Test 4 Review Flashcards
Tyrosine kinase receptors have been implicated in?
causing cancer
What are the two inactive monomers of the Tyrosine Kinase receptor?
outer surface of cell membrane for ligand binding
in cytoplasm for catylitic or enzymatic domain
What are the steps in the Tyrosine Kinase pathway?
- growth factor binds to domain (2 needed)
- monomers dimerize
- autophoshorylation of catayltic domain on one monomer
- Phosphorylation of tyrosine at 2nd monomer, which then phosphorylated the first
- enzymatic activity is turned on
- catayltic domain phosphorylated tyrodine residue of proteins
- signal proteins will activate metabolic pathways that can activate 10+ signal proteins simultaneously
- Protein phsphatase reverses action of kinase
Where is the pituitary gland located?
the underneath of the hypthalamus
The posterior pituitary directly connects to the
hypothalamus
What are the two lobes of the pituitary?
anterior (adenohyphysis0
posterior (neurohyphysis)
the notochord provides?
skeletal support
release of growth factors
The stomodeum is the?
mouth region of the body
Trophic hormones mean?
to feed
Growth hormones (Somatoptrophin) do what?
control tissue and organ growth
stimulates cell to take in more amino acids
Thyroid stimulating hormone (thyrotropin) does what?
goes into thyroid gland and causes secretion of glucocorticoids
Adrenocortiotropic hormone (corticotropin) does what?
goes to the adrenal cortex and secretes corticosteroids that in turn secrete glucocorticoids for metabolism of glucose
Follicle stimulating Hormones (FSH or folliculotropin0 does what?
stimulates ovary follicle developement
follicle then produces egg which produces estrogren
Lutenizing hormone (LH or Lutropin) does what?
Triggers ovulation in females
-development of corpus luteum
In males acts on specific interstial cells is testies
Prolactin (PRL) does what?
stimulated milk production after childbirth
PP does not produce any __________ but secretes two ___________.
hormones, but secretes two hormones
Where is PP produced?
in the supraoptic nucleus and the paraventricular nucleus in hypothalamus
What is Anti-diruetic hormone?
causes kindneys to retain water
increased concentrations of ADH cause higher urine concentration, small volume and bright yellow in color
What causes the secretion of ADH?
- osmotic pressure of blood triggers ADH release
- secretion inhibited by stretch receptors in the left atrium of heart
- increased stretching triggers the inhibition of ADH
- alcohol consumption causes inhbition of ADH
Vasopressin causes?
high doeses can cause vasoconstriction and an increase of BP
What is oxytocin?
in females it causes contractions of uterus during childbirth and milk ejection
What is the sensory input of oxytocin?
sucking
Where does oxytocin work?
on the smooth muscle of mammary glands, causing contractions
AP/AH is acted on by the?
hypothalamus
The hepatic portal vein connects?
blood from small intestine to liver
The hypothalamus uses hormones to?
cause release or inhibition of AH/AP
The median eminence is?
the capillary bed in hypthalamus that receives hormones from the neurons of hypothalamus
Thyrotropin realeasing hormone (TRH) releases?
TSH
coricotropin releasing hormones (CRH) releases
ACTH
gonadotropin releasing hormone (GNRH) releases?
FSH and LH
growth hormone releasing hormone releases?
GH
Somatostatin does what?
inhibits AH secretion
what is an example of Protein inhibiting hormone
dopamine
which inhibits prolactin secretion
Surgical removal of target glands will change what?
the pattern of secretion of the hypothalamus and AH/AP
After castration, what occurs?
high release of gonadotropin releasing hormone and GH
An example of positive feedback inhibition would be?
menstrual cycle
What are two hormones released by the medulla of adrenal glands?
80% epinephrine
20% norepinephrine
The adrenal cortex contains no?
innervation
What does the adrenal cortex secrete?
ACTH (corticosteroids)
What are the three zones of the adrenal cortex?
Zona Glomerulosa
Zona Fascuilata
Zona Reticularis
What is secreted by the Zona Glomerulosa?
secretes mineralcorticoids which regulate electrolytes in blood
What is secreted by the Zona Fasciulata?
