Physiology Unit 2: Endocrine and Skeletal Muscle
Draw/explain how hormones are released from hypothalamus to ant. pituitary
- neurons in hypothalamus release hormones into first capillary bed at median eminence - these hormones are referred to as HYPOPHYSIOTROPIC hormones (tropic means to effect secretion of) - these hormones are carried in blood vessels down to second capillary bed in anterior pituitary - there are a bunch of cells in ant. pituitary that the he hypophysiotropic hormones bind to these cells which causes anterior pituitary hormones to be released into venous system to body p. 145
explain hormonal control during the mid-follicular phase
- one follicle becomes dominant around DAY 7 - the dominant follicle around day 7 starts to express LH receptors in its granulosa cells so LH can stimulate granulose cells to secrete estrogen - estrogen acts as a paracrine agent and binds to nearby granulosa cells and causes them to grow/divide and secrete more estrogen. Positive feedback loop is causing granulosa cells to survive and thrive - there is not need for FSH to be secreted because of LH and the local pos. feedback loops from estrogen - we want other follicles to die because we only want 1 baby at a time, reason FSH decreases p. 200
What is a sarcomere?
- one unit of the repeating thin and thick filament pattern within the myofibril is called a sarcomere - the sarcomere is the "functional unit of muscle" (the smallest unit that still retains contractility) - from Z line to Z line is one sarcomere (2µm)
Where are posterior pituitary hormones synthesized?
Post. Pituitary hormone are synthesized in the HYPOTHALAMUS within the cell body's of the magnocellular neurons - Post. Pituitary is the site of release into bloodstream
What is another name for the posterior pituitary, why?
Posterior Pituitary or Neurohypophysis - neuro = it's part neural tissue - forms from the hypothalamus invaginating downwards
What is the primary adrenal insufficiency? - causes and results?
Primary Adrenal Insufficiency: ADDISON'S DISEASE - primary means the defect is at the adrenal gland itself - Caused by: destructive tumors, infection (tuberculosis), or autoimmune destruction (most common) - Results in: low blood pressure, low blood sugar, HIGH plasma ACTH and high plasma CRH ( because we loose the neg. feedback from cortisol onto ant. pituitary and hypothalamus)
how do other peptide growth factors in organs effect growth - give an example
ex.: BDNF = brain derived neurotrophic factor - paracrine and autocrine agents that stimulate localized cell differentiation and stimulate cell division of certain cell types of various organs. - Also growth inhibiting factors in certain tissues
extensor
extensor: increases angle at joint (lengthen) = triceps
flexor
flexor: decreases angle at joint (bend)= biceps
A band
full length of thick filament
What does "genesis" and "lysis" mean
genesis = to create something lysis = to break something down
what is hCG and what are 5 fun facts about it
hCG = Human Chorionic Gonadotropin 1. secreted by developing embryo 2. the basis for pregnancy test 3. rescues corpus luteum (LH-like) (because corpus luteum is what's secreting estrogen and progesterone) 4. mediated implantation 5. turns on testosterone production in male fetus testes
What stimulates the testes in utero?
hCG stimulates testes in utero - there's no LH yet
bulbourethral glands
lubricating mucus
Equations to know for lever systems
(A+B)∙C = X ∙A A= position of elbow joint to insertion of tendon B= insertion of biceps muscle to load C= Load X= tension in Bicep Muscle Vh =( (A+B)/A)∙Vm (see page. 236) Vh = hand velocity Vm = muscle contraction velocity
What happens in the Proliferative phase?
(building endometrium back up) - increased estrogen - increased growth/proliferation of epithelial cells, glands, and blood vessels of endometrium and myometrium - increased # of PROGESTERONE receptors in endometrial cells (estrogen increases # of progesterone receptors in endometrial layer. This is called "estrogen Priming"
Functions of Cortisol in Stress?
(general physiological preparation for a disaster) see page. 162!
fimbriae
(notice that the ovary doesn't touch the fallopian tube) - the fimbriae are finger like projections that are lined with cilia that beat and have a whip like patterns to draw the released egg into the fallopian tube
spermatozoan
(sperm)/ male gamete (sperm is produced in the testes)
Steroidogenic pathways in the corpus luteum
- "old theca cells" produce androgens from cholesterol - "old granulosa cells: produce estrogen from androgens and produce progesterone from cholesterol - both cells are stimulated by LH p. 202
Why is skeletal muscle so big and expensive?
- 30% (in females) and 40% (in males) of total body mass - #1 consumer of nutrients, O₂, (uses LOTS of ATP!) (uses lots of glucose and O₂ to generate ATP) - high metabolism produces abundant wastes that tend to disrupt ECF homeostasis fun facts: - there are 640 skeletal muscles that each have name - gluteus maximus is the biggest - stapedius muscle in ear is smallest
what is a cause and results of thyroid hormone disruption?
- Agricultural pesticides alter thyroid hormone levels, memory, and immune function in mice. - children in agricultural regions of Sonora, Mexico have serious deficits in motor and cognitive skills compared to kids in the foothills - hypothyroid levels in children ->cognitive defects
End Plate Potentials (EPP's)
- HUGE graded potentials - EPP's are always Excitatory; Depolarize 30-50mV (No IPSP's) - always ACh binding to Nicotinic ACh receptors
how does insulin-like growth factors (IGFs) effect growth
- IDFS are structurally similar to insulin, but IGFs have a different function than insulin - IGFs act as an autocrine or paracrine substance to stimulate the differentiating chondrocytes to undergo cell division
How Does TH control BMR and body temp.?
- MAINLY BY INCREASED Na⁺/K⁺ ATPase - every cell has Na⁺/K⁺ ATPase and it is the number 1 energy burner - T₃ stimulates carbohydrate absorption from intestine and increased fatty acid release from adipocytes provide energy for high metabolism - a decrease in ATP triggers glycolysis which causes heat production - decrease in TH causes decreases in heat production which causes decreases in body temp. and causes decrease in physiological processes
Overview of steps involved in Steroid Hormone Synthesis
- PKA cascade for steroid hormones in adrenal cortex - need to get cholesterol in cell to be made into final steroid hormone - cholesterol is made into final steroid hormone by several enzymatic conversions and PKA cascade - final steroid hormone diffuses into blood (all steroid hormones are hydrophobic and travel out of cell into blood. they have transport proteins in blood) p. 158
How does Thyroid Hormone effect B-adrenergic receptors?
- TH is permissive of B-adrenergic receptors (catecholamines like NE and Epi) expression - lots of other cells besides adipocytes express B-adrenergic receptors including: -heart "racing heart" - brain "anxiety, nervousness" (T₃ upregulates B-adrenergic receptors in many tissues, notably the heart and nervous system) - Therefore, high levels of TH can cause sympathomimetic effects (symptoms of excess Epi and NE (sympathetic NS effects) even at normal levels of Epi and NE - T₃ potentiates the actions of catecholamines - people with excess T₃ are treated with drugs that block B-adrenergic receptors to relieve sympathetic activity p. 151
explain development of a goiter
- TSH is TROPIC and TROPHIC - enlarged thyroid gland due to increase in size and # of follicular cells - result of excess TSH receptor activation p. 154
what are 3 inputs that control hormone secretion
- ions or nutrients (negative feedback) - neurotransmitters - hormones (hormones can cause release of other hormones) p. 141
how does testosterone effect growth?
- Testosterone stimulates GH and IGF-1 secretion especially at puberty - stimulates protein synthesis and muscle growth (one reason why men are typically larger than women) This is also why some athletes use androgens called anabolic steroids in an attempt to increase muscle mass and strength - prolonged exposure eventually triggers closure of epiphyseal plates (all the chondrocytes get converted to bone and there's no more growth - you reach adult height) - testosterone begins puberty growth spirt and at the end of puberty it triggers closure of epiphyseal plate.
draw/explain what makes up a thin filament structure
- actin molecules (G-actin) polymerize together to create F-actin (2 strand pearl necklace) - each actin molecule has a binding site for attachment with myosin cross bridge - actin is the main protein of thin filaments but there are 2 others with important regulatory functions: Tropomyosin: rope like protein. one tropomyosin spans 7 actin monomers Troponin: mickey mouse head with 3 little subunits. 1 troponin for every tropomyosin (1 troponin for every 7 actin monomers) - p. 210
What Environmental Factors influence growth
- adequate nutrition (especially protein) - freedom from chronic illness/disease (chronic illness/disease causes secretion of cortisol - antigrowth hormone) - freedom from chronic psychosocial stress (stress releases cortisol; catch up growth can happen to reach normal height) - sleep (growth hormone follows circadian rhythm pattern. growth hormone is releases a couple hours after falling asleep) there are also several hormones important to human growth...
What is the main (broad)action of thyroid hormone?
