Scheduled maintenance: Wednesday, February 8 from 10PM to 11PM PST
hello quizlet
Home
Subjects
Expert solutions
Create
Study sets, textbooks, questions
Log in
Sign up
Upgrade to remove ads
Only $35.99/year
Science
Biology
Anatomy
Endocrine- Quiz one
Flashcards
Learn
Test
Match
Flashcards
Learn
Test
Match
Terms in this set (74)
What systems work together to coordinate functions of all body systems?
Nervous System
Endocrine System
What is the difference between Neurotransmitters and hormones?
NT- fast response, briefer effects, acts on specific target
Hormone- travel in blood stream, slower response, longer lasting effects, multiple targets
What are they 2 types of glands in the body?
Exocrine- secrete products into ducts
Endocrine- ductless, secretes products into interstitial fluid surrounding the gland, which then diffuses into blood and travels to target cells
What are the functions of hormones?
-Helps to regulate; chemical composition and volume of interstitial fluid, metabolism and energy balance, contraction of smooth and cardiac mm fibers, glandular secretions, some immune activites.
- controls growth and development
- regulates operation of reproductive systems
- helps establish circadian rhythms
What are some examples of endocrine glands?
pituitary gland, thyroid, parathyroid, adrenal and pineal glands, hypothalamus, thymus, pancreas, ovaries, testes
What is a hormone?
a mediator molecule that is released in one part of the body, but regulates activity in another
How to hormones influence their target cells?
by chemically binding to specific protein receptors
What is down regulation?
when a hormone is present in excess, this high level may decrease the number of receptors on/in the cell. This makes the cells less sensitive to the hormone
What is up regulation?
when the hormone is deficient, the cell will increase the number of receptors, to increase sensitivity
What are the 2 hormone types?
Circulating- circulate in blood throughout the body, longer lasting
Local- act locally and inactivate quickly (further divided into paracrine and autocrine)
Hormones that act on neighbooring cells
Paracrine
Hormones that act on the same cell that secreted them
Autocrine
What are the lipid soluble hormones?
Steroids
Thyroid hormones
Nitric Oxide
What are the 3 functions of transport proteins in regards to lipid soluble hormones?
- temporarily make lipid soluble hormones water soluble
- slow the passage of small hormones through the filtration system of the kidneys
- provide a steady reserve of hormone in the bloodstream
What are the water soluble hormones?
Amines (Epinephrine and Norepinephrine)
Peptides and Proteins
Eicosanoid Hormones (prostoglandins and leukotrienes)
What are lipid soluble hormones?
hormones that require transport proteins
Where do water soluble hormones bind?
receptors on the plasma membrane of a cell
What does responsiveness of a target cell depend on?
hormone concentration
abundance of target cell receptors
influence exerted by other hormones
What is permissive effect?
hormones that require simultaneous or recent exposure to a 2nd hormone, in order to fully affect a target cell. One hormone enhances the effect of another.
What is synergistic effect?
the effect of 2 hormones acting together is greater or more extensive than the effect of each hormone alone. Both are needed for full hormonal activity.
What is antagonistic effect?
when one hormone opposes the action of another
Describe how lipid soluble hormones work in a cell?
1. lipid soluble hormone diffuses into a cell
2. activated receptor-hormone complex alters gene expression
3. newly formed mRNA directs synthesis of specific proteins on ribosomes
4. new proteins alter cells activity
Describe how water soluble proteins work in a cell?
1. binding of hormones (first messenger) to its receptor cells activates G protein, which activates adenylate cyclase
2. activated adenylate cyclase converts ATP to cAMP
3. cAMP serves as a second messenger to activate protein kinases
4. activated protein kinases phosphorylate cellular proteins
5. millions of phosphorylated proteins cause reactions that produce physiological responses
What is the purpose of the second messenger system?
hormones can induce their effects at very low concentrations because they initiate a cascade, each step amplifies or multiplies the initial effect
What are some examples of second messengers?
calcium ions, cGMP, cAMP, inositol triphosphate (IP3), and diacylglycerol (DAG)
Does the posterior pituitary synthesize hormones?
NO
What does the posterior pituitary gland do?
stores and releases 2 hormones made by the hypothalamus- oxytocin and antidiuretic hormone-vasopressin
Where is oxytocin made?
in the paraventricular nucleus of the hypothalamus
Where are the hypothalamus and the pituitary gland?
hypothalamus- small region of the brain below the thalamus
pituitary gland is attached to the hypothalamus by the infundibulum
What is the hypophyseal portal system?
hypothalamic hormones reach the anterior pituitary through this portal system- blood flows from capillary network into a portal vein and then into a second capillary network without passing through the heart
Where is antidiuretic hormone/vasopressin made?
in the supraoptic nucleus of the hypothalamus
How do neurosecretory cells work?
hormones made by specialized neurons are packaged inside vesicles which reach axon terminals by axonal transport.
