Glossary of ACNM Human Biology#2

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What is Hematology?
The study of blood and blood disorders
Blood is made up of which two components?
Plasma (mainly water) and Formed Cells (White blood cells, red blood cells, platelets)
What are some functions of blood?
Transportation (CO2, O2, Wastes, nutrients)
Heat regulation
Regulation of PH
Protection from disease and blood loss
What is the average PH of blood?
How many Litres of blood are in normal circulation in:
A male?
A female?
Male: 5-6L
Female: 4-5L
What kind of feedback system maintains constant blood volume and osmotic pressure?
Hormonal Negative feedback systems.
What are 2 methods of sampling blood?
Finger/Heel stick
What is the breakdown of blood on a hematocrit? (percentages of each substance)
55% plasma (Over 90% of which is water, 7% plasma proteins, and 2% other substances).
45% Cells (99% RBC, 1% WBC and platelets)
What are 3 Plasma Proteins found in blood?
Albumin, Globulins and Fibrinogen
Where are Plasma proteins manufactured?
In the LIVER
What is a function of Albumin?
Maintains blood osmotic pressure
What is a function of Globulins?
They are antibodies. They bind to antigens forming an "antibody-antigen" complex.
What is a function of Fibrinogen?
What is the 'Technical' name for a RED BLOOD CELL?
What is the 'Technical' name for a WHITE BLOOD CELL?
What are the 2 main divisions of Leukocytes?
Granular and Agranular
Name the Granular Leukocytes (3)
Name the Agranular Leukocytes (2)
What are the divisions of Lymphocytes? (3)
T cells
B cells
NK cells
Which Leukocyte is usually found i the highest concentration when inflamation or infection is present?
What % of blood is occupied by cells in a:
Male: ~ 46%
Female: ~ 42%
What is anaemia?
Not enough haemoglobin or Red Blood cells
What name do we give to the condition where there are too many Red Blood Cells in the blood stream (over 65%)?
What are some causes of Polycythemia?
Dehydration. Tissue Hypoxia. Blood Doping...
What is the technical name for blood cell formation?
Hematopoiesis/ Hemopoiesis
Where does Hematopoiesis occur in an adult?
Red marrow of flat bones
(Sternum, ribs, skull, pelvis and ends of long bones)
Stem cells differentiate into which 2 types of cells?
Lymphoid and Myeloid
What do Hemopoietic Growth Factors do?
Regulate differentiation and prolifereation of blood components
What are 3 Hemopoietic Growth Factors?
Erythropoietin (EPO)
Thrombopoietin (TPO)
Where do EPO, TPO and cytokines come from?
EPO - Kidney
TPO - Liver
Cytokines - Bone marrow
What affect does Erythropoietin have on blood formation?
It increases Red blood cell precursors
What affect does Thrombopoietin have on blood formation?
Stimulates Platelet formation
What affect do Cytokines have on blood formation?
They stimulate proliferation of other marrow cells, and secrete Colony stimulation factor & interleukin to stimulate White blood cell production.
In what instances may EPO, TPO and cytokines be given for medicinal purposes?
Kidney disease
Liver disease
What is the shape of a Red Blood Cell (RBC)? Why is this shape necessary?
To increase surface area and so that they are flexible.
Do RBC's have a nucleus or organelles?
Do WBC's have a nucleus?
How many oxygen molecules can each Hemoglobin unit carry?
Describe the components of a Hemoglobin molecule:
4 polypeptide chains.
One heme (Fe+2) pigment per chain.
What affect does Nitric Oxide (NO) have on blood vessels?
Causes valodilation
What affect does SUPER Nitric Oxide (SNO) have on blood vessels?
Causes Vasoconstriction
What is the life expectancy of a RBC?
120 days
Why don't RBC's repair?
They wear out from bending, but cannot repain because they have NO ORGANELLES!
Who takes care of worn out RBC's? And Where do they go to die?
Fixed macrophages remove dead/dying RBC's/
The spleen and liver.