- affects virtually every cell -> increase gene transcription and PROTEIN SYNTHESIS -T₃ binds to promoter region of target genes -> mRNA -> synthesis or new protein -> physiological effects - the actions of T₃ are widespread and affect many organs and tissues. Like steroid hormones T₃ acts by inducing gene transcription and protein synthesis p. 150
draw and explain the follicular phase of the ovarian cycle
- before birth the primary oocytes exist as primordial follicles - in childhood and during the menstrual cycle, a portion of the resting primordial follicles progress to primary/preantral/early antral follicles (more mature follicles) - in the growing follicles, granulosa cells (with help from theca cells) secrete ESTROGEN to nousih the primary oocytes - at beginning of menstrual cycle, 10-25 of the early antral follicles begin to enlarge, but only one survives = dominant follicle - throughout a woman's reproductive life, only ~ 400 follicles reach the mature follicle stage and release the oocyte (ovulation). The rest undergo "atresia" (cell death) - just prior to ovulation, the primary oocyte completes it first meiotic division to yield a secondary oocyte Primordial Follicle -> Primary Follicle -> Preantral Follicle -> Early Antral Follicle (contains antrum that stores estrogen) -> mature follicle (secondary oocyte) -> OVULATION! see top of p. 197
what is the isometric length-tension relation? - for passive tension and for active tension
- besides twitch summation (increase in AP frequency), the length of a muscle fiber before the onset of contraction determines how much tension is developed - passive tension increases as you increase stretch of the muscle fiber. Active tensions is different... (see page. 223) - resting skeletal muscle fibers are at or near their L₀ (optimal length), allowing them to develop greater tension when stimulated - optimal length is the length of a muscle fiber when it's able to achieve the greatest tension (titin is one thing that allows muscle fibers to be at their optimal length)
development of the external genitalia in males and females
- can' really differentiate males and females between 6 to 8 week - at about 10 weeks some structures start to differentiate between male and female - at 12 week fetal development, you can see typical male and female external genitalia - Male and female have HOMOLOGOUS structures (see page 188) - urethral orifice in men (where urine is expelled form body) is same duct for semen to exit body - in female urethral orifice (where urine exits) is different from vaginal orifice, so these 2 duct systems are separate from each other
H zone
- center of sarcomere - in between ends of thin filaments
What happens in "the sliding-filament mechanisms of muscle contraction"
- cross bridge and thin filament movement - rotating cross-bridge - the LENGTH of the muscle MAY or MAY NOT CHANGE!! - during isometric contractions, length of muscle doesn't change. Cross bridge necks undergo movement but the movement is absorbed in the neck Shortening (Concentric) - the sliding of thick filaments past overlapping thin filaments shortens the sarcomere w/ no changes in thick or thin filament length - the I Band and H zone are Reduced!! (shortening of sarcomere) p. 219
Draw/explain hormonal control leading to ovulation
- dominant follicle is secreting lots of estrogen, at some point before ovulation, estrogen reaches a plasma concentration in the blood. All of a sudden estrogen induces a pos. feedback loop onto the hypothalamus and ant. pituitary and this causes a large increase in LH and a small increase in FSH - "LH Surge"!! top of p. 201
Draw/explain the characteristics of a thick filament structure
- each myosin molecule contains a long rod-like segment facing the center of the sarcomere (M-line) and 2 cross-bridge heads that extend out towards the overlying actin - each cross-bridge head has 2 binding sites - one for ACTIN and one for ATP; the ATP binding sites serves as an ENZYME that hydrolyzes ATP (this is what allows for contractions to occur) - inside the cross bridge head are light chain regions, these are regions that are subject to regulation. Where phosphate groups can be added to change function of myosin top of p. 210
fertilization and implantation
- fertilization (within 24-48 hours) of ovulation - implantation (6-10 days post-fertilization, days 20-24 of menstrual cycle) (implant in uterus as a blastocyst) - once this occurs, Estrogen and Progesterone levels must stay high to prevent degradation of uterine lining... (E and P levels stay high from hCG secreted by developing embryo)
What stimuli control insulin secretion? - how do they control insulin secretion (draw/explain)
- glucose (primary stimulus) - free fatty acids - amino acids - GLP (incretin) - achetycholine (parasympathetic activity) see page. 177 and notes!
What is Rigor Mortis?
- gradual stiffening of skeletal muscles that begins several house after death and reaches a maximum after about 12 hours - caused from No ATP after death - in absence of ATP, Ca²⁺ leaks out of SR and can't be pumped back in, so binding sites on actin are exposed and cross-bridges bind and undergo power stroke - the thick and thin filaments remain bound to each other by immobilized cross-bridges - the stiffness of Rigor Mortis disappears about 48-60 hours after death as the muscle tissue decomposes
categories of chemical messengers
- hormone - Neurotransmitter - paracrine substance - autocrine substance p. 135 Certain chemical messengers can belong to more than one of these categories - ex. Somatostatin, can act as hormone and paracrine substance
Inputs to the hypothalamus
- hormone - peripheral receptors (pain, touch, temp. suckling) - higher centers (emotions) - special senses (light/dark) (circadian rhythms) - blood conditions ([glucose], osm, temp.) p. 146
Overview of Hormones from the Hypothalamus and Anterior Pituitary
- hypophysiotropic hormones - most of these hormones exist in 3 hormone cascades (hypothalamus -> ant. pituitary -> 3rd endocrine gland) see page. 145
How does Epinephrine from the adrenal medulla (and NE from nerves) stimulate glucose?
- in fight or flight we release Epi and NE to mobilize energy sources in order to send them to different tissues throughout the body, so our tissue can use glucose, fatty acids, and other amino acids to generate ATP to support their functions - epinephrine targets skeletal muscle, liver, and adipose tissue - NE (released form axon terminals in Sympathetic NS) targets Liver and adipose tissue top of page. 180
pathway of steroid hormone into cell
- in order to get hormone into target cell, the hormone has to unbind from its carrier proteins and is free to diffuse across plasma membrane of target cells -> goes into nucleus -> binds to receptor -> receptor is often translocated into DNA -> increase transcription of mRNA -> mRNA synthesized into proteins (this is the cellular response) - the bind of steroid hormone to receptor is often to increase or decrease the synthesis of new proteins p. 138
Z line (disc)
- interconnected proteins that run perpendicular to longitudinal axis of cell - from Z line to Z line is one sarcomere
M line (disc)
- interconnecting proteins. Serve as attachment point for thick filaments - M line allows thick filaments to stay at center of sarcomere
Draw/explain how hormones get from hypothalamus to posterior pituitary?
- oxytoxin, ADH, and NP are called post. pituitary hormones even though they are synthesized in the cell body (in hypothalamus) - pre-prophormone synthesis in ER followed by packaging into secretory granules in Golgi Apparatus occurs in cell body of Magnocellular Neurons (have big axons) - all the way up and down the axon, there are microtubules that have transport proteins that takes vesicles containing hormones - these transport proteins takes the vesicle and walks down the microtubule and places vesicle in axon terminal where the vesicles are stored until they are stimulated to cause calcium induced exocytosis of that neurohormone p. 144
What is the reasoning for polar bodies in ovary but not in testis
- polar bodies are suppose to degenerate/undergo cell death - a primary oocyte in ovary is only suppose to give rise to 1 ovum - a primary spermatocyte in tests is suppose to give rise to 4 gametes (4 sperm cells)
Explain Differentiation of the gonads
- primordial gonads are undifferentiated until after the sixth week of uterine life - during the seventh week, a gene on the Y chromosome, the SRY GENE, is expressed and the testes begin to develop in the genetic male (SRY = Sex-determining Region on the Y chromosome) - absence of the Y chromosome, and thus the SRY gene, causes ovaries to develop in the same area in the genetic female
What can cause Growth Abnormalities?
- problems in hypothalamus or Anterior Pituitary can decrease GH and decrease IGF-1 - insensitive GH receptors - Lack of IGF-1 secretion or insensitive IGF-1 receptors
functions of the endocrine system
- regulates electrolyte (Na⁺, K⁺, Cl⁻), water, and nutrient balance (ADH, aldosterone, insulin, glucagon - coordinates the responses to stress (cortisol, epinephrine) - regulates growth and development (growth hormone, IGFs) - regulates reproduction (estrogen, progesterone, testosterone) - regulates cellular metabolism/energy balance (thyroid hormone, insulin, glucagon) - regulates digestion and absorption of food (insulin, glucagon, and GI hormones in unit 4)
What are the 3 types of muscle?
- skeletal muscle (relatively big compared to cardiac and smooth) - cardiac muscle - smooth muscle
What are the molecule mechanisms of skeletal muscle contraction?
- skeletal muscle is an "excitable tissue" that propagates ACTION POTENTIALS along its membrane (sarcolemma) - complex processes connect action potentials along a motor neuron to the generation of force by cross-bridges
how do estrogens/DHEA effect growth?
- stimulates GH and IGF-1 secretion especially at puberty - prolonged exposure eventually triggers closure of epiphyseal plates
what hormone is decreased during stress?
- stress decreases the level of insulin - insulin is a storage hormone; with less insulin, the levels of glucose, fatty acids, and amino acids in the plasma increase to support energy needs of cells
Peptide/Protein Hormones: - structure - solubility - synthesis - storage - secretion - transport - receptor location - onset of effect - lifetime
- structure: peptides/string of amino acids (majority of hormones) (a.a's can range in length from 3 to 100's) - solubility: hydrophilic (lipophobic) (non-membrane permeant). like watery ECF and ICF but don't like getting across plasma membrane - synthesis: in ER and Golgi - storage: packaged into vesicles (many stored as prohormones) - secretion: exocytosis of pre-packaged vesicles upon stimulation (contains hormone and any "pro" fragments which can have additional effects in body) - transport: dissolved in plasma as free hormones (soluble in plasma and don't need help being carried in bloodstream) - receptor location: plasma membrane of target cells, which then initiates second messenger signaling cascades - onset of effect: mostly fast (modification of existing proteins ) minutes - lifetime: metabolized/excreted quickly (can leave plasma by enzymatic attack. the receptor with hormone can be endocytosed into cell and then the hormone chewed up releasing receptor back to membrane) p. 137
Steroid Hormones - structure - solubility - synthesis - storage - secretion - transport - receptor location - onset of effect - lifetime
- structure: synthesized from cholesterol molecules - solubility: hydrophobic (lipophilic) (membrane permeant) - synthesis: modification of cholesterol IN CELL - storage: Not stored, must be synthesized upon stimulation (the vesicle is basically membrane so they diffuse right away via exocytosis - secretion: simple diffusion (rate of secretion = rate of synthesis) - transport: require plasma protein carriers for transport in blood - receptor location:inside target cells (usually in the NUCLEUS) - onset of effect: Slower (protein synthesis takes longer) hours/days - lifetime: metabolized/excreted slowly (because they are protected by carrier proteins, they're less likely to be chewed up by enzymes so they have longer lifetime) p. 138
Isotonic Contraction
- tension development - XBs cycle - CHANGE IN LENGTH - type types: concentric and eccentric
Isometric contraction
- tension development - XBs cycle - SAME LENGTH tension = load OR Load >>>> Tension (ex. trying to move a big table)
What is the Ovarian Cycle - draw timeline
- the 28-day cycle is an elaborate hormonal pacemaker starting at puberty and stopping at menopause (interrupted by pregnancy) - After puberty, the ovary alternates between 2 phases (with OVULATION in-between on day 14) 1. The Follicular Phase - produce a mature follicle (first 14 days) 2. The Luteal Phase - prepare for pregnancy if fertilization occurs bottom of p. 196
How is sex determined?
