Skin type - dermis, Biology

DERMIS (CORIUM) -

  • Mesodermal in origin. More developed part.
  • Leather is obtained from dermis by tanning. Thinnest in eye lid. Connective tissue present.
  • In it 4 types of cell are present -

(i) Fibroblast or fibrocyte - forms fibres attached to fibres.

(ii) Histocytes - Amoeba like, phagocytic in nature.

(iii) Plasma cells - formation of antibodies (g-globuline)

(iv) Mast cells - It forms matrix, heparine & serotonine.

  • Collagen & elastin fibres are present.
  • When elasticity of dermis is lost skin becomes wrinkeled.
  • Dermis consists of b.v., lymph, vessels, unstripped muscles, nerves etc.
  • Sensory papillae present in dermis (not in epidermis to avoid unnecessary stimulation).
  • These papillae are of following types -

(i) Genital corpusulses - On tip of penis & clitoris.

(ii) Vater pecinian corpusulses or baroreceptor - For pressure deeply placed. More in palm & sole.

(iii) Frigido receptor or end bulb of krausi - For cold.

(iv) Allgesi receptor - For pain. Attached to free nerve endings mainly.

(v) Endings of Ruffini or Calore receptor - For hot.

(vi) Tectile corpuscles or missnner's corpuscles or markle's disc - For touch. Markel's disc is diffterent from other in structure.

(vii) Vibreo receptor - For vibration. Basal part of dermis is peniculus adiposa present on hypodermis (not a part of skin). Fat is stored in it. Also helpfull in temp. regulation. This part is absent in eye lid, prepuce & scrotal sac.

  • Outer part of dermis is papillary part or pars papillaris in it dermal papullae present, fibres are dense, lines of langerhanse can be seen.
  • Inner part is reticulate part or pors reticularis, papullae are absent, fibres are scattered.
  • In dermis melanophage cells engulf melanin by phagocytosis.
  • In some area of dermis blood passes from artery to vein directly by shunt or arterioveinuous anastamoses.
Posted Date: 10/1/2012 6:22:08 AM | Location : United States







Related Discussions:- Skin type - dermis, Assignment Help, Ask Question on Skin type - dermis, Get Answer, Expert's Help, Skin type - dermis Discussions

Write discussion on Skin type - dermis
Your posts are moderated
Related Questions
dialouge on cartoon between chlorophyll and haemoglobin

Q. How is excretion done in amphibians? Adult amphibians have kidneys that filter blood. Nitrogen waste is excreted as urea so amphibians are ureotelic beings. The aquatic, lar

Br u c e ll osi s It is also called as Bang's disease or contagious abortion as it causes abortion in late pregnancy and infertility. E t iology: It is cause

Lap design There are many different flap designs for implant surgery. In practically all situations a mid-crestal incision can be employed (Fig). This is especially so when th

Define Primary Prevention - preventive strategies for Food Allergy? Focuses on blocking sensitization and development of IgE-mediated response. These strategies would be useful

Determine Effects of probiotics on Animals? Let us briefly examine the effects that have been reported (remember most of it has been on animals): 1. In animals, probio

Classification of Living Organisms – Species You have by now already come across the word 'species'. The word has a definite meaning in biology. Although the living world is v

Explain First and second degree burns - Classification of Burns? First- and second-degree burns heal in days to weeks without scarring. Deep second- degree and small (less than

Why is quarrantine a must before introduction of a plant species from a dissimilar country? a) What is meant by apoplast pathway? Why does it occur in cortex and not in endoder

What is Transportation of Sick Newborn Infants with Heart Disease Communication : The decision to transport a newborn to a tertiay referral centre with facilities for specia