Urogenital System Flashcards
Kidney Function
- Regulation of the volume and composition of the body fluid, through:
1. Filtration of the blood
2. Removal of the metabolic waste products
3. Reabsorption of the useful metabolites
Renin
- a hormone secreted by the kidney
- involved in the regulation of blood pressure
Hemopoietin
- kidney produces this
- regulates the production of RBCs
Cats, Dogs, Horses, Sheep and Goats
- Unilobar, or Unipyramidal Kidneys
Bovine and Pigs
- Multilobar, or Multipyramidal Kidneys
Cortex Of the Kidney components
- Proximal Convoluted Tubule (PCT)
- Distal Convoluted Tubule (DCT)
- Cortical Collecting Duct
- Proximal and Distal straight tubules
Medulla of the Kidney components
- Loop of Henle
- Medullary Collecting Duct
- Proximal and Distal straight tubules
Renal Tubules (uriniferous tubule)
- consists of the nephron and the collecting duct system
Renal Corpuscles
- glomerulus and glomerular (Bowman’s) capsule
Nephron
- the structural and functional unit of the kidney
Nephron components
- Renal Corpuscles
- glomerulus and glomerular (bowman’s) capsule - Proximal Convoluted Tubule
- Proximal Straight Tubule
- Thin Tubule (loop of henle)
- ascending and descending parts - Distal Straight Tubules
- Distal Convoluted Tubules
Renal Corpuscle
- has a vascular pole and a urinary pole
Vascular Pole of the Renal Corpuscle
- where the arterioles (afferent or efferent) enter and leave
Urinary Pole of the Renal Corpuscle
- where the proximal convoluted tubule begins
Glomerulus
- composed of several loops of branching and anastomosing capillaries which connect the afferent and efferent arterioles
- these capillaries are lined by a porous endothelial cell
Mesengial, or Intercapillary cells
- are located between the capillaries of the glomerulus in the kidney
Glomerular capsule
(Bowman’s Capsule)
- Parietal (capsule) layer
- Visceral (glomerular) layer
- podocytes - Urinary Space
The Glomerular Basement Membrane
- separates the endothelial cells of the glomerular capillaries from the mesangial cells and podocytes
Parietal (capsular) layer
- composed of simple squamous epithelium overlying a thick basal lamina
Urinary Space
- between the parietal and visceral layers of the glomerular capsule
Visceral (glomerular) layer
- envelops the capillaries of the glomerulus
- is made of octopus-like cells called podocytes
Podocytes
- have several primary processes
- octopus-like cells in the visceral (glomerular) layer of Bowman’s Capsule
Pedicles
- secondary processes that arise from primary podocyte processes
- they embrace the capillaries of the glomerulus
Filtration Slit
- the narrow space between pedicles
- > the pedicles of one cell interdigitate with the pedicle of adjacent cell
Slit Diaphragm
- the filtration slits are bridged by this electron-dense layer
Filtration Barrier
- Glomerular endothelium
- has pores - Glomerular Basement Membrane
- Glomerular Epithelium (visceral layer of Bowman’s Capsule)
- podocyte
Proximal Convoluted Tubule (PCT) and Proximal Straight Tubule (PST) Epithelium
- simple cuboidal, or columnar
Proximal Convoluted Tubule (PCT) and Proximal Straight Tubule (PST)
- cells of this epithelium have acidophilic cytoplasm
- the cell apex has microvilli which form a brush border
- basal striations
Proximal Convoluted Tubule (PCT) and Proximal Straight Tubule (PST)
- continue into the proximal straight tubule
- > brush borders in the PST are less distinct
Proximal Straight Tubule
- similar to the proximal convoluted tubule except that brush borders are less distinct
- continued from the PCT
Thin Tubule (Loop of Henle) Epithelium
- simple squamous epithelium
Thin Tubule (Loop of Henle)
- Nuclei are somewhat flattened and protrude into the lumen
Distal Convoluted Tubule (DCT) Epithelium
- simple cuboidal epithelium
Distal Convoluted Tubule (DCT)
- larger lumen
- shorter than PCT
- NO brush borders
- cells are smaller and flatter
Juxtaglomerular Apparatus
- It is mainly formed between the afferent arteriole and distal tubules
Juxtaglomerular Apparatus Components
- Macula Dense
- Juxtraglomerular cells (JG cells)
- Extraglomerular mesangial cells
Macula Densa
- modified segment where the distal tubule establishes contact with the vascular pole of the renal corpuscle
- cells become columnar
- nuclei are closely packed
Macula Densa
- sensitive to chloride ions and regulate the filtration rate
Macula Densa
- contents of the tubular fluid produces molecular signals that promote the constriction of the glomerular afferent arteriole
- > this allows for regulating the rate of glomerular filtration
Juxtaglomerular Cells (JG)
- modified smooth muscle cells of the tunica media of the afferent arteriole
- adjacent to the macula dense
Juxtaglomerular Cells (JG)
- produce renin which raises blood pressure
Renin
- this acts on angiotensin to form angiotensin I
- angiotensin I is converted to angiotensin II by the angiotensin converting enzyme contained primarily in the lungs
Angiotensin II
- causes vasoconstriction of the arterioles
- raises blood pressure
Extraglomerular mesangial cells
