Flashcards in Quiz 12 Deck (151):
____ temperatures will stimulate thyroid hormone production to increase
Describe the hypothalamic pituitary thyroid negative feedback loop. What is stimulatory what is inhibitory?
Hypothalamus secretes TRH which stimulates the anterior pituitary to secrete TSH which then stimulates the thyroid gland to produce thyroid hormones, which then go to the target tissues. TSH will inhibit the hypothalamus from producing TRH. Thyroid hormones (T3/T4) will inhibit both the hypothalamus and the anterior pituitary
True or false... the thymus is the largest gland in the body
False. The thyroid gland is the largest gland in the body
True or false... the thyroid gland is poorly vascularized
False, it is extremely well vascularized
What is the difference between inactive and active thyroid glands in regards to...
Cells lining the follicles
Colloid in the inactive gland is more abundant
Follicles are larger in the inactive gland
Cells lining the follicles of inactive glands are flat (cuboid in active)
The edges of follicles of active glands are scalloped with many small resorption gaps resulting form the uptake of colloid
The follicular cells of the thyroid secrete ____ and ____. The parafollicular cells secrete ____
Thyroxine (T4) and Triiodothyronine (T3)
Thyroid hormones stimulate enzymes involved with ____ thus increasing _____ rates and _____ production
Calcitonin is released in response to..
High blood calcium levels
How does calcitonin lower blood calcium levels?
By inhibiting the resorption of bone by osteoclasts
Name the three key hormones in regulation of blood calcium levels and their effect on calcium levels
1, 25 dihydroxycholecalciferol - formed from vitamin D and increases calcium levels
Parathyroid hormone - secreted by chief cells of parathyroid glands - increases blood calcium levels by stimulating osteoclasts
Calcitonin - decreases blood calcium levels by inhibiting osteoclasts - secreted from parafollicular cells of the thyroid
Thyroid hormones are synthesized from ____ and ____
Iodine and tyrosine
The thyroid gland produces small amounts of ____ but primarily secretes _____
T4 is converted to T3 in what extrathyroidal organs? What percent does each organ convert?
Liver - 60%
Intestines - 20%
The other 20% is inactivated by converting T3 to rT3 (most of this occurs in the liver)
What is rT3?
The inactive form of T3. It is an isomer of T3
Which is more potent, T3 or T4?
T3 (4x more potent)
What enzyme converts T4 to T3?
5' de-iodinase enzyme
How many iodine groups are on T4? How about T3? How about rT3?
True or false... feedback inhibition at the level of the hypothalamus is the most efficient way to inhibit TRH secretion
False... feedback inhibiton at the level of the ANTERIOR PITUITARY is the most efficient way to inhibit TRH secretion
Are thyroid hormones lipophillic or hydrophilic? This means that they target ____ receptors
Under stress or fasting, the body converts (more/less) T4 to T3 and more T4 to ____ to conserve energy
Explain how insufficient iodine levels can result in a goiter
Without sufficient iodine levels, thyroid hormones are not released/produced and TSH builds up. The increased levels of TSH will cause the thyroid to experience oxidative stress
True or false... thyroid hormone precursors can be stored in vesicles
True. Although the hormones are lipophilic, the precursers can be stored in vesicles
Are the half lives of thyroid hormones long or short?
What is thyroglobulin? Explain its role in hormone production
It is stored in the follicle cavities of thyroid glands. They contain four to eight molecules of T3, T4, or both. Thyroglobulin serves as a reservoir for receiving the dietary iodine. Thyroglobulin is endocysosed by follicular cells and digested by lysosomes to release the thyroid hormones
Thyroid hormones are moved through the blood by attaching to ____
What is the best stimulus for increasing the production of TSH by the anterior pituitary?
