Exam 2 Flashcards
What is found in cardiac muscle and is made of gap junctions that help transmit electrical signals to neighboring cells much quickly?
Intercalated discs
What is attached to bone, contractions are initiated by action potentials in MOTOR NEURONs, and is under VOLUNTARY control?
Skeletal muscle
What is found in walls of HOLLOW organs and TUBES; contraction supports internal movements; controlled by autonomic nervous system, hormones, other signals; and is controlled by INVOLUNTARY movement?
Smooth muscle
What is found in the heart, contraction propels blood through circulatory system; this is regulated by autonomic nervous system, hormones, and other signals; and is controlled by INVOLUNTARY movement?
Cardiac muscle
Label the structures in order from largest to smallest of skeletal muscle?
1) Muscle cell
2) Muscle fiber
3) Myofibril
4) Thick and Thin filaments
The thick and thin filaments are arranged in a pattern called?
Sarcomeres
What helps propagate action potentials through muscle cells?
T-tubule
1) Multi-nucleated
2) Many mitochondria
3) T-tubules
4) Myofibrils (thin and thick filaments) and sarcomeres
These are characteristics of what type of muscle?
Skeletal muscle
Sarcolemma
plasma membrane
Sarcoplasm
cytoplasm
sarcoplasmic reticulum
Smooth ER
What has heavy and light chains
Myosin
What is the light chain?
Myosin head
How many binding sites does the myosin (In skeletal muscle) head have and what is the function?
1) 2
2) one site binds to actin, and the other binds ATP
(Both together are called cross bridges)
Explain the mechanism of skeletal muscle contraction?
1) Motor neuron: generate AP
2) Ca2+ enters voltage-gated channels
3) Acetylcholine is released into neuromuscular junction
4) Acetylcholine binds to receptor and open ion channel on skeletal muscle
5) Na+ enters (causing depolarization of skeletal muscle)****
6) Local current between depolarized end plate and adjacent muscle plasma membrane
7) Muscle fiber AP initiation
8) Propagated AP in muscle plasma membrane
9) Acetylcholine degraded (Acetylcholinesterase)
what is defined as a motor neuron and all of the skeletal muscle fibers it innervates?
Motor unit
Can other motor units innervates other fibers of other motor units?
NO
This is the time it takes to assess the load by recruiting the muscle fibers
Latent period
(a better understanding is this is the period before excitation)
What are the drugs that block neuromuscular transmission and are sometimes used in small amounts to prevent muscular contractions during certain types of surgical procedures?
1) Succinylcholine
2) Curare (Rocuronium and Vecuronium)
This is agonist to ACE receptors and produces a DEPOLARIZING/desensitizing block?
(which means it is no longer activated, skeletal muscle will go into relaxation)
Succinylcholine
This is a nicotinic ACH receptor antagonist, a non-depolarizing neuromuscular junction blocking drug?
(which means it try’s to block ACH from binding to it and prevents the action of ACH causing relaxation)
Curare
(other similar drugs Rouronium and Vecuronium)
What blocks the release of acetylcholine from axon terminal, it is an enzyme that breaks down proteins of the SNARE complex that are required for the binding and FUSION OF ACH VESICLES with the plasma membrane of the axon terminal?
BOTOX (Botulinum toxin)
what is the sequence of events in which an action potential in the motor end plate of a muscle fiber causes actin-myosin cross bridge formation and contraction of the muscle?
Excitation-contraction coupling
How does action potentials in skeletal muscle fibers conduct their messages into the muscle fibers? This will initiate Ca2+ release from its storage site in the lateral sacs of what structure? Ca2+ ions then available for binding to Troponin an initiating the events of what? When Ca2+ increased in the ________________ near the actin and myosin muscle contraction occurs. At the end of an action potential, __________________________ return Ca2+ ions to the SR by active transport; this leads to decrease Ca2+ concentration around actin and myosin, which results in ________________________
1) Transverse tubules
2) Sarcoplasmic reticulum
3) Sliding filament mechanism
4) Sarcoplasm
5) Ca2+ -ATPase pump
6) Muscle relaxation
What is blocking the binding site on actin?
Tropomyosin
Explain how muscle contraction occurs in skeletal muscle?
