A&P Exam I Flashcards
Cort- means?
Bark, rind: adrenal cortex–outer portion of an adrenal gland.
-crin means?
To secrete: endocrine–internal secretion
diure- means?
To pass urine: diuretic–substance that promotes urine production
endo- means?
Inside: endocrine gland–gland that internally secretes into a body fluid.
exo- means?
outside: exocrine gland–gland that secretes to the outside through a duct
horm- means?
Impetus, impulse: hormone–substance that a cell secretes that affects another cell.
hyper- means?
Above: hyperthyroidism–condition resulting from an above-normal secretion of thyroid hormone
hypo- means?
Above: hypothyroidism–condition resulting from a below-normal secretion of thyroid hormone.
lact- means?
Milk: prolactin–hormone that promotes milk production
med- means?
Middle: adrenal medulla–inner portion of an adrenal gland
para- means?
beside: parathyroid glands–set of glands on the posterior surface of the thyroid gland.
toc- means?
Birth: oxytocin–hormone that stimulates the uterine muscles to contract during childbirth.
-tropic means?
Influencing: adrenocorticotropic hormone–a hormone secreted by the anterior pituitary gland that stimulates the adrenal cortex.
Vas- means?
Vessel: vasopressin–hormone that helps maintain blood pressure by constricting blood vessels.
Regulating the functions of the human body is achieved by the partnering of the nervous system and the ____________ to coordinate and execute communication throughout the body.
Endocrine
Which is more specific in terms of which cells are affected, a neurotransmitter or a hormone? What do postsynaptic cells and target cells have in common that allow them to respond to secreted chemicals?
They are equally specific because only cells with receptors, either for the neurotransmitter or the hormone, will respond.
What are the components of the endocrine system?
The endocrine system consists of organs and glands that produce hormones.
Are the components of the endocrine system anatomically connected to each other?
No
What are the major glands of the endocrine system?
Hypothalamus
Pituitary Gland
Thyroid Gland
Parathyroid Gland
Adrenal Glands
Pancreas
Pineal Gland
Thymus
Reproductive glands (testes and ovaries)
In the endocrine system, what organs also contain cells which produce hormones?
The liver, heart, kidneys, and gastrointestinal tract.
What determines whether a cell is a target cell for a particular hormone?
Target cells contain protein or glycoprotein receptors that are specific for particular hormones. The receptors contain unique binding sites for the particular hormone.
Target cells contain _________ or _________ receptors that are specific for particular hormones.
Protein; glycoprotein
How do paracrine and autocrine secretions function differently than traditionally defined hormones?
Hormones are released into the interstitial fluid, diffuse into the blood, and are transported to their target cells elsewhere in the body. Paracrine and autocrine substances can be called “local hormones;” they do not enter the bloodstream; instead they act as local messengers. Paracrine substances act on cells in the vicinity of the cells that produce them. Autocrine substances act on the cells that produce them.
Explain how the nervous and endocrine systems are alike and how they differ.
The systems are alike in that they both regulate many bodily processes, and communicate via chemical messengers. However, the nervous system works more quickly than the endocrine system, and its effects are more short-lived. The endocrine system takes longer to begin acting, and its effects last longer. The nervous system communicates through neurons secreting neurotransmitters into synapses. The endocrine system consists of glandular epithelial cells, which secrete hormones into the body fluids; the hormones then circulate through the blood to find their target cells.
State some general functions of hormones.
Hormones regulate metabolic activities, water and electrolyte balance, growth, the response to stress, and various aspects of the physiology of many blood cells.
How are hormones chemically classified?
In general, hormones can be grouped as either steroids or non-steroids.
From what specific compound are prostaglandins synthesized?
Prostaglandins are produced from a fatty acid called arachidonic acid, which is found in cell membranes.
How does a steroid hormone act on its target cells?
A steroid hormone penetrates the cell membrane, and binds to a particular receptor protein inside the cell. The hormone-receptor complex binds to a specific region of a DNA molecule, and activates gene transcription in the nucleus, which results in the production of a certain protein. The new protein accomplishes the function of the hormone, by acting either as an enzyme, a transport protein, or a hormone receptor.
How does a nonsteroid hormone act on its target cells?
A nonsteroid hormone binds to a cell membrane receptor, since it cannot penetrate the membrane. In many cases, the hormone receptor complex activates a G protein in the membrane. The G protein activates adenylate cyclase, which converts ATP to cAMP. cAMP, acting as a second messenger, stimulates protein kinases, which then add phosphate groups derived from ATP to another substrate molecules. These phosphorylated substrates are now activated, and ready to perform the hormone’s action, by inducing a variety of cellular processes.
What is a second messenger?
A second messenger is a chemical that stimulates cellular changes in response to the binding of a nonsteroid hormone to its receptor. cAMP is an example of a second messenger. These messengers are necessary, because nonsteroid hormones cannot penetrate the cell membrane; they carry out the effects of the hormone.
