Chapter 17 PowerPoint Flashcards
Homeostasis?
Steady state of body systems that living organisms maintain
Autocrine
A chemical signal that elicits a response in the same cell that secreted it
Paracrine?
A chemical signal that elicits a response in neighboring cells; also called paracrine factor
Endocrine?
Relating to or denoting glands which secrete hormones or other products directly into the blood
What are the four classes of hormones?
Amino acid derivatives (amine hormones)
Peptide hormones
Protein hormones
Steroid hormones
What do hormones do?
Where?
What do the bind to?
Hormones circulate freely or travel bound to special carrier proteins
What are amino acid derivatives (amine hormones)?
Derivatives of tyrosine:
-____ hormones
-____
epinephrine, norepinephrine, dopamine
Derivatives of ____:
-serotonin, melatonin
Small molecules structurally related to amino acids
Derivatives of tyrosine:
-thyroid hormones
-catecholamines
epinephrine, norepinephrine, dopamine
Derivatives of tryptophan:
-serotonin, melatonin
What are the three catecholamines?
Epinephrine, norepinephrine, dopamine
What are two derivatives of tryptophan?
Serotonin and melatonin
What are peptide hormones?
What are they synthesized as?
chains of amino acids
most are synthesized as prohormones
(Inactive molecules converted to active hormones before or after they are secreted)
What are short chain polypeptides?
-2 examples
antidiuretic hormone (ADH) and oxytocin (OXT) (each 9 amino acids long)
[2-50 linked amino acids]
What are protein hormones?
-2 examples
small proteins
growth hormone (GH; 191 amino acids) and prolactin (PRL; 198 amino acids)
What are steroid hormones derivatives of?
Cholesterol
What are steroid hormones released by?
The reproductive organs (androgens by the testes in males, estrogens and progestins by the ovaries in females)
The cortex of the adrenal glands (corticosteroids)
The kidneys (calcitriol)
What type of hormone remains in circulation the longest and why?
Because circulating steroid hormones are bound to specific transport proteins in the plasma: they remain in circulation longer than secreted peptide hormones
How long do free hormones remain functional?
Less than 1 hour
What are three ways free hormones are gotten rid of?
Diffuse out of bloodstream and bind to receptors on target cells
Are broken down and absorbed by cells of liver or kidneys
Are broken down by enzymes in plasma or interstitial fluids
Thyroid and Steroid Hormones
remain in circulation much longer because most are “bound”
enter bloodstream
>____% become attached to special transport proteins
bloodstream contains substantial reserve of ____ ____?
Thyroid and Steroid Hormones
remain in circulation much longer because most are “bound”
enter bloodstream
>99% become attached to special transport proteins
bloodstream contains substantial reserve of bound hormones
What is a hormone receptor?
Responds to several ____ hormones?
Different tissues have different ____ of receptors?
Presence or absence of specific receptor determines hormonal ____?
A protein molecule to which a particular molecule binds strongly
Responds to several different hormones
Different tissues have different combinations of receptors
Presence or absence of specific receptor determines hormonal sensitivity
First messenger?
A hormone that binds to a cell membrane hormone receptor and triggers activation of a second messenger system
Second messenger?
A molecule that initiates a signaling cascade in response to hormone binding on a cell membrane receptor and activation of a G protein
What are three important 2nd messengers?
Cyclic-AMP (cAMP)
-Derivative of ATP
Cyclic-GMP (cGMP)
-Derivative of GTP
Calcium ions
G protein?
A protein associated with a cell membrane hormone receptor that initiates the next step in a second messenger system upon activation by hormone–receptor binding
Enzyme complex coupled to membrane receptor
Involved in link between 1st messenger and 2nd messenger
Adenylyl cyclase?
A membrane-bound enzyme that converts ATP to cyclic AMP, creating cAMP, as a result of G-protein activation
____ ____ is activated when hormone binds to membrane receptor and changes concentration of cAMP within cell?
↑ ____ level accelerates metabolic activity within cell
Adenylate cyclase
cAMP
How do hormones and plasma membrane receptors work? (Water soluble)
Chapter 17 page 739 or slides 15-140
How do hormones and intracellular receptors work? (Lipid soluble)
Chapter 17 page 739 or slide 19
Hormones and Intracellular Receptors:
Alter rate of DNA transcription in ____?
