lasr parf ct

Adipose

-Mainly fat cells with few scattered Structure other C.T cells -reticular fibers: support -collagen and elastic fibers

Character of white and brown adipose

Fat cells are unilocular - Less vascularity + cartenoids - affected by diet, hormones

-fat cells are multilocular -higher vascularity +cytochrome pigments: brown color -affected by hormones not by diet

Site

-Widely distributed all over body -under the skin: in females as in gluteal region & abdominal wall -mammary gland, mesentery -around kidney

present in large amounts during fetal life &newborn -it becomes lost during childhood to be replaced by the white type -In adults: in certain areas as inter scapula, mediastinal & axilla region

Function

-heat insulation -storage of fats -supporting kidneys -secretion of leptin -giving skin its contour

Heat generation (thermogenesis) in newborns

Rt cells

Reticular cells and reticular fubers

Character

Delicate type

- Silver (Ag):

brown black

Site

Forming a supporting stroma of organs e.g: lymph node, liver, spleen, endocrine glands

Function

Supportive

Areolad

• All types of C.T cells

• All types of fibers (mainly:
  collagen bundles)

• Most abundant matrix

Characters

• cavities (areolae) which can accommodate large amount of fluid or gases

• flexible and well vascularized

Site

• Found everywhere in the body except in the brain:

• filling spaces between organs

• papillary layer of dermis of skin

• submucosa and serous membrane

• around blood vessels and nerves

Funftin

• nerves

• exchange of nutrients to and from blood vessels

• binding structures together

• limiting spread of infection

Mucoid

• mainly fibroblasts

• fine collagen and reticular fibers

• large amount of soft, jelly-like ground substance

• rich in mucus and hyaluronic acid

Character

Jelly like in which ground substances predominates

Site

• umbilical cord (Wharton jelly)

• vitreous humor of eye

• pulp of teeth

Function

Supportive

White fibrous

Fibroblast

- Fibroblasts - Collagen fibers in bundles - Minimal amount of matrix

Character

dense due to collagen fibers Resistant and less flexible

Site regular white vs irregular

	Regular white	b) Irregular white
	- Regular collagen bundles with arranged fibroblasts	- Irregular arranged collagen bundles with scattered fibroblasts
	-Tendons -Cornea	-reticular layer of skin dermis -Ligaments -Sclera of the eye -Capsule of organs

Function

Withstanding stretch infone: direction

Withstanding___ stretch in plifferent direction

Staining

Mallory trichome: blue

Mallory trichome: blue

Yellow

2) Yellow elastic C.T

• Fibroblasts

• Regular parallel Elastic fibers

• Small amount of matrix

Character

dense with elastic fiber great elastic power

Location

• Aorta and large arteries

• trachea, bronchi

• bronchioles, around alveoli

• vocal cords

• some ligaments:

a) Ligamentum Flavum:

joining vertebrae

1. ligamentum nuchae: at back of neck

2. suspensory ligament of penis

Function and stain

Has great elastic power

Orcein stain: brown

Ct can be classified according to their function

differentiated cells: UMCs, pericytes

2- C.T forming cells: fibroblasts, fibrocytes and reticular cells

3- Fat containing cells: unilocular and multilocular adipocytes

4- cells for immunity and defense: macrophage, plasma cell,

mast cell and leucocyte

Extravasated leukocytes

leave blood through capillaries to perform their immunity fuMcGill

Allergic reaction

immune system recognizes antigens (allergens) as foreign bodies

B) binding of allergens to IgE on surface of mast cell of its secretion.

C) resulting in allergic RX (immediate hypersensitivity reaction)

Manifest as

🫁 Respiratory

BSS

• Bronchospasm

• Sneezing

• Shortness of breath (from bronchospasm)

🍽 Belly (GI tract)

NVDC

• Nausea

• Vomiting

• Diarrhea

• Cramping

• Redness (erythema)

• Itching

• Runny nose

Anaphylactic

in highly sensitive persons, exposure to an allergen massive

discharge of mast cell & basophil

- leading to:

A) severe vasodilatation.

B) increased permeability of blood vessels

C) resulting in severe hypotension