Chii automatism kwemoyo? Cardiac automaticity

Chii automatism kwemoyo? Mhinduro yomubvunzo uyu ine munyaya pazasi. Uyezve, rine mashoko kutyorwa utano hwevanhu migumisiro chokuita chambotaurwa nezvacho pfungwa.

Chii automatism kwemoyo?

Muscle fibers muvanhu vane mano vakaitei rutapudzo kuti kunetsa kupomba uye ipapo sequentially uchatamisa nayo munyika rutapudzo kuti tsandanyama mamiriro. Zvinonzi kwakaratidza kuti yoga pomwoyo anokwanisa vakazvimirira vaunze mufaro uye kuti mutinhimira sunga. Mano aya anonzi automatism mwoyo.

Zvinokonzera cardiac automaticity

Kunzwisisa chii automatism kwemoyo, zvinogona kubva zvinotevera. The mwoyo ane chaizvo anokwanisa kuti vaunze imwe zvemagetsi kupomba, ichiteverwa vakabata nayo tsandanyama hurongwa.

Sinoatrial raiva pedyo nebundu - sumbu peysmekerskih wokutanga mhando masero (ine vanenge 40% mitochondria-siyana riri myofibrils, hapana T-Hurongwa unotora vazhinji vakasununguka karusiyamu iri havaratidzi dzakabudirira sarcoplasmic rezvebonde) iri kurudyi rusvingo pevane vena cava, panguva confluence rwerudyi atrium .

Zvinopfuura atrioventricular raiva pedyo nebundu rechipiri mhando chakaumbwa masero kuti kuitisa nomunhu kubva sinoatrial raiva pedyo nebundu, asi pasi chaiyo ezvinhu anogona vakazvimiririra vaunze wemagetsi mutariri. masero Transitional ane mitochondria vashoma (20-30%) uye myofibrils yakati kupfuura repakutanga murayiro sero. Atrioventricular raiva pedyo nebundu iri muna interatrial septum payo ari hwakatamisirwa excitation danda uye makumbo chinogumbura tsapo bazi (mitochondria ane 20-15%).

Purkinje fibers vari inotevera Danho kuchinjwa excitation. Vanoedza anenge ari pakati partitions kubva neimwe maviri chinogumbura bazi masumbu. Masero aya ane mitochondria vanenge 10%, zvakawanda zvayakaita zvakawanda zvakafanana cardiac tsandanyama fibers.

The kwatangwa pakuonekwa wemagetsi kupomba kunoitika muna peysmekerskih sinoatrial raiva pedyo nebundu masero, izvo potentiates chinozunguzirwa excitation anotokonya 60-80 anorova paminiti. Ndiye wokutanga-hurongwa mutyairi. Ipapo akasimuka wave chakasvitswa rechipiri nerechitatu conductive marongerwo pamwero. Vanokwanisa kutakura zvose excitation wavelength uye vakazvimirira kunyengedza rutapudzo pamusoro ezasi frequencies. The mutyairi rechipiri chechetere pashure sinus atrioventricular raiva pedyo nebundu, rinogona kusika 40-50 miniti pachavo discharges dzavo pasina inhibitory basa sinus raiva pedyo nebundu. Uyezve, excitation iri chakasvitswa sechivako mutundu wake, iyo reproduces 30-40 anorova paminiti, ipapo yemagetsi mutariri runoyerera kuenda mutundu makumbo ake (25-30 cpm) uye Purkinje internet mamiriro (pulses 20 paminiti) uye anopinda kushanda tsandanyama masero ari myocardium .

Yemanyorero nomunhu kubva sinoatrial raiva pedyo nebundu yakazvimirira kugona kudzvinyirira zvemagetsi basa pane hurongwa. Kana anetseka kushanda hurongwa mutyairi, basa rake riri kutora-amire Links pazasi conduction gadziriro wokutanga.

Chemical pezvakaitwa kuti anopa mwoyo automaticity

Chii automatism kwemoyo tichitarisa kemisitiri? Panguva samolecular sandara, hwaro kuzvimirira panowanikwa yemagetsi vebasa (the chiito mukana) pamusoro membranes peysmekerskih masero ari pamberi ainzi impulsatora. basa rake (mwoyo kushanda automatism) ine muzvikamu zvitatu.