Exposure to cold
Thyroid hormones are calorigenic. Explain what this means
Thyroid hormones cause cells to consume more energy and produce heat as a byproduct
True or false.. thyroid hormones are lipophilic and can freely cross the cell membrane and form complexes which act as transcription factors for certain genes
Dis is twue
____ deiodination of T4 results in T3
_____ deiodination of T4 results in rT3
(Yes, the ' matters)
True or false... thyroid cells are the only cells in the body that can absorb iodine
What enzyme converts T4 to rT3?
5 de-iodinase enzyme
Goiters can result from chronic exposure to increased amounts of _____ and/or ____. Goiters can also result from ____ deficiency
TSH and/or HCG
Goiters can also occur during pregnancy or the autoimmune hashimoto's disease
Describe some of the symptoms of iodine deficiency disorder
Hoarseness, shortness of breath, cough, dysphasia
If the mother is deficient in iodine during pregnancy, the child may have ____. Its symptoms are....
Growth retardation (dwarfism)
Dry brittle hair
Courseness of skin
How can hasimoto's disease result in hypothyroidism and production of a goiter?
Damages the thyroid and reduces thyroid hormone production
Reduced T4 and T3 causes anterior pituitary to overproduce TSH, causing the thyroid to enlarge
Explain how graves disease can result in hyperthyroidism and a goiter
Autoimmune disease that attacks the thyroid. Thyroid defensively overproduces thyroid hormones leading to a goiter
Hormones like CCK can act as ____, _____, and ____ hormones
True or false... the GI system functions as a result of the balance between stimulatory and inhibitory hormonal events
Gastrin is released from ___ cells. And is released due to _____. It functions to____ (4 things)
Stimuli from consumption (stomach distention) and peptides in gastric lumen.
Stimulates parietal cells to secrete HCl, and chief cells to secrete zymogens. Also controls pyloric region and increases motility for digestion.
CCK is released from ____ cells due to _____ and functions to _____
Presence of fats
Contract gall bladder to release bile
Secretin is released by ___ cells due to _____ and functions to _____
Acidic pH in lumen of small intestine stimulates secretin release
Stimulate pancreas to release bicarbonate and water to neutralize the pH
Gastric inhibitory peptide is released from the ____ due to _____ and functions to ____
Mucosa of upper small intestine
Presence of fatty acids > amino acids> carbohydrates
Inhibits gastric secretions and motility as well as induce the pancreas to produce insulin
Glucagon is released from ____ and functions to_____. It is released due to ____ and inhibited by _____
Pancreatic alpha cells
Release glucose from cells to increase blood sugar. It is a counter regulatory assistance for insulin
Released due to low blood sugar and inhibited by high blood sugar
Insulin is released from ____ and functions to _____. It is released due to ____ and inhibited by _____
Pancreatic beta cells
Functions to increase cell adsorption of glucose to lower blood sugar (acts on liver cells, adipose cells, and muscle cells)
Released due to high blood sugar and inhibited by low blood sugar
Somatostatin is released by ____ and functions to ____. It is regulated by _____
Released by the pancreas
Functions to regulate GI hormones in pancreas and GI tract. It slows production of insulin, glucagon, gastrin, and other hormones
It is regulated by hormones
Name the five classes of pathogens
What are the five roles of the immune system?
Kill or control pathogens
Repair tissue damage
Maintain organ integrity and function
What is variolation?
First practice to provide immunity. Involves inhaling pathogen or scratching skin and placing pathogen in wound
Describe herd immunity
If enough people in a population are vaccinated, these people will in a sense protect the nonvaccinated people from getting sick
Name three endogenous antimicrobial properties
Sebum (has antimicrobial products in it)
The immune system responds when ____ are compromised
True or false... inflammation is always due to infection
False.. it may be due to dysfunctional body tissue or damaged body tissue
When a break of barrier occurs and bacteria is introduced, what is the first response?
The presence of bacteria activates resident effector cells to secrete cytokines
Name three common effector mechanisms that the immune system uses to destroy pathogens
Targeted cell death
Typically, how long is the response for the innate immune system? What about the adaptive immune system?