- the complete genetic composition of an individual is known as the GENOTYPE - genetic inheritance sets the sex of the individual, or SEX DETERMINATION, which is established at the moment of fertilization - sex is determined by genetic inheritance of 2 SEX CHROMOSOMES: the X chromosome (larger) and the Y chromosome (smaller) - a typical male is 46, XY male and typical female is 46 (XX) female - 46 = total number of chromosomes in each nucleated cell; genotype -Letters = indication of the sex chromosomes; genotype - Male/Female = indication of the phenotype (development of genitalia which determines appearance and function)
What is the Dystrophin Glycoprotein Complex in Skeletal Muscle
- the dystrophin-glycoprotein complex provides a structural link between the cytoskeleton (actin) and the extracellular matrix. This stabilizes the sarcolemma and prevents contraction-induced rupture - keeps actin aligned - allows for structural integrity p. 211
What causes differentiation of male and female internal and external genitalia?
- the internal duct system and external genitalia of the fetus are capable of developing into either sexual phenotype - before week 7 of fetal life, the reproductive tract includes a double genital duct system comprised of WOLFFIAN ducts and MULLERIAN ducts; usually, most of the reproductive tract develops from only one of these duct systems - in males: wolffian ducts persists and mullerian ducts regress - in females: mullerian ducts persist and wolffian ducts regress
What is Sex Differentiation?
- the multiple processes involved in the development of the reproductive system in the fetus is called SEX DIFFERENTIATION - the genes (GENOTYPE) directly determine only whether the individual will have testes or ovaries. Sex differentiation determines, in part, sexual appearance and function (phenotype) - sex differentiation depends upon the presence or absence of substances produced by the genetically determined gonads, particularly the testes
What happens to the secondary oocyte?
- the secondary oocyte is ovulated and then fertilized if sperm are present - sperm entry into the secondary oocyte triggers the 2nd meiotic division to yield a mature ovum -> ZYGOTE -if a woman never gets pregnant in her lifetime, she never actually produces a mature ovum because fertilization is required to get from secondary oocyte to ovum
how do thick and thin filaments arrange themselves?
- thin actin filaments arrange themselves in hexagon around each myosin thick filament - thick filaments arrange themselves in triangular pattern around each thin filament ~ there are about twice as many thin filaments as there are thick filaments p. 209
What is gluconeogenesis - is it anabolic or catabolic?
- to crease new molecules of glucose - Amino acids/pyruvate/lactate/glycerol -> Glucose - catabolic (in order to make new glucose, we have to use other fuel molecules that are broken down first. ex. proteins can break down into a.a.'s or fats into glycerol to make new glucose)
what is the reasoning for 2 meiotic divisions?
- we want to get gametes (4 sperm cells in male and one egg/ovum in female) - want the DNA to have 23 chromosome each with a single chromatid - so that sperm fusing with egg gives a zygote with 46 chromosomes each with a single chromatid
motor unit
-each skeletal muscle fiber is stimulated by only one alpha motor neuron, but one alpha motor neuron branches to activate a MOTOR UNIT - a single motor unit can range in size from 3-1,000 fibers
what regulates glucagon
-like insulin, glucagon is not regulated by the pituitary (no "endocrine hierarchy") - it's main stimulus is a decrease in plasma glucose, which is an organic nutrient - unlike insulin, glucagon is supported by many other hormones in its glucose mobilizing role... - stimulated by hypoglycemia and there are lots of other hormones stimulated by hypoglycemia
What is lipogenesis - is it anabolic or catabolic?
-making fats/triglycerides - fatty acids/monoglycerides -> triglycerides - anabolic
steps of the cross bridge cycle
1. (Ca²⁺ rises) cross-bridge binds to actin (A∙M∙ADP∙P) 2. Cross Bridge moves (A∙M) (ADP and P are kicked off) 3. ATP binds to myosin, causing cross-bridge to detach (ATP is an allosteric modulator of the myosin head that weakens the binding of myosin to actin) (A + M∙ATP) 4. Hydrolysis of ATP energizes cross-bridge (A + M∙ADP∙P) see top of p. 220
What are the roles of skeletal muscle in maintaining homeostasis?
1. Acquisition of nutrients/fuel (skeletal muscle allows us to get food "hunt") 2. processing food (chewing, swallowing) 3. Breathing (ex. Diaphragm, the main muscle of respiration) 4. escape from harm 5. generation of heat for temperature control (ex. shivering-rapid contractions of skeletal muscle) 6. source of amino acids for times of famine (proteins can be broken into a.a.'s which can turn into glucose)
What are 4 (more specific) actions of Thyroid Hormone?
1. Controls basal metabolic rate (BMR) and thus body temperature (BMR = rate at which cells burn fuel to maintain basic life functions) - mainly by increased Na⁺/K⁺ ATPase 2. Permissive of B-Adrenergic Receptors (catecholamine- NE and Epi) expression 3. Essential for fetal CENTRAL NERVOUS SYSTEM development and function; important for adult nervous system function 4. Permissive for overall growth and development; TH is needed for normal production of growth hormone from anterior pituitary p. 151 and 152
4 types of endocrine disorders
1. Hypersecretion: caused by tumors that ignore negative feedback (primarily) or abnormally increased amount of tropic hormone (secondary) 2. Hyposecretion: gland destruction (primary) or loss of tropic hormone (secondary) 3. Hyperresponsiveness: receptor upregulation or second messenger pathway activation (can lead to overstimulation of cell) 4. Hyporesponsiveness: receptor downregulation (not as many receptors on target cell as we should have and target cell doesn't respond to hormones as it should because there aren't as many receptors)
What 8 hormones influence growth?
1. growth hormone 2. insulin-like growth factors (IGFs) 3. insulin 4. thyroid hormone 5. testosterone 6. estrogens/DHEA 7. other peptide growth factors in organs (e.g. BDNF) 8. cortisol
what are the 3 chemical types of hormones?
1. peptides/proteins (majority of all hormones are peptide/protein hormones) 2. steroids (not many) 3. amines (not many) - memorize steroids and amines, then the remaining are peptide/protein hormones
Characteristics of Hormone Receptors
1. they determine which tissues respond to an endocrine "broadcast". (only target cells with receptors are going to bind to specific hormones) 2. High sensitivity (10⁻¹² M!) picomolar "low concentration" - receptors are highly specific with high affinity. receptors can respond to low concentrations of circulating hormones 3. Huge signal amplification (because of signal transduction mechanisms) 4. Hormone levels influence expression of their own receptors: - continued High [Hormone] -> Down-regulation to prevent overstimulation - continued Low [Hormone] -> Up-Regulation 5. Hormones can have a PERMISSIVE effect on expression of OTHER hormones' receptors...
What are the 10 actions of testosterone?
1.) Differentiation and DESCENT of testes 2.) Growth/development of genitalia, glands - increased thickness of skin, more RBCs (stimulate erythropoitin to develop RBC's) (males tend to have more Red blood cells because of higher testosterone) 3.) spermatogenesis: FSH, LH and testosterone required 4.) pubertal Growth Spurt (start and stop) (closes epiphyseal growth plates) 5.) male pattern of muscle:fat (allows typical male characteristics) 6.) growth of larynx/vocal cords (male vocal cords tend to be thicker and longer, hence lower pitch of voice) 7.) Pubic/axillary/Facial Hair (back, ear, nostrils) 8.) male pattern baldness (testosterone is taken up within cells in the head and converted to dihydrotestosterone in certain males and DHT is thought to cause male pattern baldness) 9.) establishment and maintenance of sex drive 10.) aggressive behavior? (higher than normal levels of testosterone maybe lead to aggressive behavior)
What are the 3 uterine phases in the menstrual cycle? - draw uterine phase with, ovarian phase, day, endometrial thickness and ovarian event
1.) Menstrual Phase 2.) Proliferative Phase 3.) Secretory (Progestational) Phase - top of page 203
what are 2 kinds of thyroid hormones?
1.) T₄ - (thyroxine), also called tetraiodothyronine - named for number of iodide molecules attached to hormone - 90% of secretion - "storage pool" in blood - converted to T₃ in target cells (by deiodinases) (peripheral conversion via thyronine-specific deiodinases (an enzyme that strips away 1 iodide molecule in T₄ to make T₃)) 2.) T₃ (triiodothyronine) - most active form (i.e. bound to receptors in target tissue)
Isotonic Load-Velocity Relationship - what are the 3 main comparisons to make between various loads?
1.) at heavier loads, shortening velocity gets slower 2.) at heavier loads, the distance shortened, decreases 3.) at heavier loads, the duration of the isotonic twitches are less p. 225
The "LH Surge" brings about 4 major changes in the follicle: what are they?
1.) it temporarily halts estrogen secretion and increases progesterone secretion by the granulosa cells 2.) it reinitiates meiosis in the oocyte of the developing follicle (completion of first meiotic division) (causing primary oocyte to turn into secondary oocyte) 3.) triggers production of locally acting prostaglandins, which induce ovulation by causing swelling of the follicle and enzymatic digestion of the follicular wall (causes chewing of hole in follicle and ovarian wall to allow secondary oocyte to be ovulated) 4.) causes differentiation of granulosa/theca cells into LUTEAL CELLS. (terminates follicular phase and initiates luteal phase)
What are 2 major targets of insulin?
2 major targets of insulin are muscle and adipocytes (muscle and fat cells) - muscle is 40-50% of body mass and fat is another additional fraction of body mass - insulin targets muscle and fat cells to promote glucose uptake to lower plasma glucose
NMJ Notables
2,000 - 10,000 ACh molecules per quantum (per vesicle) + 1 AP in presynaptic terminal releases 200-300 vesicles + 20 million nACh receptors in the NMJ = End Plate Potentials (EPP's) that are HUGE graded potentials 1 alpha motor neuron AP = 1 muscle fiber AP (safety factor) p. 216
draw/explain the pathway for the pattern of reproductive control in both males and females
bottom of page. 191
What is another name for Anterior Pituitary? - and why
Anterior Pituitary = Adeno-hypophysis - adeno = glandular structure (the anterior pituitary comes from tissue in back of throat) - hypophysis = pituitary
Functions of Anti-Diuretic Hormone (ADH) (vasopressin)
Anti-Diuretic Hormone: - water retention via kidney (keeps water) - constriction of smooth muscle in blood vessels
Although the arm is at a mechanical disadvantage for strength, this "set-up" allows for amplification of ___________________?
