7: Renal system Flashcards
Where does the kidneys located to the parietal peritoneum?
Posterior to it
What is the connective tissue called surrounding each kidney?
Renal capsule
What tissue surrounds the outside of the renal capsule for protection?
adipose tissue
What is the thin layer of connective tissue surrounds the adipose tissue, that anchor kidneys to the abdominal wall?
Renal fascia
What does renal sinus contain?
Fat and loose CT
What is the functional unit of the kidney called?
Nephron
What are the 4 separate regions of the nephron?
Renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule
Where does the urine flow from nephron, to the bladder?
Nephron > papillary ducts > minor calyces > major calyces > renal pelvis > ureter
What does renal corpuscle contains?
Glomerulus and Bowman capsule
What are the differences of juxtamedullary nephrons vs cortical nephrons?
Juxtamedullary nephrons’ renal corpuscle is deep in the cortex near the medulla, long loop of Henle extending deep into the medulla, makes up 15% of the nephrons. Cortical nephrons the opposite.
What is the function of Bowman Capule?
Filters blood/fluid
Names of blood vessels that enter and exits renal corpuscle.
Afferent arteriole (enter); efferent arteriole (exit)
Cell type of the parietal layer of Bowman capsule?
simple squamous epithelium - it becomes cuboidal in the PCT
What are the specialised cells wrap around the glomerular capillaries?
Podocytes
What is the common cell type of all nephron’s parts outside the renal corpuscle?
simple cuboidal; thin part of Loop of Henle is simple squamous for osmosis/diffusion
What 3 substances do PCT actively reabsorb?
Na+, K+ and Cl-
Which part of the nephron has many microvilli?
PCT
Which part of the nephron has very few microvilli?
DCT
What is the histology of ureters?
transitional epithelium
What is the triangular area on posterior wall of the bladder called that’s between the entry of the two ureters and the exit of the urethra?
Trigone
What’s the histology of the urethra?
transitional epithelium at the top, remainder is stratified columnar
What is the sphincter called at the junction of the bladder + the urethra, that prevents urine leakage?
Internal urinary sphincter
What is the sphincter called surrounding the urethra that extends through pelvic floor - voluntarily start/stop flow of urine
External urinary sphincter
What are the 3 stages of urine production?
Filtration, tubular reabsorption and tubular secretion
What and how much is the proportion of total cardiac output that passes through the kidneys?
Renal fraction - varies from 12-30% in a healthy resting adult
What makes up the filtration membrane of the glomerulus?
Podocyte cell processes, basement membrane, capillary endothelium
Filtrate consists of
water, glucose, fructose, amino acids, urea, urate ions, creatinine, Na+, K+, Ca+2, Cl-
What is the group of specialized cells at the section of the DCT, that secretes renin to regulate filtrate formation and BP regulation?
Macula densa
Where does the majority of reabsorption occur at the nephron?
PCT, after that remaining filtrate is about 35%
What hormones control the water permeability of DCT and collecting duct?
Anti-diuretic hormone
What is the substance that is a toxic by-product of protein metabolism and it diffuses into the lumen of the nephron in the tubular secretion process?
Ammonia
What 3 other substances are actively secreted into the nephron at the tubular secretion process?
H+, K+ and penicillin
What does urine contain?
Urea, uric acid, ammonia, creatinine, H+ and K+
Bile pigments,
Drug and toxins (e.g. penicillin)
What is the name of the process of eliminating urine from the bladder?
Micturition
What is the name of the muscle found in the wall of the bladder?
Detrusor
What are the 2 main causes of Chronic Kidney Diseases?
Diabetes and high blood pressure (hypertension)
What is the main health problem associated with CKD (apart from kidney / renal issues)?
Cardiovascular disease
What are the risk factors for kidney disease?
Having diabetes, hypertension, existing heart problems, having had a stroke, family history of kidney failure, being obese (BMI > 30), smoking, 60 years of age or older, Aboriginal or Torres Strait Islnder oigin, history of acute kidney injury.
The kidneys are not exactly aligned. Which kidney is displayed slightly inferiorly? Can you think of a reason for this? (Hint: what organ is above this kidney?)
The right kidney is slightly lower. The liver is on the right, and it displaces the right kidney so it is lies slightly lower than the left kidney
What organs are anterior to the left kidney?
Pancreas and colon
What organs are anterior to the right kidney?
Duodenum and colon
What are the main functions of the PCT?
Main area for reabsorption of water (80%)
100% reabsorption of amino acids and sugars
What are the main functions of the DCT?
Controlled secretion of wastes, toxin, excess ions. Alters concentration of urine by varying water reabsorption
What is the main function of Loop of Henle?
Reabsorbs ions and water.
Coffee and alcohol are diuretics. What does this mean?
Diuretics make you pass more urine by affecting the amount of water reabsorbed by the kidneys. This means, drinking too much coffee or alcohol can make you dehydrated because you lose more water in urine than you take in. Dehydration contributes to the symptoms one may experience from drinking too much alcohol
What organs lie superior to each kidney?
Right kidney – liver; left kidney – stomach and pancreas
Which body cavity does the bladder lie within when it is empty?
Pelvic
As the bladder fills it expands, do you think there may be a change in the body cavity location when the bladder is full?
It moves upwards and lies across the border of the abdominal and pelvic cavities
Note where the ureters enter the bladder, e.g. do they enter anteriorly, posteriorly, superiorly?
The ureters enter the bladder posteriorly
It may be hard to see, but the ureters enter the wall of the bladder on an angle (obliquely). This arrangement decreases the risk of the backflow of urine from the bladder to the ureter. Why do you want to prevent backflow of urine
Backflow of urine can lead to urinary tract infections, e.g. if you have a bladder infection, backflow of urine could lead to infection of the ureter and kidney. By stopping backflow, the risk of infection of the kidneys is much reduced.