What happens to the GLOBIN half of Hemoglobin when it is recycled?
The polypeptide chains are broken into amino acids and recycled.
What happens to the HEME half of Hemoglobin when it is recycled?
Heme is broken into:
*Iron (Fe+3)

Transferrin proteins take the heme to the liver, muscles or spleen. It is stores attached to ferretin of hemosiderin protein.
Biliverdin is converted to bilirubin and secreted by the liver into bile. It is converted to urobilinogen or stercobilin and excreted.
Briefly describe the process of Erythropoiesis:
In marrow:
*PROERYTHROBLAST starts to prod. hemoglobin.
*Nucleus ejected- RETICULOCYTE formed.
Escapes from marrow into blood.
Ejects organelles and becomes a MATURE RBC.
What kinds of feedback may stimulate Erythropoiesis?
Tissue hypoxia- high altitude, anaemia, blood loss, circulatory problems.
What percentage of circulation RBC's should be reticulocytes?
A HIGH reticulocyte count may indicate:
Recet blood loss. Successful Fe Therapy.
A LOW reticulocyte count may indicate:
Bone marrow problems (eg leukaemia), Nutritional deficiency, failure of marrow to respond to EPO.
Which 2 Leukocytes will normally be in highest concentration in the blood stream?
Neutrophils (60-70% of WBC)
Lymphocytes (20-25%)
What is the ratio of
What is Leukocytosis?
What may cause it?
Excessive WBC count.
Microbes, excessive exercise, anesthesia, surgery.
What is Leukopenia?
What may cause it?
Low WBC count.
Radiation. Shock. Chemotherapy.
What % of WBC population is in circulation at any one time?
Where are the rest?
In the Lymphatics, skin, lungs and spleen.
How do Neutrophils work against bacteria?
Release lysosomes, defensin proteins (poke holes) and oxidants.
What will result in High neutrophil levels?
Bacterial Infection.
What will result in High monocyte levels?
Viral or fungal infection
What will result in High Basophil levels?
Allergy and Hyperthyroid
What reactions are Basophil's involved in?
How do they contribute to this reaction?
Basophils are involved in ALLERGY and INFLAMMATORY reactions.

They release Heparin, histamine and serotonin.
What are 3 functions of Eosinophil's?
Release histaminase.
Attack Parasitic worms.
Phagocytise Antibody-antigen complexes.
Name the 2 Major categories of Lymphocyte:
B cells
T Cells
What is a function of B-cells?
Destroy Bacteria and their toxins.
Turn into plasma cells and produce antibodies.
Which cells produce antibodies?
Plasma cells
Which cell differentiate into plasma cells?
B cells
What do T-cells attack?
Attack viruses, fungi, transplanted organs, cancer cells and some bacteria.
How do natural killer cells kill invaders?
By direct attack.
Changes in WBC count can indicate...
infection, poisioning, leukaemia, chemotherapy, parasites or allergies...
Which leukocyte will be elevated in hypothyroidism?
WHERE do platelets form?
In the bone marrow
Name the 5 steps in the formation of platelets:
1. Myeloid Stem cells
2. Megakaryocyte-colony forming cells
3. Megakaryoblasts
4. Megakaryocytes
5. Platelets
What is the normal haemoglobin range for an
*Adult female?
*Adult male?
Infant- 14-20g per 100ml blood
Female- 12-16g
Male- 13.5-18g
Stoppage of bleeding in a quick & localised fashion when blood vessels are damaged.
Prevents hemorrhage.
What are 3 methods of hemostasis?
Vascular spasm.
Platelet Plug formation.
Blood clotting.
What is vascular spasm?
Reflex contraction of the smooth muscle of blood vessels, in response to damage to blood vessel (pain receptors stimulated).
Can reduce blood loss in small vessel or arteriole for several hours.
In platelet plug formation, what 'granules' are involved?
Alpha and Dense granules.
What are the 3 steps to platelet plug formation?
1- platelet adhesion.