What are prostaglandins?
Prostaglandins are a group of lipids produced from a fatty acid, called arachidonic acid, found in cell membranes. They are produced by many types of cells. They are potent, produced in small quantities, used in local areas (which makes them paracrine substances), and then quickly inactivated.
Describe one function of prostaglandins.
Some prostaglandins regulate cellular responses to hormones by activating or inactivating adenylate cyclase in cell membranes. This regulates the production of cAMP.
List the effects of prostaglandins.
Various prostaglandins cause relaxation of airway and blood vessel smooth muscle, contraction of uterine smooth muscle, secretion of hormones from the adrenal cortex, and inhibition of hydrochloric acid secretion in the stomach. They also affect blood pressure, sodium and water movement in the kidneys, male and female reproductive processes, and inflammation.
How does the nervous system help regulate hormonal secretions?
The hypothalamus (in the brain) regulates anterior pituitary hormone secretion by sending releasing or release-inhibiting hormones directly to the glandular cells of the anterior pituitary. It also sends nerve impulses to the posterior pituitary gland, to regulate the secretion of ADH and oxytocin. The nervous system also activates some endocrine glands directly via nerve impulses; for example, sympathetic impulses from the brain regulate the secretion of epinephrine and norepinephrine from the adrenal medulla.
How does a negative feedback system control hormonal secretion?
Negative feedback mechanisms maintain blood levels of hormones appropriate for maintaining homeostasis, by sensing the level of the hormone in the blood or by sensing an effect the hormone has on the internal environment. When the level of a particular hormone gets too high, a negative feedback mechanism can slow down or stop the synthesis of that hormone. If the level is too low, negative feedback will not occur, and the hormone will begin to produce again.
Where is the pituitary gland located?
At the base of the brain. It is attached to the hypothalamus by the pituitary stalk, or infundibulum. It occupies the sella turcica, a depression in the sphenoid bone.
List the hormones that the anterior and posterior lobes of the pituitary gland secrete.
Then anterior lobe of the pituitary gland secretes growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The posterior lobe secretes 2 hormones that are synthesized in the hypothalamus; these are antidiuretic hormone (ADH) and oxytocin (OT).
Explain how the hypothalamus controls the actions of the posterior and anterior lobes of the pituitary gland
The hypothalamus controls anterior pituitary activity by secreting and releasing and release-inhibiting hormones into the hypophyseal portal veins. These veins branch to form a network of capillaries that runs between these glands. The hypothalamic hormones act on their target cells in the anterior pituitary gland, to stimulate or inhibit release of their hormones. The hormones released by the posterior pituitary gland are produced by the hypothalamus, and stored in the posterior pituitary. The hypothalamus controls posterior pituitary secretion by sending nerve impulses down the pituitary stalk to the storage site.
How does growth hormone affect the cellular metabolism of carbohydrates, fats, and proteins?
Growth hormone (GH) stimulates amino acid uptake by cells, which provides amino acids for protein synthesis; this is vital in the growth process. It also increases fat catabolism for energy, and decreases the use of glucose by most cells. GH causes the liver to release glucose into the blood, which provides glucose for neurons.
What are the functions of prolactin?
In females, prolactin (PRL) causes development of the mammary glands and maintains milk production after childbirth. In males, no normal function has been determined.
How is TSH secretion regulated?
Secretion of thyroid-stimulating hormone (TSH) is regulated by two methods. TSH secretion is increased by the release of thyrotropin-releasing hormone (TRH) from the hypothalamus. TSH secretion is also regulated by negative feedback; when the level of thyroid hormones (TH) reaches a certain level, TSH secretion is inhibited.
What is the function of ACTH?
ACTH (adrenocorticotropic hormone) controls the slynthesis and release of cortisol, adrenal androgens, and other related hormones from the adrenal cortex.
What is a gonadotropin?
A substance that affects the gonads (testes or ovaries). The two gonadotropins secreted by the anterior pituitary gland are follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
Describe the functions of FSH and LH in a female and in a male.
LH stimulates the secretion of sex hormones from the gonads in both males and females, and is essential for the release of the oocyte from the ovaries (ovulation). FSH stimulates secretion of sex hormones in females and contributes to the development of the gametes (sperm and oocytes) in both sexes.
What is the function of ADH?
It acts on the kidneys to promote water retention by decreasing urine volume. This ensures that the concentration of body fluids remains in the homeostatic level. ADH also increases blood pressure by constricting blood vessels; this explains why ADH is also called vasopressin.
How is the secretion of ADH controlled?