Glucocorticoids that work in glucose metabolism
DO NOT REG. BLOOD GLUCOSE
What is secreted by the Zona Reticuularis?
Secretes small amount of sex steroids
-these weak androgens are pre-hormones
What is the primary mineralcoriticoid secreted by the Zona Glomerulosa?
Aldosterone
What does aldosterone do?
Acts on kidney to reabsorb water and salt from filtrate
raises B.V. and B.P
excretes K+
Over secretion of K+ can cause?
hyperkalemia-which is an increase of K+ in blood that can depolarize the heart cells causing death because of lack of contraction
The renin Angiotensin Aldosterone mechanism located in Zona Glomerulosa does what?
- Under low BP/Vol. kidney produces renin which triggers angiotensin
- increases BP
- acts on adrenal cortex to trigger Aldosterone secretions
What triggers the glucocorticoids from the Zona Fasciulata?
ACTH
Cortisol (Hydrocortizone) from Zona Fasciulata does what?
Conserves Glucose by restricting entry into cells
stimulates lipolysis
stimulates gluconeogenisis
causes immmune suppression
What is Cushings disease?
Hyper secretion of corticosteroids
What is the precursor to all corticosteroids?
Cholesterol
Hyper Glycemia is?
increase in blood glucose
People with Cushing’s Disease exhibit?
Hyperglycemia Hypertension Muscle Weakness Puffy appearance Moon shaped face Buffalo like hump in back
What causes the buffalo like hump in people with Cushings disease?
Prednisone
What is Addingson’s Diease?
Na+ and K+ imbalances which causes low aldosterone
- rapid weight loss
- fatal if untreated but can be treated with oral supp.
- hypoglycemia occurs
The thyroid gland exhibits only what type of function?
endocrine
What is the thyroid gland made of?
thyroid follicles that contain a colloid suspension.
What type of cells line the colloid suspension and secrete colloid
simple cubodial epithelium
Parafollicular cells secrete?
Calcotonin
What is the function of calcitonin?
- kidneys reabsorb less Ca2+ from filtrate
- inhibites osteoclasts that dissolve the bone and sacrifice your skeleton
Ca2+ is very important (In regards to calcitonin)?
Exoxytosis or NTs
Muscle contraction
The two thyroid hormones T3 and T4 act on?
Thyroid follicles
What do thyroid follicles do?
Remove Iodine from the blood and combine this iodine with Tyrosine to form Thyroglobulin
MIT stands for?
monoiodotyrosine
DIT stands for?
Diodotyrosine
T3 is made of?
MIT and DIT
T4 is made of?
DIT and DIT
TSH causes cells of the follicle to?
undergo endocytosis, taking up thyroglobulin attached to T3 and 4 and cleaving off thyroglobulin which releases T3 and T4 into blood
Genomic action is?
protein synthesis which promotes maturation of NS and Basal metabolic rate
What are the symptoms of hyperthyrodism?
- Hot
- little sleep, very active
- increased HR and quick reflexes
- Frequent bowel movements
- Weight loss
What are the symptoms of hypothyrodism?
- cold
- Tired, need alot of sleep
- depression
- low HR, slow reflexes
- constipation
- low appetite, weight gain
What is Goiter?
Enlarged thyroid gland
What are the two different types of Goiter?
- Endemic (from iodine deficency)
- Graves disease (tyrotoxicosis)
What element is ness. for production of Thyroxine?
Iodine
When there is not enough idodine in the diet, what happens?
- no negative feedback
- high levels of TRH and TSH
- Thyroid expands enormously resulting in goiter
- hypothyroid symptoms
Grave’s disease is caused by?
autoimmune disease from and unknown pathogen
What happens in Grave’s disease?
immune system produces anti-bodies that attach to pathogen marking it for destruction, but also attach to cells of thyroid
-effects similar to TSH and hyperthyroidism
Where are the parathyroid glands
2 small yellowish masses embedded in back of thyroid gland
What do parathyroid glands secrete? What does it do?