1) Ca2+ will bind to troponin
2) Troponin is released off the tropomyosin
3) Tropomyosin has a conformation change
4) exposure of the actin binding site
5)*** the cross bridge on myosin needs to be in its activated state (ENERGIZED STATE)
Explain how the t-tubule and SR work together?
1) The t-tubule are in intimate contact with the terminal cisternae of the sarcoplasmic reticulum
2) This junction involves two integral membrane proteins, one in the t-tubule membrane, and the other in the membrane of the sarcoplasmic reticulum
-the t-tubule protein is a modified voltage-sensitive Ca2+ channel known as the DIHYDROPYRIDINE (DHP) RECEPTOR
-The protein embedded in the sarcoplasmic reticulum membrane is known as the RYANODINE RECEPTOR, which forms a Ca2+ channel
3) During a T-tubule action potential, charged amino acids residues within the DHP receptor protein induce a conformational change, which pulls open the ryanodine receptor channel, Ca2+ is then released from the terminal cisternae of the sarcoplasmic reticulum
1) T-tubules are connected to the SR
2) DHP receptor on the t-tubule are voltage-gated receptors and communicate with the SR via Ry receptor located on the SR
3) Once depolarized enough the RY receptor tells the SR to release Ca2+ into the sarcoplasm
Explain the cross bridge cycle (also known as ENERGIZED cross bridge) of skeletal muscle?
1) cross bridge is bound to actin (Ca2+ rises)
2) Cross bridge moves and release of ADP + Pi
3) ATP binds to myosin causing cross bridge to detach
4) Hydrolysis of ATP energies cross-bridge to bond to actin (BY ATPase)
When there is no ATP the myosin stays binded to actin (which means continuous contraction)?
Rigor mortis
When force generation produces shortening of skeletal muscle fiber, the overlapping thick and thin filaments in each sarcomere move past each other, propelled by movements of the cross-bridges; During this shortening of the sarcomeres, there is no change in the length of either the thick or thin filaments, only in their amount of overlap this is called?
Sliding filament theory
What happens to the
1) sarcomere
2) H zone
3) I band
4) A band
When the sliding filament theory is occurring?
1) sarcomere = shortened
2) H zone = Reduced
3) I band = reduced
4) A band = unchanged
What is the A band?
the thin and thick filaments
Explain the steps in skeletal muscle contraction?
1) action potential is initiated and propagates to motor neurons axon terminals
2) Ca2+ enters axon terminal through voltage-gated Ca2+ channels
3) Ca2+ entry triggers release of ACh from axon terminals
4) ACh diffuses from axon terminals to motor end plate in muscle fiber
5) ACh binds to nicotinic receptors on motor end plate, increasing their permeability to Na+ and K+
6) More Na+ moves into the fiber at the motor end plate than K+ moves out, depolarizing the membrane and producing the end-plate potential (EPP)
7) Local currents depolarize the adjacent muscle cell plasma membrane to its threshold potential, generating an action potential that propagates over the muscle fiber surface and into the fiber along the T-tubule
8) Action potential in T-tubules induce DHP receptors to pull open ryanodine receptor channels, allowing release of Ca2+ from terminal cisternae of sarcoplasmic reticulum
9) Ca2+ binds to troponin on the thin filaments, causing tropomyosin to move away from blocking position, thereby uncovering cross-bridge binding sites on actin
10) Energized myosin cross-bridges on the thick filaments bind to actin
11) Cross-bridge binding release of ATP hydrolysis products from myosin, producing an angular movement of each cross-bridge
12) ATP binds to myosin, breaking linkage between actin and myosin and thereby allowing cross-bridges to dissociate from actin
13) ATP bound to myosin is split, energizing the myosin cross-bridge
14) Cross-bridges repeat steps 10-13 producing movements (SLIDING) of thin filaments past thick filaments. Cycles of cross-bridges movement continue as long as Ca2+ remains bound to troponin
15) Cytosolic Ca2+ concentrations decrease as Ca2+ -ATPase actively transports Ca2+ into sarcoplasmic reticulum
16) Removal of Ca2+ from troponin restores blocking action of tropomyosin, the cross-bridge cycle ceases, and the muscle fiber relaxes
What is linked to single action potential? It includes
1) Latent period
2) Contraction period
3) Relaxation phase
Twitch
When a muscle develops tension but does not shorten or lengthen (CONSTANT LENGTH), this is called?
