Hormone binds to protein receptor, activates G protein
Adenylate cyclase is activated and ATP makes it into cAMP (2nd messenger) which activates kinase.
Kinase then opens ion channels and activates enzymes
-Calcitonin, epinephrine and norepinephrine (beta1&2), PTH, glucagon, ADH, ACTH, FSH, LH, TSH
Hormone binds to protein receptor, activates G protein
Phospholipase C is activated which, via diacyl glycerol, activates protein kinase C to open calcium channels and via inositol triphosphate, releases stored calcium from SR
Calcium binds to calmodulin within the cell and this complex acts as 2nd messenger activating enzymes.
-Epinephrine and norepinephrine (alpha1), oxytocin, hypothalamus regulatory hormones, some eicosanoids
Anterior Pituitary Gland
Mouth grows upward to form this endocrine portion
From oral ectoderm
Hypothalamus controls this through a portal system (cardiovascular)
Pars Distalis - Only part with endocrine function
Pars Intermedia (MSH only but not in humans)
Pituitary Stalk (Infuntibulum) - "glove"
Releases 7 hormones (FSH, LH, ACTH, TSH, PRL, GH)
Posterior Pituitary Gland (pars nervosa)
Brain grows downward to form this neural portion
From neural ectoderm
Hypothalamus controls this through direct neurons
Has support cells (pituocytes)
Stores endocrine hormones
Anterograde movement of kinesin takes hormones from nuclei to storage
ADH (vasocressin) and oxytocin are secreted from here
One of the two major types of capillaries.
Characterized by the presence of circular fenestrae or pores that penetrate the endothelium (may be closed by a very thin diaphragm)
They are important in organs that engage in rapid absorbtion and filtration-- the kidneys, endocrine glands, small inestine, and the choroid plexuses of the brain
-Chromaffin cells make and secrete hormones
-Hormones travel into the extracellular matrix and enter the tissue of the median eminence
-They're taken up by the primary capillary plexus and travel through the portal venules into the secondary capillary plexus.
-Diffuse out of the plexus into cells that have receptors for them.
Neurosecretory cells in posterior pituitary whose axons don't stop at the median eminence. They go all the way down to the infuntibulum and hang out by blood vessels in the posterior pituitary. Synaptic terminals have a ton of hormone and cause the synaptic terminal to swell. Edit
Thyroid Releasing Hormone (TRH)
Comes from hypothalamus, goes into primary capillary plexus, portal venules, then to secondary capillary plexus, then bind to the thyrotrophs of the pituitary gland, producing thyroid stimulating hormone (TSH) which then binds to the thyroid gland causing it to secrete thyroid hormone Edit
Levels controlled dually by inhibiting and stimulating hormones.
Doesn't directly have an affect, it is sent to the liver where it is converted into insulin growth factors/sematomedins which feedback and inhibit releasing hormone or stimulate the inhibitory hormone when needed.
Follicle Stimulating Hormone (FSH)
Gonadotrphin along with LH (affect gonads)
Inducer - Gonadotrophin Releasing Hormone (GnRH) from hypothalamus
Target - Gonatotrophs on gonads
Effects - Follicular development and sperm maturation
Inhibitors - Sex hormones (estrogen and testosterone) and inhibin
Stimulates the RELEASE of milk.
Inducer - Infant nursing and crying (sensory afferent neurons in areolar region)
Targets - Uterus, breasts
Effects - Uterine contractions, stimulates smooth muscle to contract and pushes milk from secretory duct to the duct portion, which coalesces at the nipple (milk let-down)
Inhibitors - Catecholamines, stress
Vasopressin (ADH) (AVH)
Inducer - High blood osmolarity, low volume and low pressure which stimulate the cell bodies in the hypothalamus (osmoreceptors)
Targets - Kidney collecting ducts
Effect - Water re-absorption (AVH, during hemorrhage, can cause vasoconstriction)
Inhibitors - Alcohol (binds to supraoptic nerves), Low blood osmolarity, high volume and high pressure
Precursor of thyroid
T3 and T4 molecules covalently linked
Found within the lumen of the follicles
Has to be iodidated before being endocytotically taken into the cell where it is digested by lysosomal enzymes into T3 and T4 which are secreted basally into a capillary
F-Cells (PP cells)
Secretes pancreatic polypeptide, believed to influence exocrine pancreas, so it is a paracrine hormone
Targets digestive cells
Inhibits gallbladder contractions, influences rate of nutrient absorption and regulates pancreatic enzymes
Stimulated by protein-rich meal and parasympathetic stimulation
Type 1 and Type 2
Type one basically requires insulin therapy, type two can also require it.
Autoimmune disease where the pancreas or beta cells are being attacked. If pancreas is being destroyed, digestive enzymes must also be taken
Ketones are made when cells can't "see" glucose and use fat for energy while also being hyperglycemic
Tissue rejection is why beta cell therapy fails for type 1
Cardiovascular changes are the worst symptoms
Stimulates zona glomerulosa cells to produce aldosterone to cause the reabsorption of sodium from the kidneys, increasing water absorption increasing blood volume and pressure.
It also stimulates supraoptic nuclei in brain to make ADH causing further water reabsorption and increase thirst.
Vasoconstrictor, makes blood vessels smaller.
Carries a lot of heat, main reason vasodilation and vasoconstriction work in temperature regulation
Makes up 55% of blood
7% plasma proteins (albumin, globulins, fibrinogens, regulatory proteins)
1% other solutes (glucose, electrolytes, nutrients, wastes)
Differs from interstitial fluid in proteins and gases
Non-specific protein transporter of hydrophobic stuff Found in blood plasma, produced by the liver.
Significantly affects BCOP (blood colloid osmotic pressure) which keeps blood volume and pressure high enough to function.
