Cellular activities are coordinated throughout the body by the endocrine system to
preserve homeostasis
The endocrine system regulates long-term processes such as growth and development by using
chemical messengers to replay information and instructions between cells
Situations requiring split-second responses, or crisis managements, is the job of the
nervous system
Gap juctions involved in direct communication between two cells of the same type serve to
coordinate ciliary movement among epithelial cells, contractions of cardiac muscle cells, and facilitate the propagation of action potentials from one neuron to the next at electrical synapses
An example of a functional similarity between the nervous system and endocrine system is
compounds used as hormones by the endocrine system may also function as neurotransmitters inside the CNS
The chemical messengers of the nervous and endocrine systems are
neurotransmitters and hormones
Neurons communicate with one another and with effectors by
releasing chemical neurotransmitters
The release of hormones by endocrine cells alters the
metabolic activities of many tissues and organs simultaneously
The three different groups of hormones based on their chemical structure are
amino acid derivatives, peptide hormones, and lipid derivatives
The biogenic amino hormones include
E, NE, dopamine, melatonin, and thyroid hormones
Generally, the amino acid chains of peptide chains of hormones are produced as
prohormones
The reason steroid hormones remain in circulation longer than the other groups of hormones is because they are
bound to specific transport proteins in the plasma
The most notable effect of ADH produced in the neurohypophysis of the pituitary gland is to
decrease the amount of water lost at the kidneys
Stimulation of contractile cells in mammary tissue and uterine muscles in the female is initiated by secretion of
oxytocin from the posterior pituitary
Hormones alter the operations of target cells by changing the
types, quantities, or activities of important enzymes and structural proteins
Catecholamines and peptide hormones affect target organ cells by
second messengers released when receptor binding occurs at the membrane surface
Steroid hormones affect target organ cells by
binding to target receptors in the nucleus
Endocrine cells responding directly to changes in the composition of the extracellular fluid is an example of
an endocrine reflex
The hypothalamus is a major coordinating and control center because
it contain autonomic centers and acts as an endocrine organ
The structure that locks the pituitary gland in position and isolates it from the cranial cavity is the
diaphragma sellae
The pituitary gland is connected to the hypothalamus by a slender, funnel shaped structure called the
infundibulum
The small, oval pituitary fland lies nestled within a depression of the sphenoid bone called the
sella turcica
The two classes of hypothalamic regulatory hormones are
releasing and inhibiting
The two gonadotropic hormones secreted by the anterior pituitary are
Luteinizing hormone and follicle stimulating hormone
The hormone synthesized from molecules of the neurotransmitter serotonin in the pineal gland is
melatonin
The hormonal effect of ACTH produced by the adenohypophysis is
secretion of glucocorticoids by the adrenal cortex
The gonadotropins FSH and LH exert their hormonal effects in the
reproductive system of the male and female
The hormonal effects of ADH produced by the neurohypophysis is (are)
decreased water lose at the kidneys, vasoconstriction of peripheral blood vessels, elevation of blood vessels
An abnormally low production of gonadotropin produces a condition called
hypogondadism
When the posterior lobe of the pituitary gland no longer releases adequate amounts of ADH, the result is development of
diabetes insipidus
If abnormal amounts of glucocorticoids are released by the adrenal cortex, it affects
glucose metabolism
The thyroid gland curves across the anterior surface of the trachea just inferior to the
thyroid cartilage
Structurally, the thyroid gland is best described as
a two lobed gland united by an isthmus
The hormones produced by the thyroid gland are
thyroxine, triiodothyronine, and calcitonin
The overall effect of hormones secreted by the thyroid gland is
an increase in cellular rates of metabolism and oxygen consumption
The calorigenic effect of thyroid hormones enables us to
adapt to cold temperatures
Inadequate productino of thyroid hormones in infants produces cretinism, a condition marked by
inadequate skeletal and nervous system development
Hypothyroidism, myxedema, and goiter may result from an inadequate amount of
dietary iodide
The two pairs of parathyroid glands are embdedded in the
posterior surfaces of the thyroid glands
The net result of parathormone secretion is
it increases CA 2+ concentration in body fluids
The highly vascularized, pyramid-shaped suprarenal gland is located on the
superior border of each kidney
The suprarenal cortex consists of a
zone glomerulosa, zona fasciculata, and zona reticularis
The hormones released by the suprarenal medulla are
epinephrine and norepinephrine
The hormonal effects procuded by suprarenal epinephrine are