2- Platelet release reaction
3- platelet aggregation
Describe the first step of platelet plug formation- platelet adhesion:
Platelets stick to exposed collagen of damaged damaged vessel wall.
Describe the second step of platelet plug formation- platelet release reaction:
Platelets are activated by adhesion, they then extend projections & release thromboxane A2 and ADP (to activate other platelets).
Serotonin and Throm A2 are vasoconstrictors and reduce blood flow.
Describe the third step of platelet plug formation- platelet aggregation:
Activated platelets stick together and activate new platelets, forming a mass called a platelet plug. the plug is reinforced by fibrin threads.
Clotting which occurs in an unbroken vessel is called
Describe the concept of 'BLOOD CLOTTING'
Blood drawn from the body thickens into a gel. The gel separates into a liquid (serum) and a clot of insoluable fibres (fibrin) in which the cells are trapped.
What substances are required for clotting?
Ca+2, enzymes from the liver & substances released by platelets or damaged tissues.
What enzyme coverts prothrombin in thrombin?
Prothrombinase and Ca
Fibrinogen is turned into fibrin by...
What are the 2 alternate pathways involved in the clotting cascade?
Intrinsic. Extrinsic.
In clotting: trapped platelets release ????, stabilising the fibrin threads
trapped platelets release FACTOR13, stabilising the fibrin threads
What vitamin plays an essential role in clotting?
Vitamin K
What is fibrinolysis?
B'down of clots
Of the intrinsic and extrinsic clotting pathways- which occurs most rapidly?
The extrinsic pathway.
It occurs in fewer steps and within a couple of minutes.
How many stages can clotting be divided into?
What product do both the intrinsic and extrinsic pathway lead to the production of?
Describe briefly the EXTRINSIC PATHWAY to clotting:
Injury occurs.
*Tissue factor* (TF) leaks from the damaged cells.
In the presence of *Calcium*, *factor 10* is activated.
Actvated factor 10 combines with *factor 5*, again, in the presence of *Ca*.
This forms *prothrombinase*.
(it's a good idea to practice drawing this too!)
Describe briefly the INTRINSIC PATHWAY to clotting:
Endothelial cells are damaged, exposing collagen.
Platelets are damaged.
Clotting factor 12 is activated. In the presence of Ca factor 10 is activated. Platelet phospholipids from the damaged platelets will, with calcium, also activate factor 10.
Once factor 10 is activated it combines with *factor 5*, again, in the presence of *Ca*.
This forms *prothrombinase*.
(it's a good idea to practice drawing this too!)
Why is the INTRINSIC path known as intrinsic?
Because the activators are either in direct contact with the blood or contained within.
What is the pathway after prothrombinase formation called?
The common pathway
What does the common pathway involve?
Once prothrombinase is formed, it and Ca cause Prothrombin to become Thrombin.
This thrombin, in the presence of Ca, converts fibrinogen(soluable) to loose fibrin threads (insoluable). Thrombin also activates Factor 13, which stabilises the fibrin threads.
(it's a good idea to practice drawing this too!)
What feedback system does the clotting cascade follow, and at what steps?
POSITIVE feedback.
1. involving factor 5 it accellerates prothrombinase production.
2. where thrombin activates platelets.
What substnce(s) converts Fibrinogen to loose fibrin threads, in the final common pathway?
What substance strengthens these threads next?
Thrombin with Ca converts Fibrinogen into fibrin threads.
Thrombin also activates factor 13 which then strengthens the fibrin threads.
What substance(s) converts Prothrombin to Thrombin, in the common pathway?
Prothrombinase and calcium
Activated factor 10 combines with WHAT to form Prothrombinase?
Factor 5 and calcim
Extrinsic Pathway:
How is factor 12 activated?
What does it in turn activate?
Factor 12 activated by platelet damage.
Factor 12 with calcium will activate factor 10.
What is the final result of the clotting cascade?
The production of fibrin threads.
Name all the substances involved in the INTRINSIC clotting pathway:
Ca, Clotting factors 12, 10 and 5.