(-Change patterns of protein synthesis)
Directly affect metabolic activity and structure of ____ cell?
Include ____ and ____ hormones
Nucleus
Target
Steriods and thyroid
Neuroendocrine reflexes?
Pathways include both neural and endocrine components
(A physical stimulus causes a nervous signal, which triggers the release of hormones from the brain into the blood)
Complex Commands involve ____ hormones?
Issued by changing:
-____of hormone secreted?
-____ of hormone release?
Hypothalamic and pituitary hormones
released in sudden bursts
Frequency changes response of target cells
Complex Commands involve many hormones?
Issued by changing:
-Amount of hormone secreted?
-Pattern of hormone release?
Hypothalamic and pituitary hormones
released in sudden bursts
Frequency changes response of target cells
Down-regulation?
-Presence of a hormone triggers decrease in number of hormone receptors
-When levels of particular hormone are high, cells become less sensitive to it
A decrease in the number of hormone receptors, typically in response to chronically excessive levels of
a hormone
Up-regulation?
-Absence of a hormone triggers increase in number of hormone receptors
-When levels of particular hormone are low, cells become more sensitive to it
An increase in the number of hormone receptors, typically in response to chronically reduced levels of a
hormone
Cells ____ through downregulation of steroid receptor?
Desensitize
Pituitary gland?
Bean-sized organ suspended from the hypothalamus that produces, stores, and secretes hormones in
response to hypothalamic stimulation (also called hypophysis)
The Pituitary Gland
-also called ____?
-lies within ____ ____?
____ ____
a dural sheet that locks pituitary in position
isolates it from cranial cavity
-hangs inferior to ____?
-connected by ____?
The Pituitary Gland
-also called hypophysis
-lies within sella turcica
Sellar diaphragm
a dural sheet that locks pituitary in position
isolates it from cranial cavity
-hangs inferior to hypothalamus
-connected by infundibulum
Infundibulum?
Stalk containing vasculature and neural tissue that connects the pituitary gland to the hypothalamus (also
called the pituitary stalk)
The Pituitary Gland:
Releases ____ important peptide hormones?
Hormones bind to ____ ____
use ____ as second messenger?
The Pituitary Gland:
Releases 9 important peptide hormones
Hormones bind to membrane receptors
use cAMP as second messenger
Hypophyseal portal system?
A network of blood vessels that enables hypothalamic hormones to travel into the anterior lobe of the pituitary without entering the systemic circulation
Blood vessels link two capillary networks
Entire complex is portal system
-ensures that regulatory factors reach
intended target cells before entering general
circulation
Hypothalamic Control of the Anterior Lobe:
2 classes of hypothalamic regulatory hormones
____ ____(____)?
Stimulate synthesis and secretion of one or
more hormones at anterior lobe
____ ____(____)?
Prevent synthesis and secretion of hormones
from the anterior lobe
Rate of secretion is controlled by ____ ____?
Hypothalamic Control of the Anterior Lobe:
2 classes of hypothalamic regulatory hormones
Releasing hormones (RH)
Stimulate synthesis and secretion of one or
more hormones at anterior lobe
Inhibiting hormones (IH)
Prevent synthesis and secretion of hormones
from the anterior lobe
Rate of secretion is controlled by negative feedback
9 Hormones of the pituitary gland?
Chapter 17 pages 744&475 or slides 30-31
Parathyroid gland:
Number?
Location?
Size?
4 Parathyroid Glands
embedded in the posterior surface of the thyroid gland
altogether, the four glands weigh 1.6g
What hormone does the parathyroid gland secrete?
Parathyroid Hormone (PTH) or parathormone
PTH?
Parathyroid hormone is a peptide hormone produced and secreted by the parathyroid glands in response to low blood calcium levels
Parathyroid Hormone (PTH) or parathormone is
produced by parathyroid ____ ____ in response to low concentrations of ____ and is an antagonist for ____?
