Urinary and Integumentary Systems

1. Urinary system overview 2. Kidney and its excretory ducts 3. Ureters 4. Urinary bladder 5. Urethra 6. Skin – epidermis, dermis and hypodermis 7. Skin appendages SPLANCHNOLOGY UrinaryUrinary systemsystem Urinary system , systema urinaria: elimination of wastes from the body – urine homeostasis – very close relationships with the circulatory, respiratory and endocrine systems Urinary organs, organa urinaria: kidney, ren: renal calyces renal pelvis uteter, ureter urinary bladder, vesica urinaria urethra, urethra: urethra masculina urethra feminina Prof. Dr. Nikolai Lazarov 2 SPLANCHNOLOGY KidneyKidney ,, renren Kidney , ren (Gr. nephros): a paired organ excretory function: removal of wastes excessive water endocrine function: renin regulation of blood pressure erythropoietin erythrocytopoiesis calcitriol increase of blood calcium levels Kidneys in situ: at the rear of the abdominal cavity in the retroperitoneum below the diaphragm near the vertebral column Prof. Dr. Nikolai Lazarov 3 SPLANCHNOLOGY GrossGross anatomyanatomy

External morphology:morphology shape – beanlike two poles: o extremitas superior et extremitas inferior two surfaces and two margins: o facies anterior et facies posterior o margo lateralis et margo medialis hilum renale sinus renalis calyces renales size : length 1013 (~12) cm width ~6 cm thickness ~3 cm weight – 150 g(♂); 135 g (♀); 1/240 of the body weight color – reddish browny consistency – parenchymal organ Prof. Dr. Nikolai Lazarov 4 SPLANCHNOLOGY KidneyKidney topographytopography Skeletotopy: against the posterior abdominal wall at the level of

vertebrae Th 1 to L 2 right kidney – 12 cm lower than the left (liver)

Prof. Dr. Nikolai Lazarov 5 SPLANCHNOLOGY RenalRenal fasciasfascias Fascias of the kidney : fibrous organ capsule adipose capsule perinephric fat, corpus adiposum pararenale renal fascia (Gerota) fascia prerenalis fascia retrorenalis

Prof. Dr. Nikolai Lazarov 6 Imaging anatomy of the kidney

conventional X ray imaging echography (sonography ) computed tomography (CT ) magnetic resonance imaging (MRI )

CT and MRI at the level of hilum renale 7 SPLANCHNOLOGY SyntopySyntopy ofof kidneykidney

Prof. Dr. Nikolai Lazarov 8 SPLANCHNOLOGY InternalInternal anatomyanatomy ofof thethe kidneyskidneys

Renal parenchyma:parenchyma renal cortex, cortex renalis – 510 mm: brownred color granular appearance: o pars convoluta o pars radiata (cortex juxtamedullaris) o lobulus corticalis renal medulla, medulla renalis: renal pyramid – 720 (12): o pyramid base o renal papilla renal sinus o foramina papillaria area cribrosa renal columns (of Bertin ) 79 renal lobes, lobi renales

Prof. Dr. Nikolai Lazarov 9 SPLANCHNOLOGY MicroscopicMicroscopic anatomyanatomy

Nephron , nephronum – the basic structural and functional unit of the kidney: renal (Malpighian) corpuscle, corpusculum renale (Malpighi) renal tubules: proximal convoluted tubule , tubulus contortus proximalis nephron loop (loop of Henle ), tubulus atenuatus (ansa nephroni) o descending limb o ascending limb distal convoluted loop , tubulus contortus distalis collecting duct, tubulus renalis colligens o tubulus colligens arcuatus et rectus Types of nephrons: cortical, nephronum breve (corticale ) intermediate, nephronum intermedium juxtamedullary, nephronum longum (juxtamedullare) – 1/7 of all nephrons Prof. Dr. Nikolai Lazarov 10 SPLANCHNOLOGY MicroscopicMicroscopic anatomyanatomy Renal (Malpighian ) corpuscle , corpusculum renale (Malpighi) – 2 million, diameter 200 m: cortical glomeruli (80%) and juxtaglomellular (20%) a tuft of capillaries, glomerulus – rete capillare glomerulare (mirabile): tubular (urinary) pole, polus tubularis vascular pole, polus vascularis afferent arteriole, vas afferens efferent arteriole, vas efferens mesangium glomerular (Bowman’s) capsule, capsula glomeruli: internal visceral layer, paries interna external parietal layer, paries externa capsular space, lumen capsulae Prof. Dr. Nikolai Lazarov 11 SPLANCHNOLOGY BloodBlood --urineurine filtrationfiltration barrierbarrier