Osmoreceptors in the hypothalamus monitor changes in the osmotic pressure in the body fluids. When the osmoreceptors sense increased osmotic pressure, due to water loss or dehydration, ADH is released from the posterior pituitary gland, where it is stored. ADH causes the kidneys to excrete less water in the urine, and retain water in the body fluids. In cases of dilution of the body fluids due to drinking too much water, ADH secretion would be inhibited. Blood volume also influences the secretion of ADH. When blood volume is high, stretching of blood vessel walls is detected by volume receptors, which alert the hypothalamus; this results in ADH secretion being inhibited. If blood volume is too low, fewer impulses are sent to the hypothalamus, resulting in an increase in ADH secretion.
What effects does oxytocin produce in females?
In females, oxytocin has a weak antidiuretic effect. It also causes uterine smooth muscle contractions during childbirth and contraction of myoepithelial cells in the breasts for milk ejection during nursing. Oxytocin also plays a role in bonding between a mother and baby, and between sex partners.
The endocrine system, along with the __________, regulates functions of the body.
Nervous system
The endocrine system, along with the nervous system, regulates functions of the body to maintain ___________
Homeostasis
The endocrine system, along with the nervous system, regulates functions of the body to maintain homeostasis, and coordinates __________
Communication
What is the only organ system in the body where the organs are not anatomically connected?
The endocrine system
Name the major endocrine glands.
Pituitary gland
Thyroid gland
Parathyroid gland
Adrenal glands
Pancreas
Pineal gland
Thymus
Ovaries and Testes (reproductive glands)
Adrenal Gland
Hypothalamus
Ovaries
Pancreas
Parathyroid Glands
Pineal Gland
Pituitary Gland
Testes Gland
Thymus
Thyroid Gland
The two types of glands:
Endocrine and Exocrine
Endocrine glands are _________; they secrete hormones directly into the body fluids.
Ductless
What does “endocrine” mean?
Internal secretion
Hormones act only on _________ that contain receptors for them
Target cells
If a cell does not have _______ for the hormone, the cells is NOT affected by the hormone.
Receptors
________ glands are glands that secrete into ducts or tubes that lead to a body surface.
Exocrine
Exocrine glands secrete ________
Externally
_________ glands deliver products directly to a specific site; action does not depend on receptors.
Exocrine
What type of gland delivers products directly to a specific site?
Exocrine glands
What kind of gland’s action does not depend on receptors?
Exocrine glands
What kind of gland secretes hormones directly into the body fluids?
Endocrine glands
What is the main difference between endocrine and exocrine glands?
Endocrine glands secrete hormones directly into the body fluids. Exocrine glands secrete into ducts or tubes that lead to a body surface.
Besides endocrine and exocrine glands, other cells secrete ___________ internally, called “local hormones.”
chemical messengers
What are the chemical messengers called which are secreted by cells but are not actually hormones?
Local hormones
What are the two types of local hormones?
Paracrine and autocrine secretions
What is the difference between paracrine and autocrine secretions?
Paracrine secretions affect nearby cells. Autocrine secretions affect only the cells that secrete them.
Both the nervous and endocrine systems function in ___________
Communication
Both the nervous and endocrine systems communicate via:
Chemicals that bind to receptor molecules
What do the nervous and endocrine systems have in common?
They both function in communication via chemicals that bind to receptor molecules
The nervous system releases _________ into synapses
Neurotransmitters
The nervous system releases neurotransmitters into __________
Synapses
The ________ system releases neurotransmitters into synapses
Nervous
The ___________ system secretes hormones into bloodstream
Endocrine
The endocrine system secretes ________ into the bloodstream
Hormones
Where does the endocrine system secrete hormones into?
The bloodstream
Which responds faster? The nervous or endocrine system?
The nervous system
Which system’s effects can last longer? The endocrine or nervous system?
The endocrine system
While the Nervous system responds ________, the endocrine system’s effects can ___________.
Faster; last longer
What are the cells of the nervous system?
Neurons
What are the cells of the endocrine system?
Glandular epithelium
What are the chemical signals of the nervous system?
Neurotransmitters
What are the chemical signals of the endocrine system?
Hormones
What is the specificity of action for the nervous system?
Receptors on the postsynaptic cell
What is the specificity of action for the endocrine system?
Receptors on target cells
What is the speed of onset for the nervous system?
1 second
What is the speed of onset for the endocrine system?
Seconds to hours
What is the duration of action for the nervous system?
Very brief unless neuronal activity continues
What is the duration of action for the endocrine system?
May be brief or may last for days even if secretion ceases
When a neuron conducts an impulse, the neurotransmitter is released into the:
Synaptic cleft
When a neuron conducts an impulse, what type of cell responds?
Post-synaptic cell
When glandular cells secrete hormones into the bloodstream, what type of cells respond?
Target cells
All of the hormones MADE and RELEASED from the hypothalamus are either __________ or _________ hormones
Releasing; inhibiting
All hormones made and released from the hypothalamus control the production and release of hormones from the ___________ gland.
Anterior pituitary
Where do the hormones come from that control the production and release of hormones from the anterior pituitary gland?
Hypothalamus
What do the hormones released from the hypothalamus control?