Parathyroid Hormone (PTH) or parathormone is
produced by parathyroid (chief) cells in response to low concentrations of Ca2+ and is an antagonist for calcitonin
Chief cells?
Produce and secrete PTH
What are the three effects of PTH?
It stimulates osteoclasts and inhibits osteoblasts
-accelerates mineral turnover and releases Ca2+ from bone
-reduces rate of calcium deposition in bone
It enhances reabsorption of Ca2+ at kidneys, reducing urinary losses
It stimulates formation and secretion of calcitriol by the kidneys
-effects complement or enhance PTH
-also enhances Ca2+, PO43- absorption by digestive tract
Adrenal glands:
Location?
The Adrenal Glands lie along the superior border of each kidney
Adrenal glands?
endocrine glands located at the top of each kidney that are important for the regulation of the stress response, blood pressure and blood volume, water homeostasis, and electrolyte levels
Two subareas of adrenal glands?
Superficial adrenal cortex
Inner adrenal medulla
Superficial adrenal cortex:
What does it store?
What does it manufacture?
stores lipids, especially cholesterol and fatty acids
manufactures steroid hormones (corticosteroids)
Inner adrenal medulla:
Controlled by?
Produce?
How long do changes last?
secretory activities controlled by the sympathetic division of ANS
produces epinephrine (adrenaline) and norepinephrine
metabolic changes persist for several minutes
Adrenal cortex?
outer region of the adrenal glands consisting of multiple layers of epithelial cells and capillary
networks that produces mineralocorticoids and glucocorticoids
Corticosteriods?
any of a group of steroid hormones produced in the adrenal cortex or made synthetically
Adrenal medulla?
inner layer of the adrenal glands that plays an important role in the stress response by producing epinephrine and norepinephrine
Fill out the chart on adrenal glands?
Chapter 17 slide 41 or page 759
Zona glumerulosa:
Where/what?
Produce?
Example?
Function?
When secreted?
outer region of adrenal cortex
produces mineralocorticoids
for example, aldosterone
stimulates conservation of sodium ions and elimination of potassium ions
increases sensitivity of salt receptors in taste buds
secretion responds to:
drop in blood Na+, blood volume, or blood pressure
rise in blood K+ concentration
Zona glomerulosa?
most superficial region of the adrenal cortex, which produces the hormones collectively referred to as mineralocorticoids
Aldosterone?
hormone produced and secreted by the adrenal cortex that stimulates sodium and fluid retention and increases blood volume and blood pressure
Zona fasciculata:
Produce?
Example?
Functions?
Has an inhibitory effect on?
produces glucocorticoids
(eg., cortisol in humans; corticosterone in animals)
accelerate glucose synthesis and glycogen formation
show anti-inflammatory effects
inhibit activities of white blood cells and other components of immune system
secretion regulated by negative feedback
has inhibitory effect on production of:
corticotropin-releasing hormone (CRH) in hypothalamus
ACTH in adenohypophysis
Zona fasciculata?
Glucocorticoids?
hormones produced by the zona fasciculata of the adrenal cortex that influence glucose metabolism
Cortisol?
glucocorticoid important in gluconeogenesis, the catabolism of glycogen, and downregulation of the immune
system
Corticosterone?
The animal version of cortisol
Anti-inflammatory?
(chiefly of a drug) used to reduce inflammation.
Inflammation:
Response to?
4 signs?
Response to tissue injury
redness, swelling, pain, and local heat
Zona Reticularis:
network of ____ cells?
forms narrow band bordering each ____ ____?
produces ____ under stimulation by ____?
Zona Reticularis:
network of endocrine cells
forms narrow band bordering each adrenal medulla
produces androgens under stimulation by ACTH
Zona reticularis?
deepest region of the adrenal cortex, which produces the steroid sex hormones called androgens
The Adrenal Medulla
contains two types of secretory cells
one produces ____ (____)
____-____% of medullary secretions
the other produces ____ (____)
____-____% of medullary secretions
The Adrenal Medulla
contains two types of secretory cells
one produces epinephrine (adrenaline)
75 – 80% of medullary secretions
the other produces norepinephrine (noradrenaline)
20 – 25% of medullary secretions
How many types of cells does the adrenal medulla contain?