Isometric Contraction
A contraction in which the muscle changes length while the load on the remains constant (CONSTANT TENSION) is called?
isotonic contraction
When tension exceeds load, shortening occurs, and the contraction is called?
Concentric contraction
When an unsupported load is greater than the tension generated by cross-bridges, the load pulls the muscle to a longer length in spite of cross-bridges; this is an?
eccentric contraction
the increase in muscle tension from successive action potentials occurring during the phase of mechanical activity is known as?
Summation
A maintained contraction in response to repetitive stimulation is known as a?
Tetanus (tetanic contraction)
This is lined to titin protein, stretch of non-stimulated muscle fiber and doesnt require ATP?
Passive tension
This is when the stretch of tetanically stimulated muscle fiber, it rely on active cross-bridge movement and requires ATP?
Active tension
How does creatine produce energy for the muscle?
Creatine phosphate donates its phosphate to ADP to make it ATP
What type of pathway includes myoglobin, mitochondria, and red meat?
Oxidative
Which type of pathway includes glycogen and white meat?
Glycolytic
slow-oxidative fibers show?
No fatigue
Fast-oxidative-glycolytic fibers and Fast-glycolytic fibers show?
More fatigue
Slow-oxidative fibers (Type 1)
1) Primary source of ATP
2) Mitochondria
3) rate of fatigue
4) Fiber diameter
5) Motor unit size
1) Oxidative phosphorylation
2) Many
3) SLOW
4) **SMALL
5) Small
**Remember that Fast glycolytic fibers (Type IIB) is the opposite **
When the amount of contractile activity increases
1) The size of muscle fibers increase
2) Their capacity for ATP production increases
When there is a decrease in size this is called? Normally occurs due to disuse or denervation.
Atrophy
What are some skeletal muscle disorders?
1) Poliomyelitis
2) Muscle cramps
3) Hypocalcemic tetany
4) Muscular dystrophy
5) Myasthenia Gravis
This is cause by a viral disease that destroys motor neurons?
Poliomyelitis
This is caused by involuntary tetanic contraction of skeletal muscle, action potentials fire at abnormally high rates, over -exercise or persistent dehydration imbalances, and chemical (electrolyte) imbalances?
Muscle cramps
This disease is caused by involuntary tetanic contraction of skeletal muscle, and is linked to low calcium levels and sodium channels?
Hypocalcemic tetany
1) Most frequent encountered genetic disorder
2) progressive degeneration and weakening of skeletal and cardiac muscle fibers
3) Defect in COSTAMERES
What disease is this?
Muscular dystrophy
1) Destruction of nicotinic Ach receptor proteins of the motor end plate (if eye muscles get affected, ptosis could occur)
2) Liked to auto-antibodies and inflammation
What disease is this?
Myasthenia Gravis
What are the treatment options for myasthenia gravis?
1) Acetylcholinesterase inhibitors (NEOSTIGMINE)
2) Immuno-suppressing drugs
3) Plasmapheresis
4) X-linked recessive disorder, liked to dystrophin protein
What disease is this?
Duchenne muscular dystrophy
What causes muscle fatigue?
1) Repeated stimulation linked to decline in muscle tension
2) Decreased velocity
3) Slow rate of relaxation
Tentanus causes
Muscle fatigue due to constant contraction
Characteristics of smooth muscle are?
1) The thick and thin filaments are not organized into myofibrils, and there are NO SARCOMERES, which accounts for the absence of a banding pattern
2) Smooth muscle contraction occurs by a sliding-filament mechanism
3) Smooth muscle surrounds hollow structures and organs that undergo changes in volume with accompanying changes in the lengths of the smooth muscle fibers in their walls
These have gap junctions to help communicate to other cells?
Single-unit smooth muscle
nerves use these to carry neurotransmitters?
Varicosity
Explain smooth muscle contraction?
1) Increase in Ca2+
2) Ca2+ binds to CALMODULIN
3) Ca2+-calmodulin complex binds to myosin light-chain kinase
4) Myosin light chain kinase uses ATP to phosphorylate myosin cross-bridges
5) Phosphorylated cross-bridges bind actin filaments
6) Cross-bridges cycles produce tension and shortening
Explain skeletal muscle contraction?