The production and release of hormones from the anterior pituitary gland
What are the two hormones made by the hypothalamus?
Antidiuretic hormone (ADH) and Oxytocin
What are the two hormones that are made by the hypothalamus, but RELEASED by the posterior pituitary gland
Antidiuretic hormone and oxytocin
What gland releases ADH and oxytocin?
Posterior pituitary gland
Which gland releases hormones that travel to the peripheral endocrine glands?
Anterior pituitary gland
What are the peripheral endocrine glands?
Thyroid, pancreas, etc.
Why does the anterior pituitary gland release hormones to travel to the peripheral endocrine glands?
To stimulate or inhibit the release of specific hormones such as epinephrine, testosterone, estrogen, thyroxine, etc.
What are the hormones from which the hypothalamus is the source?
Corticotropin-releasing hormone
Gonadotropin-releasing hormone
Somatostatin
Growth-hormone releasing hormone
Prolactin releasing-hormone
Prolactin-releasing factor
Thyrotropin-releasing hormone
What is CRH?
Corticotropin-releasing hormone
What is GnRH
Gonadotropin-releasing hormone
What is SS?
Somatostatin
What is GHRH
Growth hormone-releasing hormone
What is PIH?
Prolactin-release-inhibiting hormone
What is PRF?
Prolactin-releasing factor
What is TRH?
Thyrotropin-releasing hormoen
What is GnRH also known as?
LHRH - Luteinizing hormone-releasing hormone
What is SS (somatostatin) also known as?
Growth hormone release-inhibiting hormone (GHRIH)
What are the hormones sourced from the anterior pituitary gland?
Adrenocorticotropic hormone
Follicle-stimulating hormone
Growth hormone
Luteinizing hormone
Prolactin
Thyroid-stimulating hormone
What is ACTH?
Adrenocorticotropic hormone
What is FSH?
Follicle-stimulating hormone
What is GH?
Growth hormone
What is LH?
Luteinizing hormone
What is PRL?
Prolactin
What is TSH?
Thyroid-stimulating hormone
What is the synonym for corticotropin?
ACTH, adrenocorticotropic hormone
What is the synonym for follitropin?
FSH, follicle-stimulating hormone
What is the synonym for somatotropin (STH)?
GH, growth hormone
What is the synonym for lutropin, interstitial cell-stimulating hormone (ICSH)?
LH, luteinizing hormone
What is the synonym for thyrotropin?
TSH, thyroid-stimulating hormone
What is the source of CRH (corticotropin-releasing hormone)
Hypothalamus
What is the source of GnRH (gonadotropin-releasing hormone)
Hypothalamus
What is the source of SS (somatostatin)
Hypothalamus
What is the source of GHRH (growth hormone-releasing hormone)
Hypothalamus
What is the source of PIH (prolactin-release-inhibiting hormone)
Hypothalamus
What is the source of PRF (thyrotropin-releasing hormone)
Hypothalamus
What is the source of TRH (thyrotropin-releasing hormone)
Hypothalamus
What is the source of ACTH (adrenocorticotropic hormone)
Anterior pituitary gland
What is the source of FSH (follicle-stimulating hormone)
Anterior pituitary gland
What is the source of GH (growth hormone)
Anterior pituitary gland
What is the source of LH (luteinizing hormone)
Anterior pituitary gland
What is the source of PRL (prolactin)
Anterior pituitary gland
What is the source of TSH (thyroid-stimulating hormone)
Anterior pituitary gland
What are the hormones released by the posterior pituitary gland?
Antidiuretic hormone and oxytocin
Antidiuretic hormone (ADH) and oxytocin are MADE in the _________, but RELEASED in the:
hypothalamus; posterior pituitary gland
What is the synonym for vasopressin?
ADH, antidiuretic hormone
What are the three hormones made in the thyroid gland?
Calcitonin, thyroxine, and triiodothyronine
What is the abbreviation for thyroxine?
T4
What is the abbreviation for triiodothyronine?
T3
What is the synonym for triiodothyronine (T3)?
Tetraiodothyronine
What is the hormone made by the parathyroid gland?
Parathyroid hormone
What is the abbreviation for parathyroid hormone?
PTH
What is the synonym for PTH (parathyroid hormone)
Parathormone
What hormones are made by the adrenal medulla?
Epinephrine and norepinephrine
What is the abbreviation for epinephrine?
EPI
What is the abbreviation for norepinephrine?
NE
What is the synonym for epinephrine?
Adrenalin
What is the synonym for norepinephrine?
Noradrenalin
What are the hormones made by the adrenal cortex?
Aldosterone
Cortisol
What is the synonym for cortisol?
Hyrdocortisone
What are the hormones made by the pancreas?
Glucagon
Insulin
Somatostatin
What is the abbreviation for somatostatin?