- are present between the macula dense and arterioles
- continuous with the mesangial cells of the glomerulus
Collecting Duct System
- Arched Collecting Duct (collecting Tubules)
2. Collecting Ducts (straight collecting tubules)
Arched Collecting Duct (collecting Tubules)
- connects the DCT to a collecting duct
- simple cuboidal epithelium
Collecting Ducts (straight collecting tubules) Components
- Cortical Collecting Duct
- Medullary Collecting Duct
- Papillary Duct
Cortical Collecting Duct
- smaller collecting duct
- lateral borders are clear
- simple cuboidal epithelium
Collecting Ducts
- are a major component of the urine-concentrating mechanism
Medullary Collecting Duct
- larger collecting ducts
- simple columnar epithelium
Papillary Duct
- 2 layered epithelium
- becomes transitional towards the opening
Collecting tubules
- simple cuboidal epithelium
- distinct lateral borders
Vasculature Flow of the Kidney
- Renal Artery
- Interlobar arteries
- Arcuate Arteries
- Interlobular arteries
Vasculature Flow of the Kidney
- Renal Artery
- Interlobar arteries
- Arcuate Arteries
- Interlobular arteries
- Afferent arteriole
- glomerulus
- efferent arteriole
- Peritubular capillary network (cortex)
- descending vasa recta
- peritubular capillary network (medulla)
- ascending vasa recta (venules)
- Interlobular Vein
- Arcuate vein
- Interlobar vein
- Renal vein
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Interstitium, or Stroma of the Kidney
- present between the renal tubules and blood vessels
- sparse in the cortex
- plentiful in the inner medulla
- collagen fibrils and some fibroblasts
- lipid laden interstitial cells are prominent in the inner medulla
Urinary Passages
- all have transitional epithelium
1. Calyces and renal pelvis
2. Ureter
3. Urinary Bladder
Calyces and Renal Pelvis in Horses
- have mucous glands (simple branched tubuloalveolar glands) are present under the endothelium
- responsible for the mucous in their urine
Ureter
- mucosa is folded
- lamina muscularis is absent
- tunica muscularis has three ill defined layers
- tunica adventitia, or serosa has loose CT, blood vessels and nerves
Ureter in horses
- propriasubmucosa contains tubuloalveolar mucous glands
Urinary Bladder
- the transitional epithelium becomes increasingly flattened as the bladder fills
Urinary Bladder in horses, ruminants, dogs and pigs
- lamina muscularis in the urinary bladder is present
Urinary Bladder in cats
- lamina muscularis in the urinary bladder is absent
Detrusor muscles
- smooth muscles of the tunica muscularis in the urinary bladder
- composed of irregularly shaped interweaving bundles
- > not well layered
Avian Kidney
- extends cranially up to lung and caudally at end of synsacrum
Avian Kidney Divisions
- Cranial
- Middle
- Caudal
- outer cortex and inner medulla
Two Types of Nephrons in Avian Kidney
- Cortical Type
2. Medullary Type
Cortical Type of Nephron in Avian Kidney
- forms the majority
- devoid of a medullary loop (of Henle)
- is confined to the cortical region of the lobule
Medullary Type of Nephron in Avian Kidney
- has a medullary loop which penetrates the medullary region of the lobules.
Male Avian Testis
- covered by a very thin tunica albuginea
- Septa, lobulation and mediastinum testis are absent
Male Avian Epididymis
- is smaller and less conspicuous
- numerous efferent ductules
Efferent Ductules of the Male Avian Epididymis
- lined by ciliated pseudostratified columnar epithelium
- head, body and tail region can NOT be distinguished
No organs in male birds similar/homologous with mammalian organs
- Seminal Vesicle
- Prostate gland
- Bulbourethral Gland
- Ampulla
Avian Male Seminal glomus
- acts as a storage organ for spermatozoa
Avian Phallus
- homologous with the penis of mammals
Avian Male Phallus Components
- The Median Phallic Body
2. A Pair of Lateral phallic bodies
Avian Male Ejaculation
- Cloacal Kiss
Avian Female Reproductive System
- only the left ovary and oviduct are retained in the adult as functional entities
Avian Ovaries Cortex
- consists of follicles in various stages of development
- antrum does not develop
Avian Ovulation
- not followed by the development of a corpus luteum
Avian Infundibulum
- the funnel like cranial extension of the duct
Avian Magnum
- responsible for the deposition of the majority of the egg white (albumin)
- ciliated and non-ciliated columnar epithelium
Avian Oviduct
- Infundibulum
- Magnum
- Isthmus
- Shell Gland
- Vagina
Avian Isthmus
- responsible for the formation of the shell membrane
- ciliated and non-ciliated columnar epithelium
Avian Shell Gland (uterus)
- secretory activity is responsible for the formation of the egg shell
- pseudostratified ciliated columnar epithelium
Avian Vagina
- sperm-host glands at utero-vaginal junction to nourish and store sperm
- pseudostratified ciliated columnar with few goblet cells
Avian Vagina
- mostly nonglandular, except at the utero-vaginal junction
- > utero-vaginal junction is glandular
Utero-vaginal junction
- glandular
- sperm host glands are present here to nourish and store sperm