Transports fatty acids, thyroid hormones and steroids
Most abundant plasma protein
Most abundant WBC - 60-70%
Responsible for specific immune response (seek&attack)
Attack marked bacteria (antibodies by B-Cells), phagocytosing it into a phagosome which is bound to a lysosome which degrades it
Undergo respiratory burst, a time of more oxygen creating more free radicals and breaking cell up
Nucleus has many lobe (polymorphous structure)
Elevated number could mean cancer, bacterial infection
Least abundant WBC
Contains granules of histamine and heparin in cytoplasm (purplish-blue granules)
Mast cell in connective tissue is analogous
Histamine induces inflammation, making blood vessels leaky while heparin prevents hemostasis to allow plasma to leak into the site of infection
Contains pink granules (membrane-bound vesicles)
High levels are strong indication of parasitic infection
Attack and phagocytose objects coated with antibodies (antibody-antigen complexes during allergic reaction), but smaller things than neutrophils
Attacks parasitic worm by exocytosing chemicals onto the organism and creating holes in the plasma membranes of its cells
Nitric oxide and other compounds are created to do this
Percentage of RBCs in a sample of blood
Heparin or other anticoagulent is put in a tube which is put in a centrifuge to separate the cells.
Plasma on top, buffy coat layer (platelets, leukocytes, only 1%) then RBCs on bottom
Higher in males due to higher androgen content (testosterone stimulates hematopoeisis)
Tells if person is anemic, their oxygen-carrying capacity
Has 4 nitrogen and 4 carbon termini
Can bind 4 oxygen atoms (heme), Carbon dioxide (to N-termini), protons (to R-groups), 2,3 BPG (middle), CO (heme, fits better than O2) and NO (R-groups)
Has tense and relaxed states
Low affinity for oxygen when other things are bound to it (CO2, H+ and 2,3 BPG)
Single point mutation in protein sequence, glutamic acid (polar) made to valine (nonpolar)
Entire hemoglobin molecule becomes more hydrophobic, causing hemoglobin agglutination.
Can no longer fold, can damage capillaries as it goes along and oxygen-carrying capacity is reduced (poor perfusion to tissue as well)
Life span is only 10 days
Erythroblastosis Fetalis (HDM)
Hemolytic disease of newborn
An Rh negative mother gives birth to an Rh positive fetus Fetus has antigens on its blood cells causing her to become sensitized to the it when hemhoragging happens during labor.
When the second Rh fetus is made, Antibodies formed during first delivery cross over to the fetus, cause agglutination of blood cells causing them to lyse, making the fetus anemic and eventually killing it.
Treated prophylactically with Rogan
A metabolic process in activated phagocytes (i.e. neutrophils) in which the rapid uptake of oxygen is used to produce reactive oxygen intermediates that are toxic to ingested microorganisms
Superoxide, hydrogen peroxide, hyperchlorous acid etc steal electrons from tissue and breaking bonds in them
Cardiac Conduction System
No neurons, no synapses on cardiocytes that create baseline heartbeat in this system
Modified myocardial cells - some can spontaneously depolarize and/or conduct action potentials
SA Node can generate a resting membrane potential but can't maintain it.
Cardiocytes have beta 1 and 2 receptors so they can overtake this system to keep the heart beating
SA (sinoatrial) Node
Conducts signal to internodal fibers of atrial muscle cells, which connect it to the AV node
On right side of heart - posterior wall of right atrium
Pacemaker - sets the rate spontaneously
As they are depolarized, they depolarize the rest
RMP of -60mV slowly drifts away to -40mV with no stimulation, ions just leak in causing an action potential
AV Bundle (Bungle of His)
Travels down interventricular septum
Branches into two conductile tissue fibers, left and right bundle branches
After the bundle branches is the fiber, moderator band, which goes into the right ventricle and tells the papillary muscles to contract
At the apex of the heart, the bundle branches merge into the Perkinje fibers
Atrial Systole/Ventricular Diastole Pressure
Aortic valve closes (second heart sound) and Left AV valve opens
Left ventricular volume is slowly rising passively, pressure is going down. Isovolumetric ventricular relaxation until pressure is lower in ventricle than atrium allowing blood in
Left atrial pressure is slightly higher than left ventricular, both are very low
Pressure of aorta is around 90mmHg, much higher than both
Atrial Diastole/Ventricular Systole Pressure
After Left AV valve closes (first heart sound) and then Aortic valve opens
Left ventricle pressure rises in isovolumetric ventricular contraction and both it and aortic pressure reach about 120 mmHg, opening the aortic semilunar valve going into rapid ejection phase.
Left atrial pressure remains low
Arterial blood pressure
Position the cuff around the brachium with pressure gauge and balloon lines on antebrachium (brachial artery)
Completely shuts off blood supply to the arm
Take pressure above 120mmHg (~140) then release. Stethoscope is positioned over brachial artery distal to the cuff, and at the point at which blood begins leaking through the blood vessel, sounds start indicating systolic blood pressure.
You continue hearing Korotkoff sounds as pressure is slowly released until sounds stop and blood vessel is as open as it can be, which is diastolic pressure.
Property of hemoglobin.
When hemoglobin has no oxygen bound, it has a certain affinity for oxygen. When an oxygen binds, the other sites have increased infinity.
When another oxygen binds, the last two sites raise in affinity even more until they're all bound
Also, when one falls off, the others fall off more quickly
Right shift in the oxygen-hemoglobin saturation curve due to CO2, which binds to hemoglobin creating carbonylhemoglobin which has a lower affinity for oxygen
Bicarbonate buffer system goes to the right, making a lot of protons, lowering the oxygen affinity even more along with the production of 2,3 BPG