XI Chap 22 Chemical Coordination Integration Flashcards
Nerve fibres innervate all cells of the body as cellular functions need to be continuously regulated. T or F?
False, nerve fibres DO NOT innervate all cells, rest is true
Endocrine glands lack __________ and hence are called __________
duct, ductless glands
Secretions of the endocrine are called __________
hormones
Classical definition of hormone?
Chemical produced by endocrine glands and released into the blood and transported to a distantly located target organ
Current scientific definition of hormones?
Non-nutrient chemicals - intercellular messengers - trace amounts
__________ possess very simple endocrine systems with few hormones
invertebrates
__________ and __________ constitute the endocrine system
Endocrine glands,
hormone producing diffused tissues/cells
Organised endocrine bodies? (8)
pituitary pineal thyroid adrenal pancreas parathyroid thymus gonads (testis in M, ovary in F)
In addition to the organized endocrine bodies, __________, __________, __________ and __________ also produce hormones
gastrointestinal tract, liver, kidney, heart
Hypothalamus is the basal part of the ____________, forebrain
diencephalon
Hypothalamus contains several groups of neurosecretory cells called ____________ which produce ____________
nuclei, hormones
Nuclei hormones regulate ____________
synthesis and secretion of pituitary hormones
The hormones produced by hypothalamus are of 2 types: ____________ and ____________
releasing, inhibiting
Releasing vs. inhibiting hormone?
Releasing - stimulating secretion of pituitary
Inhibiting - inhibit secretions of pituitary
Gonadotrophin releasing hormon (GnRH) is a ____________ hormone that stimulates the ____________
hypothalamic,
pituitary synthesis and release of gonadotrophins
____________ from the hypothalamus inhibits the release of growth hormone from the pituitary
Somatostatin
Hypothalmic hormones originate in the ____________ pass through ____________ and are released from ____________
hypothalamic neurons,
axons,
axon nerve endings
Hypothalamic hormones reach the pituitary gland through a ____________ system and regulate the functions of the ____________
portal circulatory, anterior pituitary
___________ pituitary is under the direct neural regulation of hypothalamus
Posterior
The pituitary gland is located in a body cavity called ____________ and is attached to the ____________ by a stalk
sella tursica, hypothalamus
Pituitary gland is divided anatomically into:
adenohypophysis, neurohypophysis
Adenohypophysis consists of ____________ and ____________
pars distalis
pars intermedia
Pars distalis region of pituitary is commonly called ____________
anterior pituitary
Anterior pituitary/pars distalis region of pituitary produces which hormones?
Growth hormone (GH) Prolactin (PRL) Thyroid stimulating hormone (TSH) Luteinizing hormone (LH) Follicle stimulating hormone (FSH) Adrenocorticotropic hormone (ACTH)
Pars intermedia produces which hormones:
Melanocyte stimulating hormone (MSH)
In humans, the pars intermedia is almost merged with the pars distalis. T or F?
True
Pars intermedia is aka posterior pituitary. T or F?
False, pars intermedia is part of adenohypophysis. Neurohypophysis / pars nervosa is aka posterior pituitary
Neurohypophysis stores and releases two hormones called ____________ and ____________
oxytocin, vasopressin
Oxytocin and vasopressin are synthesised by the ____________ and are transported axonally to the ____________
hypothalamus, neurohypophysis
Neurohypophysis synthesizes oxytocin and vasopressin. T or F?
False, it only stores and releases, hypothalamus synthesizes
Over-secretion of ____________ stimulates abnormal growth of body leading to ____________ and low secretion results in stunted growth resulting in ____________
GH, gigantism, pituitary dwarfism
Excess secretion of growth hormone in adults especially in middle age can result in severe disfigurement called ____________
acromegaly
Acromegaly may lead to serious complications and premature death if unchecked. T or F?
True
Acromegaly often goes undetected for many years as it is hard to diagnose in early stages. T or F?
True
Prolactin regulates ____________ and ____________
growth of mammary glands,
formation of milk
TSH stimulates the synthesis and secretion of thyroid hormones from the thyroid gland. T or F?
