Introduction to Endocrinology
Gonadotropins
( Follicle-Stimulating Hormone, Luteinizing Hormone)
What is the half-life of Polypeptide/Protein Hormones in plasma?
10 to 30 Minutes or less
__% of children with growth retardation have endocrine problems
15
How big is the pituitary gland?
1cm or less in height and width
GH in healthy adults remains stable and relatively low <___ng/mL?
2
GH Spikes during the day usually occur after eating or exercise, after _____ hours
3
Steroid Hormones have what half life?
30 to 90 minutes
How much the pituitary gland weight in mg?
500
GH Secretions generally start occurring after __minutes after sleep.
90
Acutely GH Causes what?
A decrease in blood glucose concentrations
What regulates growth of adrenal glands, and synthesis and secretion of adrenal gland hormones?
ACTH
Anterior glandular lobe of the pituitary gland
Adenohypophysis
What secretes growth hormone, prolactin, thyrotropin, adrenocorticotropin, follicle stimulating hormone, and luteinizing hormone?
Adenohypophysis
GH Accelerates the mobilization and metabolism of fat from ________ to the liver
Adipose Tissue
What acts primarily on the Adrenal Cortex with stimulating its growth, and synthesis and secretion of corticosteroids, along with production being increased during times of stress?
Adrenocorticotropin (ACTH)
What acts primarily on the adrenal cortex?
Adrenocorticotropin (ACTH)
What is a peptide hormone that is secreted by the Adenohypophysis?
Adrenocorticotropin (ACTH)
What interact with membrane-associated receptors and use a second messenger system?
Amino Acid Derivatives
Which is water soluble, and circulate in plasma either free or bound to proteins?
Amino Acid Derivatives
These are predominantly the hormones of what? ->Gonadotrophins ->ACTH ->Thyroid-Stimulating Hormone
Anterior Pituitary Gland
Adenohypophysis is what?
Anterior portion of the pituitary gland
Mode of hormone action in which a hormone binds to receptors on or in the cell type that produced it and thereby affects the function of that cell
Autocrine
Which system has a hormone action on the cells of origin, regulating their own synthesis and secretion, via what system?
Autocrine
The pituitary gland(Hypophysis) is located where?
Base of the skull in a bone cavity called the SElla Turcica(Turkish Saddle)
Chornic GH Leads to an increase in what?
Blood Glucose Concentration (Hyperglycemia)
Which, such as epinephrine, have a very short half-life of a minute or less?
Catecholamines
Some examples of Amino Acid-Related Hormones are which? (Hormones that are amino acid derivatives)
Catecholamines and Thyroxine
What is responsible for the downstream actions of the hormone
Cell Surface Receptors
Which is relating to the change resulting from this binding activates an effector system?
Cell surface Receptors
Peptide Hormones bind to
Cell surface receptors
Normal growth and development of the whole human organism is dependent on what?
Complex integrative function of hormones
The activation of the receptor enables the hormone-receptor complex to bind to specific regulatory DNA sequences of a target gene permitting what?
Control of the specific Gene Expression
Growth Hormone and Prolactin act primarily on __________ target tissue?
Diffuse
Which system produces hormones at one site, and exert actions at distant sites?
Endocrine
System of glands that release their secretions(Hormones) directly into the circulatory system. In addition to the endocrine glands, included are the chromaffin system and the neurosecretory system
Endocrine System
Scientific study of the function and pathology of the endocrine glands
Endocrinology
This type of stress has been shown to inhibit pituitary and hypothalamic function
Enviornmental
Control of the functional relationship between the pituitary gland and its target organs is based on the principle of _____________
Feedback Control
What is synthesized in the adenohypophysis, stimulates the growth and maturation of ovarian follicles, stimulates estrogen secretion, promotes endometrial changes characteristic of the first phase of the mammalian menstrual cycle, and stimulates spermatogenesis in males?
Follicle-Stimulating Hormone (FSH)
Gonadotropic Cells of the Anterior Lobe of the pituitary gland secrete what?
Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
What two hormones are grouped together under the generic term gonadotropins?
Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
Which exert physiological action, enter the cell by passive diffusion, and bind with intracellular receptors either in the cytoplasm or the nucleus?