Nerve impuses stimulate vesicles to undergo exocytosis.
Hormones then diffuse into the primary plexus of the hypophyseal portal system and flow with the blood to the secondary plexus
allows hypothalamic hormones to act immediately
What regulated release of hormones by the anterior pituitary gland?
releasing and inhibiting hormones from the hypothalamus
negative feedback
What are anterior pituitary hormones that act on other endocrine systems called?
tropic hormones
How many hormones does the hypothalamus produce? The pituitary gland?
hypothalamus produces 9 hormones
pituitary secretes 7 of its own
How is blood brought to the hypothalamus?
through the superior hypophyseal arteries (branch of internal carotid artery)
What are they 5 types of anterior pituitary cells?
1. somatotrophs- secrete human growth hormone (somatotropin)
2. thyrotrophs- secrete thyroid stimulating hormone (thryotropin)
3. Gonadotrophs- secrete follicle stimulating hormone and lutenizing hormone
4. Lactotrophs- secrete prolactin
5. Corticotrophs- secrete adrenocroticotropic hormone or corticotropin and melanocyte stimulating hormone
What is the neurohypophysis, what are its 2 parts?
posterior pituitary
pars nervosa (bigger part) and infundibulum
What is the primary plexus of the hypophyseal portal system?
where the arteries divide into a capillary network at the junction of the hypothalamus and infundibulum
What are the 2 ways release of hormones is regulated in the anterior pituitary?
1. neurosecretory cells in the hypothalamus secrete 5 releasing hormones and 2 inhibiting hormones that affect anterior pituitary
2. negative feedback occurs when hormones released by the target gland decreases secretion of 3 of the cells (thyrotrophs, gonadotrophs, corticotrophs)
What is the adenohypophysis, what are its 2 parts?
anterior pituitary
pars distalis (bigger part) and pars tuberalis (sheath around infundibulum)
How does blood drain from the hypothalamus?
into the hypophyseal portal veins, which pass down outside the infundibulumw where they split to form a secondary plexus of the hypophyseal portal system surrounding the anterior pituitary
What does human growth hormone (somatrotropin) do? What regulates it? How often is growth hormone released?
stimulate secretion of insulin like growth factors (IGF) that promote growth and protein synthesis
Regulated by growth hormone releasing hormone and growth hormone inhibiting hormone
growth hormone is released every few hours, especially during sleep
What are the functions of insulin like growth factors (IGFs)?
- causes cells to grow and multiply by increasing amino acid uptake
- decreases breakdown of proteins and decreases use of amino acids for ATP production to increase growth of skeleton and muscles in youth
- helps maintain mm and bone mass in adults and promotes healing
- enhances lipolysis in adipose tissue, increased use of fatty acids for ATP production
- decreases glucose uptake to ensure it is available to neurons for ATP production during glucose scarcity
What does thyroid stimulating hormone do? What controls it?
stimulates synthesis and secretion of thyroid hormones (T3 and T4) by thyroid
Stimulated by thyrotropin releasing hormone from hypothalamus
Inhibited by Somatostatin/Growth hormone inhibiting hormone
What does lutenizing hormone do? What controls it?
triggers ovulation by ovaries and testosterone production by testes. Stimulates secretion of estrogen
controlled by gonadotropin releasing hormone
What does oxytocin do?
- affects uterus and breasts after delivery of baby
- enhances smooth mm contraction of uterus
- stimulates milk ejection from mammary glands
- fxn in men and non pregnant women unclear
- synthetic oxytocin (pitocin) used to induce labour
What does antidiuretic hormone do?
decreases urine production by causing kidneys to reabsorb water and return it to the blood
decreases water lost through sweating and causes constriction of arterioles which increases BP
What inhibits antidiuretic hormone?
alcohol
What does follicle stimulating hormone do? What controls it?
targets gonads, initiates development of oocytes in women and stimulates sperm production in men
controlled by gonadotropin releasing hormone
inhibited by negative feedback
What does prolactin do? What controls it?
promotes milk production in mammary glands
regulated by inhibitory hormone (dopamine) and releasing hormone (prolactin releasing hormone)
Describe the steps in the synthesis of thyroid hormones?
