Biomehanika mokraćnog mjehura

undergraduate thesis

• Title (english): Biomechanics of the urinary bladder
• Author: Kristina Dumančić
• Mentor: Tanja Jurčević Lulić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2019-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Mokraćni sustav zadužen je za izbacivane toksina i ostalih štetnih tvari iz organizma i održavanje optimalnog volumena tekućine unutar tijela. U ovom radu obrađen je mokraćni mjehur, njegove anatomske, fiziološke i mehaničke osobine. Kako bi mokraćni mjehur normalno radio potrebni su neuronski podražaji, odnosno impulsi koji dolaze iz sakralnog dijela kralježnice. Postoji cijeli niz poremećaja vezanih za mokraćni mjehur gdje dolazi do prekidanja provođenja živčanih impulsa do mjehura, odnosno od mjehura do leđne moždine i samog mozga, nedovoljne ili izrazite osjetljivosti mišića detruzora na istezanje uzrokovanog punjenjem samog mjehura, nemogućnosti kontroliranja mokrenja i slično. Sama biomehanika mokraćnog mjehura još uvijek nije u potpunosti poznata, stoga se brojni znanstvenici bave istraživanjima kako bi dobili što vjerodostojniji model i simulaciju rada mokraćnog mjehura. Testirana su uglavnom provedena na uzorcima tkiva mjehura životinja iz razloga što je izrazito teško održati fiziološku postojanost tkiva ljudskog mokraćnog mjehura izvan tijela domaćina. Prilikom modeliranja i matematičkih pokušaja opisivanja ponašanja mjehura, korištene su brojne pretpostavke i pojednostavljenja i samim time do sada nije dobiven model koji bi znatno pomogao u rješavanju patofizioloških poremećaja mokraćnog sustava. Generalna ideja koja se proteže kroz nekoliko istraživanja je promatranje mokraćnog mjehura kao tankostijene sferične ljuske. U samom radu proveden je proračun naprezanja mokraćnog mjehura pomoću teorije ljusaka. Izračunata su meridijalna i cirkularna naprezanja nakon određenih unutarnjih meridijalnih i cirkularnih sila pri opterećenjima koja uzrokuju tlak unutar samog mjehura te intraabdominalni tlak.

Abstract (english)

The urinary system is responsible for the removal of toxins and other harmful substances from the human body and maintaining the optimal volume of fluid within the body. The paper deals with the bladder, to be more exact, it deals with its anatomical, physiological and mechanical properties. In order for the bladder to function normally, neural stimuli or neural impulses from the sacral part of the spine are required. There are a number of disorders related to the bladder, which cause interruption of nerve impulses to the bladder, i.e. from the bladder to the spinal cord and the brain itself. For example, insufficient or pronounced sensitivity of the detrusor muscles to stretching caused by filling the bladder itself, inability to control urination and other disorders. The sole biomechanics of the bladder is still not fully known, and many scientists are conducting research in this area to get as most accurate model and simulation of bladder function as possible. Experiments have generally been performed on animal bladder tissue samples because it is extremely difficult to maintain the physiological stability of human bladder tissue outside the human body. In modeling and attempting to mathematically describe the behavior of the bladder, numerous assumptions and simplifications have been used. Thus, no model has been obtained so far that would significantly assist in the resolution of pathophysiological disorders of the urinary system. A general idea that runs through several studies is the observation of the bladder as a thin-walled spherical shell. In this paper, a bladder stress calculation was performed using shell theory. The meridional and circular stresses due to certain internal meridional and circular forces at loads that cause pressure within the bladder and intra-abdominal pressure were calculated.

• Keywords: mokraćni mjehur; model mokraćnog mjehura; teorija ljusaka; opterećenja mokraćnog mjehura.
• Keywords (english): bladder; bladder model; shell theory; loads of the bladder
• Language: croatian
• URN:NBN: urn:nbn:hr:235:585580
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-09-24 13:07:23