1) Aa2+ increases
2) Ca2+ binds to troponin on thin filament
3) Conformational change in troponin moves tropomyosin out of blocking position
4) Myosin cross-bridges bind actin
5) Cross-bridges cycles produce tension and shortening
Explain cardiac muscle contraction?
1) the membrane is depolarized by Na+ entry as an action potential begins
2) Depolarization opens L-type Ca2+ channels in the T-tubule
3) A small amount of trigger Ca2+ enters the cytosol contributing to cell depolarization. that trigger Ca2+ binds to, sarcoplasmic reticulum membrane
4) Ca2+ flows into the cytosol, rising the Ca2+ concentration
5) Binding of Ca2+ to troponin exposes cross-bridge binding sites on thin filaments
6) Ca2+-ATPase pumps return Ca2+ to the sarcoplasmic reticulum
7) Ca2+-ATPase pumps (and also Na2=/Ca2+ exchangers) remove Ca2+ from the cell
8) The membrane is repolarized when K+ exits to end the action potential
Skeletal muscle vs. Cardiac muscle contraction and action potential?
1) Skeletal muscle action potential occurs before contraction
2) Cardiac muscle action potential occurs at the same time as the contraction
The anterior pituitary gland hormone that controls the function of exocrine secretions of mammary gland such as its involvement in lactation would be ______________.
Prolactin
The transition between the ___________ phase and the ____________ phase of the uterine cycle coincides with ___________ (process).
Proliferative; secretory; ovulation
Iodine is a necessary nutrient in humans, since it is needed for thyroid hormone synthesis.
True
Malignant hyperthermia can lead to depletion of ATP, increased CO2 production, acidosis, elevated body temperature, flushing of the skin, and rapid breakdown of muscle tissue
true
A 63-year old woman has been diagnosed with hypocalcemia. If her hypocalcemia is due to low levels of parathyroid hormone (PTH) in the blood, the patient’s condition can also be called as _____________.
Primary hypoparathyroidism
Parietal cells secrete _____________ into the gastric lumen to promote protein digestion
Hydrochloric acid
Type II b fibers typically ___________.
fatigue easily
In smooth muscle cells, calcium triggers contraction by binding to _______________
calmodulin
____________ is (are) stimulated by decreased levels of glucagon
1) Glycogenesis
2) Lipogenesis
Which of the following cells do not typically produce androgens?
Sertoli cells
The contractile protein in the thick filament of the skeletal muscle cells is ______________
myosin
A 55-year old man presenting with increased fatigue and lethargy to the physician, also had low blood pressure and low blood glucose. Based on the symptoms and findings, what could be an (the) appropriate diagnosis (-es) from the options given below?
1) addision’s disease
2) Adrenal insufficiency
The adrenal cortex secretes ___________.
1) Cortisol
2) Mineralocorticoid
3) A male sex hormone
Curare acts as a skeletal muscle relaxant by _____________ on skeletal muscle cells
Blocking nicotinic receptors
The first step of fat digestion is _____________
fat emulsification
Duckless glands
endocrine
sweat glands and have ducts?
exocrine
what is the precursor of steroid hormones?
Cholesterol
Which chemical class of hormones have receptors located on the plasma membrane of cells and are free bound in the plasma and they are fast acting?
Peptide and catecholamines
Which chemical class of hormones have the ability to bind inside the cell (intracellular), they are protein bound in the blood and insoluble in water and act slow?
Steroid hormones (T3, and T4) included
Endocrine control can be controlled by?
1) Hormones (ex. thyroid gland is controlled by the hypothalamus it releases hormones to the pituitary that are released to the thyroid)
2) Ions (ex. parathyroid responds to low blood Ca2+ by releasing PTH)
3) Neurotransmitters (by increasing sympathetic response in the nervous system it increases the adrenal medulla to secrete hormones)
What transports hormones from the hypothalamus to the anterior pituitary?
Hypothalamo-hypophyseal portal system
(portal system means blood vessels)
What transports hormones from the hypothalamus to posterior pituitary system?
Hypothalamo-hypophyseal tract
(this is a bundle of neurons)
What hormone is stored in the posterior pituitary and produced in the hypothalamus used for milk ejection reflex and promotes contraction during child birth?