Amplification of VELOCITY and RANGE OF MOVEMENT
What is ACTH, is it hydrophilic or hydrophobic?
ACTH = Adrenocorticotropic Hormone - hydrophilic
What is glycogenolysis - is it anabolic or catabolic?
Glycogen -> Glucose - catabolic
What is glycogenesis - is it anabolic or catabolic?
Glycogenesis is making glycogen Glucose -> Glycogen - anabolic
explain Androgen Insensitivity Syndrome (a disorder of sexual differentiation)
Androgen Insensitivity Syndrome (a disorder of sexual differentiation) - genotype = male - phenotype = female (46, XY female) - mutations in androgen-receptors - no internal ducts system develops (infertile) - FEMALE external genitalia and a vagina develop top of page. 190
Fallopian Tubes
Fallopian tubes = oviducts - this is where fertilization usually happens
What are 2 types of growth abnormalities(involving too much GH)? - symptoms
Acromegaly - too much GH AFTER epiphyseal plates close - can have symptoms like diabetes, too much GH leads to excessive levels of plasma glucose and elevated fatty acids - they could be average height, but their bones become much thicker, especially in the hand, feet, and face. Thickened skin and internal organs can continue to enlarge - many have cardiovascular problems because heart keeps growing but Rib cage can't grow Gigantism - too much GH BEFORE epiphyseal plates close - ex. Rober Wadlow (really tall!)
Active tension vs. Passive Tension
Active Tension = cross-bridge cycling (what we've been talking about) Passive Tension = mostly comes from stretching of the protein titin - stretching muscle fiber (like rubber band) - titin is a coiled protein that attaches thick filament to Z-line
What happens in the Luteal Phase of the Ovarian Cycle?
After ovulation, old granulosa and theca cells collapse and form the CORPUS LUTEUM (corpus means body and luteum means yellow. It's called yellow body because it becomes a storage site for cholesterol (fatty cholesterol is yellow). - cells hypertrophy, becomes active steroidogenic tissue - secretes estrogen and lots of PROGESTERONE (both are steroid hormones that need cholesterol to be synthesized) - storage site for lots of cholesterol - becomes vascularized - if No fertilization -> corpus luteum dies and becomes corpus albicans
What are the main events of the Absorptive and Postabsorptive states
Anabolism: "building up" - (anabolic steroids) - dominant during the ABSORPTIVE STATE (fed state) - fuel molecules must be stored Catabolism: "breaking down" to extract energy - dominant during the POSTABSORPTIVE STATE (fasted state) - occurs ~4 hours after eating a meal, during a fast, or when energy requirement is not being met by available stores - rely on stores from liver, fat(adipose tissue) and muscle - food intake is variable, but blood/ECF nutrient levels must remain relatively constant (15 minutes without blood glucose kills neurons)
additional effects of gonadal steroids (as well as adrenal androgens)
At Puberty: - stops bone growth (DHEA starts growth spurt) - development of breasts, genitalia - pelvis widening - female fat distribution (breasts, hips, subcutaneous) Other Roles: - osteoblast activation (build bone) - permissive of vasodilation (estrogen) - protection from atherosclerosis (estrogen) (estrogen is important in helping to build bone, which is why people in menopause suffer from osteoporosis because they loose estrogen. After menopause w/estrogen levels decrease, atherosclerosis and heart disease can increase)
Biceps and triceps are _________?
Biceps and triceps are ANTAGONIST - both exert pulling force and shortening of muscles, but in opposite direction
Draw the curves for muscle fiber action potential, intracellular Calcium concentration, and muscle contraction
bottom of page. 220
cervix
bottom of uterus, part that has to dilate 10 cm
What are the causes and results of thyroid disease HYPOTHYROIDISM?
Caused (mainly) by: iodine deficiency, thyroid damage, or autoimmune destruction (HASHIMOTO's disease, which is the most common cause) Results in: low metabolism, fatigue, decreased alertness, low heart rate, low blood pressure, weight gain, cold intolerance - also a GOITER may develop under hypothyroid conditions (the resulting overstimulation of the thyroid gland can produce goiters (abnormal enlargement of thyroid gland)
Name common steroid hormones and amine hormones
Common Steroid Hormones: - cortisol - aldosterone - testosterone - estradiol - progesterone - vitamin D Amine Hormones: - Catecholamines (Dopamine, Epinephrine, Norepinephrine) - Thyroid Hormone (T₃ and T₄) - the rest are likely peptide protein hormones
Concentric
Concentric = shortening - tension in muscle fiber is greater than load
explain Congenital Adrenal Hyperplasia
Congenital Adrenal Hyperplasia (a disorder of sexual differentiation) - virilization of an XX fetus (masculinized external genitalia) - see bottom of page 190 - XX newborn can have ambiguous genitalia - it is not obvious whether the baby is a phenotypic boy or girl
What is Contraction? - what are other words for it?
Contraction = activation of myosin cross-bridges to exert force on the thin filaments Contraction = Active Force Generation = Tension Development
What is Cortisol Hypersecretion? - cause and results
Cortisol Hypersecretion: Cushing's Syndrome and Disease - Caused by: hyper-secreting tumors (of adrenal or pituitary) - Results in: osteoporosis(too much bone resorption), thin skin ( & easily bruised because its protein poor. Cortisol is catabolic and breaks down proteins), muscle weakness, immunosupression, high blood sugar, high blood pressure, redistribution of fat (buffalo hump, moon-shaped face of fat, fat in abdomen, limbs tend to be relatively thin), prone to infertility
what is another name for cortisol hyposecretion?
Cortisol Hyposecretion = Adrenal Insufficiency - cortisol is released from adrenal glands. if adrenal glands are not releasing cortisol that's an insufficiency
how does cortisol effect growth?
Cortisol exerts anti-growth effects such as protein catabolism, decalcification of bone, and inhibits GH and IGF-1 secretion. (note: glucocorticoid treatment can stunt growth) - high GH + LOW(appropriate/normal level) Cortisol = Growth - High GH + HIGH Cortisol = Fuel mobilization, no growth - inhibits growth - stimulates protein catabolism
How does cortisol mobilize glucose
Cortisol is a catabolic hormone, it breaks down energy and doesn't allow for things to be stored up - see chart on page 180
draw the regulation of cortisol secretion - also draw the daily pattern of serum cortisol
Cortisol is considered the main "stress hormone" Page. 159
what are examples of steroid hormones? - what determines the type of steroid hormone?
Cortisol, aldosterone, testosterone, estradiol, progesterone, vitamine D - these are all steroid hormones. convertion of cholesterol into other steroid hormone depends on the cellular enzymes that are within the cells creating the hormones TYPE OF STEROID HORMONE IS DEPENDENT ON ENZYMES IN CELL MODIFYING CHOLESTEROL
What is Cretinism - what is another name for it?
Cretinism (now known as Congenital Hypothyroidism) - cretinism is when a fetus is not getting enough thyroid hormone - this syndrome is characterized by a poorly developed Nervous system and severely compromised intellectual function (mental retardation) - a common cause of congenital hypothyroidism is the failure of thyroid gland to develop normally or dietary iodine deficiency in mother (normal thyroid can't synthesize TH)
Cushing's Syndrom vs. Cushing's Disease
Cushing's Syndrome: anything that increases plasma cortisol - hypercortisolism and all of its effects, regardless of the original cause - the most common cause of Cushing's Syndrom is glucocorticoid (corticosteroid) therapy ex. little boy with resp. problems was given cortisol and developed Cushing's Syndrome Cushing's Disease: - a case of Cushing's Syndrome when the cause is identified as an ACTH-SECRETING TUMOR
what causes cyclic endometrial changes?
Cyclic uterine endometrial changes are caused by hormonal changes during the ovarian cycle
What is different about the hypothalamic neurons in ant. pituitary route compared to post. pituitary route?
Different group of hypothalamic neurons than post. pituitary. These neurons are entirely within the thalamus! - no part of neuron goes into infundibulum. Notice that these axon terminals end at capillaries in the median eminence
What are key proteins involved in excitation-contraction (EC) coupling
Dihydropyridine Receptors (DHPR): - VOLTAGE SENSOR within T-tubular membrane - (main functoin of DHPR is not to conduct Calcium but rather to act as a voltage sensor) Ryanodine Receptor (RyR): - Ca²⁺ channel within terminal SR membrane (forms calcium channel) - DHPR and RyR ARE CONNECTED!! (RyR includes foot provesses that attaches to DHPR) SERCA: (Ca²⁺ ATPase pump) within longitudinal SR membrane p. 217
What is Duchenne Muscular Dystrophy
Duchenne Muscular Dystrophy - complete absence of dystrophin protein - so actin isn't attached to anything how it should be and skeletal muscle undergoes lots of contraction and without structural integrity, repeated contractions can cause tears in the muscle and cause disarray of proteins ->impair muscle function and cell death
Eccentric
Eccentric = lengthening - the load is greater than the tension in muscle
Functions of Growth Hormone and IGF-1
End Results: enhances body protein, burns fat, prevents glucose storage see page. 169
What are endocrine glands
Endocrine glands are DUCTLESS (no duct) glands that secrete hormones -> into interstitial space -> into blood stream
what is the difference between endocrine and exocrine?
Endocrine glands release chemical substances directly into the bloodstream or tissues of the body.The chemical substances released by the endocrine glands are known as hormones. Exocrine glands release chemical substances through ducts to outside the body or onto another surface within the body.
are endocrine secreting tissues widely dispersed or shortly dispersed?
Endocrine-secreting tissues are widely-dispersed. Blood vessels connect the endocrine organs
What are functions of the adrenal catecholamines?
