The renal Systems Flashcards
Whwat does the macula densa do to regulate fluid electrolytes and blood pressure?
- releases renin from juxtaglomerular cells
- responds to [NaCl] or hypotension
- reversed cellular polarity
THe juxtaglomerular cells have what purpose?
- release renin with sympathetic nerve stimulation.
and are smooth muscles cells in afferent arteriole in order to secrete the renin
What parts make up the renal tubules?
- proximal convoluted tubule
- loop of henle
- distal convoluted tubule.
What cells are located in the Bowman’s capsule and the proximal convoluted tubule?
-starts as simple squamous and continues on to form simple cuboidal
The renal filtration barrier is formed by what?
- fenestrated endothelium glomerular capillaries
- fused basal lamina of endothelial cells and podocytes
- pedicels of the podocytes are attached by integrins
- podocytes feet form the “filtration slit” between fenestration
In general what components are generally filtered by the renal filtration barrier?
- water, glucose, and ions pass into bowman’s capsule
- no proteins
- no large negative charge due to the electrostatic charges
Simple cuboidal cells in the proximal convoluted tubule is made up of what cells and components>
- formation of truncated pyramidal cells
- multiple mitochondria
- pale staining nuclei
- eosinophilic cytoplasm
Where are the majority of large indigitations of cells generally found?
-mostly in cells that participate in active transport and therefore have high amount of mitochondria associated.
What is a histological feature of the “fuzzy” appearance in the lumen side of the tubule?
-this represents the microvilli and forms the brush border.
What is significant about the loop of henle?
- thick segments are low cuboidal epithelium
- thin segments are simple squamous
- thick ascending limb has more basal vertical striation and no brush border
What is the major function of the Loop of Henle?
- establish the counter-current exchange system that allows for the gradient to pull and push water in and out.
- ADH is used in the distal convoluted tubule and the collecting duct.
Why is the distal convoluted tubule have a larger diameter than the proximal tubule?
-no brush border, and smaller simple cuboidal cells
What cells are contained in the collecting duct. Further, the collecting duct has a different embryological origin than what section?
- principal cells: reabsorb Na, and secrete K actively
- intercalated cells: absorb K with a K-H-ATPase pump. H secreted to form bicarbonate
- the nephron has different origin than the collecting duct.
What are the three components that form the excretory passages?
- renal pelvis
- ureter
- urinary bladder
What are the layers of the excretory passages?
- mucosa
- submucosa
- muscularis
- adventitia
- FECT external to the adventitia
- serosa over the superior portion of the bladder
The mucosa of the excretory passage consist of what layers of cells?
- transitional epithelium
- basement membrane
- lamina propria of FECT
- loose lymphoid tissue
- smooth muscle cells
Muscularis of the excretory passage is mostly contained in what area?
- the ureter that contains a longitudinal and circular muscle coat
- the last 3rd has a 3rd muscular layer longitudinally
- these form the detrusor muscles
What are the three sections that form the male urethra?
- prostatic
- membranous
- cavernous
Where is the prostatic urethra and what cells are associated with it?
- passes through the prostate
- transitional epithelium and high venous vascularization
The membranous urethra has what cells and is located where?
- variable pseudostratified columnar cells
- runs through the urogenital diaphragm
- receives striated cells to form the voluntary external sphincter
The cavernous urethra runs where and has what cells to make it up?
-pseudostratified epithelium with sections of stratified squamous epithelium
What is the lucanae of Morgagni in the urethra?
-gland that contain single or grouped intrepithelial mucous cells.
What is the Glands of Littre?
-branched tubular glands that open into the lacuna morgagni
The female urethra has what cell layers?
stratified or pseudostratified columnar epithelium. High vascularization with elastic tissue. Contains the longitudinal and circular muscles but not easy to discern.
Where does the angiotensin converting factor come from?
-the pulmonary and the endothelium
What RAS hormone is circulating in the blood from the liver?
-angiotensinogen
What RAS stimulator/enzyme is formed in the lungs?
Angiotensin !
What is contained in the juxtaglomerular apparatus?
- macula densa
- extraglomerular mesangial cells
- juxtaglomerular cells