Oxytocin
What hormone is released from the posterior pituitary and is used for the regulation of water balance and osmolality?
ADH
What suppresses ADH secretion?
Alcholol
What increases ADH secretion and used to treat hypertension?
Diuretics
iodine in the blood is important for?
the synthesis of T3 and T4
What is secreted from follicular cells, stimulates protein synthesis, increases rates of cellular respiration, and elevates basal metabolic rate?
T4
T4 is converted to T3 by the?
Liver
Which is stronger T3 or T4?
T3
Which is more abundant T3 or T4?
T4
What hormone is produced from the parafollicular cells, inhibits Ca2+ being released from bone, stimulates excretion of calcium in the kidneys to lower blood calcium?
Calcitonin
The parafollicular cells aren’t part of?
Axis pathway
What disease is caused by a decrease in T3, And T4, symptoms include weight gain, decreased appetite, cold intolerance, low heart rate, and hair loss?
Hypothyroidism
What disease is caused by an autoimmune attacks the thyroid causing hypothyroism?
Hashimotos thyroiditis
What disease is caused by an increase in T3 and T4, symptoms include wight loss, increase appetite, palpitation, heat intolerance, tachycardia (increased heart rate)?
Hyperthyroidism
What autoimmune disorder is caused by hyperthyroidism?
Grave’s disease
What is the name of the disease that is caused by enlargement of the thyroid gland could be caused by either hypo/hyper thyroidism?
(In the case of hypothyroidism bc T3, T4 levels are low the negative feedback speeds up the process causing more secretion of TRH from hypothalamus more secretion of TSH form anterior pituitary trying to over stimulate the thyroid gland thus causing ENLARGEMENT)
Goiter
This disease causes mental retardation in child if pregnant women doesn’t maintain normal levels of thyroid hormones?
cretinism
Zona glomerulosa secretes?
Aldosterone
Zona Fasciculata secretes?
Cortisol and small of androgens
Zona reticularis secretes?
Androgens and small amounts of cortisol
What are the 3 structures of the adrenal cortex?
1) Zona glomerulosa
2) Zona Fasciculata
3) Zona reticularis
The medulla secretes?
Norepinephrine and epinephrine
The adrenal cortex is influenced by the?
Axis pathway
The adrenal medulla is influenced by?
Sympathetic neurons
What reabsorbs (retains) Na+, which helps to increases blood pressure?
Aldosterone
This helps with gluconeogenesis and lipolysis, which promotes increase in blood glucose, this also inhibits inflammation and immune responses?
Cortisol
What are the effects of cortisol release during stress?
1) increase in blood glucose (gives us more ENERGY during stress)
2) Inhibition of inflammation and specific immune responses
3) Inhibition of nonessential function (GROWTH/ REPRODUCTION WHEN UNDER STRESS)
What other hormones are released during stress?
Vasopressin and aldosterone
This disease occurs due to chronic low plasma cortisol, the symptoms are weakness, lethargy, loss of appetite, low blood sugar, and hypotension,?
Adrenal insufficiency
What can cause primary adrenal insufficiency?
1) TB (virus infiltrates adrenal gland)
2) Tumors and autoimmune attack
(Notice for primary it involves the gland itself)
What is a type of primary adrenal insufficiency?
Addisons disease
This is causes by low production of cortisol, it causes low blood pressure and the symptoms are fatigue, nausea, darkening of skin and dizziness?
Addison’s disease
This disease is caused by an increase in cortisol. This disease can also have primary and secondary effects on the gland. The primary effect is caused by a tumor which releases a lot of cortisol. Clinical problems are osteoporosis, muscle weakness, increased blood sugar, immunospression, buffalo hump, hypertension. What is this disease?
Cushing’s SYNDROME
What disease is caused by a secondary effect on the adrenal gland that causes an increase in cortisol, the symptoms are breakdown of bone, muscle, skin and other organs?
Cushing’s DISEASE
What are the actions of growth hormone?
1) Increased cartilage formation and skeletal growth
2) increased protein synthesis, and cell growth, and proliferation
3) increased lipolysis
4) increased blood glucose and other anti-insulin effects
which hormones promote growth?