Epi reinforces SYMPATHETIC NS effects (NE) during "fight or flight" stress response: - increased hepatic and muscle glycogenolysis (provides a quick source of glucose) - increased breakdown of adipose tissue triglyceride (provides a supply of glycerol for gluconeogenesis and of fatty acids for oxidation) - increased cardiac function (e.g. increased heart rate) - diversion of blood from viscera to skeletal muscles by means of vasoconstriction in the viscera and vasodilation in the skeletal muscles - increased lung ventilation by stimulating brain breathing centers and dilating airways p. 157
Events at NMJ lead to ....?
Events at NMJ lead to skeletal muscle EXCITATION!
How does Calcium increase within the skeletal muscle cell?
Excitation-Concentration (EC) Coupling!
explain/draw Excitation-Contraction (EC) Coupling in Skeletal Muscle
Excitation-Contraction (EC) Coupling in Skeletal Muscle: 1. AP propagation into T-tubles (excitation) 2. DiHydroPyridine receptor tugs on Ryanodine Receptor 3. Ca²⁺ is released through RyR = increased cytosolic Ca²⁺ (Voltage-Induced Ca²⁺ Release)(VICR) 4. Ca²⁺ "activates" the thin filament, contraction occurs 5. Ca²⁺ ATPase actively transports Ca²⁺ back into SR see page. 218
What are fats transported in the blood by? - explain them
Fats are transported in the Blood by different types of LIPOPROTEINS - these are amphipathic molecules where the hydrophobic region faces the fat on the inside of lipoprotein and the hydrophilic protein is facing surface in order to allow these fat molecules to travel in the blood plasma - fats that are hydrophobic are at center of lipoprotein - there are different kind of lipoproteins( in order from small to biggest): HDL, LDL, VLDL, chylomicron
function of follicles
Follicles trap iodide for the synthesis of thyroid hormone (TH) - need iodide to have thyroid hormone built
What does glucagon do?
Glucagon is going to promote glycogen breakdown to free up glucose and put glucose into blood stream - glucagon also stimulates gluconeogenesis, so takes things like a.a.'s, glycerol, pyruvate, and lactate to be converted in the liver to glucose and that can be a source of blood glucose - fatty acids that are taken up by the liver can be converted into ketone bodies so glucagon stimulates the conversion of fatty acids into ketones and ketones can be released into blood plasma and all cells including cells of the NS can use ketones for their energy source - overall, glucagon increases plasma glucose and plasma ketones and this is a negative feedback loop to bring plasma glucose to normal homeostatic set point
Fuel metabolism
Fuel Metabolism: Reactions involving the degradation, synthesis, and transformation of the energy-rich organic molecules (fuels)
What are physiological functions basal levels of cortisol?
Functions of BASAL LEVELS of Cortisol - cortisol secreted in circadian rhythm pattern - before we even wake up in the morning ~ around 3 a.m., we spike the release of cortisol. These are basal levels of cortisol that are secreted every day even when we are not stressed out - these basal levels are important for certain functions for homeostasis to be maintained (listed below) 1. Metabolic effects: liver glucose production between meals (provides substrates and main enzymes in liver involved in in metabolic homeostasis to keep plasma glucose concentrations regular) - it's important that we always maintain certain level of glucose 2. Permissive of adrenergic receptors (receptors for Epi and NE) in the cardiovascular system (maintain blood pressure, reduce orthostatic hypotension (make sure there isn't a big decrease in blood pressure) - permissive of this receptor type in smooth muscle cells that surround blood vessels 3. Anti-inflammatory/anti-immune (prevent hyper-response) - cortisone/prednisone/dexamethasone - puts a break on immune system to set perfect level, so immune response doesn't cause damage 4. Fetal.Neonatal development of brain, intestines, lungs, glands - cortisol levels triple in pregnancy for fetal development!
Fused tetanus
Fused tetanus is maximal tension - the greatest amount of tension possible - 3-5 times grater than a single twitch - does not allow for relaxation
How does GH mobilize glucose?
GH has lot of same effects as cortisol, it stimulates gluconeogensis within liver, break down of fats, and inhibits glucose uptake by muscle and adipose tissue
pattern of growth hormone secretion throughout life
GH is secreted throughout life, never declines to 0 - GH has little effect on fetal growth but is the most important hormone for growth after the age of 1-2 years - high at childhood - peak at puberty - still need GH as adults, it never goes down to zero because it has important metabolic effects on glucose p. 166
Functions of Growth Hormone
GH promotes postnatal growth directly by: - stimulating cell differentiation and division (mostly in growing bone) - stimulating protein synthesis (muscle and liver) - STIMULATING SECRETION of IGF-1 (IGF-1 promotes most of the growth effects of tissues) GH metabolic effects include: - elevating blood glucose by preventing uptake into adipose and muscle tissue (inducing insulin resistance) (allows blood glucose to stay within blood plasma; does opposite of insulin) - elevating free fatty acids by stimulating lipolysis in adipose tissue (so cell can use fatty acids for ATP production) see page. 168
What does GHRH stand for? What does SST stand for? - what do they do?
GHRH = Growth Hormone Releasing Hormone (increases growth) SST = Somatostatin (which decreases growth) - they both affect GH secretion
How is GnRH secreted?
GnRH needs to be secreted in a pulsatile patterns. It has a burst of secretion and then stops, then another burst of secretion and then stops because if GnRH is present at high concentrations and it's not pulsatile then the cell types within ant. pituitary loose sensitivity to it. - has to be secreted in pulsatile manner in order for cells in Ant. Pituitary to be able to secrete FSH and LH
Gonadal Functions
Gonadal Functions: 1. Steroid hormone production (secrete sex hormones, testosterone in testes, estrogen and progesterone in ovaries) 2. Gametogenesis
What can Growth Abnormalities (involving too little GH) lead to?
Growth Abnormalities leads to SHORT STATURE (DWARFISM) - Short stature or dwarfism can be caused by several different causes, some could be due to local paracrine growth factors that don't allow tissues to grow properly - people with any problems with either GH or IGF-1 secretion of responsiveness are going to have stunted bone growth and poorly developed muscles because a decrease in amino acids uptake and decrease in protein synthesis, and tend to have excess subcutaneous fat because GH allows for fats to be be broken down and fat mobilization
describe signaling within the endocrine system
Hormone- secreting gland cell -> Hormone -> blood vessel -> target cells in ONE OR MORE DISTANT places in the body - there is also Neurocrine signaling: chemical product from nerve terminal into the blood (NEUROHORMONES = chemical product released into bloodstream) p. 135
definition of a hormone
Hormone: chemical messengers released into the BLOOD, which influence the activity of target cells that can be a considerable DISTANCE AWAY...
what are the signals of the endocrine system?
Hormones are the signals of the endocrine system
What are the causes and results of Thyroid Disease, Hyperthyroidism - what is another name for hyperthyroidism
Hyperthyroidism (or thyrotoxicosis) -caused by: tumors or GRAVES' disease (which is the most common cause), where TSI stimulates the TSH receptor on the thyroid gland leading to chronic overstimulation of the growth and activity of the thyroid gland (TSI = Thyroid-stumulating immunoglobulin) - TSI mimics TSH - TSI is an antibody produced in sick people. Nothing turns TSI off, it doesn't get neg. feedback Results in: nervousness, anxiety, increased heart rate, insomnia, weight loss, increased appetite, heat intolerance, goiter (TSI, like TSH is trophic), and exophthalmos(bulging of eye).. - increased sympathetic activity - can treat with radioactive iodine to kill tumor p. 155
What type of hormones are released in Ant. pituitary route?
Hypophysiotropic Hormones: - tropic means to effect secretion of - these are released into first capillary bed at median eminence - ex.) GnRH, GHRH, SST, TRH, DA, CRH Anterior Pituitary Hormone: - released in anterior pituitary to venous system - FSH and LH, Growth Hormone, TSH, Prolactin, ACTH
function of hypothalamus
Hypothalamus = master command center for neural output and endocrine output. - single most important control area to take in a lot of sensory afferent neurons about what's happening in body
What are the central endocrine glands
Hypothalamus and pituitary glands
What does the hypothalamus do?
Hypothalamus controls homeostasis!
What secretes IGF's?
IGF's are secreted by the Liver and other cell types all over the body
Functions of IGF-1
IGF-1 promotes postnatal growth in organs body-wide by: - stimulating cell division (hyperplasia) - stimulating protein synthesis (hypertrophy) Most of the growth effects are achieved by IGF-1 rather than GH directly see page 169
draw/explain the pathway from hypothalamus to posterior pituitary
If supraoptic and apraventricular nuclei get enough EPSP's for initial segment to hit threshold, then they're going to fire Action potentials. - the axons travel down infundibulum and then the axon terminals stop at the capillary bed in the post. pituitary - There are chemical messengers stored in vesicles within the axon terminals and those chemical messengers can be secreted in the bloodstream as "hormones"! - these hormones are taken into venous circulation and can be carried within rest of body p. 144
explain thin filament regulation of skeletal muscle contraction
In a relaxed Muscle - low cytosolic Calcium - troponin pushes tropomyosin to cover cross bridge binding sites along actin filament so cross bridges can't bind to actin pearl - energized cross-bridge cannot bind to actin In an Activated Muscle - high cytosolic calcium - calcium binds to binding site on troponin (troponin C subunit) which changes troponin shape and troponin stops pushing on tropomyosin so it moves out of the way - cross bridge binding sites are exposed - cross bridge binds to actin and generates force for contraction to occur Increasing calcium leads to contractility - the myosin cross-bridge and actin can physically interact to cause the muscle to CONTRACT p. 212
What does Permissive effect mean?
In endocrinology, permissiveness is a biochemical phenomenon in which the presence of one hormone is required in order for another hormone to exert its full effects on a target cell. Hormones can interact in permissive, synergistic, or antagonistic ways.
What does exercise do to GLUT 4 transporters?
In exercising muscles, GLUT 4 transporters go to membrane without insulin stimulation (regular exercise improves Type II diabetes)
What is one way to increase tension development in muscle fibers?
