Urinary System Flashcards
What does the urinary tract accomplish?
Water and electrolyte homeostasis, acid base balance and body fluid osmolarity
What acts as an endocrine gland, producing renin and erythropoietin?
Kidney and urinary tract
What is the kidney covered in?
Capsule of dense collage fibres
What is the kidney composed of?
Cortex and medulla
What is the medulla subdivided into?
Medullary pyramids with apices
What is the blood supply of the kidney?
Anterior and posterior renal arteries
What branches to form arcuate arteries?
Interlobular arteries
What is the nephron composed of?
Renal corpuscle and renal tubules
Function of renal corpuscle?
Production and collection of glomerular filtrate
Function of Proximal Convoluted tubule?
Reabsorption of water, proteins, amino acids, carbs and glucose
Function of Loop of Henle?
Creation of hypertonic environment in medulla
Function of Distal Convoluted Tubule?
Acid-base and water balance, absorption of water, sodium and bicarbonate, excretion of potassium and hydrogen ions
What forms the renal corpuscle?
Tuft of capillaries (glomerulus) and the cup of simple squamous epithelium at the Bowmans capsule
What is the glomerulus supplied by?
Afferent arteriole
What is the glomerulus drained by?
Efferent arteriole
What are the two cell layers that separate the glomerular filtrate and blood?
Capillary endothelium and podocytes
What are podocytes?
Epithelial cells with interdigitating cell processes
What is between the cell layers that separate the glomerular filtrate and blood?
Feltwork of GAGs
Where are scattered mesangial cells found between?
The endothelial cells and the basal lamina
What is the functions of the mesangial cells?
Controlling filtration rate and removal of debris
What are the blood vessels called in the loop of henle?
Vasa Recta
What is the reabsorption of sodium ions controlled by?
Aldosterone that is secreted by renal cortex
How does the permeability of the ducts to water vary?
As ADH from the posterior pituitary gland increases water permeability
Is pressure high or low during passage of medulla?
High
What is the juxtaglomerular apparatus?
A specialised region formed at the site where the distal tubule passes adjacent to the vascular pole of the same renal corpuscle
What makes up the juxtaglomerular apparatus?
Macula Densa, Juxtaglomerular cells and extraglomerular mesangial cells
Where is urine produced?
The renal papilla
Where is urine collected?
Minor calyx, flows into major calyx, ureter and then bladder
What lines the urinary tract?
Transitional epithelium
What are the cells called present at the luminal surface?
Umbrella cells
Describe umbrella cells
Domed shaped and have a thickened and inflexible membrane
What is the lumen of the ureter lined with?
Urothelium
What do the smooth muscle layers form within the bladder?
Detrusor muscles
Function of detrusor muscle?
Micturation
When does the urethra in a female become stratified squamous?
As it nears the surface of the body posterior of clitoris
What are the largest collecting ducts?
Ducts of Bellini
What is the pelvicalyceal space in humans?
Minor calyx
How does the medulla receive nutrients and oxygen?
Vasa recta
What happens to the urine during voiding?
Flows into urethra and exits the body
What can be found in the detrusor muscle?
Parasympathetic ganglia innervated by neurone in the sacral spinal cord
What controls the micturation reflex in the bladder?
Adventitia
Non-hormonal function of the urinary tract
Production, storage and voiding of urine
Where is the kidney?
Retroperitoneal area
What enters and exits the hilum of the kidney?
Renal artery enters
Renal vein and ureter exits
Structures of the kidney?
Renal pelvis, major calyces ad minor calyces
Where do the apices of the medullary pyramids point to?
The hilum of the kidney
What are the apices of the medullary pyramids called?
Papillae
What is the capsule of the kidney continuous with?
Connective tissue that lines the renal sinuses
Where are medullary rays found?
In the cortex
What is the basic functional unit of the kidney?
Nephron
What type of epithelium do the podocytes make?
Fenestrated epithelium with pores
What do the interdigitating cell processes of the podocytes make?
Filtration slits
What is the glomerular filtrate?
An ultrafiltrate of plasma
What are the three components of the glomerular filtrate?
Fenestrated endothelium of the capillaries,
Thick basement membrane,
Filtration slits between podocytes
The proximal convoluted tubule leads to?
The proximal straight tubule
How is sodium reabsorbed?
Active transport
How is water reabsorbed?
Diffusion
How is glucose and carbohydrates reabsorbed?
Cotransport
What is the border of distal convoluted tubules?
Sparse microvilli
What controls reabsorption of sodium in the distal convoluted tubule?
Aldosterone
What secretes aldosterone?
The adrenal cortex
What controls aldosterone secretion?
The renin-angiotensin system
What increases the collecting ducts permeability to water?
Vasopressin
What secrete vasopressin?
Posterior pituitary
What is the function of macula densa?
Sensing sodium content
What do the juxtaglomerular cells contain?
Renin
What are the lacis cells?
Modified mesangial cells extending outside the renal corpuscle
Function of the lacis cells?
Signalling that alters glomerular filtrate
What innervates the bladder?
Parasympathetic ganglia