1) GH
2) Insulin
3) Thyroid hormones
4) testosterone
5) estrogen
Which hormones inhibits growth?
Cortisol
What factor is released from the liver to promote growth?
IGF-1
What hormone inhibits the release of GH?
SST (somatostatin)
What part of the bone controls growth?
Epiphysis
What hormone brings down blood Ca2+ levels?
Calcitonin
Where are the 3 main sites that influence the amount of Ca2+ released into the blood?
1) Bone
2) Kidney
3) GI tract
How does PTH increased blood plasma Ca2+?
1) Bone: increase osteoclast activity
2) Kidney: Promotes active for of vitamin D (which increases Ca2+ absorbed from food into the blood)
-Stops Ca2+ from being excreted in urine
What is hypocalcemia?
Low blood calcium
What is the cause of primary hypoparathyroidism?
Parathyroid gland doesn’t produce enough PTH
What disease is caused by a failure to absorb vitamin D from the GI tract, or decreased kidney 125-(OH):D production, which can occur in kidney disease?
Secondary hyperparathyroidism
What is the disease caused by excessive ingestion of Vitamin D, this causes an increase in blood calcium?
Secondary hyperparathyroidism
What is the disease associated with a deficiency of vitamin D in children?
Rickets
What is the disease associated with a deficiency of vitamin D in adults?
Osteomalacia
What disease is a associated with an imbalance between bone resorption and bone formation, normally occurs in elderly women?
Osteoporosis
What carries nutrient rich blood from the small intestine to the liver?
Hepatic portal vein
This is the inner most layer made of epithelial cells that have endocrine and exocrine cells?
Mucosa
which layer of the GI is the muscle (smooth muscle) that has involuntary control and is controlled by the ANS?
Muscularis externa
What 2 structures in the GI tract are controlled by the Enteric nervous system?
1) Submucosal plexus
2) Myenteric plexus
What are absorbed by the intestinal cells for use in the body?
Monosaccharides (all the rest are to large)
What breaks down polysaccharides in to disaccharides in the small intestine?
Pancreatic amylase
Since disaccharides are to large to be absorbed what breaks it down into monosaccharides?
Brush border
Proteins are broken down in the stomach by?
Pepsin
Proteins are broken down in the small intestine by?
Trypsin and chymotrypsin
What secretes trypsin and chymotrypsin?
Pancreas
The fragments of proteins that have been broken down by trypsin and chymotrypsin are further broken down to free amino acids by? Where are these enzymes located?
1) Carboxypeptidase
2) On the membrane in the small intestine (brush border)
What are tryglycerides?
1) Glycerol
2) Fatty acids
What is the main enzyme that breaks down fatty acids in the small intestine?
Pancreatic lipase
The speed of lipid digestion is increased by?
Emulsification
This is the separation of large lipid droplets into smaller droplets, to increase the surface area for lipase action?
Emulsification
What are the steps in fat digestion and absorption?
1) Fat droplet —-> (Emulsification) emulsion droplets
2) Lipase —–> (breakdown to) Fatty acids
3) Now they can diffuse into the epithelial cell
4) Now they get packaged into CHYLOMICRONS (immune/lymphatic)
5) Chylomicron goes to the liver to be converted into VLDL/LDL/HDL
What vitamins follow the pathway for fat absorption like other lipids?
A,D,E and K
Water soluble vitamins are absorbed by diffusion or mediated transport except ________________, which must first bind to a transport protein called ________________
1) Vitamin B12
2) Intrinsic factor
Why is water important to be absorbed in the small intestine?
Water helps with breaking down (Amylase uses hydrolysis to breakdown larger molecules)
This is when food get mixed with acid?
Chyme
What are the GI hormones?
1) Gastrin
2) CCK
3) Secretin
Where is the site of production of Gastrin?
Antrum of stomach
What causes the release of gastrin?
Amino acids, peptides in stomach (parasympathetic nerves)
What inhibits the release of gastrin?
Acid and somatostatin
Gastrin stimulates
Acid secretion and motility in the stomach
What is the site of production of CCK?
small intestine
What stimulates the release of CCK?
Amino acids, fatty acids in small intestine
CCK inhibits?
Acid secretion and motility in the stomach
Where is the site of production of Secretin?