Free Steroid Hormones
Additional responses to _____ include increased intestinal absorption of calcium, and decreased urinary excretion of sodium and potassium
GH
Exercise, physical and emotional stress, Hypoglycemia, increased circulating amino acid concentrations, and hormones, such as testosterone, estrogens, and thyroxine are all stimuli that evoke an increase of what secretion
GH
GH-RH stimulates what release?
GH
SRIF inhibits what release?
GH
The overall physiological effect of ________, is to promote growth in soft tissue, cartilage, and bone.
GH
What in healthy adults remains stable and relatively low <2 ng/mL?
GH
What is controlled by hypothalamic GH-RH and SRIF?
GH
What is synthesized by the cells of the adenohypophysis, and is stored within intracellular granules.
GH
____ Secretion may be important to anabolic and repair processes and for proper skeletal growth
GH
Premature Mortality, Abnormal Body Composition, Impaired Serum Lipids, Decreased Bone Density with an increase in fracture risk, along with overall an impaired quality of life can all be causes of what?
GH Deficiency
What can be congenital or Acquired, idiopathic, or caused by anatomical damage to the pituitary gland or hypothalamus, or caused by isolated or associated deficiencies of other pituitary hormones?
GH Deficiency
What has a striking acceleration of linear growth?
GH Excess
What is evident in the face and extremities?
GH Excess
Children who have inadequate what will not grow normally?
GH Production
In high concentrations of _________, GH secretion is suppressed
Glucocorticoids
What is Luteinizing Hormone [LH] and follicle stimulating hormone [FSH]? Together?
Gonadotrophins
What is a luteinizing Hormone[LH], and follicle stimulating hormone[FSH]?
Gonadotrophins
What regulate development, growth, and function of ovary/testis, along in term regulate pubertal growth, development and maintenance of secondary sex characteristics, growth and development, and maintenance of the skeleton and muscles, along with the distribution of body fat?
Gonadotrophins
Children who have a GH Receptor Defect do not what?
Grow Normally
Children who have inadequate GH production or a GH receptor defect do not what?
Grow Normally
What is associated with Adenomas of the Pituitary gland?
Growth Hormone Excess
Gonadal Steroids (Estrogen + Androgen), Growth Hormone, Cortisol, and Thyroxine and all related with?
Growth and Development
What is a chemical substance produced in the body by an organ, cells of an organ, or scattered cells that have a specific regulatory effect on the activity of an organ or organs?
Hormone
The functions of __________, are classified through ->Growth and Development ->Homeostatic control of metabolic pathways ->Regulation of energy production, use and storage
Hormones
The production and release of the pituitary hormones are controlled by which hormones, of the hypothalamo-hypophyseal system?
Hypothalamic
Hormones from the hypothalamus, reach the pituitary through what portal system?
Hypothalamic hypophyseal portal system
System of neurons, fiber tracts, endocrine tissue, and blood vessels that are responsible for the production and release of pituitary hormones into the systemic circulation
Hypothalamo-Hypophyseal System
Secretion of hormones from the anterior lobe of the pituitary gland is controlled by what?
Hypothalamus
Vasopressin (ADH) and oxytocin and produced in the what?
Hypothalamus
What is the most important requirement for the diagnosis of acromegaly is the demonstration of what?
Inappropriate and Excessive GH Secretion
Chronic GH Excess stimulates hepatic glycogenolysis and antagonizes the effect of what, on glucose uptake by peripheral cells?
Insulin
What are some examples of Polypeptide or Protein Hormones?
Insulin, Parathyroid Hormone (PTH) and adrenocorticotropin (ACTH)
Which hormones are transported in plasma bound to carrier proteins?
Lipid-Soluble
What is synthesized in the adenohypophysis, acts with Follicle-Stimulating Hormone to promote ovulation and secretion of androgens and progesterone, initiates and maintains the second phase of mammalian estrus and menstrual cycle, and in females its concerned with corpus luteum formation, along with in males it stimulates the development and functional activity of testicular leydig cells
Luteinizing Hormone (LH)
Blood concentration of circulating hormones and the pituitary gland and hypothalamus is what kind of feedback control
Negative
What type of feedback control maintains an optimal concentration of hormones in the blood under a fluctuating variety of circumstances
Negative
What is typically opposite to that of the initial stimulus?
Negative Feedback
GH stimulates the uptake of what by muscle?
Nonesterified Fatty Acids
For the receptor with bound hormone to bind to nuclear DNA, it must move to the what?