Name all the substances involved in the EXTRINSIC clotting pathway:
Ca, Clotting factor 10 & 5.
What is the purpose of a clot?
To plug the ruptured area of a blood vessel.
How does a clot enable tissue to repair?
The clot plugs the damaged area. Platelets pull on the fibrin threads causing clot retraction, the edges of the damaged vessel are pulled together. Fibroblasts and endothelial cells repair the tissue.
Is vitamin K fat or water soluable?
What can inhibit absorption?
Fat soluable.
Decreased bile release can inhibit, as can diet void of fats.
What is the dissolution of a clot called?
What is an embolus?
A clot, air bubble or fat from a bkoken bone, travelling in the blood. A thrombus that has moved.
What is the function of THROMBOXANE A2?
It strenghtens clotting.
What does an anticoagulant do?
Suppress or prevent blood clotting.
Name an anticoagulant:
Name a thrombolytic agent (a substance that will b'down a clot)
Tissue plasminogen activator (t-PA).
Name the 4 blood types?
A, B, AB, O.
What is it that determines a persons 'blood type'?
Agglutinogens (also called isoantigens).
Agglutinogens are surface markers on the surface of a RBC. They are made of glycoproteins and glycolipids.
Blood type A will have what plasma iso-antibodies?
Anti B
Blood type B will have what plasma iso-antibodies?
Anti A
Blood type AB will have what plasma iso-antibodies?
Blood type O will have what plasma iso-antibodies?
Anti A & Anti B
Who is the universal blood donor?
Blood type O.
Blood type O has NO AGGLUTINOGENS marking it's surface, so it won't be seen as foreign!
Who is the universal blood recipient?
Blood type AB.
A person with blood type AB has NO ISO-ANTIBODIES in it's plasma, so they won't attack foreign blood.
Can type A give to type A? B? AB? O?
It can give to Type A (because it's the same) & AB (because it has no iso-antibodies)
I can recieve type AB blood. What blood type am I?
Type AB.
(Type AB is the tight-arse. It will recieve from everyone and give to itself, but nobody else.)
I can recieve type O blood. What blood type am I?
All blood types can recieve type O, it is the universal donor, because it has no surface agglutinogens.
What is RHESUS factor (Rh factor)?
Rhesus factor, first discovered in the blood of a rhesus monkey, refers to the presence of an EXTRA surface agglutinogen, which appears alongside the agglutinogens which determine blood type.
You either HAVE it (you're Rh+), or you DON'T (Rh-)!
I'm blood type O+. Describe the agglutinogens on my RBC's.
Blood type O has no surface agglutinogens. The Rhesus Agglutinogens will be present.
I'm blood type AB+. describe the agglutinogens on my RBC's.
Blood type AB:
has both A and B surface agglutinogens. Because it is +, it contains the rhesus factor agglutinogen, too! (pretty crowded on there!)
I'm blood type B-. describe the agglutinogens on my RBC's.
Blood type B will have B-type agglutinogens. Because the person is B- there will be no rhesus agglutinogens present.
I'm blood type B+. What agglutinogens are on my RBC?
Blood type B will have B-type agglutinogens. Because the person is B+ there will also be rhesus agglutinogens present.
I have blood which is Rh+. Can i ever develop antibodies against Rh-?
No. Rh+ will NEVER develop antibodies against Rh-.

*This is because a Rh- cell is blank! It contains no Rh aglutinogens*
I have blood which is Rh-. Can i ever develop antibodies against Rh+?
A person with Rh- blood will develop antibodies against Rh+ blood. A reaction will occur with the SECOND exposure.
Mother: Rh+. Baby: Rh-.
Will there be a problem?
Mother: Rh-. Baby: Rh+.
Will there be a problem?
Yes. When the baby's blood mixes with the mothers at birth, the mother will manufacture antibodies agianst this foreign rhesus blood. (her blood doesn't have a rhesus marking, so she will see it as foreign).
What is the result of an incompatible blood transfusion?
Antibody-antigen complexws form.