2
Pineal gland:
Location?
Contain?
Synthesizes?
pineal gland
lies in posterior portion of roof of third ventricle
contains pinealocytes
Synthesize hormone melatonin
3 functions of melatonin?
inhibits reproductive functions
protects against damage by free radicals
influences circadian rhythms
Epinephrine?
primary and most potent catecholamine hormone secreted by the adrenal medulla in response to short-term stress; also called adrenaline
Norepinephrine?
secondary catecholamine hormone secreted by the adrenal medulla in response to short-term stress; also called noradrenaline
Two gonads?
Testes and ovaries
Testosterone?
steroid hormone secreted by the male testes and important in the maturation of sperm cells, growth and
development of the male reproductive system, and the development of male secondary sex characteristics
Inhibin?
hormone secreted by the male and female gonads that inhibits FSH production by the anterior pituitary
Nurse cells?
Sertoli cells-cells that support germ cells through the process of spermatogenesis; a type of sustentacular cell
Sertoli cells of the testes have been called “nurse cells” because they provide nutrients and growth factors to developing germ cells
Testes:
produce ____ in ____ cells
____ is the most important male hormone
secrete ____ in ____ cells
support differentiation and physical maturation of sperm
Testes:
produce androgens in interstitial cells
testosterone is the most important male hormone
secrete inhibin in nurse cells
support differentiation and physical maturation of sperm
Estrogens?
class of predominantly female sex hormones important for the development and growth of the female reproductive tract, secondary sex characteristics, the female reproductive cycle, and the maintenance of pregnancy
Estradiol?
a major estrogen produced in the ovaries.
Progestins?
a natural or synthetic steroid hormone, such as progesterone, that maintains pregnancy and prevents further ovulation during pregnancy.
Progesterone?
predominantly female sex hormone important in regulating the female reproductive cycle and the maintenance of pregnancy
Ovaries:
produce ____
principal estrogen is ____
after ovulation, follicle cells:
reorganize into corpus luteum
release ____ and ____, especially ____
Ovaries:
produce estrogens
principal estrogen is estradiol
after ovulation, follicle cells:
reorganize into corpus luteum
release estrogens and progestins, especially progesterone
Pancreas:
Location?
Two things is contains?
Lies between:
inferior border of stomach
ad proximal portion of small intestine
contains exocrine and endocrine cells
Pancreas?
organ with both exocrine and endocrine functions located posterior to the stomach that is important for
digestion and the regulation of blood glucose
Exocrine Pancreas:
Consist of?
What percentage of volume?
What do they secrete?
consists of clusters of gland cells called pancreatic acini and their attached ducts
takes up roughly 99% of pancreatic volume
gland and duct cells secrete alkaline, enzyme-rich fluid
That reaches the lumen of the digestive tract through a network of secretory ducts
Endocrine Pancreas consists of cells that form clusters known as ____ ____, or ____ ____ ____?
Endocrine Pancreas consists of cells that form clusters known as pancreatic islets, or islets of Langerhans
Endocrine pancreas:
Types of cells and what they secrete?
Alpha cells produce glucagon
Beta cells produce insulin
Delta cells produce peptide hormone identical to GH–IH (growth hormone-inhibiting hormone)
F cells secrete pancreatic polypeptide (PP)
Alpha cells?
pancreatic islet cell type that produces the hormone glucagon
Beta cells?
pancreatic islet cell type that produces the hormone insulin
Delta cells?
minor cell type in the pancreas that secretes the hormone somatostatin/GH–IH (growth hormone-inhibiting hormone)
F cells/PP cells?
minor cell type in the pancreas that secretes the hormone pancreatic polypeptide
Blood Glucose Levels
When levels rise:
_________________________, stimulating transport of glucose across plasma membranes
When levels decline:
___________________________, stimulating glucose release by liver
Blood Glucose Levels
When levels rise:
Beta cells secrete insulin, stimulating transport of glucose across plasma membranes
When levels decline:
Alpha cells release glucagon, stimulating glucose release by liver
Insulin:
is a ____ hormone released by ____ cells?
5 affects on target cells?