Small intestine
What stimulates the release of Secretin?
Acid in the small intestine
Food + saliva =
Bolus
What is the function of Mucous cells in the GI?
Mucus and bicarbonate secretion
What is the function of parietal cells in the stomach?
Acid and intrinsic factor secretion
If the parietal cells are damaged what occurs?
Anemia
What is the function of ECL cell in the stomach?
Histamine secretion
What is the function of chief in the stomach?
Pepsinogen secretion (it is the inactive form of pepsin)
How is pepsinogen activated?
HCL
What activates parietal cells to secret HCL?
1) Gastrin
2) Histamine
3) ACH
What are the things that inhibit HCL secretion from parietal cells?
Somatostatin
What are the enzymes secreted by the pancreas and there function?
1) Trypsin: breaks down protein
2) Chymotrypsin: Breaks down proteins
3) Lipase: Breaks down fats
4) Amylase: breaks down polysaccharides
Hormonal control of pancreatic secretion?
1) Increase Acid from stomach
2) Increase secretion of in small intestine
3) Increase plasma secretin
4) increase bicarbonate secretion from the pancreas
5) Increase flow of bicarbonate into small intestine
6) Neutralization of acids in small intestine
important functions of the liver?
1) Produces bile and stores nutrients
What is the function of bile?
Emulsification of fats
This is specialized vasculature that delivers absorbed nutrients to the liver for processing before they enter the general systemic circulation?
Hepatic portal system
what stores bile?
Gallbladder
When the Duodenum increase CCK what occurs?
Gallbladder contracts and releases bile into the duodenum through the common bile duct
What increases surface area in the small intestine and are used for absorption of nutrients?
Villi
What produces amylase?
Pancreas and salivary glands
Glucose —–> ATP
Glycolysis
Glucose —>stored as glycogen
Glycogenesis
Fatty acids + Glycerol —–> Stored as lipids and fats
Lipogenesis
Keto-Acids/ fatty acids —-> ATP
Oxidation
Glycogen—> glucose
Glucogenolysis
Glycerol—->glucose
Gluconeogenesis
Lipids—->fatty acids+ glycerol
Lipolysis
Fatty acids + Glycerol —> Ketones
Ketogenesis
Amino acids —-> Glucose
Gluconeogenesis
What makes and secretes insulin?
Pancreatic Beta cells
What is the function of insulin?
To help uptake of glucose from the blood into the cell
What tissues does insulin target?
1) Muscle
2) Adipocytes
3) Liver
(this is where glucose is stored)
If there is an increase of plasma glucose what occurs?
1) pancreatic beta cells secrete insulin
2) Plasma insulin increases
3) Adipocytes, muscle and liver uptake glucose
What are the factors that induce insulin secretion?
1) Increase plasma glucose
2) Increase plasma amino acids
3) incretins
4) Increase parasympathetic activity
What are the factors that inhibit the release of insulin?
Sympathetic stimulation (plasma epinephrine)
what is defined as low plasm glucose concentrations?
Hypoglycemia
If there is a decrease in plasma glucose what occurs?
1) pancreatic islet ALPHA cells secrete glucagon
2) the liver increases:
-glycogenolysis
-Gluconeogenesis
-Ketone synthesis (lipolysis)
3) this causes an increase in plasma glucose and plasma ketones
Step in sympathetic response to low glucose
1) decrease in plasma glucose
2) adrenal medulla increases epinephrine secretion
3) Skeletal muscle (increases glycogenolysis), Liver (increases glycogenolysis and gluconeogenesis), and adipose tissue (increases lipolysis)
4) This increases plasma glucose, fatty acids, and glycerol
What disease is associated with less insulin production from pancreatic beta cells, symptoms include: polyuria (excess urination), polydipsia (excessive thirst), and polyphagia (excessive hunger)?
Diabetic ketoacidosis
What is the disease associated with high blood plasma glucose?
Diabetic ketoacidosis
what is a 2 step process, in which MITOSIS is followed by MEIOSIS?
Gametogenesis
What is the production of sex cells, sperm or ova, containing 23 chromosomes; developing gametes can be called germ cells?
Gametogenesis
During the seventh week of fetal development _____________ located on the Y chromosome is expressed, leading to the development of testes in males
SRY gene
Name the steps that cause congenital adrenal hyperplasia?
