kidneys a&p

What does retro-peritoneal mean?

There are two kidneys, they are located behind the peritoneum, which is the membrane lining the abdominal cavity

Why retro-peritoneal important to the kidney?

It protects the kidneys and creates a direct pathway to the bladder

What are the six general functions of the kidney?

Volume (BP), concentration of ions, pH, metabolic, excretion, and endocrine

What is reabsorption?

This is where the nephrons pull useful substances like H2O, salts, glucose, and amino acids from the filtrate back into the bloodstream

What is secretion?

Waste that goes to the bladder or colon to be excreted

How are reabsorption and excretion different?

Reabsorption is where you still take out amino acids, glucose, H2O, and salts to put back into the body. Excertion is where you get rid of the waste like peeing or pooping.

In whaat part of the nephron does the majority of reabsorption take place?

Majority takes place in the Proximal Convoluted Tubule

What is GFR?

Glomerular filtration rate

How does the diameter of the AA and EA afftet GFR?

To decrease GFR: Constrict AA and dilate EA. To increase GFR: Dilate AA and Constrict EA

Where is glucose reabsorbed into the nephron?

In the PCT

What transporter is responsible for reabsorbing glucose in the nephron?

Sodium Glucose Co-Transporter 2 (SLGLT-2)

What is osmolarity as it applies to human physiology?

Total concentration of all solutes in the blood

What things are reabsorbed in the nephron?

water, glucose, amino acids, sodium, potassium, chloride, bicarbonate, calcium, and phosphate

What things are secreted in the nephron?

H+, K+, creatinine, Nh3, and urea

What is reabsorbed in the three sections of the Loop of Henle?

In the descending tubule it reabsorbs H2O througuh passive transport. In the ascending tubule it will reabsorb NaCL, Na+, K+, Mg2+. Cl-, and HCO3-

What is secreted in the three sections of the Loop of Henle?

In the descending tubule it secretes only urea. In the In the ascending tubule it does not secrete anything

How does osmolarity affect water and NaCl in the Loop of Henle?

High osmolarity draws water out, low osmolarity of medulla draws NaCl out and dilutes filtrate in the lumen

What is an aquaporin?

Water channels

Distal convoluted tubule (DCT) and collecting ducts can synthesize what ion?

K+ and H+

What is vasopression (ADH)?

it is an antidiuretic hormone that is secreted by the posterior pituitary

What is the reaction for the body’s reversible buffer system?

This is the equilibrium betwen CO2 and H2O, which reversibly form H2CO3.  They make sure that we are not too acidic or akaline.

What is the anion gap?

To counteract the amount of Na+, there is Cl- and HCO3-, along with the anion gap that is primarily composed of albumin and comtains phosphate, sulfate, and other anions

How is bicarb reabsorbed?

The kidney will increase/decrease reabsorption of HCO3- and secretion of H+ as needed to maintain pH.  It is absorbed in the capillary with Na+ as a cotransporter

What are the two ways H+ is secreted?

Instead of combining with HCO3-, it combines with filyered phosphate ion HPO42-. The second way is that amino acid metabolism in the liber will produce glutamine, i

How do we measure renal function?

Clearance- the volume of plasma from which that substance is completetly removedper units of time. Ex: Creatinine Clearance- creatinine is a waste product released by the muscle and does not undergo reabsorption— slightly overestimates the GFR

What is renin?

It is a proteolytic and converts angiotensinogen to angiotensin I

What is angiotensin?

A hormone that is produced in the liver

What is aldosterone?

A steriod hormone produced by the adrenal glands that plays a crucial role in regulating the body’s salt, water, and potassium balance

What are the functions of angiotensin II?

Poten arterila vasoconstrictor (increases blood pressure), promotes aldosterone secretion from the adrenal gland (increase sodium and water retention), prompts the pituitary to release antidiuretic hormone (ADH) which also increases water retention, and it is sympathomimetic (increases HR and BP).

What are 3 ways the kidney is informed to produce more renin?