Glomerular filtration barrier – 170 l of primary urine: fenestrated continuous endothelium, lamina fenestrata endothelial cells, endotelocyti fenestrati o pores 0.040.1 m o not spanned by diaphragms basement membrane, membrana basalis – 30 m lamina rara interna lamina densa lamina rara externa internal layer of Bowman’s capsule podocytes, podocyti – 2030 m o foot processes , primary and secondary processes (pedicels) o filtration slits – 2030 nm o a thin diaphragm – 6 nm thick

Prof. Dr. Nikolai Lazarov 12 SPLANCHNOLOGY MesangiumMesangium,, mesangiummesangium Mesangium (Gr. mesos, middle + angeion, vessel ):) intraglomerular mesangial cells, mesangiocyti in islets, insulae perivasculares masangii supporting role – production of glomerular matrix contractile and phagocytic functions receptors for angiotensin II and ANF produce chemical mediators – IL1 and prostaglandins extraglomerular mesangial cells – juxtaglomerular apparatus

Prof. Dr. Nikolai Lazarov 13 SPLANCHNOLOGY RenalRenal tubulestubules

Proximal convoluted tubule, tubulus contortus proximalis : length 15 m; width 5060 nm parts: initial portion, neck pars convoluta pars recta cuboidal, or low columnar epithelium brush border microvilli basilar infoldings of the membrane reabsorption of water, amino acids, sodium, proteins and glucose Distal convoluted tubule , tubulus contortus distalis: shorter and wider parts: straight portion, pars recta convoluted, pars convoluta simple cuboidal epithelium short sparse microvilli basal membrane invaginations absorption of Na, K and water macula densa

Prof. Dr. Nikolai Lazarov 14 SPLANCHNOLOGY RenalRenal tubulestubules

Prof. Dr. Nikolai Lazarov 15 SPLANCHNOLOGY RenalRenal tubulestubules

Nephron loop (loop of Henle ), tubulus atenuatus (ansa nephroni): in the renal medulla (pyramids) parts – a long Ushaped structure descending limb – 30 nm , simple squamous epithelium ascending limb – 60 nm , simple cuboidal to columnar epithelium in the thick limb single microvilli involved in water retention creates a gradient of hypertonicity Collecting duct, tubulus renalis colligens: parts: tubulus colligens arcuatus tubulus colligens rectus simple cuboidal epithelium light cells – aquaporin1, 2 and 3 dark cells one layer two layers (in calyces) columnar epithelium basement membrane water absorption (ADH), major component of the urineconcentrating mechanism

Prof. Dr. Nikolai Lazarov 16 SPLANCHNOLOGY EndocrineEndocrine kidneykidney Juxtaglomerular apparatus:apparatus juxtaglomerular cells : modified smooth muscle cells in the tunica media of afferent arteriole secretory granules (1040 nm) – renin absent internal elastic membrane macula densa: tall columnar cells o closely packed together nuclei o signaling molecules enzyme renin absence of basement membrane extraglomerular mesangial cells [lacis, Goormaghtigh, or Polkissen (polar cushion) cells] – erythropoietin interstitial cells – prostaglandins Prof. Dr. Nikolai Lazarov 17 SPLANCHNOLOGY ExcretoryExcretory ductsducts ofof thethe kidneykidney

Minor calyces, calyces renales minores: 89 in number fornix Major calyces, calyces renales majores: 2(3) in number Renal pelvis , pelvis renalis: in the renal sinus pelvis ampullaris et ramificans Forms of the excretory system: embryonic fetal mature Prof. Dr. Nikolai Lazarov 18 SPLANCHNOLOGY UreterUreter ,, ureterureter UreterUreter ,, ureter:ureter: muscular tube length 30 cm diameter 78 mm AnatomicalAnatomical parts:parts: abdominal part – – retroperitoneal position pelvic part intramural part Three anatomical constrictions: diameter 34 cm

Prof. Dr. Nikolai Lazarov 19 SPLANCHNOLOGY MicroscopicMicroscopic anatomyanatomy tunica mucosa : lamina epithelialis – transitional epithelium lamina propria – 350700 m fibroelastic connective tissue lymphocytes and lymphatic follicles tunica muscularis – 750800 m: stratum longitudinale stratum circulare stratum longitudinale – lower ⅓

tunica adventitia: nerves loose connective tissue blood and lymph vessels

Prof. Dr. Nikolai Lazarov 20 SPLANCHNOLOGY UrinaryUrinary bladderbladder ,, vesicavesica urinariaurinaria

Urinary bladder , vesica urinaria (Gr. cystis): reservoir – collects urine, 120230 (max. 500) ml on the pelvic cavity floor sphere or pearshaped Anatomical parts: fundus, fundus vesicae neck, cervix vesicae body, corpus vesicae summit , apex vesicae lig. umbilicale medianum Internal surface: trigone, trigonum vesicae ostium ureteris ostium urethrae internum plica interureterica, uvula