Increasing AP frequency! - this in turn causes cytosolic calcium to be elevated longer; actin is available to myosin (increase in number of bound cross-bridges)
How does insulin effect growth
Insulin stimulates glucose and amino acid uptake into cells, favoring protein synthesis and growth - stimulates fetal growth - stimulates postnatal growth by stimulates secretin of IGF-1 - stimulates protein synthesis
What are Islets of Langerhans?
Isles of Langerhans are clusters of endocrine cells in the Pancreas - they contain α, β, and δ cells
What is LPL what is TG
LPL = lipoprotein lipase; an enzyme found in high concentration along capillary endothelial cells facing adipocytes. - used to chew up chylomicrons to free up fatty acids and glycerol TG = Triglycerides; the stored form of fats within adipocytes
What is the latent Period?
Latent period = the delay between the beginning of the AP and the initial increase in tension top of p. 217
Muscles, Bones and Joints are arranged in _________ systems
Lever systems
definition of "load":
Load = force exerted by an OBJECT on a MUSCLE ( = the object's weight)
Long-Loop Feedback
Long Loop Feedback: 3rd hormone feeds back and tells the anterior pituitary and hypothalamic hormones what to do p. 145
what maintains the estrogen and progesterone levels after ~ 3rd month?
Luteal Placental Shift happens ~ 3rd month - shifting from corpus luteum secreting estrogen and progesterone to the placenta doing it - hCG levels fall after ~3rd month but we have estrogen and progesterone that continues to climb. Because after 3rd month the placenta takes over and we don't need the corpus luteum in the ovary anymore
Draw/explain hormonal control during the luteal phase - try to draw out graph of concentration of all the hormones in the blood throughout ovarian cycle
Luteal phase is ovulation -> day 28 LH "maintains" the corpus luteum: - stimulates ongoing hormonal secretion of estrogen and progesterone - luteal phase is dominated by PROGESTERONE Corpus luteum is secreting lots of Estrogen, progesterone, and inhibin. These hormones have strong neg. feedback influence on hypothalamus and ant. pituitary causing LH and FSH levels to decrease see top of page. 202
What chooses the most efficient combination for motor task
Many different muscles cross most joints; they have different "gearing ratios" and fiber type proportions. The brain subconsciously "chooses" the most efficient combination for the motor task you consciously pan
Median Eminence
Median Eminence = where capillaries are - a juncture, the boundary between the hypothalamus on one side and the infundibulum on the other side - there are capillaries at the "median eminence" - where TRH and CRH are released - place where 1st hormones are released in 3 hormone series
What happens in the Menstrual Phase
Menstrual Phase = bleeding phase - estrogen and progesterone decrease because corpus luteum is dead - decreased estrogen and progesterone causes the release of prostaglandins, which cause vasoconstriction of uterine blood vessels and myometrial contractions (excess prostaglandins can lead to lots of cramping and headaches because of vasoconstriction) - endometrium dies - sloughs off and exits body (3-5 days) (vasoconstriction causes decrease in blood flow to uterus so decrease in oxygen and nutrients so uterine lining (endometrium) dies)
Motor controls involves what specific division of the Nervous System?
Motor Control involves the EFFERENT DIVISION of the PERIPHERAL NERVOUS SYSTEM - specifically, SOMATIC MOTOR is what innervates skeletal muscle cells
What is the primary reproductive organ? - function of this organ
OVARY - site of oogenesis (ovum = egg) - steroid sex hormone secretion (estrogen and progesterone) - ovary is where we ovulate (release an egg)
What is oogenesis? - what is the status of all oogonia from until puberty?
Oogenesis: production of the ova (eggs) - before birth, OOGONIUM divides mitotically to give rise to 2-4 million oogonia. (5-7 months after conception, this process ceases) - just before birth, oogonia begin first meiotic division, but do not complete it. All oogonia are now known as PRIMARY OOCYTES until puberty - the oogonia are in "Meiotic Arrest" - primary oocytes has 46 chromosomes with 2 chromatids per chromosome
functions of oxytocin
Oxytocin: - contraction of uterine smooth muscle during birth - milk ejections from beast tissue upon suckling - bonding behavior in both males and females (released when holding baby -> trust)
How does inhibition of skeletal muscle occur
send interneurons to cell body of alpha motor neuron to have IPSP for inhibition p. 216
Sarcolemma
Sarcolemma = Plasma Membrane and Transverse-tubules (t-tubules) - transverse tubules are invaginations of plasma membrane that dives into skeletal muscle; wraps around myofibrils and comes out other side - inside transverse tubules is ECF
Sarcoplasmic Reticulum
Sarcoplasmic Reticulum = Smooth (longitudinal) ER, and Terminal Cisternae - basically the ER in muscles - Terminal Cisternae is where we have lots of Calcium stored - in between terminal cisternae is the Smooth (longitudinal) ER. It is lattice like, connects terminal cisternae on each end and surrounds myofibrils as well p. 211
What is secondary adrenal insufficiency? - causes and results?
Secondary means the problem is with the anterior pituitary gland function - Caused by: anterior pituitary dysfunction = loss of ACTH (so there is nothing to stimulate the release of cortisol, so cortisol is low) - Results in: similar symptoms as in primary adrenal insufficiency, but with LOW plasma ACTH (because that's where the problem/defect occurs
What happens in the Secretory Phase?
Secretory (Progestational) Phase - increased progesterone - endometrium/myometrium is thickened even further - increased VASCULARIZATION - becomes filled with stored glycogen to support embryo (secretion into invaginated glands to make nourishing environment for fertilized embryo if fertilization where to happen)
Draw/explain the functional anatomy of the testis
Seminiferous tubules (250 meters long!) contain: - Sertoli Cells ("nurse"): form blood-testes barrier, location of sperm proliferation/differentiation, nourish developing sperm - Leydig Cells ("interstitial"): make and release steroids like testosterone which is important for normal sperm development. (located in interstitial space) see bottom of p. 192
What is Spermatogenesis? - where does is take place? - draw/explain key points
Spermatogenesis: production of spermatozoa - takes place in testes in seminiferous tubules (specifically Sertoli cells) - sertoli cells regulate spermatozoa maturation; tight junctions protect sperm from immune attack (tight junctions limit what can get from blood on basement side into lumen side with developing sperm) - Spermatogonia are present throughout life (64-72 days to build a spermatozoa) (present at birth but really turns on at puberty) - spermatogenesis builds 30 million new sperm/day (MUST occur 2-3 degrees Celsius below body temp.) - final maturation and activation occur within female tract see top of p. 193
What is "stress" (in physiological terms)?
Stress = real or perceived threat to homeostasis - surgery - trauma - cold - heavy exercise - infection - shock - low oxygen supply - starvation - sleep deprivation - pain - fear - other strong emotions
Other hormones released during stress
Stress increases the levels of: - Aldosterone: increases Na⁺ retention and blood pressure - Vasopressin: increases water retention and blood pressure, works on kidneys - Growth Hormone: breaks down fat, mobilizes blood glucose (to provide energy for cells during times of stress) - Glucagon: mobilizes glucose from liver stores (opposite of insulin) - Beta-Endorphin: pain reliever/ mood elevation (co-released with ACTH) (analgesic hormones provide pain relied) - Epinephrine: (and norepimephine) as previously described (mobilizes/uses energy stores; puts nutrients into blood plasma)
Summation
Summation involved # of cross-bridges, not AP's!! - cytosolic calcium is elevated longer; actin is available to myosin head longer - increasing tension means more cross-bridges are bound
what are the 2 different clusters of cell bodies with the hypothalamus that lead to posterior pituitary?
Supraoptic Nuclei and Paraventricular Nuclei - these are nuclei (CNS cell bodies)
Compare sympathetic ganglion neuron to adrenal medulla
Sympathetic Ganglion: - has postganglionic neuron - secretes norepinephrine - NT action, FAST ONSET - adrenergic receptors - acts on target cells at point of release Adrenal Medulla (chromaffin cells) - no postganglionic neuron - secretes epinephrine (80%) and norepinephrine (20%) into the blood - NEUROHORMONE action, DELAYED ONSET (Neurohormone in blood is slower than NT) - also has adrenergic receptors - acts on distant target cells p. 157
What does TRH stand for? - what kind of hormone is it?
TRH = Thyrotropin-releasing hormone - a hypophysiotropic hormone
what does TSH stand for?
TSH = Thyroid Stimulating Hormone
definition of target cells
Target Cells: express hormone-specific receptors (with high AFFINITY and SPECIFICITY for the hormone) that respond to the hormone by producing a biologic response
definition of "tension"
Tension = force exerted by muscle on an object
Tetanus
Tetanus is sustained contraction in response to repetitive stimulation - tetanic means more than 1 AP to fiber
What kind of hormones does the adrenal cortex secrete? - what does each zone secrete?
The Adrenal Cortex secretes STEROID HORMONES 1. zona glomerulosa: - secretes mineralocorticoids (aldosterone) - aldosterone regulates [Na⁺], [K⁺], and blood volume (because water follows salt) 2. Zona Fasciculata: - secretes mostly glucocorticoids (a.k.a corticosteroids (CORTISOL) 3. Zona Reticularis: - secretes mostly sex steroids (androgens) - the androgen, DHEA, contributes to the pubertal growth spurt in both sexes and is important in inducing secondary sex characteristics in females
What organs do not need insulin for glucose transport? - how does this work?
The BRAIN and LIVER don't need insulin for glucose transport! - they have other isoforms of these glucose facilitated diffusion carriers that do NOT rely on insulin (GLUT-1, -2, and -3) - the brain primarily uses glucose as energy source so this is important, we need to keep the brain alive!
What regulates the ovarian cycle?
The Ovarian cycle is regulated by hormonal interactions - lost of estrogen is released in the follicular phase - lots of progesterone with some estrogen is released in the Luteal phase - these hormonal changes are essential for oogenesis and for preparing the UTERUS to be a suitable site for implantation of a fertilized ovum -also important for a primary oocyte to become secondary oocyte
Function, Location, and anatomy of adrenal glands
The adrenal glands secrete several hormones involved in the stress response - located on top of kidneys anatomy: see page 156
What does the adrenal medulla do? - what does it secrete?