Produces Parathyroid hormone (PTH)
- antagonistic to calcitonin
- increases Ca2+ in blood
- kidneys pull Ca2+ from filtrate
- osteoclast cells dissolve bone
What activates parathyroid hormone?
Decreasing Blood Ca2+
A spongy, airy organ located in the loop off the duodem that has both exocrine and endocrine fuctions is the?
pancreas
What does the pancreatic duct do?
releases secretions into the duodenem
Melatonin is made from ___________, and is similar to ________.
tryptophan; serotonin
What inhibits the secretion of serotonin?
light
What gland secretes melatonin?
pineal
What is the purpose of melatonin?
1) Entrains circadian rythmns
2) Entrains photoperiodism
What is photoperiodism?
A response to a change in day length
Antigonadotrophic means?
Melatonin is inhibiting gonads from producing sex hormones and gametes
This is why animals breed in the spring because less melatonin so gonads are not as inhibited
The placenta is responsible for ?
an exchange of materals between the mother and fetus
The testes are?
hollow organs lined with germinal epithelium called seminiferous tubules
Sperm is produced by a process called
Miosis
What are the cells located between the seminiferous tubules?
Cells of Leydig that produce testosterone
Testosterone is resonsible for?
Maintaining integrity of genital organs
development of 2ndary male sex characteristics such as body fat distribution, muscle size, and bone size
Where does FSH act on males?
acts on the seminiferous tubules to produce sperm
What are the different estrogens?
Estradoil 17 beta
Estriol
Estrone
Estradoil 17 beta is.
principle estrogen made by ovaries after puberty and until menopause
Estriol is?
made during pregnancy by the placenta
Estrone is?
made after menopause by fat cells
What influences follical to develop?
FSH influences follice to develop by undergoing meiosis to mature graphian follicle
The graphian follicle does what in regards to the egg?
Bursts and releases the future egg in a process called ovulation
What is the time period between ovulation and when an egg can be fertilized?
72 hours
If the egg is not fertilized within 72 hours what occurs?
it disintegrates
The remains of the graphian follicle then become the?
corpus lutem
Corpus Lutems produce?
progesterone and Estradiol 17 beta
the surface of the uterus is called the?
perimetrium
The middle of the uterus is called?
the myometrium
The inner surface of the uterus is called the?
Endometrium
What is the smooth muscle that contracts during childbirth?
the myometrium
The single layer of cells called the Stratum Basalis undergoes mitotic division to form thicker layers of cells called?
Stratum Functionalis
Where does the embryo plant when pregnant?
into the stratum functionalis
If no pregnancy occurs, what layer of the uterus is shed?
the stratum functionalis during menstration
Ovulation occuring on day 14 on the menstrual cycle involves the?
release of ovum from ovary into peritoneal cavity surrounded by a halo of follicle cells
What structure help draw egg into the fallopian tube?
Fimbriae
Etopic pregnancy involves the?
fertilized egg implanting in the falopian tube
Etopic pregancies may be more common in someone who had untreated syphillis, why?
Because of the scarring of the fallopian tubes
Endometriosis also increases chances of etopic pregnancies
Where is the egg fertilized?
in upper third of fallopian tube
How long does it take the egg to reach the uterus after fertilization?
6 days
What type of cell forms the embryo’s part of the placenta?
Trophoblasts
What form’s the mother’s part of the placenta?
The mother’s stratum functionalis
How long is the menstrual cycle?
28 days
Menstration occurs from day?
1-5
What hormones are present during the menstration stage of the menstrual cycle?
FSH acts on follicles causing them to develop, and these follicle cells start to secrete Estrogen
The proliferation stage occurs in what days of the menstrual cycle?
Days 6 to 13
What occurs during the proliferation stage of the menstrual cycle?
Follicles are still growing increasing estrogen
AH/AP are putting out FSH at low levels
Stratum Basalis under estrogen influence grouws a stratum functionalis
What day does ovulation occur?
Day 14
What occurs during ovulation?