increased cardiac activity, increased blood glucose levels, increased glycogen breakdown
The mineralocorticoid aldosterone targets kidney cells and causes the
retention of sodium ions and water, reducing body fluid losses
The pineal gland is located in the
posterior portion of the roof of the third ventricle
The pinealocytes of the pineal gland produce the hormone melatonin, which is believed to
be an effective antioxidant, maintain basic circadian rhythms, inhibit reproductive function
The pancreas lies in the J-shaped loop between the stomach and the small intestine in the
abdominopelvic cavity
The cells of the pancreatic islets of the endocrine pancreas include
alpha, beta, delta, and F cells
The hormones produced by the pancreatic islets that regulate blood glucose concentrations are
insulin and glucagon
The pancreatic hormone pancreatic polypeptide (PP)
may control the rate of nutrient absorption
Inadequate insulin production results in abnormally high glucose concentrations, resulting in
diabetes mellitus, hyperglycemia, glycosuria
A common diabetic-related medical problem is
partial or complete blindness
The normal effect of erythtopoietin (EPO) produced by the kidney is
to stimulate red blood cell production
One of the major effects of ANP produced by the heart is that is
decreases thirst
The thymosins produced by the thymus affect the
coordination and regulation of the immune response
Testosterone produced in the interstitial cells of the testes is responsible for
promoting the production of functional sperm, determining male secondary sexual characteristics, affecting metabolic operations throughout the body
The hormone leptin produced in adipose tissues targets the hypothalamus to affect the
suppression of appetite
Of the following choices, the two hormones that have an antagonistic of opposing effect are
insulin and glucagon
The additive effects of growth hormone and glucocorticoids illustrate the
synergistic effect
The differing but complementary effects of calcitriol and parathyroid hormone on tissues involved in calcium metabolism illustrate the
integrative effect
The hormones that are of primary important to normal growth include
GH, thyroid hormones, insulin, PTH, and reproductive hormones
Insulin is important to normal growth because it promotes
providing adequate amounts of energy and nutrients to growing cells
The body's response to stress is the general adaptation syndrome (GAS), which consists of the phases
alarm, resistance, and exhaustion
In an attempt to restore normal body temperature after its decline, the homeostatic adjustment necessitates
shivering or changes in the pattern of blood flow
In children, when sex hormones are produced prematurely, the obvious behavioral changes will cause the child to be
aggressive and assertive
In adults, changes in the mixtures of hormones reaching the CNS can have significant effects on
memory, learning, emotional states, and intellectual capabilities
The endocrine system assists the nervous system in responding to
general adaptation syndrome
An organic compound that has been implicated in causing heart and blood vessel problems, but is necessary for the production of corticosteroids is
cholesterol
The specialized cells in the parathyroid glands that secrete parathormone are
chief cells
The two basic categories of endocrine disorders are
abnormal hormone production or abnormal cellular sensitivity
The most dramatic function change that occurs in the endocrine system due to aging is
a decline in the concentration of reproductive hormones
All of the hormones secreted by the hypothalamus, pituitary gland, heart, kidneys, thhymus, digestive tract, and pancrease are
peptide hormones
The binding of a peptide hormone to its receptor starts a biochemical chain of events that changes the pattern of
enzymatic activity within the cell
The hypothalamus has a profound effect on endocrine functions through the secretion of
releasing and inhibiting hormones
A pituitary endocrine cell that is stimulated by a releasing hormone is usually
inhibited by the peripheral hormone it controls
Endocrine reflexes, the functional counterparts of neural reflexes, can be triggered by
humoral stimuli, hormonal stimuli, neural stimuli
The body system that adjusts metabolic rates and substrate utilization is the
endocrine system
Sustentacular cells in the testes support the
differentiation and physical maturation of sperm
The protein hormone prolactin is involved with the
production of milk
The amino acid derivative hormone epinephrine is responsible for
increased cardiac activity, glycogen breakdown, release of lipids by adipose tissues
The zona fasciculata of the adrenal cortex produces steroid hormones that are known as glucocorticoids because of their
effects on glucose metabolism
Corticosteroids are hormones that are produced and secreted by the
cortex of the adrenal glands
The endocrine functions of the kidney and the heart include the production and secretion of the hormones
erythropoietin and atrial natruiretic peptide
The testis of the male produces the endocrine hormones
inhibin and testosterone
The endocrine tissue of the ovaries in of the female produce
estrogens, inhibin, and progesterone