Agglutination- visible clumping.
Donated RBC's destroyed.
Loose hemoglobin can cause kidney damage.
Name at least 4 types of anaemia
Iron Deficiency.
Sickle Cell.
What is hemophilia?
Inherited deficiency of clotting factors.
What organs are part of the lymphatic system?
Red bone marrow.
Lymph nodes.
Diffuse lymphatic tissue (tonsils, adenoids, peyers patches).
What are 3 functions of the Lymphatic system?
*DRAINING excess interstitial fluid & plasma from tissue spaces.
*TRANSPORTING dietary lipids and vitamins from GI tract to blood.
*Facilitation of IMMUNE RESPONSES
Lymphatic vessels empty into...
Name the major Lymph trunks and ducts of the thorax:
(possibly a labelling Q!)
Intestinal trunk. R&L Lumbar trunk. Cisterna Chyli. Right lymphatic duct. Thoracic duct (left lymphatic). R&L mediastinal trunk. L&R subclavian trunk. L&R jugular trunk.
Where in the body is lymphatic tissue not present?
Avascular tissue -cartilage, epidermis and cornea. Also CNS and parts of the spleen.
Lymphatic capillaries in the GI tract are known as ? and contain ?
They contain Chyle.
Lymphatic system:
The right side of the head, arm and chest empty into the ?? duct
The right side of the head arm and chest empty into the RIGHT LYMPHATIC duct
The left side of the head, arm, chest and rest of the body empties into the ?? duct
The left side of the head, arm, chest and rest of the body empties into the THORACIC duct
What promotes the flow of lymph?
Respiratory and muscular pumps.
What are the primary lymphatic organs?
Red bone marrow.
What are the secondary lymphatic organs?
Lymph nodes.
Lymphatic nodules.
What is present in the thymus:
Cortex: Tightly packed Tcells and lymphocytes

Medella: Thymic hormones produced. Hassall's corpuscles.
What is the function of a lymph node?
To filter the lymph fluid.

Nodes contain dendritic cells, APCells, macrophages and Bcells. - to kill bad guys.
What is metastasis?
Movement of cancer cells from one part of the body to another.

Cancer cells often travel via lymphatic system or blood.
The parenchyma of the spleen contains what two colours of tissue?
What is found in each part?
RED and WHITE pulp.
White is lymphatic tissue (lymphocytes and macrophages)
Red is venous sinuses filled with blood and spleenic tissue.
What is M.A.L.T?
Mucosa associated lymphoid tissue.

Concentrations of lymphatic tissues not surrounded by a capsule. scattered throughout m.membranes.
Eg. tonsils, appendix, peyers patches.
Immediate protection against wide variety of pathogens and foreign substances.
Mechanisms function regardless to type of invader.
Include External mechanical barriers and Internal non-specific defences.
*Antimicrobial proteins (inteferons, complement proteins, transferrins).
*NK cells (attack cell displaying abnormal MHC antigens) and phagocytes (neutrophils and macrophages).
Inflamation and fever.
Name the 4 steps to phagocytosis:
1. Chemotaxis
2. Adherence
3. Ingestion
4. Digestion and killing
What is M.H.C?
Major Histocompatability Complex
What causes fever?
Resetting of the hypothalamic thermostat.
What substances cause fever?
Cytokines such as Interleukin-1
The bodies ability to defent itself against specific foreign material of organisms.
*Specificity *Memory
What are the 2 types of T cells?
Killer & Helper
Where are T-cells formed? Where do they mature?
T cells are formed in the bone marrow. They mature in the thymus.
Where are B-cells formed? Where do they mature?
B cells are formed and mature in the bone marrow.
What is another name for a 'Platelet?'
What are some benefits of a fever?
Decrease bacterial activity.
Increase action of interferons,
and tissue repair.
What is the function of a:
KILLER T cell?
HELPER T cell?
Killer - attack antigens
Helper - stimulate T and B cells
What is a T4 cell?
What is a T8 Cell?
