids-active lipid with local hormone like activity
What are some examples of amino acids (protein) hormones?
Amines, thyroxine, peptide, and protein
Insulin, glucagon
Name some examples of steroid (cholesterol/fat) hormones.
Gonadal (testosterone, estrogen, progesterone), adrenocortical:(aldosterone,cortisol))
(Gonads and adrenal)
What are two ways hormones alter target cell?
Second messengers -amino acids bases (except t3 t4 thyroid)
Direct gene activation- steroid
*response depends on type of target cell and type of hormone
How do steroid hormones work?
Enter nucleus and alters gene expression, prompting DNA transcription to produce mRNA.
Which is translated into proteins.
Endocrine system is the body’s second great controlling system which influences ________ activities of cells by means of _________.
Metabolic
Hormones
What receptors are found on the adrenal cortex cells?
ACTH
Thyroxine receptors are found on nearly all cells of _________.
The body
What are the three factors of target cell activation?
Blood levels of the hormone.
Relative number of receptors on target sale.
The affinity of those receptors for the hormone.
What is up and down regulation?
Up– Target cells for more receptors in response to hormones. Affects gets bigger.
Down – target cells lose receptors in response to hormones. Affects get smaller.
Hormones circulate the blood and what two forms?
Free or bound.
*Steroids and thyroid hormone are attached to plasma lipoprotein’s.
All others are encumbered.
Hormones are removed from the blood by…
Degrading enzymes
the kidneys
liver enzyme systems
What are the three types of hormone interaction at target cells?
Permissiveness
synergism
antagonism
What is permissiveness? (Hormone/Target cell interaction)
Hormone cannot exert its effects without another hormone being present.
Thyroid hormone/growth hormone
What is synergism? (hormone/target cell interaction)
More than one hormone produces the same affects on a target cell.
(Glucagon epinephrine Cortisol)
What is antagonism? (Hormone/target cell interaction)
One or more hormones opposes the action of another hormone.
insulin/glucagon, parathyroid hormone/calcitonin, GHRH/GHIH
Hormones are synthesized and released in response to…
Humoral stimuli
Neural stimuli
hormonal stimuli
What is humoral stimuli?
Secretion of hormones in direct response to changing blood levels in ions and nutrients
What is neural stimuli?
Nerve fiber stimulate hormone release
Adrenal Medulla
What is hormonal stimuli?
Release of hormones in response to hormones produced by other endocrine organs.
- hypothalamus—>anterior pituitary—> target recep.
What can override normal endocrine controls?
The nervous system.
The pituitary gland is a two lobed organ that secretes nine major hormones.
Name the two parts and their function.
Neurohypophysis-posterior lobe (neural tissue) and infundibulum. Receives stores and releases hormones from hypothalamus
Adenohypophysis-anterior lobe, (glandular tissue)
Synthesizes and secretes a number of hormones
Nuclei of the hypothalamus synthesize
________ and ________.
Oxytocin and antidiuretic hormone
What is the vascular connection between the hypothalamus and anterior lobe of pituitary? (Adenohypophysis)
Hypophyseal portal system (portal vein)
The hypothalamus sends a chemical stimulus to the anterior pituitary. What two types of hormones?
Releasing hormones – stimulate the synthesis and release of hormones.
Inhibiting hormones – shut off the synthesis and release of hormones.
What are the seven hormones made by the hypothalamus that act on the anterior pituitary?
Growth hormone releasing hormone Growth Hormone inhibiting hormone Corticotropin releasing hormone thyrotropin releasing hormone gonadotropin releasing hormone Prolactin releasing hormone prolactin inhibiting hormone
What are the tropic (hormones that trigger other hormones) hormones of the anterior pituitary? (4)
Thyroid stimulating hormone adrenocorticotropic hormone
follicle-stimulating hormone
luteinizing hormone