Isikhumba yisitho esikhulu kunabo bonke, esiningi esingaba kathathu kwesibindi. Ebonisa izinto eziyingozi zemvelo, isikhumba siyisivikelo esivikelayo emzimbeni, futhi sibamba iqhaza ezinkambisweni zokushisa, ukuguqulwa komzimba, ukuphefumula. Isakhiwo sakhe sokwahlulela sesikhumba sabantu sinzima ngokwanele, ngakho-ke sizokucabangela ngomusa olula kakhulu.
Izendlalelo zesikhumba
Isikhumba somuntu simelwe izingxenye ezintathu:
- i-epidermis, ebuye ibe nezinhlaka ezinhlanu;
- i-dermis - izicubu ezimbili ezihlangene;
- hypodermis noma fat subcutaneous.
Ingqimba engenhla (engaphandle) yile-epidermis, ubukhulu bayo obuhlukahluka ezingxenyeni ezahlukene zomzimba. Kuncike kulokhu, isikhumba sihlukaniswa sibe sinyene (emagqumeni, izintende) futhi sincane (ezingxenyeni ezisele zomzimba).
Isikhumba sisekelwa yi-derivatives yayo (ama-appendages):
- izipikili;
- izinwele;
- i-sweat glands;
- izigulane ezisabekayo.
I-Epidermis
Ku-epidermis azikho imithwalo yegazi - amaseli anikezwa ngesikhala se-intercellular.
Izendlalelo ze-epidermis:
- i-horny - ungqimba olungaphandle, olune-epithelium ekeratinizing; amangqamuzana ayo agcwele amaprotheni keratin futhi, eqinisweni, asefile kakade;
- i-shiny - igcwele iphrotheni ekhethekile ephikisayo ukukhanya;
- i-granular - emelelwe ama-1-5 imigqa yamaseli aphethwe;
- i-spiny - iqukethe imigqa engu-3-8 yamaseli anemiphakathi ye-cytoplasmic;
- i-basal - ungqimba oluphansi kunawo onke, olusekhanda elisebuseni, olumngcele wedermisi, futhi luqukethe i-epithelium ye-prismatic.
Amaseli e-stratum corneum ahlale ehlukana, athathelwa yizintsha, ezifuduka ezigabeni ezijulile.
I-Dermis ne-hypodermis
Isakhiwo se-dermis (empeleni isikhumba) simelwe izingqimba ezimbili.
Emgqeni we-papillary kukhona amangqamuzana asemasipha aluhlaza, axhunyiwe nama-hair bulbs, ukuphela kwezinzwa nama-capillari. Ngaphansi kwe-papillary ungqimba olungasese, olumelelwa ukuqina okusikhenyayo, okubushelelezi kanye nama-collagen, ngenxa yokuthi isikhumba siqinile futhi sinwebeka kanjani.
I-fat subcutaneous noma i-hypoderma inezinqwaba zokubuthelwa kwamafutha kanye nezicubu ezixhunyiwe. Lapha, izakhi zinqwabelene futhi zigcinwe.
Isikhumba sobuso
Ukwakhiwa kwesikhumba somuntu kuhluke kwezinye izindawo zomzimba.
Esikhathini esibhekene naso kunesisindo esincane kakhulu sezingqimba zomzimba - lokhu kubuye kube nokucaca kwesakhiwo sesikhumba sobuso. Ngokuya ngesilinganiso semfihlo esenziwe yi-glands, kuyisiko ukuhlukanisa isikhumba sibe uhlobo olune-fat, evamile, olomile nolunhlanganisayo. Emkhatsini wamehlo nakwezinkophelo yindawo ye-layer ye-epidermal ye-thinnest. Isikhumba sobuso sithinteka kakhulu emoyeni kanye nemithonya yemvelo, ngakho-ke sidinga ukunakekelwa okuhlelekile.
Isikhumba sezandla
Ezintendeni (kanye nasenhlakeni yezinyawo) azikho izinwele zezibhamu nezinhlayiya ezithungayo, kodwa izigulane ezikhukhulayo kulezi zindawo ziningi kakhulu - ngenxa yezinto ezikhishwe yizo, izandla azidli lapho zihamba. Ukwakhiwa kwesikhumba sezintendeni zezandla kuncike ngokwengeziwe ngamathissi angaphansi. Emuva kwezintende zezandla, isikhumba sinwebeka kakhulu, sithandeka futhi sibucayi - ngenxa yalezi zici umuntu angacindezela iminwe.
Isikhumba senhloko
Izici zesakhiwo se-scalp zibangelwa ukutholakala kwezinwele zezinwele, ezakhiwe ngokuthunjwa kwe-anyanisi ye-tissue e-toion, ekhonjeni le-sac follicle. Umkhawulo omncane we-bulb ubizwa ngokuthi impande, izinwele ngokwayo zikhula kulo. Ingxenye etholakala ngenhla ye-epidermis ibizwa ngokuthi i-shaft hair, ezungeze yiziphetho zezingqimba ze-sebaceous and sweat. Kumapilla, ukuphela kwemizwa nama-capillary ezondla isibani nokukhula kwezinwele zifanelekile.
Imisebenzi Yesikhumba
Ukwakhiwa nokwakhiwa kwesikhumba kunqume ukubaluleka kwalo kanye nemisebenzi esemqoka:
- Ukuvikela (kusuka emathonyeni amakhemikhali, ama-UV, ukulahlekelwa umswakama);
- ukufudumala (ngenxa yokukhuphuka kwesithukuthezi nokushisa komlilo);
- i-excretory (i-excretion ye-usawoti, imikhiqizo yemithi, izidakamizwa ezinezikhukuphuku);
- i-endocrine ne-metabolic (i-synthesis of hormones, i-vitamin D);
- receptor (ngenxa yokuphela kwezinzwa);
- ukuzivikela emzimbeni (ukubamba iqhaza ekwakheni impendulo yomzimba).