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blood clotting: a three step program. 1. plug it up 2. slow the flow 3. seal the slice site. 1. plug it up. this is accomplished by the platelets, those small blood cells we talked about earlier they undergo a drastic change in shape when they
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blood clotting: a three step program 1. plug it up 2. slow the flow 3. seal the slice site
1. plug it up this is accomplished by the platelets, those small blood cells we talked about earlier they undergo a drastic change in shape when they contact collagen and other compounds not encountered in the blood vessel wall, but found on the outside of the vessels. why do they encounter the outside of the vessel? skin collagen blood vessel wall blood vessel before after Texas A&M-Kingsville, Dr. J.C. Pérez
2. slow the flow signals released from clumped platelets (including serotonin) cause the blood vessels to constrict this slows the flow of blood to the cut site clumped platelets after before Texas A&M-Kingsville, Dr. J.C. Pérez
3. seal the slice site floating around in your bloodstream are blood clotting proteins in their inactive form contact with the wound site, collagen, and possibly other factors start a cascading process where these proteins are transformed into their active forms at the end of this complex cascade is the production of a fibrous protein called "fibrin" which first forms a soft clot eventually, through cross-linking, the fibrin proteins form a hard clot (a "scab") Texas A&M-Kingsville, Dr. J.C. Pérez
Hemophilia a genetic disease effecting mostly males at a rate of about 1 in several thousand hemophiliacs have problems with blood clotting they also can start to bleed internally with light trauma in their joints and muscles without treatment, this can lead to severe pain, joint damage, disability and early death it is caused by alterations in the DNA sequence of either factor VIII, factor IX or (more rarely) factor XI Texas A&M-Kingsville, Dr. J.C. Pérez
so how do the blood clots form that cause strokes? it's not known entirely, but experiments with mice have suggested that a product of fat cells in the body - leptin - somehow causes platelets to clump together improperly, leading to blood clots. ...so people with excess fat cells presumably have higher levels of leptin in the blood than normal, which could explain the increased blood clotting in overweight people the resulting stoppage or decrease in blood flow can lead to a stroke recent studies suggest, though, that what may be happening is that leptin buildup leads to "plaques" - fatty deposits on the walls of blood vessels. If these plaques burst, then the body initiates a blood clotting reaction, and this can lead to a stroke or heart attack thanks Beth! centers for disease control
blood types determined by "antigens" on the surfaces of red blood cells these antigens are proteins produced from genes for our purposes, there are two classes of these antigens (there are actually many more than that) 1) ABO 2) Rh factor
ABO blood types ABO refers to the three types of antigens in this class: "A" "B" and "O" ("O" means no antigen at all) Since you inherited one antigen from your mother & one from your father, then different people have one of the following 6 combinations: AA, AO, BB, BO, AB, OO AA and AO are "type A" BB and BO are "type B" AB is "type AB" OO is type "type O"
Rh factor blood types this is easier, since there are only two possibilities: either you inherited, (from each parent) an Rh antigen or you didn’t "+" means that you inherited an Rh antigen "-" means that you didn't again, there are three possibilities, since you inherited one Rh gene from your mother and one from your father: ++, +-, and -- ++ and +- are "Rh+" -- is "Rh-"
what are the universal donor and universal acceptor blood types and why? Rh don’t people who have one of the blood antigen types on their red blood cells have the other type of antibody in their blood so...if you are blood type A then you have antibodies in your blood and if you are blood type B then you have antibodies in your blood and if you are blood type O then you have antibodies in your blood and if you are blood type AB then you have antibody in your blood and if you are blood type Rh- then you have antibodies in your blood and if you are blood type Rh+ then you have antibodies in your blood B A A and B neither Rh+ these antibodies will react to blood cells that have an antigen of the same type. so if you receive such blood, then your body will reject it! that would be bad!
the red cross wants YOU! http://gammillustrations.bizland.com/ monsterkid3/html/3dmons3.html so...... if you are type AB+, then you have no A,B, or Rh antibodies so you are a "universal blood acceptor" - your immune system will reject no blood (lucky you!) and if you are type O-, then you have all the antibodies, so you can only accept O- blood. BUT, since, you have no A, B, or Rh antigens you are a "universal blood donor" - since no one will reject your blood!
what are hormones, and what are they good for? substances produced in one part of the body that are carried in the bloodstream and have effects on other parts of the body a way for one part of the body to communicate with other parts of the body a way for the body to coordinate responses in multiple parts of the body at the same time a way to control a process that needs to vary over time
endocrine system body function hormone(s) (examples) digestion, basal metabolism, etc. insulin, noradrenaline, thyroid hormone, corticosteroids water and salt regulation, excretion, etc. vasopressin, prolactin calcium metabolism calcitonin growth and development growth hormone, thyroid hormone reproductive organs & reproduction FSH, LH, estrogen, prolactin, testosterone progesterone
types of hormones steroid hormones - derived from cholesterol peptide hormones - transcribed from genes (e.g. insulin, melatonin, adrenaline) modified amino acids(e.g. thyroid hormone)
control of levels of hormones 1) via both positive and negative control (e.g. oxytocin) 2) negative feedback systems e.g. corticotropin - corticosteroid thyroid stimulating hormone - thyroid hormone follicle-stimulating hormone - sex steroids
some endocrine glands (and examples of hormones produced there) pituitary gland (in the brain) (thyroid stimulating hormone, growth hormone, prolactin) thyroid (in the throat) (thyroid hormones) adrenal (on top of the kidney) (aldosterone, glucocorticoids) pancreas (accessory digestive organ) (insulin, glucagon) kidney (erythropoietin) reproductive (ovaries/testes) (LH, FSH, sex steroids) Kidney training.seer.cancer.gov