Insulin:
is a peptide hormone released by beta cells
-accelerates glucose uptake
-accelerates glucose utilization and enhances ATP production
-stimulates glycogen formation
-stimulates amino acid absorption and protein synthesis
-stimulates triglyceride formation in adipose tissue
Insulin?
pancreatic hormone that enhances the cellular uptake and utilization of glucose, thereby decreasing blood glucose levels
Glucagon?
pancreatic hormone that stimulates the catabolism of glycogen to glucose, thereby increasing blood glucose levels
Glucagon:
released by ____ cells?
____ energy reserves?
3 affects on target cells?
Glucagon:
released by alpha cells
mobilizes energy reserves
-stimulates breakdown of glycogen in skeletal muscle and liver cells
-stimulates production of glucose in liver (gluconeogenesis)
-stimulates breakdown of triglycerides in adipose tissue
Diabetes mellitus?
condition caused by destruction or dysfunction of the beta cells of the pancreas or cellular resistance to insulin that results in abnormally high blood glucose levels
What three things is diabetes mellitus characterized by?
Diabetes Mellitus:
characterized by glucose concentrations high enough to overwhelm the reabsorption capabilities of the kidneys
hyperglycemia=abnormally high glucose levels in the blood in general
glucose appears in the urine, and urine volume generally becomes excessive (polyuria)
Hyperglycemia?
abnormally high blood glucose levels
Glucose?
a simple sugar which is an important energy source in living organisms and is a component of many carbohydrates.
Polyuria?
production of abnormally large volumes of dilute urine
Type 1 diabetes mellitus:
AKA?
Characterized by?
What do people with this require?
Percent of cases?
When does it develop?
Insulin dependant diabetes
characterized by inadequate insulin production by the pancreatic beta cells
persons with type 1 diabetes require insulin to live and usually require multiple injections daily, or continuous infusion through an insulin pump or other device
this form of diabetes accounts for only around 5–10 percent of cases
it often develops in childhood
Type 2 diabetes mellitus:
AKA?
What is it?
Associated condition?
Effective treatment?
Type 2 (non-insulin dependent) diabetes
the most common form of diabetes mellitus
most people with this form of diabetes produce normal amounts of insulin, at least initially, but their tissues do not respond properly, a condition known as insulin resistance
type 2 diabetes is associated with obesity
weight loss through diet and exercise can be an effective treatment
Insulin resistance?
when cells in your muscles, fat, and liver don’t respond well to insulin and can’t easily take up glucose from your blood
5 Complications of untreated/poorly manged diabetes mellitus?
kidney degeneration
peripheral tissue damage
peripheral nerve problems
early heart attacks
retinal damage
What five organs of other body structures have secondary endocrine functions?
thymus (lymphatic system and immunity)
heart (cardiovascular system)
intestines (digestive system)
kidneys (urinary system)
gonads (reproductive system)
The Heart produces ____ ____ (ANP ____ ____ ____ and BNP ____ ____ ____)?
natriuretic peptides
atrial natriuretic peptides
brain natriuretic peptides
What do natriuretic peptides do?
-when blood volume becomes excessive
-action opposes angiotensin II
-resulting in reduction in blood volume and blood pressure
The Intestines produce hormones important to the ____ of ____ activities?
The Intestines produce hormones important to the coordination of digestive activities
the Kidneys:
produce the hormones ____ and ____ (____)?
produce the enzyme ____?
the Kidneys:
produce the hormones calcitriol and erythropoietin (EPO)
produce the enzyme renin
Calcitriol?
the active form of vitamin D stimulates absorption of calcium and phosphate from digestive tract
Erythropoietin?
(EPO) protein hormone secreted in response to low oxygen levels that triggers the bone marrow to produce red blood cells
Renin?
Stimulates release of aldosterone (keeps sodium in and potassium out of the body)
an enzyme secreted by and stored in the kidneys which promotes the production of the protein angiotensin
What hormone does adipose tissue secrete?
Leptin
Leptin:
feedback control for ____?
Sometimes called the “____ ____”?
controls normal levels of ____, ____ synthesis
feedback control for appetite
Sometimes called the “satiety hormone”
controls normal levels of GnRH, gonadotropin synthesis