The adrenal medulla is considered a modified sympathetic ganglion that does not give rise to postganglionic fibers - adrenal medulla secretes amine hormones (80% Epi, 20% Norepinephrine)
what are the body's main control systems? - compare them
The body's "control systems" are the NERVOUS SYSTEM and the ENDOCRINE SYSTEM - the endocrine system tend to be slower because hormones have to be released from endocrine glands into the blood stream then travel to target cells which can be scattered in the body
What is a key feature of hypothalamus to anterior pituitary connection?
The connection between the anterior pituitary and hypothalamus is entirely vascular
what is the endocrine system?
The endocrine system is a "wireless control system" that monitors the ECF and directs the activity of many other organ systems to maintain HOMEOSTASIS
What is the main point of the postabsorptive state
The main point of the postabsorptive state is to maintain plasma levels of blood glucose
What is the most common cause of excess growth hormone?
The most common cause of excess growth hormone is a hyper-secreting tumor of the anterior pituitary
What are the most important controls of transition between absorptive and post absorptive states? - where are they secreted?
The most important controls of transitions between absorptive and post-absorptive states are INSULIN and GLUCAGON - they are secreted from the endocrine portion of the PANCREAS
What is the primary target of glucagon?
The primary target of glucagon is the Liver
What determines the production of specific adrenal steroid hormones in each zone?
The production of specific adrenal steroid hormones in each zone depends on which enzymes are present in each zone - cholesterol can become any steroid hormone. What it converts to depends on what enzymes are present in zones
uterus
The uterus contains the endometrium and myometrium Endometrium: inner lining where fertilized embryo is going to implant - if pregnancy doesn't occur, the endometrium is the lining that is shed Myometrium: outer layer of uterus - thick muscle layer where oxytocin binds and allows for contractions to occur during labor
Amine Hormones: - structure - solubility - synthesis - storage - secretion - transport - receptor location - onset of effect - lifetime
There are 2 different categories of amine hormones: Catecholamines (Dopamine, NE, E) and Thyroid Hormones - structure: derivatives of tyrosine - Catecholamine have same traits as peptide and proteins - Thyroid Hormones have traits like steroids (mostly..) but.. thyroid hormones tend to be stored
what determines hormone transport in the blood, hormone metabolism and excretion, and mechanisms of hormone action?
These are mostly determined by the chemical type of hormone
what influences hyperplasia and and hypertrophy in bone growth?
These processes are influences by local factors and circulating hormones
How are thyroid hormones transported?
Thyroid Hormone is transported in the blood bound to carrier proteins: - thyroid-binding globulin - TBG (~70%) - transthyretin - TTR (~10-15%) - albumin (~15-20%)
What stimulates all steps of TH synthesis/release?
Thyroid Stimulating Hormone (TSH) binding stimulates all steps of synthesis/release of TH - all the steps are stimulated by TSH binding to its receptor on basolateral side of follicle cell
What does the thyroid gland secrete?
Thyroid gland secretes thyroid hormones
explain how thyroid hormone has a permissive effect on expression of epinephrine receptors
Thyroid hormone -> little or no fatty acids released from adipocyte Epinephrine -> small amount of fatty acids released from adipocyte Epi + Thyroid Hormone -> Large amount of fatty acids released from adipocyte - fatty acids can be used during time of need(like during sympathetic NS) - synergistic (increase in fatty acid release when Epi and TH combined) - TH increases the # of epi receptors within the adipocyte membrane - We need TH in order to PERMIT epinephrine to have its FULL EFFECT on target cells, because TH builds epi receptors in target tissue p. 140
Thyroid Hormones are Steroid-Like Amine Hormones (but remember, they can be stored) - how can thyroid hormone be stored if it is so hydrophobic?
Thyroid hormone is conjugated to THYROGLOBULIN, a protein that cannot pass across membranes and is stored in colloid - thyroglobulin is a big hunk of protein that can't pass across the membrane with out being exocytosed or endocytosed - TH gets built in colloid spaces
-what type of hormone is thyroid hormone? - Is TH hydrophobic or hydrophilic - where does it bind?
Thyroid hormone is lipophilic (hydrophobic) amine hormone, and thus binds to receptors located inside the target cells
How does Thyroid Hormone effect growth?
Thyroid hormone is permissive - stimulates growth hormone synthesis and directly affects bone by stimulating growth factors, chondrocytes, and blood vessels - permissive for growth hormone's secretion and actions - permissive for development of the central nervous system
Define Trophic Effect
Trophic Effect: when a hormone binds to its receptor within a gland, it causes a growth or increase in protein synthesis, or cell division within that gland. To grow or to nourish, or to make bigger p. 142
Define Tropic Effect
Tropic Effect: one hormone effects the secretion of another hormone - ex. hormone 1 causes secretion of hormone 2, hormone 1 is tropic
What proteins regulate whether skeletal muscles contract?
Tropomyosin, Troponin, and Actin - regulate whether skeletal muscles contract
twitch
Twitch is the mechanical response of a single fiber or whole muscle to a single AP - not typically useful, physiologically! (because it's very brief and a single twitch is submaximal. One AP removes all troponin but calcium can remove quickly and have no power stroke)
What is released from axon terminals in the posterior pituitary
Two Peptide NEUROHORMONES: 1. Oxytocin 2. Anti-Diuretic hormone (ADH) (a.k.a. vasopressin)
What is Diabetes Mellitus Type 1? - caused by? - results in? - treatment?
Type 1 (insulin-dependent/Juvenile-onset) - 5% of people with Diabetes have type 1 (less common that type 2) - Caused by: autoimmune destruction of B-cells -> no insulin secretion - Results in: extreme hyperglycemia (high plasma glucose) (not able to store glucose in adipocytes as fats or in muscle tissue as glycogen) - exaggerated post-absorptive state (fatty acid mobilization and ketoacidosis) (insulin inhibits the absorptive state events so lots of fatty acids in bloodstream that can be taken up and converted to ketone bodies -> ketoacidosis) - "starvation in the midst of plenty" (there are lots of energy sources in blood stream but we can't take them up to be used) - atherosclerosis, kidney failure, small blood vessel damage (are a few examples) (glucose can attach itself to different tissues of the body and cause those tissues to not function normally. ex. extra glucose attaches to walls of blood vessels, causes hardening of blood vessels which is atherosclerosis. ex. problems with eye sight and nerves Treatment: insulin injections
What is Diabetes Mellitus Type 2? - caused by? - results in? - treatment?
Type 2 (non-insulin-dependent/ adult onset) - not called adult onset anymore because so many children have it now Caused by: Desensitized insulin receptors or REDUCED NUMBER of receptors on target cells; often associated with obesity and inactivity - example of hyporesponsiveness - there are insulin receptors on target tissue but they aren't responding normally to insulin (hyporesponsiveness) Results in: hyperglycemia and other symptoms like Type 1, but usually milder (because you do have insulin present to block the extreme postabsorptive state to breakdown of fuel molecules) - insulin secretion is normal to elevated (prediabetes) (still have normal B-cells) - insulin secretions is reduced (diabetes) (B-cells start to give up) Treatment: diet and exercise (managing weight is effective to make receptors more sensitive to insulin. Exercise allows for facilitated diffusion carriers to go to target cell membranes w/out needing presence of insulin) - people with full blown diabetes can be treated with insulin injections too just to try to get some insulin to get a little glucose uptake into tissues We're in the midst of an epidemic!!
Why is TH essential for fetal CNS development and function; adult NS function?
T₃ exerts many effects on CNS during development, including formation of axon terminals, synapses, dendrites, myelin, etc. - T₃ is needed for proper nerve and muscle reflexes
Why is reproduction important?
Unlike most physiological processes we have discussed thus far, reproduction is not necessary for the survival of an individual; it is however, important for the survival of the species
What merges in the male duct system for urine and semen
Urinary duct and ejaculatory duct merge in male duct system! - urine and semen come out same duct in males
what determines what type of amine hormone is made?
What type of amine hormone is made depends on what ENZYMES the cell has
Gonadal Sex Hormones and Adrenal Androgen Synthesis - what determines what cholesterols turns into?
Whether cholesterol turns into estrogens or testosterone depends on presence or absence of certain enzymes that exist within the gonads - aromatase enzyme - see top of p. 191
what are the structures that make up skeletal muscle?
Whole Skeletal Organ (an organ) -> Muscle Fiber (one cell) -> Myofibrils (cylinders of intracellular contractile structures arranged in repeating units) (an organelle) -> thick and thin filaments (myofibrils are made up of repeated pattern of thick and thin filaments) -> myosin (thick) and actin (thin) molecules p. 208
what causes free hormone to unbind from carrier protein
a decreases in free hormones causes a shift to make free hormone unbind p. 138
What is a Karyotype
a karyotype uses tissue culture visualization of all the chromosomes - it can be used to identify genetic sex abnormalities (XXX, XXY, XO). The end results of these combinations is usually the failure of normal anatomical and functional sexual development
What other 3 hormones mobilize glucose
all 3 are stimulated by hypoglycemia 1. Epinephrine from the adrenal medulla (and NE from nerves) 2. Cortisol 2. Growth Hormone
prostate
alkaline mucus and clotting factors - has alkaline mucus because uterus is very acidic
where do alpha motor neurons terminate on skeletal muscle fibers?
alpha motor neurons terminate on skeletal muscle fibers near their center at a specialized synapse known as the NEUROMUSCULAR JUNCTION (NMJ) - most NMJs are located near the middle of a muscle fiber, and newly generated muscle AP's propagate from this region in both direction towards the ends of the fiber
What is protein synthesis - is it anabolic or catabolic?
amino acids -> protein - anabolic
draw the summary pathway of insulin secretion
bottom of page 178
draw/explain pathway summary of sex differentiation
bottom of page 189
Overall, What happens in muscle, adipose, and liver cells when plasma insulin increases? - when plasma level decreases?
bottom of page. 177
Some effects can only be mediated by Epi and NOT BY NE! - WHY?
because of receptor location, type, and receptor affinity! (remember adrenal medulla secretes mostly Epi (80%) in blood and can reach distant target cells, but sympathetic postganglionic neuron only secretes NE)
draw / explain Diabetic Ketoacidosis - draw pathway
bottom of . 181
draw/explain the cascade for hormonal control of the male reproductive function
bottom of p. 193
1st class lever vs. 3rd class lever
bottom of p. 235
what is a stimulus for TH
cold - increased sensitivity to cold (cold intolerance) + weight gain due to decrease in calorgenic actions by TH, can stimulate the thyroid hormone pathway p. 153
hyperplasia in bone growth
chondrocytes undergoing cell division - towards the top of growth plate are baby chondrocytes undergoing cell division
seminal vesicles
contains fructose and prostaglandins - fructose nourishes the sperm - prostaglandins get into female to help the sperm get to the egg. Prostaglandins induce smooth muscle contraction
Vas Deferens
duct work - smooth muscle for contracting to allow sperm to move up tube - merges with seminal vesicle
ovum
egg/ female gamete (egg or ovum is produced in ovary)
What causes Wolffian or Mullerian ducts to progress?
essentially Y chromosome!