1. iodine trapping in blood plasma
2. synthesis of TGB (thyroxine-binding globules)
3. oxidation of iodine
4. iodination of tyrosine
5. coupling of T3 and T4
6. pinocytosis and digestion of colloid
7. secretion of thyroid hormone
What does adrenocorticotropic hormone do? What controls it?
stimulates glucocorticoid secretion by adrenal cortex
regulated by corticotropin releasing hormone
What does melanocyte stimulating hormone do? What controls it?
increases melanin production, overall function not clear
receptors found in brain tissue
Where is the thyroid gland located?
inferior to larynx
What connects the 2 lobes of the thyroid gland?
isthmus
Where is the thyroid are thyroid hormones produces?
follicular cells (T3 and T4)
parafollicular cells (calcitonin)
What are the 3 thyroid hormones?
T3, T4 and calcitonin
What is the function of T3 and T4? Which is present in greater abundance?
increase BMR, stimulate protein synthesis, increase use of glucose and fatty acid for ATP production
T4 in greater abundance, T3 has greater effect
What is the function of calcitonin?
lowers blood calcium by inhibiting bone resorption
What endocrine gland stores its secretory products in large abundance?
the thyroid gland
What controls thyroid hormone secretion?
thryotropin-releasing hormone from hypothalamus
thyroid stimulating hormone from anterior pituitary
growth hormone inhibiting hormone is inhibitory
What are some symptoms of hyperthyroidism?
increased heart rate, more forceful heartbeats, increased BP
Where is the parathryoid gland?
embedded in posterior surface of the lateral lobes of the thyroid gland (usually there is 4)
What controls secretion of calcitonin and parathyroid hormone through negative feedback?
blood calcium levels
Explain how hormones control
...
Explain how hormones play a role in calcium homeostasis?
1. high level of calcium in glood, stimulates thyroid gland parafollicular cells to release more calcitonin
2. calcitonin inhibits osteoclasts, thus decreasing blood calcium levels
3. low levels of calcium in blood stimulates parathyroid gland chief cells to release more parathyroid hormone
4. parathyroid hormone promotes release of calcium from bone extracellular matrix into blood and slows loss of calcium in urine, thus increasing blood calcium level
5. parathyroid hormone also stimulates the kidneys to release calcitriol
6. calcitriol stimulates increased absorption of calcium from foods, which increases blood calcium level
...back to step one!
What cells secrete parathyroid hormone?
chief cells
...
...
What are thyroid hormones synthesized from?
iodine and tyrosine with a large glycoprotein (thyroglobulin)
...
...
What are the 2 types of epithelial cells in the parathyroid gland and what doe they do?
chief (principal) cells: produce parathyroid hormone
oxyphil cells: unknown function
...
...
What is the function of parathyroid hormone?
-the major regulator of caclium, magnesium and phosphate ions in the blood
- increase number and activity of osteoclasts
-elevates bone resorption
-acts on kidneys to slow loss of calcium and magnesium from blood
- promotes formation of calcitriol (active form of vit D) which increases absorption rate of Ca, Mg, and P from GI tract
Other sets by this creator
Vision- Quiz 2
16 terms
Hearing
30 terms
Layers of Eye Diagram
14 terms
Neuro- Vision Quiz 1
99 terms
Verified questions
chemistry
What is an atom mostly made of? A. air c. neutrons B. empty space D. protons
computer science
Create class IntegerSet for which each object can hold integers in the range 0 through 100. Represent the set internally as a vector of bool values. Element a[i] is true if integer i is in the set. Element a[j] is false if integer j is not in the set. The default constructor initializes a set to the so-called “empty set,” i.e., a set for which all elements contain false . Provide an additional constructor that receives an array of integers, and uses the array to initialize a set object.
physics
A free proton moves back and forth between rigid walls separated by a distance $L=$ $0.01 \mathrm{~nm}$. (a) If the proton is represented by a one-dimensional standing de Broglie wave with a node at each wall, show that the allowed values of the de Broglie wavelength are given by $\lambda=2 L / n$, where $n$ is a positive integer. (b) Derive a general expression for the allowed kinetic energy of the proton and compute the values for $n=1$ and 2 .
astronomy
At what time would you look to see a first-quarter Moon at its highest position in the sky?
Recommended textbook solutions
Hole's Human Anatomy and Physiology
13th Edition
•
ISBN: 9780073378275
(15 more)
David N. Shier, Jackie L. Butler, Ricki Lewis
1,402 solutions
Hole's Human Anatomy and Physiology
15th Edition
•
ISBN: 9781259864568
(1 more)
David Shier, Jackie Butler, Ricki Lewis
1,952 solutions
Body Structures and Functions
13th Edition
•
ISBN: 9781337269148
Ann Senisi Scott, Elizabeth Fong
743 solutions
Body Structures and Functions
13th Edition
•
ISBN: 9781305978881
Ann Senisi Scott, Elizabeth Fong
743 solutions
Other Quizlet sets
SocSci Sec 3
53 terms
Middle Ages Cards from the PowerPoint
32 terms
Industrial Psych
91 terms
Enviro Sci Test 1
176 terms