SS
Hormones are released into:
extracellular fluid
Hormones diffuse into:
Blood
Hormones are released into __ and then diffuse into __
Extracellular fluid; blood
The method of hormone transport through blood depends on whether the hormone is ______ or ______
Lipid-soluble; water-soluble
______ are very powerful substances in low concentrations
Hormones
Hormones are ______ compounds
Organic
What are the two general types of hormones?
Steroid or steroid-like
Describe steroids?
Lipids containing complex rings of carbon and hydrogen atoms
All steroid hormones are produced from what?
Cholesterol
What are a few examples of steroid hormones?
Sex hormones (testosterone and estrogen) and adrenal cortex hormones (cortisol and aldosterone)
What are the four types of nonsteroid hormones (chemically)
Amines
Proteins
Peptides
Glycoproteins
_______ are derived from tyrosine
Amines
_______ are composed of long chains of amino acids
Proteins
____ are short chains of amino acids
Peptides
______ are carbohydrates joined to proteins
Glycoproteins
A hormone derived from tyrosine is an
Amine
A hormone composed of long chains of amino acids is
Proteins
A hormone composed of short chains of amino acids is a
Peptide
A hormone composed of carbohydrates joined to proteins is
Glycoproteins
What are some examples of nonsteroid hormones?
Epinephrine, norepinephrine, thyroxine (amines), growth hormone (proteins), ADH, oxytocin (peptides), or TSH (glycoproteins)
Are steroid or steroid-like hormones composed of lipids or amino acids/peptides?
Lipids
Are non-steroid hormones composed of lipids or amino acids/peptides?
Amino acids/peptides
A hormone made out of 9 amino acids is a
peptide
A hormone composed of 30 amino acids is a
Protein
A hormone made from the amino acid tyrosine is called a
Amine
Amines are formed from?
Amino acids
peptides are formed from
Amino acids
proteins are formed from
Amino acids
Glycoproteins are formed from
Protein and carbohydrate
Steroids are formed from
Cholesteral
What are examples of amine hormones?
Norepinephrine and epinephrine
What are some examples of peptide hormones?
ADH, OT, TRH, SS, GnRH
What are some examples of protein hormones?
PTH, GH, PR
What are some examples of glycoprotein hormones?
FSH, LH, TSH
What are some examples of steroid hormones?
Estrogens, testosterone, aldosterone, cortisol
Only 4 hormones are _______, all the rest are protein based
Steroids
How will the structure (protein based or steroid/lipid based) affect how the hormone crosses the plasma membrane?
Amino acid derived hormones and polypeptide hormones are not lipid-derived (lipid-soluble) and therefore cannot diffuse through the plasma membrane of cells, so they bind to receptors on the outer surface of the plasma membrane. Steroid/lipid-based hormones CAN diffuse through the plasma membrane.
Do cortisol, norepinephrine, parathyroid hormone, oxytocin, and prostaglandin all have the same structure?
No; they are all shaped differently according to their function and purpose.
Are cortisol, norepinephrine, parathyroid hormone, oxytocin, and prostaglandin all based on the same organic molecule?
No. They are formed from different organic molecules.
When it comes to hormones, does structure = function?
YES. It is similar to a “lock and key” system; certain structures will only “lock” into certain receptors.
How does the structure of each hormone affect their ability to cross the plasma membrane?
Hormones that are not lipid-derived will NOT pass through the lipid-soluble bilayer of the plasma membrane; they bind to receptors on the outer layer of the cell instead.
Hormones may alter ______ activity
Enzyme
Hormones may change the rate of ________ of a substance.
Membrane transport
Hormones may alter _______ activity
Enzyme
Hormones deliver messages by binding to their______ on/in target cell
Receptors
Hormones are powerful in ______ quantities
Small
Hormones can cause changes in target cells even in extremely _____ concentrations
Low
The number of ________ determines the strength of hormone response
Receptors
The number of receptors can be _______ to alter the response
Changed
The increase in number of receptors on target cells, in response to a decrease in hormone level
Upregulation
The decrease in number of receptors on target cells, due to an increase in hormone level
Downregulation
Steroid hormones have poor ______-solubility
Water
What are steroid hormones transported by?
Carrier hormones
What type of hormones are transported through blood bound to plasma proteins (carrier proteins)
Steroid hormones
_______ hormones can diffuse through the lipid bilayer of cell membranes and bind directly to receptors in the nucleus.
Steroid
What type of hormones can diffuse through the lipid bilayer of cell membranes and bind directly to receptors in the nucleus?
Steroid
What type of hormones cause transcription of particular genes in DNA?
Steroid hormones
Steroid hormones cause _______ of particular genes in DNA
Transcription
What leads to the action of steroid hormones?
Protein synthesis (translation)
What is the first step in the sequence of steroid hormone action?
Endocrine gland secretes the steroid hormone
What is the second step in the sequence of steroid hormone action?
Blood carries the hormone molecules (often weakly bound to transport protein) throughout the body.