T4 = Helper T cell
T8 = Killer T cell
Of the T & B cells, which have antigen receptors?
B cells and T4 (helper T cells)
What 2 characteristics must something posess to be considered an antigen?
What is an epitope?
The tip of an antigen which triggers an immune response. The ANTIGENIC DETERMINANT.
Large complex molecule, usually protein.
What is a Hapten?
A smaller version of an epitope, but too small to trigger a reaction.
What is MHCI?
Surface markers on a cell. Built into the cell membrane of all cells (except RBC)
What is MHCII?
Surface markers on a cell. Seen only on the membranes of antigen presenting cells (Macrophages, B cells, Thymus cells)
What happens to a cell, in regard to MHCI, if it is attacked by a virus?
If a cell is attacked by a virus, the MHCI of the cell will display this data, informing other cells ("help! help!")
What happens to an Antigen presenting cell, in regard to MHCII, if it ingests a foreign protein?
The APC (macrophages, B-cell's) ingests the foreign matter, and then displays part of the antigen, as a part of it's MHCII.
When will T cells 'see' an antigen?
A Helper T cell will 'see' an antigen when it is shown to them on the MHCII of an APC.
Killer T cells will recognise the MHCI of infected body cells.
After an APC phagocytises a foreign invader, what happens?
The APC will digest the invader and display fragments of it on their MHCII.
The APC will the migrate into lymphatic tissue to show the T cells.
What is a cytokine?
Where is it secreted?
Small protein hormones, involved in immune response. Secreted by lymphocytes & APC's.
What does T8 differentiate into?
After being stimulated by a helper T cell, the cytotoxic T cell proliferates and differentiates into: Clone Tc Cells (Attack!) & Memory Tc cells (long lived)
What does T4 differentiate into?
Helper T cell binds to foreign antigen fragment, proliferates and differentiates into Population/Clone Th Cells & Memory Th cells (long lived)
What 3 classes will a mature T cell differentiate into?
T4 Helper (Th),
T8 cytotoxic/killer (Tc),
Memory T cells.
What is antibody mediated immunity?
B cells sit in lymph nodes/spleen/peyers patches.
Antigens are brought to them.
Once activated- B cells differentiate into plasma cells- secrete antibodies.
How does an antibody work?
Antibodies enter circulation and combine with the epitope of the antigen.
This will *neutralise antigen *block toxins *immobilise *Agglutinate *activate complement *Attract phagocytes
What shape is an antibody generally?
What are the 5 types?
T or Y.
IgG, IgA, IgM, IgE, IgD
What is the complement system?
A defensive system involving plasma proteins- destroys microbes.
Produces: Inflammation, opsonization, cytolysis.
Do cytotoxic T cells recognise MHCI? or MHCII?
Do Helper T cells recognise MHCI? or MHCII?
What system am I?
Hormones being released into the bloodstream and travelling throughout the body. Results of my actions take minutes or hours, but will last longer.
The endocrine system.
What system am I?
I release hormones and neurotransmitters. Results of my actions occur in milliseconds, but don't last long.
The nervous system.
What are 3 functions of Hormones?
Growth & Development.
Regulation of body systems.
What are some examples of bodily functions that Hormones help regulate?
Extracellular Fluid.
Biological clock.
Contraction of cardiac and smooth muscle.
Glandular secretion.
Some immune functions.
What is an exocrine gland?
Give an example of one.
Glands that secrete products into ducts, emptying into body cavities or body surface.
eg. sweat, oil, mucous, digestive glands...
What is an endocrine gland?
Give an example of one.
Glands that secrete products (hormones) into the bloodstream.
eg. pituitary, thyroid, parathyroid, adrenal, pineal..etc.
Hormones only affect target cells with specific membrane proteins called ______?
Hormones only affect target cells with specific membrane proteins called RECEPTORS.
What are the 2 types of regulation used by hormone receptors?
What is down-regulation?
Causes a decrease in the sensitivity of a target cell to a hormone.