1) Increase ACTH secretion from the hypothalamus
2) Increase Cholesterol transport into mitochondria
3) Since there is a mutation that causes a decrease in cortisol
4) Increases in plasma adrenal androgens
5) Virilization (where male sexual characteristics)
6) INCREASE IN CELL numbers
Hormonal control of reproduction is under the
Axis pathway
This is when GnRH, the gonadotropions, and gonadal sex hormones are secreted at relatively high levels?
Fetal Life to infancy
This is when GnRH, the gonadotropins, and gonadal sec hormones are very low and reproductive function is at rest?
Infancy to puberty
What processes occur in the absorptive state?
(anabolism)
1) Glycogenesis
2) Lipogenesis
3) GLuconeogenisis
what processes occur in the post-absorptive state?
(catabolism)
1) Glycolysis
2) Oxidation
3) Gluconeogenisis
4) Lipolysis
5) Ketogenesis
What vitamins are made in the large intestine?
Vitamin K and B
Epinephrine binds to the ___________receptors while cortisol binds ___________receptors.
1) membrane bound receptor
2) intracellular receptor
What inhibits acetylcholinesterase?
Sarin
What is the function of CCK?
Increases the secretion of pancreatic enzymes
Where is CCK secreted from?
the duodenum
What leads to CCK secretion?
Food
Effect of testosterone in the male
1) decreases GnRH secretion via an action on the hypothalamus
2) Inhibits LH secretion via a direct action on the anterior pituitary
3) Stimulates protein anabolism, bone growth, and cessation of bone growth
4) Stimulates erythropoietin secretion by the kidney (helps increase the production of red blood cells–> increase blood thickness—->decreases blood flow
Explain the hormonal control of male reproductive function of FSH?
1) Hypothalamus secretes GnRH
2) GnRH (in hypothalmo-pituitary portal vessel)
3) Anterior pituitary secretes FSH
4) Seroli cells either stimulate spermatogenesis or Secrete inhibin
What is the function of inhibin?
only inhibits FSH secretion
Explain the hormonal control of male reproductive function of LH?
1) Hypothalamus secretes GnRh
2) GnRh (in hypothalmo-pituitary portal vessel)
3) Anterior pituitary secretes LH
4) Leydig cellls are activated and secret testosterone
5) Testosterone can activate sertoli cells, or contribute to reproductive tract or other organs
6) Negative feed back mechanism when to much testosterone is present it will inhibit either GnRH secretion or LH Secretion (Only LH)
This part of the female reproductive system captures ova in secondary oocyte?
fimbriae
This is where fertilization occurs?
Fallopian tube (uterine tube)
What is the middle layer of the uterus?
Its called the myometrium and it is made of smooth muscle (this is where contractions occur and promote childbirth)
What is surrounding the oocyte and it nourishes the oocyte?
Follicle
Explain the hormonal control of ovarian function of FSH (early and middle follicular phase)
1) Hypothalamus secretes GnRH
2) Anterior pituitary secretes FSH and LH
3) FSH activates granulosa cells
4) Granulosa cells influence oocyte, release inhibin, and help convert androgens convert into estrogen
Explain the hormonal control of ovarian function of LH (early and middle follicular phase)
1) Hypothalamus secretes GnRH
2) Anterior pituitary secretes LH and FSH
3) LH activates theca cells
4) Theca cells produce androgens
5) Androgens get converted into estrogen by granulosa cells
What phases are associated with the follicular phase?
1) Menstral
2) Proliferative
What phase occurs when the follicle secretes estrogen to thicken the endometrial wall?
Proliferative
What phases are associated with the Luteal phase?
Secretory
what occurs during the secretory phase?
progesterone and estrogen are secreted from corpus luteum
Explain the steps when LH surge and ovulation?
1) Hypothalamus secretes GnRH
2) Anterior pituitary secretes LH
3) Large amounts of estrogen release the secondary oocyte from the dominant follicle
4) Then follicle gets captured by the fallopian tube and becomes corpus luteum
What promotes ovulation?
Increase in LH
During the follicular phase what hormone is high?
Estrogen
During the luteal phase what hormones are high?
Estrogen and progesterone