What is the third step in the sequence of steroid hormone action?
Unbound steroid hormones diffuse through the target cell membranes and enter the cytoplasm or nucleus.
What is the fourth step in the sequence of steroid hormone action?
Hormone combines with a receptor molecule in the cytoplasm or nucleus
What is the fifth step in the sequence of steroid hormone action?
Steroid hormone-receptor complex binds to DNA in the nucleus and promotes transcription of messenger RNA.
What is the sixth step in the sequence of steroid hormone action?
Messenger RNA enters the cytoplasm and directs protein synthesis
What is the last (seventh) step in the sequence of steroid hormone action?
Newly synthesized proteins produce the steroid hormone’s specific effects
What type of hormone CANNOT penetrate the lipid bilayer of cell membranes?
Nonsteroid hormones
What type of hormones bind to receptors on the target cell plasma membrane?
Nonsteroid hormones
What type of hormone is considered a “first messenger”?
Nonsteroid hormones
The chemical that induces changes leading to hormone’s effect is considered a what?
Second messenger
What is cAMP?
Cyclic adenosine monophosphate
Many hormones us what as a second messenger?
cAMP (cyclic adenosine monophosphate)
The entire process of chemical communication, from outside cells to inside, is called what?
Signal transduction
What is the first step in the sequence of actions of nonsteroid hormones using cAMP?
Endocrine gland secretes nonsteroid hormone
What is the second step in the sequence of actions of nonsteroid hormones using cAMP?
Blood carries the hormone molecules throughout the body
What is the third step in the sequence of actions of nonsteroid hormones using cAMP?
Hormone combines with receptor site on membrane of its target cell, activating G protein
What is the fourth step in the sequence of actions of nonsteroid hormones using cAMP?
Adenylate cyclase molecules are activated in target cell’s membrane
What is the fifth step in the sequence of actions of nonsteroid hormones using cAMP?
Adenylate cyclase converts ATP into cyclic AMP
What is the sixth step in the sequence of actions of nonsteroid hormones using cAMP?
Cyclic AMP activates protein kinases
What is the seventh step in the sequence of actions of nonsteroid hormones using cAMP?
Protein kinases activate protein substrates in the cell that change metabolic processes
What is the last step in the sequence of actions of nonsteroid hormones using cAMP?
Cellular changes produce the hormone’s effects
Why are hormones generally abused by athletes to improve performance?
To increase muscular strength
What are some of the harmful effects that come from abusing steroids to improve athletic performance?
Decreased natural testosterone production
Stunted growth
Breast development in males
Male sexual characteristics in females
Damage to kidneys, liver, or heart
Increase in LDL cholesterol
Psychiatric problems
What is HGH specifically used for when abused by athletes?
To enlarge muscles
What and why is the hormone commonly used instead of, or along with, steroids when it comes to athletic abuse of hormones?
HGH (human growth hormone); to enlarge muscles
What steroid is often abused to increase the number of red blood cells and oxygen delivery to muscles?
Erythropoietin
What is the steroid used to treat certain forms of anemia, bus using it to improve athletic performance is not advised because it can lead to heart attack and death
Erythropoietin
Hormone secretion is precisely regulated and is primarily controlled by what type of feedback mechanisms?
Negative feedback
How long do the effects of hormone secretion generally last?
Can be short-lived ( a few minutes) or may last for days.
Some _______ are excreted in the urine after exerting their effects
Hormones
Hormones can be broken down by ______, mainly from the liver, to stop their effects
enzymes
What is the most common type of homeostatic mechanism?
Negative feedback
What type of feedback prevents sudden, severe changes in the body?
Negative feedback
What are some examples of negative feedback in the body?
Control of: body temperature, blood pressure, glucose level in blood.
Rising/increasing level of a hormone leads to a decrease in hormone secretion describes….
Negative feedback
What is the main control of hormone secretion?
Negative feedback
Control mechanism in which rising level of a hormone leads to an increase in secretion; used in small number of cases of hormone control, mainly in reproductive system
Positive feedback
What gland lies at the base of the brain?
Pituitary gland
The pituitary gland is located where?
Sella turcica of the sphenoid bone
The pituitary gland is controlled by what?
The brain
The pituitary gland is considered part of what system?
The nervous system
The pituitary gland is attached to the what?
Hypothalamus
What is the pituitary gland connected to the hypothalamus by?
The pituitary stalk
What is another name for the pituitary stalk that connects the pituitary gland to the hypothalamus
Infundibulum
What are the two distinct portions of the pituitary gland?
Anterior and posterior lobe
What is the name for the anterior lobe of the pituitary gland?
Adenohypophysis
What is the name for the posterior lobe of the pituitary gland?
Neurohypophysis
In the _______ gland, secretion from 2 lobes is controlled by different methods by the hypothalamus
Pituitary
What is the small intermediate lobe of the pituitary gland called?