What is the Hypothalamo-hypophyseal tract?
hypothalamo-hypophyseal tract = AXONS!
pituitary gland
hypothalamus signals to pituitary what our endocrine output has to be in order to maintain homeostasis within the body
I band
in between regions of thick filament
How does iodine deficiency cause hypothyroidism?
in iodine deficiency, the synthesis of thyroid hormone is compromised, leading to a decrease in plasma conc. of TH. - this in turn, releases the hypothalaus and anterior pituitary gland from neg. feedback inhibition. - this leads to an increase in TRH concentration in portal circulation that drains into the ant. pituitary gland. Plasma TSH is increased due to increased TRH and loss of thyroid hormone neg. feedback on ant. pituitary gland. Resulting in overstimulation of thyroid gland can produce goiters. - this form of hypothyroidism is reversible if iodine is added to the diet p. 154
in Lever systems, location of muscle insertion point relative to joint location influences .......?
influences force generation and velocity - insertion farther from joint: ↑ force (but don't have as good of velocity ex. moles are made for digging - insertion closer to joint: ↑ velocity ex. horses are made for running
Infundibulum
infundibulum = the stock that connects hypothalamus on top to pituitary gland on bottom - axons travel through it that connect hypothalamus to posterior pituitary - bloos vessels (portal system) connects hypothalamus to anterior pituitary
What is insulin regulated by?
insulin is NOT regulated by the pituitary (no "endocrine hierarchy") - insulin is stimulated by glucose - the main stimulus of insulin secretion is an elevation of plasma glucose concentration - insulin is one of the only hormones and the primary hormone that decreases plasma glucose, it doesn't have other friends that help
Short-Loop Feedback
is when we have a hormone that's released from the anterior pituitary that feeds back and changes the amount of hormone released in hypothalamus p. 145
Growth hormones effect on growth
it's major growth-promoting effect is stimulation of cell division in its many target tissues. Thus, GH promotes bone lengthening by stimulating maturation and cell division of the chondrocytes in the epiphyseal plates, thereby continuously widening the plates and providing more cartilaginous material for bone formation - major stimulus of postnatal growth - induces precursor cells in bone and other tissues to differentiate and secrete insulin-like growth factor 1 (IGF-1), which stimulates cell division - stimulates liver to secrete IGF-1 -stimulates protein synthesis, predominantly in muscle - anti-insulin effects (particularly at high concentrations) A.) renders adipocytes more responsive to stimuli that induce breakdown of triglycerides, releasing fatty acids into the blood B.) stimulates gluconeogenesis C. Reduces the ability of insulin to stimulate glucose uptake by adipose and muscle cells, resulting in higher blood glucose concentration
what is the location and composition of the thyroid gland?
located in neck, on top of trachea - the thyroid gland is mainly composed of spherical follicles - colloid is the "lake" and follicular cells are the "shoreline" - the follicles have colloid which is considered an extracellular space and thyroglobulin - colloid is a thick and jelly like and contains lots of proteins p. 147
many stimuli that enhance cortisol secretion also enhance _______________?
many stimuli that enhance cortisol also enhance catecholamine secretion - there are a lot of stressers that lead to release of cortisol and activation of sympathetic nervous system output - release of cortisol, epinephrine, and norepinephrine, together constitute an emergency guide of hormones that are going to all do functional consequences to allow you to adapt to that stresser
penis
more ductwork
hypertrophy in bone growth
older chondrocytes enlarging (the chondrocytes closest to shaft region are older)
what do osteoblast do?
osteoblast come up and convert cartilaginous tissue (the old chondrocytes) into bone. which causes shaft region to get longer and pushes epiphyseal growth plate up
explain the synthesis of a peptide protein hormone
p. 137, not sure how in depth we need to know synthesis: preprohormone -> prohormone (in Rough ER) Packaging: prohormone -> hormone (Golgi Apparatus) Storage: Hormone (stored in secretory vesicles) Secretion: hormone (and any other "pro" fragments) -> can have additional effects in body
draw the hypothalamus-pituitary axis
p. 146 - the specific hormones vary, but the pattern of hormone activity and feedback involves the hypothalamus-pituitary axis (HPA)
Draw/explain all the steps of TH synthesis and release
p. 149
Draw/explain the control of Thyroid Function
p. 150
draw/explain the pathway of cortisol secretion
p. 159
draw epiphysis, shaft, and epiphyseal growth pate, along with a labeled image of bone growth
p. 165
draw the relative growth of the brain, reproductive organs, and total body height
p. 165
draw/explain the negative feedback for IGF-1
p. 168
draw/explain the regulation of growth hormone and insulin-like growth factor secretion
p. 168
draw/explain gametogenesis in testis and ovary
p. 184
explain Isotonic Twitch contraction
p. 224
explain/ draw how fatty aids get into adipocytes - explain lipogenesis in adipose tissue
page. 174
Draw/explain the events at the Neuromuscular Junction
page. 215
daily pattern of growth hormone secretion
peaks in front half of night - cortisol peaks in second half of night. they both have same effect on glucose - GH takes care of increasing plasma glucose for 1st half of the night and cortisol keeps it maintained during second half p. 166
gonads
primary reproductive organs
ovaries
primary reproductive organs in females
testes
primary reproductive organs in male
What is proteolysis - is it anabolic or catabolic?
protein -> amino acids - catabolic
gametogenesis
reproduction of the reproductive cells, or gametes
Why is intracellular calcium curve left shifted compared to the contractile curve?
right after AO, some calcium increases in cytosol because RyR but it takes some time for muscle contraction because Calcium has to find troponin and attach to move tropomyosin out of way - notice calcium gets taken up by SR quickly
draw/explain the pathway for hormonal control during the early/mid follicular phase - include negative feedback - draw levels of hormones at early/mid follicular phase
see all of page. 199
What are the major fuels we'll consider? - what are their mobile and storage forms?
see bottom of page 171
What happens to glucose, amino acids, and triglycerides in the absorptive state? - maybe draw
see page 173 and note paper
What are the events of the postabsorptive state? DRAW
see page 175 and Notes
Estrogens and Progesterone
sex hormones that predominate in females - males also produce a little progesterone
Epididymis
sperm storage
titin
spring like protein - attached to Z line and runs along thick filament and attaches to M line as well - allows for thick filament to be center of sarcomere and allows everything to stay in place
sex hormones
steroid hormones secreted by the gonads - necessary for normal gametogenesis
testes
steroid production, gametogenesis - where spermatogenisis happens, located outside body because needs to be ~2 degrees Celsius lower than body temp - they start in abdominal cavity and then descend into scrotum - sperm development and testosterone secretion
stimulus
stimulus = change in extracellular fluid variable
androgens
testosterone and dihydrotesterone (DHT), sex hormones that predominate in males (but females can also produce and secrete a little testosterone and DHT)
Motor end plates
the motor end plates is the highly-folded region of the sarcolemma that lies directly beneath the alpha motor nerve terminal at the NMJ
what is the primary stimulus for insulin secretion?
the primary stimulus is elevation of plasma levels of glucose
What is the stimulus of skeletal muscle contraction - where does it originate
the stimulus for skeletal muscle contraction is an ACTION POTENTIAL arriving along an ALPHA MOTOR NEURON originating in the BRAINSTEM or in the VENTRAL HORN of the spinal cord - remember that efferent signaling comes out ventral horn. - it is a SINGLE AXON (one alpha motor neuron innervates skeletal muscle fibers) - one alpha neuron can branch and target different muscle cells - it's called alpha motor neuron because they are the largest diameter neurons and they are myelinated -> FAST! p. 213
What is the Gonadal Ridge (or Urogenital Ridge)
the structure inside the fetus that will become either testes or ovaries
Steroidogenesis in the Dominant follicle
theca cells make androgen, which are steroids so they can go across the cell membrane and the androgens can get into granulosa cells - granulosa cells have aromatase to convert androgens into estrogen
draw the lifetime patterns of testosterone secretion
top of p. 194
What are the reproductive roles in adult females of estrogen and progesterone on: - endometrium - myometrium - cilia/fimbria - cervical mucus - breast (pregnancy) - follicle - body temperature
top of p. 204
draw/explain the mechanism of insulin action in muscle and fat cells
top of page 178
draw the cascade for glucagon secretion
top of page. 179
What is lipolysis - is it anabolic or catabolic?
triglycerides -> fatty acids/monoglycerides - catabolic
unfused tetanus
unfused tetanus = AP frequency allows for partial relaxation but NOT complete relaxation - a typical physiological pattern is unfused tetanus top of p. 222
What is the hypothalamo-hypophyseal portal vessels
used in Anterior Pituitary gland - 2 capillary beds in a series - capillary bed -> veins -> another capillary bed
What do α-cells (alpha-cells) do?
α- cells secrete glucagon - (catabolic/mobilization) - stimulates postabsorptive state - inhibits absorptive state
What do β-cells (beta cells) do?
β-cells secrete INSULIN - (anabolic/net storage) - stimulates absorptive state - inhibits post-absorptive state
What do δ-cells (delta cells) do?
δ-cells secrete somatostatin - inhibits both insulin and glucagon secretion - prevents insulin and glucagon from being oversecreted - a paracrine agent - keeps system of checks and balances