Juxtaglomerular (JG) cells recieve input by: renal sympathetic nerves stimulating JG cells whenever plasma volume is low, afferent tubule has intrarenal baroreceptors (so when plasma is low, they are less stretched, which signals renin secretion), ans Macula densa (located in the ascending loop of henle)- it senses the Na+ concentration in the tubular fluid flowing past it- if low, it will secrete paracrine factors that diffuse to the JG cells.

What is the role of the kidney with vitamin D?

Converts vitamin D from sun and diet to active form

What is erythropoietin?

A glycoprotein hormone produced by peritubular cells in the kidney- it stimulates red blood cell production

What is the difference between AKI and CKD?

Acute Kidney Injust, Chronic Kidney Disease

What are the three type of AKI?

Pre-renal, intrinsic (intra-renal), and post renal

How is pre renal cause?

When the kidney is hypoperfuse— there is an increase in salt and water reabsorption, so renin is released, causing the production of angiotensin II, this enhances Na+ reabsorption at the PCT and stimulates arental aldosterone releasem which increases Na+ reabsorption in the DCT. ADH is released, which increases water retention.

What are the stages of kidney failure?

Stages 1-5

How is CKD managed?

Controlling BP, using an ACE or ARB, periodic urine albumin checks, avoid AKI, decreasing salt inctake, exercise, smoking cessation, bicarb supplement, etc

What metabolic issues may exist in someone with late stage CKD or ESRD?

Metabolic acidosis, electrolyte imbalances like hyperkalemia

What is RRT?

Renal Replacement Therapy

What are the different types of RRT?

Intermitten hemodialysis, continuous renal eplacement theray, and peritoneal dialysis

What are the advantages of PD?

Flexibility and convenience, allowing patients to perform treatments at home on their own schedules, as opposed to going to a clinc

What is RTA?

Renal Tubular acidosis, this is when the kidneys do not remove acids from the blood into the urine as they should, making the acid level high in the blood.

What is SIADH?

Syndrome of inappropriate antidiuretic hormone secretion, this is a condition where the body makes too much antidiuretic hormone (vasopressin).

What is DI?

Diabete insipidus, this is a condition where the kindeys are unable to prevent excretion of water.

What is rhabdomyolysis?

muscle injury following trauma or prolonged immobilization, the muscle breaks down and releases myoglobin and creatinine kinase (CK)

What is the significance of myoglobin?

In rhabdomyolysis, myoglobin is the cause of the injury, since the muscle breaks down and releases myoglobin.

What is the significance of CK in rhabdomyolysis?

It is used as a biomarker, since it is released by muscle cells as well when they are broken down.

How much percent does the Proximal conviluted tubule reabsorb?

65%

How much percent does the Distal convoluted tubule reabsorb?

15%

How much percent does the Loop of Henle reabsorb?

15%

How much percent does the Corticol Collecting duct reabsorb?

5%

How is intra renal AKI-ATN caused?

Acute Tubular Necrosis, there are two causes: one being ischemia, which are cells that are dying due to lack of O2. Or from medications that are toxic to the tubule. It presents as a rapid deterioration of kidney function, with an abrupt fall in GFR. This leads to a metabolic imbalance, common to see hyperkalemia and metabolic acidosis. Urine often contains muddy brown casts or renal tubular cells. Most common cause of AKI in hospitalized patients

How is post renal AKI caused?

There is a downstream obstruction in the uteters, blatter, or urethra causing backup- can be caused by tumors, crystals, neck of pladder (BPH if prostate gets too large), and nephrolithiasis (unilateral)

How is intra renal AKI-AIN caused?

Acure Interstitial Nephritis- damage to connective tissue between the nephrons. Kidneys are having an allergic reation- caused bt medications like NSAIDS or PPIs, renal function usually improves after cessation of the offending xenobiotic. It can also be caused by vasculatur, like trauma or mivroangiopathy. Or it can be caused by glomerulonephritis