Prof. Dr. Nikolai Lazarov 21 SPLANCHNOLOGY MicroscopicMicroscopic anatomyanatomy

tunica mucosa – wrinkled or folded: lamina epithelialis – transitional epithelium lamina propria – 350700 m areolar connective tissue lymphocytes and lymph follicles tela submucosa – mucosal rugae, mucosal stroma tunica muscularis – detrusor muscle internal longitudinal layer circular layer m. sphincter vesicae external longitudinal layer tunica serosa (adventitia): superiorposterior surface – serosa loose connective tissue blood and lymph vessels

Prof. Dr. Nikolai Lazarov 22 SPLANCHNOLOGY

MaleMale andand femalefemale urethraurethra

Prof. Dr. Nikolai Lazarov 23 MaleMale urethraurethra Urethra masculina ~20 cm: intarmural part prostatic part – 3 cm membranous part – 12 cm spongy (penile) part – 15 cm

24 SPLANCHNOLOGY MicroscopicMicroscopic anatomyanatomy

tunica mucosa : lamina epithelialis transitional epithelium pseudostratified columnar epithelium stratified squamous nonkeratinized – in the navicular fossa lamina propria – basement membrane; stroma urethral glands (Littre ); urethral lacunae (Morgagni) tunica muscularis – prostatic and membranous parts str. circulare m. sphincter urethrae (externus) str. longitudinale

Prof. Dr. Nikolai Lazarov 25 FemaleFemale urethraurethra Urethra feminina : ostium urethrae internum ostium urethrae externum length 34 cm diameter 610 mm Microscopic anatomy: tunica mucosa – longitudinal folds, urethral crest transitional epithelium stratified squamous nonkeratinized epithelium stratified squamous keratinized lamina propria o urethral glands o urethral lacunae tela submucosa tunica spongiosa tunica muscularis internal layer, smooth muscle fibers external layer, striated muscle fibers 26 SPLANCHNOLOGY

TheThe integumentintegument

1. Skin and its main functions 2. Structure of the skin: epidermis – microscopic structure dermis – microscopic structure hypodermis (subcutaneous tissue) 3. Appendages of the skin: hairs and nails sebaceous and sweat glands

Prof. Dr. Nikolai Lazarov 27 SPLANCHNOLOGY Human skin SkinSkin andand skinskin functionsfunctions

the largest single organ of the body: ~16% (~4 kg) of the total body weight major role – a barrier between the organism and the environment protect ion of the body against pathogens and damage some other functions:functions thermal insulation and heat regulation excretion by sweating temperature regulation control of evaporation and water resistance prevents excessive water loss and body dessication storage and synthesis : storage center for lipids and water synthesis of vitamin D absorption – oxygen, nitrogen and carbon dioxide, medicine sensation – nerve endings, cutaneous receptors aesthetics and communication

NB:NB: The adjective cutaneous literally means “of the skin" Prof. Dr. Nikolai Lazarov 28 (from Latin cutis, skin ) Prof. Dr. Nikolai Lazarov SPLANCHNOLOGY Human skin StructureStructure ofof thethe skinskin two major layers – Gr. derma , skin: epidermis epithelial layer derived from embryonic ectoderm generates skin appendages high capacity of regeneration non -vascular but richly innervated dermis (corium) connective tissue layer mesenchymal origin highly vascularized hypodermis (subcutis) loose irregular connective and fatty tissue, panniculus adiposus two skin types – thickness of the epidermis : thick (glabrous, hairless) skin palms and soles – 1.5 mm thin (hairy) skin – 0.08 m m elsewhere on the body thinnest on the eyelids – 0.05 mm Prof. Dr. Nikolai Lazarov 29 SPLANCHNOLOGY Human skin EpidermisEpidermis stratified squamous keratinized epithelium main cell types: keratinocytes – 85 -95% of all epidermal cells keratin -producing cells melanocytes neural crest cells production and storage of melanin darkening of the skin (tanning) Langerhans cells – 2-8% macrophages dendriticcells with Birbeck granules immune, antigen -presenting cells Merkel cells present in the thick skin "touch cells" mechanoreceptors APUD cells neuroendocrine function Prof. Dr. Nikolai Lazarov 30 SPLANCHNOLOGY Human skin EpidermisEpidermis –– microscopicmicroscopic structurestructure