True
ACTH stimulates the synthesis and secretion of steroid hormones called ____________ from the adrenal cortex
glucocorticoids
LH and FSH stimulate gonadal activity and hence are called ____________
gonadotrophins
In males, LH stimulates the synthesis and secretion of hormones called ____________ from testis
androgens
In males, ____________ and ____________ hormones regular spermatogenesis
FSH, androgens
In females, LH induces ____________ and maintains ____________
ovulation of fully mature follicles (graafian follicles);
the corpus luteum
Corpus luteum is formed from the remnants of the ____________ after ovulation
graafian follicles
FSH stimulates growth and development of the ____________ in females
ovarian follicles
MSH acts on the ____________ and regulates ____________
melanocytes, pigmentation of the skin
Melanocytes are cells containing ____________
melanin
Oxytocin acts on ____________ and stimulates their ____________
smooth muscles of our body, contraction
In females, oxytocin stimulates a vigorous contraction of uterus at the time of __________ and ____________
child birth
milk ejection from mammary gland
Vasopressin acts mainly at the ____________ and stimulates resorption of water and electrolytes by the ____________
kidney, distal tubules
Vasopressin reduces water loss (through ___________)
urine (diuresis)
Vasopressin is aka the ___________ hormone
anti-diuretic hormone
An impairment affecting synthesis or release of ADH results in ___________ and is known as ___________
diminished ability of kidney to conserve water
=> water loss
=> dehydration
Diabetes Insipidus
Pineal gland is located on the ___________ side of the forebrain
dorsal
Pineal secretes a hormone called ___________
melatonin
Melatonin plays a very important role in the regulation of ___________
regulation of a 24-hour (diurnal) rhythm of our body
__________ helps in maintaining the normal rhythms of sleep-wake cycle and body temperature.
Melatonin
_________ also influences metabolism, pigmentation, the menstrual cycle as well as our defense capability
Melatonin
Thyroid gland is composed of ____ (how many?) lobes which are located on either side of the __________
2, trachea
Both the thyroid lobes are interconnected with a __________ tissue called __________
thin flap of connective tissue, isthmus
Thyroid gland is composed of __________ and __________
follicles, stromal tissues
Each thyroid follicle is composed of __________ cells, enclosing a __________
follicular, cavity
The thyroid follicular cells synthesise 2 hormones:
tetraiodothyronine or thyroxine (T4)
triiodothyronine (T3)
__________ is essential for the normal rate of hormone synthesis in the thyroid
Iodine
Deficiency of iodine in our diet results in __________
hypothyroidism and goitre (enlargement of the thyroid gland)
Hypothyroidism during pregnancy causes defective development and maturation of the growing baby leading to:
stunted growth (cretinism), mental retardation, low intelligence quotient, abnormal skin, deaf-mutism
In adult women, hypothyroidism may cause menstrual cycle to become irregular. T or F?
True
Due to the __________ or due to __________, the rate of synthesis and secretion of thyroid hormones is increased.
cancer of the thyroid gland,
development of nodules of the thyroid glands
Abnormal high levels of thyroid hormones leads to a condition called __________ which adversely affects the body physiology.
hyperthyroidism
Exopthalmic goitre is a form __________ aka __________
hyperthyroidism, Graves’ disease
Characteristics of exopthalmic goitre:
Enlargement of thyroid gland,
protrusion of eyeballs,
increased BMR,
weight loss
Thyroid hormones play and important role in regulation of the BMR. T or F?
True
Thyroid hormones also support process of RBC formation. T or F?
True
Thyroid hormones control metabolism of __________, __________ and __________
carbs, proteins, fats
Maintenance of water and electrolyte balance is also influenced by thyroid hormones. T or F?
True
Thyroid gland also secretes a protein hormone called __________ which regulates the blood calcium levels
thyrocalcitonin (TCT)
In humans, _______ (how many?) parathyroid glands are present on the ______ (front/back) side of the thyroid gland, one pair each in the __________ of the thyroid gland
4, back, two lobes
Parathyroid glands secrete a peptide hormone called __________
parathyroid hormone (PTH)
The secretion of PTH is regulated by the circulating levels of __________
calcium ions
Parathyroid hormone __________ (increases / decreases) the Ca2+ levels in the blood
increases
PTH acts on bones and stimulates the process of __________
bone resorption (dissolution / demineralisation)
PTH also stimulates reabsorption of Ca2+ by the __________ and increases Ca2+ absorption from __________
renal tubules, digested food
It is thus clear that PTH is a __________ hormone i.e. increases the blood Ca2+ levels
hypercalcemic
_____ and _____ plays a significant role in calcium balance in the body
TCT and PTH
The thymus gland is a lobular structure located between __________ behind __________ on the __________ side of the aorta
lungs, sternum, ventral
__________ plays a major role in the development of the immune system
Thymus
Thymus secretes the peptide hormones called __________
thymosins
Thymosins play a major role in the differentiation of __________
T-lymphocytes
Thymosins also promote production of __________ to provide humoral immunity
antibodies
Thymus is __________ in old individuals resulting in decreased production of thymosins
degenerated
Immune systems of old persons become weak due to the decreased production of thymosins. T or F?
True
Our body has _____ pair(s) of adrenal glands. Where are they located?
one pair,
one at the anterior part of each kidney
Adrenal gland is composed of 2 types of tissues:
adrenal medulla (centrally located) adrenal cortex (outside)
Addison’s disease?
