Term
| Route Of Urine from nephron to renal pelvis |
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Definition
| Distal tubules of several nephrons join one collecting duct then run through meduallry pyramids and form a papillary duct which delivers urine to the calyces and renal pelvis. |
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Term
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Definition
| Distend retroperitoneally (behind peritoneum) runnng vertically through abdomen and run obliquely through bladder |
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Term
| What 3 layers are the ureters composed of? |
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Definition
1. Transitional epithelium - osmotic barrier
2. Muscularis- detruzor muscle squeezes urine from bladder
3. Adventitia- FCT |
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Term
| What is the trigone and what openings make up the trigone |
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Definition
3 openings:2 ureters and 1 urethra
Trigone is the region of the all 3 openings on floor of bladder |
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Term
| What 3 types of epithelium is found in the urethra |
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Definition
1.Transitional near bladder
2.Columnar
3. Stratified Squamous near opening
Also mucus cells for protection from acid urine |
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Term
| Describe the 2 sphincters of the urethra |
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Definition
Internal urethral=detruzor muscle forms this at bladder/urethra junction, involuntary, parasympathetic.
2.External sphincter where urethra passes thro urogenital diaphragm
Skeletal muscle and voluntary control |
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Term
| Differences between male and female in urethras and position of bladder |
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Definition
Male:Bladder superior to prostate gland and has a longer urethra(25cm) is also involved in reproductive system
Female:Bladder anterior to vagina, shorter urethra(5cm) and is not involved in reproductive system |
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Term
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Definition
Bowmans Capsule
Renal Tubules
Collecting Duct- connects to distal tubule |
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Term
| What are the 2 types of Nephrons |
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Definition
1.Juxtamedullary- extend deep in medullary and form concentrated urine
2. Cortical- lie mainly in cortex- 85% |
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Term
| 2 types of capillary beds |
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Definition
1. Glomerular capillaries- filtration,
fed and drained by arterioles and high pressure
2. Peritubular capillaries- absorption, low pressure, blood is viscous and protein rich |
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Term
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Definition
| a ball of capillaries(glomerulus) enclosed by Bowmans Capsule. |
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Term
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Definition
| has afferent and efferent arterioles(brings in from interlobular artery). capillaries allow most blood components(water,salt,sugar) to filgter to Bowmans capsule.Glomerular capillaries single layer ENDOthelium, highly fenestrated and high bloody pressure. |
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Term
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Definition
| Not fully understood but only found in the Renal Corpusle |
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Term
| Describe Bowmans Capsule 2 layer |
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Definition
Outer layer:simple squamous
Inner Layer Podocytes
Between layeers is Capsular space |
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Term
| What is the structure of Podocytes |
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Definition
| Podocytes surround Glomerular capillaries- branched special epithelium. Branches form foot processes called pedicels. Filtration slits form foot processes. |
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Term
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Definition
lies between blood and capsular space
3 layers:
fenestrated endothelium of glomerular capillary
basment membrane
slits between pedicels of podocytes
Restrict passage of most proteins |
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Term
| Proximal Convoluted Tubule |
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Definition
Nearest to Bowmans capsule
Cuboidal epithelial cells
dense microvilli
mitochondria |
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Term
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Definition
| Cuboidal epithelium but thinner than PCT less mitochondria and microvilli |
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Term
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Definition
Penetrates into medulla
Descending and Ascending Limb
Thin segment- simple squamous
Length important in production of high conc urine |
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Term
| Juxtaglomerular Apparatus |
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Definition
Controls Glomerular filtration rate: Maculua Densa chemoreceptors sense NaCl decrease so increase glomerular filtration rate
Stabilisation of blood pressue |
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Term
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Definition
| mechanoreceptors sense decreased blood pressure, renin released which stimulates angiotensin formation which increases vasoconstriciton |
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Term
| What is the normal Glomerular filtration rate? |
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Definition
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Term
| How is glomerular filtration rate regulated? |
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Definition
Intrinsic: vascular smooth muscle and via JGA
Extrinsic: sympathetic nerves, angiotensin |