Innate - hours
Adaptive - days to weeks
Which is worse, an ineffective innate immune system or an ineffective adaptive immune system?
Ineffective innate immune system because the adaptive system relies on the innate immune system
Complement is produced by ____
Immune cells function through direct and indirect interactions to eliminate pathogens. Describe the two types of direct interaction
Phagocytosis - pathogen internalization and destruction
Immune synapse - T Cell - mediated killing
Describe the four indirect methods in which immune cells can eliminate pathogens
Define cytokines. Which are inflammatory and which are anti-inflammatory? (3 each)
Molecules that activate and innactivate immune function through cell surface receptors
Inflammatory: IL1, IL8, TNF-a
Anti-inflammatory: IL4, IL10, TGF-b
What are chemokines?
Molecules that attract immune cells to a region in the body
What are cytotoxins? Name three examples
Molecules that interact with cells and pathogens to kill them.
TNF-a (can act as a cytotoxin if the cells possess the proper receptors)
T cells are produced in the ____ but mature in the ____
Describe the 5 leukocyte distribution and their percentages
Eosinophil ~ 6%
Basophil ~ >1%
Monocyte ~ 10%
Lymphocyte ~ 30%
True or false... natural killer cells kind of fall under both categories, innate and adaptive immune system
The common precursor cell for all immune cells and blood cells are ____ cells
Hematopoietic stem cells
The precursor for all innate immune system cells as well as red blood cells and platelets are ____
Common myeloid precursors
The common precursor cell for all of the adaptive immune system cells is the ___
Common lymphoid precursor
Name the common cell cell that gives rise to all innate immune cells but not red blood cells and platelets
Granulocytes macrophage progenitor cell
After birth all blood cell production (not maturation) takes place in the bone marrow. However in early fetal development, blood cell production occurs in the ____, mid fetal development it occurs in the ____, and late fetal development in occurs in the ____
Liver and spleen
What are the innate immune cell first responders?
Large reserves of neutrophils are stored in the_____ and are released when needed to fight infection
Monocytes give rise to the two antigen presenting cells which are the ___ cells and _____. Which is better at activating the adaptive immune system?
Dendritic cells and macrophages
Dendritic cells are best at activating the adaptive immune system
These both function to activate and inhibit inflammation as well as eat up pathogens and dead neutrophils
What three immune cells are involved in fighting off parasites?
True or false... mast cells, eosinophils, and basophils are all granulocytes
What are the two main types of T cells that we need to know?
T helper cells
T cytotixic cells
True or false... natural killer cells have a short half life
False. They have a very long half life
_____ drives B cell and T cell pathogen specificity
___ receptors bind antibodies
MHC class 1 and class 2 stimulate ____
T cell receptors
Name the five classes of antibodies
Which antibody is the most abundant in the body?
Which is the first antibody produced and released?
IgM. This antibody can also make pentomeric structures to coaggregate the pathogen
which antibody is secreted from mucosal glands?
Which antibody is a B cell surface antibody?
Which antibody is a basophil and mast cell surface antibody?
IgE - these are released to defend against multicellular pathogens
True or false... all of the different classes of antibodies will differ in their Fc fragment
True. This will result in different responses with different cells for each antibody family. However the Fc fragment within a family of antibodies are all the same
Name the two things antibodies can do as part of an immune response
Neutralization or opsonization
Describe the two types of T cells
Cytotoxic T cells (CD8) - Kill altered self cells
Helper T cells (CD40 - support the functions of the immune system and other organ systems
Regulatory function for innate immune system
CD8 cells bind to MHC class ____ whereas CD4 cells bind to MHC class ____
Define primary lymphoid organs. What are the two primary lymphoid organs?
These are the organs in which immune cells develop
Define secondary lymphoid organs. Name the three secondary lymphoid organs.
