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
Q. What is Streatorrhoea? Streatorrhoea is more common in Crohn's disease due to heal resection. This may favour calcium-fatty acid complex formation and increased excretion. I

Q. What are the main manifestations of leishmaniasis? There are two key forms of leishmaniasis: visceral leishmaniasis and cutaneous leishmaniasis (also known as kala-azar). Th


Define Distribution of body iron in different compartments? In humans, the total quantity of iron in the body varies with haemoglobin concentration, body weight, gender and the

Explain Sound production - Ethological Approach in Taxonomy The most used, ethological feature in identification is the sound produced by various species of animals. This is


Exercise- Heat Production During physical activity heat production by exercise can to some extent substitute for heat generated by shivering. However, exercise also tends to

Single-cell organisms, protists, have always been a problem for taxonomists who have trouble describing categories for organisms. Their mixed feeding habits that include being capa

RESPIR A T ORY ORGANS IN ANIMALS - In Protozoa plasmalemma functions as respiratory surface. In Porifera, respiration occur through body wall. In Coelentrata resp

Cosmid: The type of artificially constructed vector taken in use for cloning the 35-45 kb of DNA. These are plasmids carrying the phage l cos site (which permits packaging into l