Pars intermedia
What part of the pituitary gland produces melanocyte-stimulating hormone (MSH)
The small intermediate lobe (pars intermedia)
What type of hormone does the small intermediate lobe (pars intermedia) of the pituitary gland produce?
Melanocyte-stimulating hormone (MSH)
What hormone starts melanin production?
Melanocyte-stimulating hormone (MSH)
The hypothalamus controls the pituitary gland by what two types of regulation?
Anterior lobe and posterior lobe regulation
How is the anterior lobe of the pituitary gland controlled by the hypothalamus?
Hypothalamic releasing hormone (or release-inhibiting hormones) are transported to the anterior lobe through the hypophyseal portal veins
The hypophyseal portal veins are an example of what type of system?
Portal system
What type of hormones are transported to the anterior lobe through the hypophyseal portal veins?
Hypothalamic releasing hormones
What is another name for hypothalamic releasing hormones?
Release-inhibiting hormones)
How is the posterior lobe of the hypothalamus regulated?
Nerve impulses from the hypothalamus travel along axons to posterior lobe through the infundibulum
_________ from the hypothalamus travel along axons to posterior lobe of the pituitary gland through the infundibulum
Nerve impulses
Nerve impulses from the hypothalamus travel along axons to the posterior lobe of the pituitary gland through the ___________-
Infundibulum
The hypothalamus, which is an endocrine gland, controls hormone secretion from peripheral endocrine glands via what?
3-step pathways
What are the three 3-step pathways used by the hypothalamus to control hormone secretion from peripheral endocrine glands?
Releasing (or release-inhibiting) hormone, anterior pituitary hormone, and peripheral endocrine gland
What from the hypothalamus acts on specific hormone-secreting cells in the anterior pituitary gland?
Releasing (or release-inhibiting) hormone
What acts on cells in a peripheral endocrine gland to stimulate its secretion?
Anterior pituitary hormoen
What secretes its hormone, which exerts effects on target cells?
Peripheral endocrine gland
What are the major anterior pituitary hormones?
Growth hormone (GH)
Prolactin (PRL)
Thyroid-stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Hormone which Stimulates cells to enlarge and divide rapidly, increases amino acid uptake and protein synthesis, decreases rate of carbohydrate
usage, increases rate of fat usage
Growth hormone (somatotropin)
Hormone which Promotes milk production in females, uncertain function in males
Prolactin
Hormone which Stimulates secretion of thyroid hormones (T3 and
T4) from thyroid gland
Thyroid-stimulating hormone (TSH)
Hormone which Stimulates secretion of cortisol and other
glucocorticoids from adrenal cortex
Adrenocorticotropic hormone (ACTH)
Hormone which Causes growth and development of ovarian
follicles in females, sperm production in males
Follicle-stimulating hormone (FSH)
Hormone which Causes ovulation in females, sex hormone production in
both genders
Luteinizing hormone (LH)
What is hypopituitary dwarfism caused by?
deficiency of human growth hormone (HGH) during childhood
Characteristics of hypopituitary dwarfism?
Short stature, but body proportions and mental development are normal
In hypopituitary dwarfism, HGH treatment must start before bones completely _______ to be effective
ossify
What is caused by oversecretion of GH during childhood?
Gigantism
Characteristics of gigantism
Height may exceed 8 feet, may have other metabolic problems
Gigantism is often caused by what?
Pituitary tumor
What is caused by oversecretion of GH during adulthood, after epiphyseal
ossification
Acromegaly
Characteristics of acromegaly
No increase in height, but bones thicken
Acromegaly causes enlargement of…
Tongue, nose, hands, feet, jaw, heart, thyroid gland
_________ lobe of pituitary gland consists of nerve fibers from hypothalamus and
neuroglia, unlike glandular epithelium of anterior lobe
Posterior
Posterior lobe of _______ gland consists of nerve fibers from hypothalamus and
neuroglia, unlike glandular epithelium of anterior lobe
Pituitary
Posterior lobe of pituitary gland consists of _______ from hypothalamus and
neuroglia, unlike glandular epithelium of anterior lobe
Nerve fibers
Posterior lobe of pituitary gland consists of nerve fibers from _________ and
neuroglia, unlike glandular epithelium of anterior lobe
Hypothalamus
Posterior lobe of pituitary gland consists of nerve fibers from hypothalamus and
________, unlike glandular epithelium of anterior lobe
Neuroglia
What are the two hormones made in the hypothalamus?
ADH and oxytocin
How are ADH and oxytocin transported to the posterior pituitary gland?
Via the pituitary stalk (infundibulum)
Which posterior pituitary hormone Decreases urine production by reducing volume of H2O the kidneys excrete
ADH (antidiuretic hormone)
Which posterior pituitary hormone causes vasoconstriction to increase blood pressure
Antidiuretic hormone (ADH)
Which posterior pituitary hormone causes muscle contraction in the uterine wall during childbirth?