Nucleus
What is known as Acromegaly in adults?
Overgrowth of the skeleton and Soft Tissue
Prolonged Exposure to GH Excess causes what?
Overgrowth of the skeleton and Soft Tissue, known as acromegaly in Adults
Type of hormone function in which hormone synthesized in and released from one type of cell binds to the hormones receptor in nearby cells of a different type and affects their function
Paracrine
Which system exert hormone actions locally from where it was synthesized?
Paracrine
The Hypothalamus manufactures small _____ hormones known as releasing/inhibitory factors
Peptide
In severe or advanced cases of GH Excess, the diagnosis is made on the basis of what?
Physical Appearance Alone
What is the condition called before long bone growth is complete?
Pituitary Gigantism
What is intimately involved in the regulation of growth, development, thyroid function, adrenal function, gonadal function, and water+salt homeostasis, and is called the master endocrine organ?
Pituitary Gland
What regulates the endocrine system by integrating chemical signals from the brain with regulatory feedback from the concentration of hormones in the circulation to stimulate intermittent hormone release from target endocrine glands
Pituitary Gland
Which gland is located at the base of the skull in a bone cavity called the Sella Turcica(Turkish Saddle)
Pituitary Gland
What is anatomically divided into the anterior (Adenohypophysis) and the posterior(Neurohypophysis) lobes?
Pituitary Gland(Hypophysis)
What is called the master endocrine organ?
Pituitary gland
The half-life of which, in plasma, is 10 to 30 minutes or less?
Polypeptide / Protein Hormones
Which are generally water soluble and circulate freely in plasma as the whole molecule or as active/inactive fragments?
Polypeptide / Protein Hormones
Which circulate freely in plasma as the whole molecule, or even as an active or inactive fragment?
Polypeptide / Protein Hormones
Which initiate their response by binding to a cell membrane receptors, and exciting a cellular second messenger system.
Polypeptide / Protein Hormones
What is the Neurohypophysis?
Posterior portion of the pituitary gland
What has the primarly role to stimulate and sustain lactation in postpartum mammals?
Prolactin
What is one reversible GH Deficiency state known as what
Psychosocial Dwarfism
What has important effects on the gastrointestinal hormone secretion and causes inhibition of insulin and glucagon release
SRIF
What is found in the delta cells of the pancreatic islets and in many other sites in the digestive tract?
SRIF
What brings about the specific actions of these hormones on the cell when Polypeptide / Protein Hormones excite this?
Second Messenger System
Corticotrophin-Releasing Hormone (CRH) Thyrotropin-Releasing Hormone (TRH) GH-Releasing Hormone (GH-RH) Somatostatin PRL-Inhibiting Factor (PIF) are all what?
Small peptide hormones
Cortisol and Estrogen are examples of what?
Steroid Hormones
Which below are hydrophobic and insoluble in water?
Steroid Hormones
Which below circulate reversibly bound to transport proteins?
Steroid Hormones
Which below has a half-life of 30 to 90 minutes?
Steroid Hormones
Hormones are generally classified as what?
Steroid, Amino Acid Deriviatives, Polypeptide/Protein
Prolactin has the primary role to what?
Stimulate and sustain Lactation in Postpartum Mammals
In high concentrations of glucocorticoids, GH secretion is ____________
Suppressed
This regulates the growth of the thyroid gland, and iodination of amino acids to produce the thyroid hormones triiodothyronine and thyroxine
Thyroid Stimulating Hormone(TSH)
Thyrotropin, Adrenocorticotropin, and gonadotrophin (LH + FSH) act primarily on specific target endocrine glands such as what?
Thyroid gland, adrenal cortex, and gonads)
Which binds avidly to three binding proteins and has a half life of about 7 to 10 days?
Thyroxine
What is specifically responsible for growth and development of the endocrine glands?
Trophin
What is carried through the neurohypophyseal nerve axons to the neurohypophysis?
Vasopressin(ADH) and Oxytocin
Neurohypophysis(Posterior) of pituitary, functions as a reservoir for what two hormones?
Vasopressin(ADH), and Oxytocin
When a hormone changes the molecular conformation of the intracellular receptor, this is called the
activation of the receptor
Free hormone enters the cell via passive diffusion; which then
binds to intracellular receptors in the cytoplasm or nucleus
Some of other Prolactin effects will include
maintenance of immune system along with ovarian steroidogenesis