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Term
| Filtration is determined by |
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Definition
1. Pressure gradient between glomerular capillaries and bowmans capsule
2.Surface area of capillary
3. Permeability of capillary |
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Term
| What is the effective filtration pressure? |
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Definition
| 10mmHg determined by (glomerular hydrostatic + capsular osmotic)- ( glomerular osmotic + capsular hydrostatic) |
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Term
| What are the normal values for renal blood flow and plasma flow |
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Definition
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Term
| What is Filtration Fraction |
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Definition
fraction of plasma going through glomeruli
125ml/min GFR/RPF |
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Term
| What is filtered load and the formula? |
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Definition
amount of solute filtered per minute
GFR x Solute plasma conc |
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Term
| What is Creatinine useful for and what is the formlua? |
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Definition
Creatinine is useful for measuring the GFR as it is filtered and neither reabsorbed nor secreted
GFR= (urine conc x urine volume) / plasma conc
Uselful to see if someone has renal failure- less than 0.125 |
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Term
| What molecules are reabsorbed, secreted or both? |
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Definition
Glucose- all reabsorbed 98% mostly all amino acids
Organic cations and anions(bile salts, drugs) all secreted
K ,H HCO3 NH3 Urea all reabsorbed and secreted |
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Term
| Describe the role of the proximal tubule |
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Definition
Bulk re absorption- glucose, Na, H2O secretes K+ reabsorption is driven through Na reabsorption
Na conc low in cells due to Na- K pump
HCO3 filtered and coupled with H+ to make water in urine. Tubular cells can synthesis more HCO3 is blood is low |
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Term
| Describe the role of the distal tubule |
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Definition
Fine tuning electrolytes
Collecting duct: fine tuning water
secrets K and H
Hormonal control: Aldosterone(Na) and ADH(k) |
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Term
| How does glucose end up in urine and what is this a sign of? |
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Definition
| Diabetes- the amount filtered exceeds capacity of the body to reabsorb so end up with glucose in urine Glucosuria |
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Term
| What is the HOMG and how is it achieved? |
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Definition
Hyperosmotic medullary Gradient- helos reabsorb water back into the blood, done by making the kidney salty outside so water will move out of the tubule
Vasa recta help trap the salt |
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Term
| What is the % of water in male and female body mass? |
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Definition
| 60% in males and 55% in females |
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Term
| What fraction of water is each ICF, and ECF? |
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Definition
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Term
| What happens when water is lost? In terms of ECF and ICF |
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Definition
| loss from ECF, water moves from ICF to ECF to even out, cells shrink = NOT GOOD |
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Term
| What happens when water is gained in terms of ECF and ICF? |
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Definition
| Gain into ECF, water moves from ECF to ICF to balance, cells expland = NOT GOOD |
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Term
| What detects a change in ICF or ECF and what action is taken? |
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Definition
Osmoreceptors in hypothalamus detect a change of either:
1.Increased ECF osmolarity
2. Decreased blood pressure
Acts on posterior putuitary gland to release ADH
ADH then acts on collecting duct and causes water channels called aquaporins to be inserted into the apical membrane and water to be retained |
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Term
| What is isoosmotic loss/gain? |
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Definition
| Losing/gaining water and solutes(vomiting, diarrhoea) no change in cell size |
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Term
| What happens when there is a decrease/increase of ECF in regards to isoosmotic? |
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Definition
| a decrease of ECF means a decrease in circulating blood= NOT GOOD |
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Term
| Where are the 3 sensors that sense pressure |
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Definition
High pressure receptors: Aorta, carotids, acts on SNS and ADH
Low pressure: vena case, right atrium(veins) act on ANP secretion
intra-renal baroreceptors and macula densa- rennin secretion |
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Term
| What is the function of the hormone ANP |
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Definition
increases amount of Na filtered
Decreases reabsorption of Na+
Decreases rennin secretion |
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Term
| Rennin-angiotensin- aldosterone |
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Definition
Rennin is released from the JGA once both cells(tubular and arteriolar) pick up on low BV
Rennin converts angiotensin into angiotension 1 which is converted to angiotensin 2 by ACE. Angiotensin vasoconstricts, stimulates Na reabsorption releases aldosterone (adrenal gland)
aldosterone works on DT and CD increasing Na reabsorption even further |
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