Excess hormone produces a decrease in the number of receptors (receptors-endocytosis-degraded).
What is up-regulation?
Deficiency in hormone produces an increase in the number of receptors. Target tissue becomes more sensitive to the hormone.
What is a circulating hormone?
What is a local hormone?
Circulating: Acts on distant target, travels in blood. eg. ADH, adrenalin.
Local: Panacrines act on neighbouring cells, autocrines act on the same cell that secreted it. eg. TSH.
Name 2 Lipid-soluable hormone classes:
Thyroid hormones.
Nitric Oxide gas.
Name 2 Water soluable hormone classes:
Eicosanoids (prostoglandins leukotrienes).
Amine, peptide and protein hormones (serotonin, melatonin, histamine, adrenaline)
What is the difference between the way PROTEIN and STEROID hormones circulate in the blood?
Protein hormones circulate in free form. Steroid hormones must attach to transport proteins synthesised in the liver.
What is the difference between the way LIPID-SOLUABLE and WATER-SOLUABLE hormones enter a cell?
Steroid hormones diffuse through phospholipid biolayer. Water soluable hormones cannot. Water soluable hormones must utilise hormone receptors, G-Proteins, adenine cyclase, etc.
Describe the path a WATER SOLUABLE HORMONE follows to affect a cell.
Hormone cannot diffuse through the cell.
*HORMONE RECEPTORS in the membrane act as the 1st MESSENGER. They activate
*G-PROTEIN, who activates
*ATP is converts to *cAMP (2nd messenger). cAMP activates
*KINASES (alter physiological processes).
*cAMP is quickly decativated by *PHOSPHODIESTERASE.
The end.
What is the first and second messenger involved in the entry of a water-soluable hormone into a cell?
1st messenger- Hormone receptors: integral membrane proteins.
2nd messenger: Cyclic AMP
How many units of G-protein does 1 molecule of hormone activate? In turn how many units of adenine cyclase does each G-protien activate?
Hormonal interactions:
What is the permissive effect?
A second hormone strengthens the effects of the first.
eg. thyroid hormone strengthens the effect of adrenalin on lipolysis.
Hormonal interactions:
What is the synergistic effect?
2 hormones act together for greater effect.
eg. Oestrogen and LH
Hormonal interactions:
What is the antagonistic effect?
2 hormones with opposite effects.
eg. Insulin and glucagon
What are 3 controlling effects over hormone secretion?
Chemical changes (in blood).
Other Hormones.
Nervous system signals.
Describe negative feedback?
A decrease or increase in blood level in reversed.
Describe positive feedback?
The change produced by a hormone causes more hormone to be released.
What are the 2 "master" endocrine glands?
Hypothalaus and pituitary Gland.
Where is Human Growth Hormone released from?
What is the target cell for it's action?
*Somatotrophs in the anterior pituitary.
*Act on liver, skeletal muscle, cartilage and bone. Increases cell growth and division.
What effect does low blood sugar have on hGH? and high blood sugar?
Low BS: stimulates release of GNRH. More hGH is released to break down more glycogen to glucose.
High BS: Stimulates GHIH. Less hGH is released.
What is the DIABETOGENIC effect of hGH?
If excess hGH is released, the level blood glucose is constantly elevated, stressing the pancreas. This will lead to burnout and diabetes mellitis, in time.
Where is Thyroid Stimulating Hormone (TSH) released from? What gland regulates its activity?
The THYROID gland (thyrotroph cells).
Regulated by Hypothalamus.
What is the effect of TSH?
TSH stimulates the release of T3 and T4 - Metabolic rate is stimulated.
Where is Follicle Stimulating Hormone (FSH) released from? What gland regulates its activity?
FSH is released by gonadotrophs (ovary/testes).
It is controlled by the hypothalamus.
What is the effect of FSH?
Initiates formation of follicles in ovary.
Stimulates follicle cells to secrete oestrogen.
Stimulates sperm production in testes.
Where is Luteinizing Hormone (LH) released from? What gland regulates its activity?