Grafian Follicle increases estrogen
This critical level of estrogen signals the pituitary gland
Follicle is mature
Surge of LH
When the secretory phase of the menstrual cycle occur?
Days 15-26
What occurs during the secretory phase?
Development of corpus lutem from folliicle remains in ovary
Surge of LH triggers development
Production of Estrogen and Progesterone occur
The production of estrogen and progesterone does what during the secretory phase?
1) Inhibits AH/AD from secreting any more FSH and LH (due to possible pregnancy no more follicles develop)
2) Triggers maturation of stratum functionalis
Critical levels of estrogen cause critical levels of?
*****
LH
The pre-menstrual stage of the menstrual cycle occurs?
from days 26-28
What occurs in the pre-menstrual stage?
- no pregnancy
- Corpus lutem disintegrates
- drop in Estrogen and Progesterone
- AH/AP is no longer inhibited
- Stratum functionalis is no longer supported and therefor disintegrates and sheds in menstration
The placentas Human chorionic gonadotropin supports?
the corpus lutem
A pro-hormone is?
A molecule that is synthesized into final hormone
What are the side effects of body builder’s taking testosterone?
violence and erectile disfunction
Hormones DO NOT accumulate in blood and are?
Rapidly removed and targeted by liver cells
The Physiological range of concentration of hormones are?
normal effects of hormones
The Pharmacologial range of concentration of hormones are?
Taking hormones as a drug to produce Abnormal effects
What is an example of some hormones binding to receptors for other hormones?
Estrogen can bind to both estrogen and testosterone receptors due to them being similar in structure
Estradiol 17 Beta is manufactured in ovaries from what?
testosterone
In men, the enzume Aromatase converts testosterone to?
Estradiol 17 Beta
What are the side effects from the converstion of testosterone to Estradiol 17 beta?
- Bulk up
- Gynecomastia, Testicular Atrophy, Erectile disfunction, Acene, Male pattern baldness, agressive behavior
What is upregulation?
Exposure of target cells to a hormone results in target cells making more receptors and at a later time a hormone has a larger effect
An example of upregulation is?
FSH stimulates follicles to develop and upregulate so that the same amount of FSH has a bigger effect later
What is downregulation?
Target cells have fewer receptors
does not occur in vivo
Endometriosis causes?
Pain and sterility damage to fallopian tibes
Benign prostatichyperhia is able to be treated by?
downregulation using GNRH hormone agonist
How does treating Benign prostatichyperhia work?
GNRH agonists cause downregulation so AH/AP will respond less to GNRH and produce less LH and FSH which in females will relieve endometriosis.
In makes, low LH means low Testosterone and prostate will diminish in size
What are prostaglandins?
Paracrine factors-substances that are released by cells in an organ and act on cells in the same organ
Where is Nitric oxide produced?
by cells of the endothelium of arteries and veins and acts on smooth muscle to create vasodilation
Where are cytokines produced?
by the immune system
Both nitric oxide and cytokines are examples of?
prostaglandins
Ulf von Euler thought that prostaglandins were produced where?
in the prostate gland
NSAIDS are?
nonsteroid antinflammation drugs
NSAIDS inhibit?
cyclooxygenase which provides relief of Pain and fever
Cyclooxygenase is a example of a?
prostoglandin
What are the three isoenzymes of Cyclooxygenase?
Cox 1-produced all the time
Cox 2-Inflammation
Cox 3-Only produced in CNS and promotes pain and fever
Both celebrex and vioxt are examples of _____ ______ __________ but where removed from the market because of the increased chance of stroke and heart attack and blood clots
Cox 2 cyclooxygenase
What is an example of a Cox 3 inhibitor?
Acetaminophen (tylenol)
Relieves pain and fever but does nothing for inflammation
What attaches muscle to bone?
Tendons
What are the three types of connective tissue in muscles?
Epimysium- Muscle surface
Perimysium-Surrounds groups of muscle cells fibers
Endomysium- Delicate and wispy that surrounds individual muscle fibers
The surface of bone is a dense connective tissue that is called?
the periosteum
What connects to the periosteum?
the tendon
Dark bands of muscle are referred to as?