This is where the adaptive immune system initiates.
Mucosa-associated lymphoid tissue (MALT) (tonsils, peyer's patches, etc.)
What is the difference between negative and positive selection?
Negative selection - selection against binding to self antigens
Positive selection - selection for binding to the pathogen
True or false... swollen lymph nodes in the neck means that the infection could have occurred anywhere in the body
Most likely false. Because lymph nodes are mostly useful for that particular region of the body. This allows the immune response to stay more local
_____ are like immune sentry points where as the _____ filter blood borne antigens. _____ are points of pathogen susceptibility, kind of function in a reverse fashion compared to lymph nodes
Describe the 9 steps of the basic process of pathogen resolution
2) REsident immune cells respond
3) inflammatory response
4) innate pathogen targeting
5) pathogenic antigens presented in the lymph nodes
6) adaptive immune system initiated
7) ongoing immune response
8) pathogen destroyed or sequestered
9) Memory cells formed
Name the three extranasal muscles. What are they innervated by? What is their blood supply?
Nasalis (2 parts)
Levator labii superioris alaeque Nash
Innervated by facial nerve (CN7)
Blood supply from facial artery and opthalmic artery
Name the 6 different bone or cartilage structures that make up the nose
What is the difference between the nasal conchae and nasal meatuses?
The superior middle and inferior conchae are the bony structures that are like shelves in the nasal cavity
The nasal meatuses are the spaces between the shelves
Name the major sources of blood to the lateral nasal cavity
ICA - opthalmic - ethmoidal arteries (anterior and posterior )
ECA - maxillary - sphenopalatine (lateral posterior nasal arteries)
Describe the major sources of blood for the nasal septum
ICA - opthalmic - ethmoidal arteries (anterior septal branch only)
ECA - maxillary - sphenopalatine (posterior septal branches only)
- Facial - septal branch of superior labial artery
What gives general sensory innervation to the nasal cavity and septum? What about special sensation?
V1 - anterior nasal septum and cavity (anterior ethmoidal nerve)
V2 - rest of nasal septum and cavity. (Sphenopalatine branch of V2 via the sphenopalatine foramen)
CN1 gives olfaction sensation to the nasal cavity
Where does the nasolacrimal duct drain?
In the nasal cavity
Name the four paranasal sinuses
Ethmoid sinus (air cels)
The sphenoid sinus doesn't drain into the middle meatus, it drains into the ____
Sphenoidal recess, which then goes to the superior meatus
What sinuses drain into the middle meatus of the nasal cavity?
Frontal, maxillary, ethmoidal air cells
The hole in the middle meatus in which the sinuses drain through is called the ____
Name the five sites of drainage in the nasal cavity. What do they drain?
(All those drain sinuses)
Lacrimal duct (drains the eye)
Pharyngeal orifice of eustacian tube (drains the ear)
The lacrimal duct drains into what meatus?
Why is it that children get more ear infections that adults?
Their eustacian tube is more horizontal whereas adults have a steeper eustacian tube
What is the tragus?
Triangular flap over the external auditory meatus on the auricle
The external ear sensory innervation is kinda scrambled. But describe the basic generalizations of what nerves innervate what portions of the ear. Helix, lobule, tragus
Helix - lesser occipital (C2)
Lobule - greater auricular (C2, C3)
Tragus/anterior portion of ear - V3 (Ariculotemporal branch)
What nerves do motor innervation in the ear?
Vagus and facial.
Vagus innervates closer to the external auditory meatus
What gives sensory innervation to the outer portion of the tympanic membrane? What about inner portion?
V3 and vagus
Glossopharyngeal does inner
What sinus connects with the middle ear?
Mastoid air cells
What muscles do you use to pop your ears?
Tensor veli palatini and levator veil palatini and salpingopharyngeous
What artery will supply the middle ear?
Branches of maxillary artery
What nerves are involved with the middle ear?