Underproduction of hormones by adrenal cortex => alters carb metabolism => acute weakness and fatigue
Adrenal medulla secretes two hormones called. __________ and __________
adrenaline / epinephrine
noradrenaline/norepinephrine
What are catecholamines?
Hormones secreted by adrenal medulla
__________ and __________ are rapidly secreted in response to stress of any kind. They are aka __________ hormones.
Adrenaline, noradrenaline,
emergency/ fight or flight
Adrenaline / noradrenaline effects?
Increase alertness, pupilary dilation, piloerection (raising of hairs), sweating, increased heart beat, increased strength of heart contraction, increased rate of respiration
Catecolamines also stimulate the breakdown of __________ resulting in an increased concentration of __________ in blood
glycogen, glucose
Catecholamines also stimulate the breakdown of lipids and proteins. T or F?
True
Adrenal cortex can be divided into 3 layers:
zona reticularis (inner) zona fasciculata (middle) zona glomerulosa (outer)
Adrenal cortex secretes many hormones, commonly called as __________
corticoids
Corticoids involved in carb metabolism are called __________
glucocorticoids
In our body, __________ is the main glucocorticoid
cortisol
Corticoids which regulate the balance of water and electrolytes in our body are called __________
mineralocorticoids
__________ is the main mineralocorticoid in our body
Aldosterone
Glucocorticoids stimulate __________, __________ __________ and ___________
gluconeogenesis, lipolysis, proteolysis, erythropoiesis
Glucocorticoids inhibit cellular uptake and utilisation of __________
amino acids
__________ is involved in maintaining the cardio-vascular system as well as the kidney functions
Cortisol
Glucocorticoid, particularly cortisol, produce __________ reactions and suppresses the immune response
anti-inflammatory
Aldosterone stimulates RBC production. T or F?
False, cortisol
Aldosterone acts mainly at the __________ and stimulates the reabsorption of __________ and excretion of __________
renal tubules,
Na+ and water,
K+ and phosphate ions
Aldosterone helps in maintenance of electrolytes, body fluid volume, osmotic pressure and blood pressure. T or F?
True
Pancreas is a __________ gland
composite - exocrine and endocrine
Endocrine pancreas consists of __________
Islets of Langerhans
There are how many Islets of Langerhans in a normal human pancreas?
1-2 million
Islets of Langerhans represent _____% of pancreatic tissue
1-2%
The two main types of cells in the Islet of Langerhans are called __________ and __________
alpha-cells and beta-cells
Alpha cells secrete hormone called. __________ while beta cells secrete __________
glucagon, insulin
Glucagone is a __________ hormone and plays an important role in maintaining __________
peptide, normal blood glucose levels
Glucagon acts mainly on the __________ cells and stimulates __________ resulting in __________
hepatocytes (liver cells),
glycogenolysis,
hyperglycemia (increased blood sugar)
Glucagon stimulates the process of __________ which also contributes to hyperglycemia
gluconeogenesis
Glucagon __________ (increases / decreases) the cellular glucose uptake and utilisation.
reduces
__________ is a hyperglycemic hormone
Glucagon
Insulin is a __________ hormone which plays a major role in the regulation of __________
peptide, glucose homeostasis
Insulin acts mainly on __________ and __________ and enhances cellular uptake and utilization of __________
hepatocytes, adipocytes, glucose
There is a rapid movement of glucose from __________ to __________ as a result of insulin, resulting in __________
blood, hepatocytes and adipocytes
hypoglycemia
Insulin also stimulates the conversation of __________ to __________ (aka __________) in the target cells
glucose, glycogen, glycogenesis
Glucose homeostasis in blood is maintained jointly by __________ and __________
insulin and glucagon
Prolonged hyperglycemia leads to a complex disorder called __________
diabetes mellitus
Diabetes mellitus is associated with loss of glucose through __________ and formation of __________
urine, ketone bodies (harmful compounds)
Diabetic patients are successfully treated with __________
insulin therapy
A pair of testis is present in the ___________ sac (outside abdomen) of male individuals.