LH is released by gonadotrophs (ovary/testes). It is controlled by the hypothalamus.
What is the effect of LH?
stimulates secretion of OESTROGEN,
OVULATION of 2nd osteocyte from ovary, formation of CORPUS LUTEUM,
Males: stimulates interstitial cell to secrete testosterone.
Where is Prolactin(PRL) released from? What gland regulates its activity?
Prolactin in released from lactotroph cells in the mammary glands. It is regulated by hypothalamus- suckling causes prolactin to rise.
What is the effect of PRL?
Under right conditions, Prolactin causes milk production.
Where is Adrenocorticotropic Hormone(ACTH) released from? What gland regulates its activity?
Released from corticotrophs in the Adrenal cortex.
Regulated by hypothalamus.
What is the effect of Adrenocorticotropic Hormone(ACTH)?
Stimulates cells in the adrenal cortex to produce glucocorticoids.
Where is Melanocyte-Stimulating Hormone(MSH) released from? What gland regulates its activity?
Released from corticotrophs in the Adrenal cortex.
Regulated by hypothalamus.
What is the effect of Melanocyte-Stimulating Hormone(MSH)?
Function not certain in humans.
How is the posterior pituitary gland different from the anterior?
It does not synthesis hormones. Consists of axon terminals from hypothalamus neurons. Neurons release 2 neurotransitters (antidiuretic hormone, oxytocin).
What are 2 target tissues involved in 'neuroendocrine reflexes'?
The uterus & mammary glands - childbirth.
What is an effect of Oxytocin (OT)?
Causes uterine contractions during childbirth.
What hormone is also known as vasopressin?
ADH- antidiuretic hormone.
What is a function of ADH?
Decrease urine production, decrease sweating, increase blood pressure.
What are some target tissues of ADH?
Sudoriferous (sweat) glands.
Where is calcitonin produced?
Thyroid gland.
What is the process of thyroid hormone formation?
Iodide TRAPPED (follicular cells).
Synthesis of thyroglobin (TGB), released into the colloid.
Iodination of tyrosine (colloid).
Combination of T1 & T2 forms T3 & T4.
Uptake & digestion of TGB by folicular cells.
Secretion of T3&4 into blood.
Name 3 thyroid hormones:
T3. T4. Calcitonin.
What are the actions of Thyroid hormones T3 & T4?
Responsible for metabolic rate, synthesis of protein, b'down of fats, use of glucose for ATP production.
What are the actions of Thyroid hormone Calcitonin (CT)?
Responsible for building of bone & stops reabsorbtion of bone. Lowers blood calcium levels. Opposite to Parathyroid hormone.
What is triiodothyronine?
What is thyroxine?
What feedback system controls t3 and t4 secretion?
Negative feedback system.
Low levels stimulate hypothalamus. It stimulates pituitary to release TSH. TSH stimulates gland to produce hormone.
What effects does Parathyroid hormone (PTH) have on the body?
Raises blood calcium levels.
Opposite to calcitonin.
How many types of hormone does the adrenal cortex produce? From how many zones?
3 from 3.
What hormones does the adrenal medulla produce?
Adrenalin and noradrenalin.
What are the layers of the adrenal glands, from outer coat to inner?
Capsule. Cortex (3 zones). Medulla.
Of the Mineralocortcoids, which hormone is responsible for most hormonal activity?
Of the Glucocortcoids, which hormone is responsible for most hormonal activity?
What do mineralocorticoids increase the reabsorbtion of? What excretion do they promote?
Increase reabsorption: Na, Cl, bicarbonate and water.

Protote excretion: K and H.
What are 4 functions of glucocorticoids?
*Anti-inflammatory effects (reduce histamine release, decrease capillary permeability & phagocytosis)
*Raise BP (vasoconstriction)
*Help regulate metabolism.
*Provide resistance to stress- more nutrients available for ATP.
*Increase protein catabolism & lipolysis.
*Convert amino acids to glucose.
*Stimulate lipolysis.

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