Name the three external ear muscles. What are they innervated by? What artery supplies them?
Posterior auricular artery
Superficial temporal artery
What muscle causes your eyelid to close? What nerve innervates this muscle?
Innervated by facial nerve
What muscle is involved in keeping the eyelid elevated? What nerve innervates this muscle?
there is a second muscle that does the same thing but under the flight or fight response, what muscle is this, what is it innervated by?
Levator palpebrae supeiroris muscle innervated by oculomotor nerve (CN3)
Superior tarsal muscle innervated by sympathetics from t1 in the spinal cord
The sympathetics that arise from T1 to innervate the superior tarsal muscle synapses in the ____ and then follows the _____ to reach the muscle
Superior cervical ganglion
ICA ad opthalmic artery
The lacrimal gland is innervated by ___
True or false.... parasympathetic innervation input is what causes the lacrimal gland to tear
Describe the pathway of tears from the lacrimal gland to the nasal cavity
Lacrimal gland to eye to superior/inferior puncta to lacrimal caniculi to lacrimal sac to nasolacrimal duct to nasal cavity
What is the name for the white part of the eye?
the cornea has sensory innervation from ___
What is the function of the cornea?
When the ciliary muscles contract, do the suspensory ligaments tighten or loosen? What happens to the lens as a result?
Upon contraction, the suspensor ligaments loosen and the lens goes into a more spherical shape, allowing short distance focusing
Light traveling from a distance needs more or less refraction to focus on the retina
The sphincter papillae muscle is innervated by ___ and functions to ____
Cranial nerve 3
Constrict the iris
The parasympathetics of CN 3 will innervate what muscles in the eye? They arise from what nucleus? Where do the preganglionic and postganglionic neurons synapse?
Accessory oculomotor nucleus
The sympathetics innervate what muscles in the eye?
Dilator pupillae muscle
Superior tarsal muscle
What causes Horner's syndrome? What are its symptoms?
Lack of sympathetic innervation to the head
Symptoms include ptosis (droopy eyelid), anhydrosis (decreased sweating), and miosis (constricted pupil)
What is the fovea centralis?
An area of the retina that has the highest concentration of cones
True or false... CN 2 has fibers that synapse in the ciliary ganglion.
Describe how shining light in one eye will cause both eyes to constrict their irises
The signal coming from the optic nerve will synapse in the pretectal nucleus. An inter neuron bifurcated goes from the pretectal nucleus to both the ipsilateral and contralateral edinger-westphal nuclei. Then fibers stay ipsilateral from there and go to the sphincter papillae muscles to constrict both irises
What direction does the inferior oblique muscle move the eye?
What direction does the superior oblique move the eye?
What direction does the superior rectus move the eye?
What direction does the inferior rectus muscle move the eye?
If you are looking down and to the right. Explain the muscle activity of each eye
Right eye is using the superior oblique
Left eye is using the inferior rectus
What is a secondary action of the superior oblique? What about inferior oblique?
Superior oblique - medial rotation
Inferior oblique - lateral rotation
What is a secondary action of the superior rectus? What about inferior rectus?
Superior rectus - Addiction and medial rotation
Inferior rectus - addiction and lateral rotation
the opthalmic artery arises from ____ and enters the orbit via the ____. Which branch of the opthalmic artery runs through the optic nerve to reach the retina?
Central artery of the retina
Name the three superficial orbit muscles. What innervates these muscles? What arteries supply these muscles?
The pharyngotympanic tube opens up in the...
What is the effect of the dose response curve if you add irreversible competitive inhibitor to the mix?
Lowers Emax, similar to a noncompetitive allosteric inhibitor
The pentose phosphate pathway will convert glucose 6 phosphate into ____ which are precursors for _____. It forms ___ in the process
Ribose 5 phosphate
What are three fates of acetyl coA?
Citric acid cycle
Ketone body formation
Conversion into cholesterol