A-bands
Light bands of muscle are referred to as?
I-bands
________ fuse together to make muscle cells.
Myoblasts
Each individual muscle fiber (cell) has a _______ ______ on it’s surface
plasma membrane
Muscle plasma membranes are referred to as?
sarcolemmas
What is the cytoplasm of muscle tissue referred to?
Sarcoplasm
The endoplasmic reticulum of muscle cells is referred to as?
Sarcoplasmic reticulum
Myofibrils are divided into repeating structures that are known as?
sarcomeres
What are the smaller filaments inside sarcomeres called?
Myofilaments
Thick myofilaments are made of?
Myosin
Thin myofiliaments are made of?
Actin
The Z band/disk/line is?
At the border attached to thin actin myofilaments
A-bands are?
thick myosin filaments at the center that are dark in color
I-bands are?
Light containing only thin actin myofilaments that are in between the Z-disk and the A-band
M bands are?
at the centers of A bands and are networks of proteins that anchors the myosin in plance
The region located in the middle of the A-band that contains only thick myofilaments are called?
H-bands
What is titin?
protein that runs through myosin that allows muscle tissue to relax
The elastic recoil of titin does what?
Elastic recoil pushes outward when contracting to return to resting length
What is the sliding filament theory?
Muscle shortens because faciculi shorten because muscle fibers shorten because myofibrils shorten because sarcomeres shorten
sarcomers
Myofilaments do NOT ___________ but instead slide past each other.
shorten
Cross bridges on thick myofilaments can?
attach to thin myofilaments
When a cross bridge from a thick myofilament attaches to a thin myofilament, it pulls?
- thin myofilament toward M-line
- Z-disk touch thick myofilament
- Thin myofilaments overlap at M-line
- I band shortens and dissapears
- A band stays the same
- H band shortens and dissapears
If cross bridgges release all at one, the elastic recoil of _______ returns them to resting length.
Titin
What are cross bridges made of?
Myosin
What are the two different conformations of cross bridges?
Phosphorylated- When cross bridge is cocked
De-phosphorylated-Power stroke occurs when de-phos.
What are the two forms of Actin:
G Actin=Globular and contains myosin binding site
F Actin=Filamentous and is a whole bunch of G actin bound together
Cross bridge has what type of domain, that does what?
ATP domain and it hydrolyzes ATP
When an ATP molecule binds to a cross bridge, what occurs?
It is hydrolyzed into A and P and is phosphorlated which causes a change in conformation, entering into cocked position
When the cross bridge binds to Actin it triggers?
dephosphorylation which causes change in conformation
What does the power stroke do?
Pulls actin towards M line, ejecting ADP from ATPase binding domain
When fresh ATP binds to cross bridge is causes cross bridge to release?
the actin
How much does a single cycle of all cross bridges shorten a sacromere and muscle cell?
1%
To relax a muscle, what needs to be prevented?
cross bridge attachment
What resembles a rope that lies between the groove between two F actins and blocks myosin binding domains of G actin?
Troponin/Tropomyosin
Troponin is made of 3 proteins that are:
Troponin C (TNC) Troponin I (TNI) Troponin T(TNT)
Troponin C (TNC) has?
a Ca+ binding site
Troponin I, the I stands for?
interference and triggers conformational change of troponin that has two conformations:
- Allows for contraction
- Prevents contrations
Troponin T, the T stands for
Tropomyosin
If no calcium is present what happens to Tropomyosin?
Tropomyosin blocks myosin binding domains of B actin so cross bridges cannot attach
Where does calcium bind?
Binds to TNC, and causes TNI to change conformation.
When conformation change occurs it essentially pulls tropomyosin rope
What is the trigger for muscle contraction?
Calcium
What is the concentration that Ca+ must be over to allow for muscle to contract?
10^6 molar
Excitation contraction coupling connects?