5 layers of keratinocytes: stratum basale (germinativum) single layer of columnar cells renewal of the epidermis stratum spinosum several layers of polygonal spiny cells desmosomes stratum granulosum 3-5 layers of flattened polygonal cells with keratohyalin granules stratum lucidum only in thick skin flattened eosinophilic cells stratum corneum 15 -20 layers of flattened nonnucleated keratinized (horny) cells keratinization: every 15 -30 days due to mitotic activity of the malpighian layer Prof. Dr. Nikolai Lazarov 31 SPLANCHNOLOGY Human skin Dermis,Dermis, coriumcorium

connective tissue – though, flexible and elastic variable thickness – max. 4 mm on the back two layers: papillary layer – thin and superficial: dermal papillae ridges loose connective tissue • collagen fibers anchoring fibrils • fibroblasts, mast cells, macrophages increase and reinforce dermal -epidermal junction reticular layer – deep and much thicker: irregular dense connective tissue • collagen type I and elastic fibers • fewer cells rich lymph and capillary network – 4.5% of the blood volume epidermal derivatives Prof. Dr. Nikolai Lazarov 32 SPLANCHNOLOGY Human skin DermisDermis –– microscopicmicroscopic structurestructure

Prof. Dr. Nikolai Lazarov 33 SPLANCHNOLOGY Human skin HypodermisHypodermis subcutaneous tissue – synonyms: superficial fascia, panniculus adiposus: loose connective tissue and elastin binds the skin loosely to the subjacent organs supplying skin with blood vessels and nerves renewal of the epidermis components: fat cells – varying in number and size, contains 50% of body fat fibroblasts, macrophages

Prof. Dr. Nikolai Lazarov 34 SPLANCHNOLOGY Human skin SkinSkin appendagesappendages Appendages associated with the skin: hairs – functions: sensation heat loss filter for breathing protection nails – function: protection sebaceous glands – function: secrete sebum onto hair follicle to oil the hair sweat glands – function: produce sweat to help keep the body cool secreted with strong odour (apocrine) , with a faint odour (eccrine) arrector pilli muscle – function: smooth muscle that pull s hairs straight Prof. Dr. Nikolai Lazarov 35 SPLANCHNOLOGY Human skin HairHair structurestructure andand colourcolour three parts length-wise: hair bulb – stem cells hair root – beneath the skin surface hair shaft – above the skin surface three parts in cross-section: hair medulla – area in the core: contains loose cells and airspaces hair cortex : contains densely packed keratin responsible for the pigmentation, shape and texture of hair hair cuticle : single layer of cells covering the cortex last cell line to differentiate natural hair colours:colours phaeomelanin – responsible for the yellowish -blond to red colors eumelanin is responsible for the brown to black shades gray hair – little or no pigment Prof. Dr. Nikolai Lazarov 36 SPLANCHNOLOGY Human skin SebaceousSebaceous glandsglands small, sacculated, holocrine glands: embedded in the dermis; 100 glands/cm 2 absent in the glabrous skin of palms and soles 400-900/cm 2 on the face, forehead and scalp begin to function at puberty structure: secretory portion: 2-5 acini of flattened epithelial cells larger fat-containing sebaceous cells basal lamina single short duct: in the upper portion of a hair follicle sebum (Lat, fat or tallow ) – functions: complex mixture of lipids and waxes, triglycerides, squalene and cholesterol natural lubricant of the hair and skin antibacterial and antifungal properties no importance in preventing water loss Prof. Dr. Nikolai Lazarov 37 SPLANCHNOLOGY Human skin SudoriferousSudoriferous (sweat)(sweat) glandsglands

widely distributed in the skin absent in the glans penis two types: eccrine (merocrine) glands: most numerous simple, coiled tubular glands ducts opened at the skin surface secretory portion in the dermis, surrounded by myoepithelial cells • dark (mucoid) cells glycoproteins • clear cells – no secretory granules innervated by cholinergic nerve endings apocrine glands: in axillae , eyelids, areola and nipple, anal region , embedded in the subcutaneous tissue much larger (3 -5 mm in diameter) tubular with extensive coiled secretory portion cuboidal cells with secretory granules straight ducts opened into hair follicles produce odorless viscous secretion innervated by adrenergic nerve endings sweat – functions: clear and not viscous, salty fluid keep the body cool proteins, water, sodium chloride, urea, uric acid Prof. Dr. Nikolai Lazarov 38 SPLANCHNOLOGY Human skin NailsNails Lat. ungues , Gr. onyx, onychos fingernails and toenails – on the dorsal surface of each distal phalanx tough keratin as animals' hooves and horns nail parts: root – proximal part body – exposed part free border – distal end structure: matrix – the only living part of the nail eponychium (cuticle) paronychium – the 'live' skin hyponychium nail plate – layers of keratin nail bad – pink colour of the nail lunula – visible whitish crescent part of the matrix nail fold – overlaps the base and sides of nails nail groove – guide the direction of nail growth Prof. Dr. Nikolai Lazarov 39 SPLANCHNOLOGY

ThankThank youyou ...... NB:NB: HumanHuman skin:skin: thethe mostmost valuablevaluable 22 mm Prof.222!!!!!! Dr. Nikolai Lazarov