Zvokukura impulsatora:

• 1st danho regadziriro (superoxide kubudikidza kukurukurirana reokisijeni pamwe chokwadi mhosva phospholipids pamusoro sero pamusoro Kamudzira peysmekerskoy payo anowana akaipa nokuchengeta, izvozvo anopa achizorora zvinogona);
• 2nd danho potassium uye yavaibvisa kushingaira chokufambisa, umo kwokunze mutariri sero rinova akaenzana 30 MW;
• 3rd danho kusvetuka electrochemical - kushandisa simba kwakaita panguva marara ose reactive okisijeni marudzi (pamusoro ionized okisijeni uye rehydrogen peroxide) kushandisa makemikari catalase uye superoxide dismutase. Akagarisa simba quanta kuwedzera biocapacity pacemaker saka zvakunokonzera chiito nekugona.

Kurongedza kupomba generating masero - pacemakers hazvo kuitika mumamiriro ezvinhu pamberi samolecular okisijeni, iyo anonunurwa kwachiri erythrocytes inflowing ropa zvakakwana.

Kuderedza basa kana kukwana kumira kushanda mumwe kana kupfuura matanho impulsatora hurongwa anotyora yakabvuma basa peysmekerskih masero, zvichiita arrhythmia. Ichivharira mumwe dzinotsanagura ino kunokonzera kungoerekana cardiac kusungwa. Kuziva kuti automatism mwoyo kwakadaro, kunzwisisa uye muitiro.

Matambudziko ari autonomic tsinga kuti pomwoyo

Kuwedzera kwavo nemano kuti vaunze magetsi nomunhu, basa mwoyo inotongwa anonongedzera kubva mhasuru innervating tsitsi uye parasympathetic tsinga, pamusoro kukundikana izvo zvinogona kukanganisa cardiac automaticity.

Igaroziva aimunzwira tsitsi weboka ukurumidze mwoyo, kunobatsira. Tsitsi innervation ane yakanaka chronotropic, inotropic, dromotropic mugumisiro.

Under yemamiriro zviito ari parasympathetic tsinga , deceleration depolarization peysmekerskih masero (inhibitory chiito), uye nokudaro tava kuderera kwemwoyo mwero (kunaka chronotropic chiito), kuti conductivity kuderera mukati mwoyo (kunaka dromotropic zvazviri), vasanyanye simba systolic marwadzo (kunaka inotropic mugumisiro), asi akanatsiridzwa excitability mwoyo (zvakanaka batmotroponoe chiito). The yokupedzisira zvakare sokugamuchira kutyorwa cardiac automaticity chaitika.

Zvinokonzera mwoyo automatism

1. Myocardial ischemia.
2. Kuzvimba.
3. Kudhaka.
4. Kutyora nepakati yavaibvisa, potassium, magnesium, karusiyamu.
5. Hormone dysfunction.
6. Kutyora matambudziko ari zvionera tsitsi uye parasympathetic harinzwi.

Mhando arrhythmias nokuda kutyorwa automaticity mwoyo

1. Sinus tachy-uye bradycardia.
2. Kufema (akura) arrhythmia.
3. Extrasystole arrhythmia (sinus, atrial, atrioventricular, ventricular).
4. Paroxysmal tachycardia.

Kusiyanisa arrhythmia nokuda conduction zvirwere automaticity uye reentry kuumba mafungu (reentry wave) imwe kana kupfuura dzakananga zvikamu mwoyo, zvinoguma ari fibrillation kana atrial flutter.

Ventricular fibrillation - kumwe arrhythmias zvinouraya, inova migumisiro pakarepo cardiac kusungwa uye rufu. Nzira inobudirira zvikuru kurapa - magetsi defibrillation.

mhedziso

Saka vaiona, chii automatism kwemoyo, unogona kunzwisisa kuti kutyorwa zvinogoneka kana urwere. Izviwo, zvinoita kuti tikwanise kurwisa nzira chirwere nani uye tibudirire.