Action potientials with contraction
_______ motor neurons innervate skeletal muscle
Somatic
In target muscles, how many axons are there?
1 long axon
How many muscle cells can a single neuron innervate?
200 muscle fibers
What is the smallest neuron motor unit?
23 muscle fibers
What is the largest neuron motor unit
2,000 muscle fibers
Contraction of muscle occurs in a?
All of none fashion
More forceful contractions are generated not by greater action poteintials but by?
More motor neurons
What is the neuromuscular junction?
Where axon contacts the muscle
Sarcolemma closest to the terminal buton edges will have Na+ and K+ voltage gated channels (called Motor end plate)
Where does the Ca+ for contraction come from?
Most comes from sarcoplasmic reticulum.
What are terminal cisternae?
Large channels that are located next to or T tubules and are extensions of the sarcolemma that go deep into each muscle fiber
Where is the action potential for muscle contraction generated?
Motor end plate
muscle cell portion of neuromuscular junction
How is action potential generated in the motor end plate?
Ach binds to nicotenic receptors and generated an EPSP
it does this by depolarizing the motor end plate to threshold which generates the AP that sweeps sarcolemma
What happens as a result of the depolarization of the motor end plate?
Ca+ voltage channels open
Where does the Ca+ come from that flows into the voltage channels that are opened?
the extracellular fluid
What are the two release channels that are found in the sarcoplasmic reticulum (mostly terminal cisternae)?
1) Mechanically coupled-electrochemical mechanisms
2) Ca+ ligand gated channels-Ca+ binds to these channels and opens them
Mechanically coupled-electrochemical mechanisms are physically?
attached to Ca+ voltage gated channels
After Ca+ enters the cell, what does it bind to?
Troponin C
which triggers conformational change which pulls tropomyosin out of myosin building domains of actin
The repeated generation of Action potentials, will keep the muscle?
contracted
To stop muscle contraction what must occur?
somatic motor neurons will need to be stopped
ATP is needed both for muscle _________ and ______.
contraction and relaxation
rigor mortis occurs how long after death?
3-4 hours
max stiffness ~12hr. after death
What exactly is rigor mortis?
all muscles are contracted- and stay that way for a while
What causes rigor mortis?
No oxygen=no ATP synthesis=no muscle relaxation
No ATP results in rigor mortis how?
because the myofilaments are in locked position because corss bridges cannot de-attach
Ca+ pumps can no longer function
When does rigor mortis dissapate?
36-48 hours due to bacterial decomposition
What dermines max force/tension of a muscle?
The length of a muscle
-only optimum length can produce max force
What are the innervation ratios?
1:23 generate little force but are super precise
Example: extrinsic ocular muscles
1:2000 generate alot of force by not very precise
Cell bodies of somatic motor units relate in size how?
Small motor units=smaller cell bodies
large motor units=large cell bodies
Large motor units are?
harder to activate due to their size
What is summation?
multiple shocks of same amplitude
All muscles contain a series of elastic elements called?
tendons
What has to occur in a tendon before muscle contraction can occur?
the slack has to be pulled out of the tendon
What is tetanus?
A sustained contraction
Imcomplete tetanus is?
some relaxation due to individual contractions
Complete tetanus is?
Sustained contraction with no relaxation
In vivo-what sustatins a contraction?
the asychronous activation of motor units
What are the types of skeletal muscle fibers?
Type 1-slow twitch
Type 2-Fast twitch
How quickly does a Type 1 muscle fiber generate max force?
in 100ms
How quickly does a Type 2 muscle fiber generate max force?
in 10ms
What is muscle fiber contraction speed?
How quickly to max force after stimulus
What determines the contraction speed of muscle fibers?
Different ATPases
Oxidative ATP synthesis in muscle fibers makes the muscle?
red, with many mitochondria and myoglobin and well vascularized
~30 ATP per glucose molecule
Glycolytic ATP synthesis in muscle fibers makes the muscle?
White , few mitochondria and myoglobin, large stores of glycogen + glycolytic enzymes
~2 ATP per glucose mol.
Fibers are largers than oxidative