scrotal
Testis performs dual functions as a ___________ and ___________
primary sex organ, endocrine gland
Testis is composed of ___________ tubules and ___________ tissue
seminiferous,
stromal/interstitial
Leydig/interstitial cells which are present in the intertubular spaces produce a group of hormones called ___________ mainly ___________
androgens, testosterone
Androgens regulate the development, maturation and functions of the ___________
male sex organs
___________ stimulate muscular growth, growth of facial and axillary hair, aggressiveness, low pitch of voice, etc.
Androgens
Androgens play a major stimulatory role in the process of ___________
spermatogenesis
Androgens act on the ___________ neural system and influence the ___________
central, libido (male sexual behavior)
Androgens produce ___________ effects on protein and carb metabolism
anabolic (synthetic)
___________ is the primary female sex organ which produces ___________ (how many) ovum during each menstrual cycle
Ovary, one
Ovary also produces 2 groups of steroid hormones: ___________ and ___________
estrogen, progesterone
Ovary is composed of ___________ follicles and ___________ tissues
ovarian, stromal
Estrogen is synthesised and secreted mainly by ___________
growing ovarian follicles
After ovulation, the ruptured follicle is converted to a structure called ___________
corpus luteum
Corpus luteum secretes mainly ___________
progesterone
___________ produce wide ranging actions: stimulation of growth and activities of female sex organs, development of growing ovarian follicles, high pitch voice, mammary gland development, etc.
Estrogens
___________ regulate female sexual behaviour
Estrogens
___________ (hormone) supports pregnancy
Progesterone
Progesterone also acts on the ___________ glands and stimulates the formulation of ___________ and ___________
mammary, alveoli, milk secretion
Atrial wall of our heart secretes a very important peptide hormone called ___________
atrial natriuretic factor (ANF)
ANF decreases ___________
blood pressure
When blood pressure is increased, ANF is secreted which causes dilation of ___________ which ___________ (increases/decreases) blood pressure
blood vessels, decreases
Juxtaglomerular cells of kidney produce a peptide hormone called ___________ which stimulates ___________
erythropoietin,
erythropoiesis (formation of RBC)
Endocrine cells present in different parts of the gastro-intestinal tract secrete four major peptide hormones:
gastrin,
secretin,
cholecystokinin (CCK)
gastric inhibitory peptide (GIP)
Gastrin acts on ___________ and stimulates the secretion of ___________
gastric glands,
hydrochloric acid, pepsinogen
Secretin acts on the ___________ and stimulates secretion of ___________
exocrine pancreas,
water, bicarbonate ions
CCK acts ___________ and stimulates the secretion of ___________
pancreas, gall bladder;
pancreatic enzymes, bile juice
GIP inhibits ___________ and ___________
gastric secretion, motility
What growth factors?
Hormones secreted by other non-endocrine tissues
essential for normal growth of tissues and their repairing/regeneration
Hormones produce their effects on target tissues by ___________
binding to specific proteins called hormone receptors located in the target tissues only
Hormones receptors present on the cell membrane of the target cells are called ___________
membrane-bound receptors
Hormones receptors present inside the target cells are called ___________
intracellular receptors
Intracellular receptors are mostly ___________ receptors
nuclear i.e. present in the nucleus
Binding a hormone to its receptor leads to the formation of ___________
a hormone-receptor complex
Most receptors are specific. T or F?
False, ALL are specific to one hormone only
Hormone-Receptor complex formation leads to certain ___________ changes in the target
biochemical
Target tissue metabolism and hence physiological functions are regulated by ___________
hormones
On the basis of their chemical nature, hormones can be divided into how many groups? What are they?
- peptide, polypeptide, protein hormones
- steroids
- iodothyronines
- amino-acid derivatives
Match the hormone to the group (based on the their chemical nature): thyroid hormones cortisol insulin epinephrine estradiol progesterone glucagon pituitary hormones, testosterone hypothalamic hormones
thyroid hormones - iodothyronines
cortisol - steroids
insulin - peptide/polypeptide/protein hormones
epinephrine - amino-acid derivatives
estradiol - steroids
progesterone - steroids
glucagon - peptide/polypeptide/protein hormones
pituitary hormones - peptide/polypeptide/protein hormones
testosterone - steroids
hypothalamic hormones - peptide/polypeptide/protein hormones
Hormones which interact with membrane-bound receptors normally enter the target cell post second message. T or F?
False, they do not enter, generate second messengers
Cyclic AMP, IP2, Ca++ are examples of ?
second messengers
Second messengers in turn regulate ___________
cellular metabolism
Hormones which interact with intracellular receptors mostly regulate ___________ or ___________ by the interaction of ___________
gene expression, chromosom function,
hormone-receptor complex with the genome
Steroid hormones and iodothyronines usually interact with ___________ (membrane-bound / intracellular) receptors
intracellular
___________ produces six trophic hormones
Pars distalis
___________ secretes only one hormone, while ___________ secretes two hormones
Pars intermedia,
Pars nervosa
___________ hormones regulate the growth and development of somatic tissues and activities of peripheral endocrine glands
Pituitary
___________ regulates calcium levels in our blood by decreasing it
Thyrocalcitonin
Glucocorticoids stimulate cardio-vascular system, blood pressure and glomerular filtration rate and inhibit inflammatory reactions. T or F?
True
Insulin ___________ and/or insulin ___________ result in a disease called diabetes mellitus
deficiency, resistance