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37 Cards in this Set
- Front
- Back
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Which three vessels does the umbilical cord comprise of? |
Umbilical arteries x2 Umbilical vein |
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Does the umbilical vein carry oxygenated or deoxygenated blood? |
Oxygenated. Placenta to baby |
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Do the umbilical arteries carry oxygenated or deoxygenated blood? |
Deoxygenated. Baby to placenta |
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What is the fetal part of the placenta called? |
Chorionic plate |
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What is the maternal part of the placenta called? |
Basal plate. Comes into contact with the uterine wall |
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What is the area between the basal plate and the chorionic plate? |
Pool of blood? |
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What are the 5 anatomical adaptations of fetal circulation compared to adult circulation? |
1) Umbilical vein 2) Ductus venosus 3) Ductus arteriosus 4) Umbilical arteries 5) Foramen ovale |
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How can blood get from the placenta to the right atrium? |
Umbilical vein and via - Ductus venosus into IVC - Portal vein, capillary beds, hepatic vein, then ICV |
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What is hypoxic pulmonary vasoconstriction? |
Where hypoxia in the alveoli leads to vasoconstriction of arterioles and therefore an increase in resistance and pulmonary pressure |
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Describe the fetal circulation of the heart, lungs and placenta |
RA: Increase in pressure due to increase pulmonary pressure. Rises above LA pressure which results in the opening of foramen ovale RV: Increase in pressure due to increase in pulmonary pressure Pulmonary artery: Increase in pressure due to increase pulmonary pressure due to hypoxic pulmonary vasoconstriction. Takes blood straight to the aorta via the ductus arteriosus Pulmonary vein: not much blood flow due to increase pressure in the lungs LA: Receives blood through foramen ovale and pulmonary vein LV: Pumps blood into the aorta Descending aorta branches into illiacs, then internal iliacs. Internal iliacs join to umbilical arteries and return deoxygenated, waste filled blood to the low resistance placenta for gas exchange |
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What happens to fetal circulation after birth? |
1) Placenta is removed - Clipped off therefore resulting in a high resistance placenta so decrease in blood flow - Wharton's jelly contracts around the umbilical cord in response to decrease in temperature - Decrease in prostaglandin secretion 2) Lungs breath air - Results in a decrease in pulmonary resistance as the arterioles vasodilate - Results in a decrease in back pressure on all of the right side of the heart 3) Foramen ovale - Close due to the decrease in R side pressure 4) Ductus arteriosus - Closes due to decreased pressure in pulmonary artery. Smooth muscle in walls sense increase in p02 and vasoconstrict. Furthered due to decrease in prostaglandins 5) Ductus venosus - Becomes closed, therefore allowing IVC to just carry deoxygenated blood. Smooth muscle in walls sense increase in p02 so vasoconstrict as well as the decrease in prostaglandins |
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What happens when the foramen ovale does not close in an adult? |
Creates a patent foramen ovale which can be opened if there is an increase in RA pressure |
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What does the umbilical vein become in an adult? |
Ligamentum teres hepatis |
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What does the ductus venosus become in an adult? |
Ligamentum venosum |
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What does the ductus arteriosus become in an adult? |
Ligamentum arteriosum |
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What do the umbilical arteries become in an adult? |
Medial umbilical ligaments |
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What causes the closure of ductus arteriosus? |
Decrease in prostaglandin E2 Decrease in pulmonary resistance |
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When should the ductus arteriosus usually close? |
Within 48 hours of birth |
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What produces saliva? |
Sublingual, submandibular and parotid glands |
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What is the role of saliva? |
Moistens mouth, allows of taste, begins chemical digestion of carbohydrates by amylase |
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What is the role of cholecystokinin? |
Secreted by the SI in response to food in stomach Causes gallbladder to release bile to digest fat |
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What is contained in pancreatic juice? |
Bicarbonate Amylase Lipase Nucleases Enzymogens |
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Which cells are found in the crypts of the stomach? |
Parietal cells, enterochromaffin cells, G cells, D cells |
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Which cells are found on the tops of the crypts in the stomach? |
Mucus cells, chief cells |
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What are the role of parietal cells in the stomach?
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Secrete HCl into the stomach lumen via a proton pump |
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How does a proton pump work? |
H is secreted into the stomach lumen in exchange for K K is then secreted back into the stomach lumen along with Cl, allowing HCl to form in the lumen of the stomach |
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What is the role of enterochromaffin cells in the stomach? |
Secrete histamine in response to gastrin from G cells, ACh from vagus. Histamine binds to H2 receptors on parietal cells, leading to HCl secretion |
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What is the role of G cells in stomach? |
Endocrine cells which secrete gastrin Gastrin binds to parietal cells and leads to HCl secretion |
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What is the role of D cells in the stomach? |
D cells secrete somatostatin which binds to parietal cells, G cells and enterochromaffin cells, resulting in a decrease in HCl release |
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How is HCl produced in the stomach? |
Parietal cells produce HCl via the proton pump Stimulated by gastrin and histamine Histamine is from enterochromaffin cells, which are stimulated by gastrin and ACh from vagus |
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Which is HCl secretion inhibited/neutralised in the stomach? |
D cells secrete somatostatin COX-1 synthesises arachadonic acid into PGE2 and PGI2 Binds to PG receptors on parietal cells to inhibit HCl secretion. Also binds to mucus cells to secrete mucus and bicarb |
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How can NSAIDs lead to peptic ulcers? |
Stop the synthesis of PGs which can lead to an imbalance of mucus and HCl |
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Which cells release glucagon in the pancreas? |
Alpha cells |
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Which cells release insulin in the pancreas? |
Beta cells |
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What are some of the effects of glucagon? |
- increases the breakdown of glycogen in the liver which releases glucose into the blood stream - Activates the conversion of amino acids into glucose - Breaks down triglycerides into fatty acids |
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What are some of the effects of insulin? |
- Increase glucose uptake in cells - Increase in the synthesis of glycogen from glucose - Increase in the synthesis of adipose tissue |
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How is insulin released? |
Increase in blood glucose levels leads to an increase of glucose uptake. This leads to an increase in ATP and therefore cellular metabolism. K channels close and Ca channels open, leading to intracellular calcium influx which leads to insulin release by exocytosis. |