Oxytocin
Which posterior pituitary hormone causes milk ejection during lactation?
Oxytocin
Which posterior pituitary hormone has no proven function in males, but may help with sperm movement or sexual response?
Oxytocin
Hormone which Stimulates increase in size and rate of
division of body cells; enhances
movement of amino acids through
membranes; promotes growth of long
bones
Growth hormone (GH)
hormone which Sustains milk production after birth;
amplifies the effect of LH in males
Prolactin (PRL)
Which hormone Controls secretion of hormones from the
thyroid gland
Thyroid-stimulating hormone (TSH)
Which hormone Controls secretion of certain hormones
from the adrenal cortex
Adrenocorticotropic hormone (ACTH)
Which hormone Promotes development of egg-
containing follicles in ovaries; stimulates
follicular cells to secrete estrogen; in
males, stimulates production of sperm
cells
Follicle-stimulating hormone (FSH)
Which hormone Promotes secretion of male and female
sex hormones; releases egg cell in
females
Luteinizing hormone (LH)
What is the source of control for growth hormone (GH)
Secretion inhibited by somatostatin (SS)
and stimulated by growth hormone-
releasing hormone (GHRH) from the
hypothalamus
What is the source of control for prolactin (PRL)?
Secretion inhibited by prolactin inhibiting
hormone (PIH) from the hypothalamus
What is the source of control for thyroid-stimulating hormone (TSH)?
Thyrotropin-releasing hormone (TRH)
from the hypothalamus
What is the source of control for adrenocorcitotropic hormone (ACTH)?
Corticotropin-releasing hormone (CRH)
from the hypothalamus
What is the source of control for follicle-stimulating hormone (FSH)?
Gonadotropin-releasing hormone
(GnRH) from the hypothalamus
What is the source of control for luteinizing hormone (LH)?
Gonadotropin-releasing hormone
(GnRH) from the hypothalamus
What hormone Causes kidneys to reduce water
excretion; may help maintain blood
pressure
Antidiuretic hormone (ADH)
What hormone Contracts smooth muscle in the uterine
wall; forces liquid from the milk glands
into the milk ducts, ejects milk
Oxytocin
What is the source of control for antidiuretic hormone (ADH)
Hypothalamus in response to changes
in body fluid concentration and blood
volume
What is the source of control for oxytocin (OT)?
Hypothalamus in response to stretching
uterine and vaginal walls and
stimulation of breasts
The thyroid gland consists of how many lobes?
Two lateral lobes
The two lateral lobes of the thyroid gland are connected by an
Isthmus
The ______ gland lies just below the larynx, anterior and lateral to the trachea
Thyroid gland
Where is the thyroid gland located?
Anterior and lateral to the trachea?
The thyroid has a special ability to remove what from blood?
Iodine
What 3 hormones does the thyroid produce?
T4 (thyroxine)
T3 (triiodothyronine)
Calcitonin
Thyroid is composed of round secretory units called what?
Follicles
Each follicle in the thyroid is surrounded by a single layer of what type of cells?
Follicular
What fills the follicle cavities of the thyroid gland?
Viscous colloid
What type of cells lie outside the follicles of the thyroid gland?
Extrafollicular (C) cells
What cells in the thyroid produce calcitonin?
Extrafollicular (C) cells
What hormone Increases rate of energy
release from
carbohydrates; increases
rate of protein synthesis;
accelerates growth;
necessary for normal
nervous system
maturation
Thyroxine (T4)
What hormone Increases rate of energy
release from
carbohydrates; increases
rate of protein synthesis;
accelerates growth;
necessary for normal
nervous system
maturation, but is much more potent
Triiodothyronine (T3)
What hormone Lowers blood calcium and
phosphate ion
concentrations by
inhibiting release of
calcium and phosphate
ions from bones and by
increasing the rate at
which calcium and
phosphate ions are
deposited in bones;
increases excretion of
calcium by the kidneys
Calcitonin
What is the source of control for thyroxine (T4)?
TSH from the anterior pituitary gland
What is the source of control for calcitonin?
Elevated blood calcium ion concentration, digestive hormones
What are the two hyperthyroid conditions?
Hyperthyroidism, and graves disease
What hyperthyroid condition results in High metabolic rate, sensitivity to heat, restlessness,
hyperactivity, weight loss, protruding eyes, goiter
Hyperthyroidism
What hyperthyroidism condition results in Autoantibodies (against self) bind TSH receptors on thyroid
cell membranes, mimicking action of TSH, overstimulating
gland (hyperthyroidism); exopthalmia (protrusion of the eyes)
and goiter
Graves disease
What are the four hypothyroid conditions?
Hashimoto disease, hypothyroidism (infantile), hypothyroidism (adult), and simple goiter
Neutrophil
Eosinophil
Basophil
Monocyte
Lymphocyte
