What is Connective Tissue?
Connective tissue is a group of
tissues that support, protect, and connect other
tissues together to give structure to other tissues and organs in the body.
Connective tissue provides connection, support, cohesion, and internal support, help bind or connect several different
tissues in the body and maintain the form of the body and
its organs.
Know here the embryonic
origin of connective tissue.
Classification of Connective Tissue
Connective tissue is categorized into two groups-
1. Embryonic connective tissue
Embryonic connective tissue is divided into-
A. Mesenchyme connective tissue
B. Mucus connection tissue
2. Mature connective tissue
Mature connective tissue is divided into-
A. Connective tissue proper
1. Loose connective tissue
Types of loose connective tissue-
A. Areolar connective tissue
B. Adipose connective tissue
C. Reticular connective tissue
2. Dense connective tissue
Types of Dense connective tissue-
A. Dense regular connective tissue
B. Dense irregular connective tissue
C. Elastic connective tissue
B. Specialized connective tissue
1. Cartilage
Three types of cartilage are-
A. Hyaline cartilage
B. Fibrous cartilage
C. Elastic cartilage
2. Bone
3. Blood/ lymph
Also, check out here types of
epithelial tissue.
Embryonic Connective Tissue
Embryonic connective tissue is present primarily in embryos or foetus,
found in the early embryos and umbilical cord.
Embryonic connective tissue is divided into two categories-
A. Mesenchyme Connective Tissue
(In
embryos)
Mesenchyme
originates from mesoderm.
Found first 2 months embryo (1-2 months).
Location
Around developing bones under the skin of embryo.
Function
1. Capable of developing into connective tissue.
2. Form cartilage, Bone, lymphatic system, circulatory
system, muscle.
2. Mucus Connective Tissue
Found in the fetus; from two months of pregnancy to birth (2-3
months).
Location
Found in the umbilical cord (fetus).
Function
From padding for blood vessels in the umbilical cord and prevent a cord from tangling when the fetus turns within the uterus.
Mature Connective Tissue
Mesenchyme connective tissue replaces with mature connective
tissue after delivery.
Mature connective tissue exists in newborns.
Types of Mature Connective Tissue
1. Connective Tissue Proper
Connective tissue proper has a complete proper function-
1. Binding and supporting
2. Binding them together
3. Protecting
4. Immunity provider
5. Strong reserve energy
6. Transporting substance within the body
Connective Tissue Proper includes; Loose connective tissue and Dense connective tissue.
A. Loose Connective Tissue (LCT)
Loose connective tissue is loosely woven having lots of
ground substance. It holds the organs in place.
It’s like weave appearance,
fibres are closely organized leaving large space in between.
Location
Blood vessel surrounds provide support to the internal organ.
Loose connective tissue are; areolar tissue, reticular tissue, and adipose tissue.
1. Areolar Connective Tissue
It is the most widely distributed connective tissue in the body, especially in those organ systems with external openings. It is found in almost every part of the body, providing elasticity and tensile strength.
It has characteristic stretch without breaking.
Areolar connective tissue contains cell-
1. Fibroblasts
2. Macrophages
3. Plasma cell
4. Mast cells
5. Adipocytes
6. Few WBCs
Location
1. Beneath the Epidermis layer
2. Between muscles
3. Supporting trachea blood vessels and nerve
4. In the esophagus
4. In the alimentary canal
5. In glands supporting secretory cells
6. Mucus membrane
Function
1. Allow passage of nerve and blood vessels through other
tissue.
2. Act as protective packing material between organs.
3. Provide strength, elasticity, and support.
4. Support, tissues, organs, blood vessels, and nerves.
5. Forms subcutaneous layers (that connect the skin to
underlying tissue and organ).
6. Allow for free movement of body parts.
2. Adipose tissue
Adipose tissue is derived from fibroblasts. Adipose tissue
consists of adipocytes (fat cells), has large fat globules.
Adipose tissue is found where ever areolar connective tissue is
located.
Adipose tissues are two types –
1. White Adipose Tissue (WAT)
White adipocytes stores energy. It is mainly found in adults.
Location
1. Surrounding kidneys
2. Orbital fat (Eyes)
3. Between muscle fibers, and
4. Under the skin, where it acts as a thermal insulator and energy
store.
5. Padding around the joint.
2. Brown Adipose Tissue (BAT)
Present in Newborn. Brown adipose tissue generates body
heat.
It contributes to the maintenance of body temperature prevents Hypothermia.
It has a more extensive capillary network than white adipose
tissue.
Function
1. Energy reserve providers
2. Storing fat
3. Support, protect the organ
4. Shock absorption
5. Provide insulation against loss of body heat
6. Produces heat to help maintain body
temperature
3. Reticular lymphoid tissue
Reticular connective tissue consists of fine interlacing, interwoven branching reticular fibre (thin networks of fibres) and reticular cells
provide structural support.
It contains the reticular cell and white blood cells, monocytes, and lymphocytes and after appears dark purple or black.
Lymphoid tissue is found in lymph nodes and all organs of the lymphatic system (spleen, tonsils), bone marrow, and liver.
Location
1. Interior of liver
2. Spleen
3. Lymph nodes
4. Tonsils
5. Stomach
6. Intestine
7. Trachea, bronchi
8. Supporting adipose cells
9. Around blood vessels and muscle
Function
1. Forms connecting and supporting framework of reticular
fibres for lymphatic organ (lymph node, thymus gland, bone marrow, spleen).
2. Binds together smooth muscle cells.
2. Dense Connective Tissue or Dense Fibrous Tissue
Dense Connective tissues are tightly packed, it
contains more numerous and thick fibres bind fewer cells than loose connective
tissue.
A tightly packed compact arrangement of collagen fibre, serve
to resist stretch. These fibres are mainly composed of type I
collagen.
Use to join bones (capsules; envelop surround synovial joint)
and ligament of joints and tendons to connect muscle to bone.
Dense connective tissue is divided into; dense regular, dense irregular, and elastic connective
tissue.
A. Dense Regular Connective Tissue
Dense regular connective tissues are mainly closely packed
bundles of collagen fibres. It is mainly made up of type-I collagen fibres, arranged in parallel and run in one direction. It has great tensile strength.
Fibroblasts that produce fibres and ground substances appear
rows between fibres.
Location
1. Ligament (attached bone to bone)
2. Tendons (attached muscles to bone)
Function
1. Forming ligaments, which bind bones together
2. Outer protective covering for bone called periosteum.
3. Outer protective covering of some organ.
4. Forming muscle sheaths, tendons that attach muscle to bone.
B. Dense Irregular Connective Tissue
Dense irregular connective tissue contains collagen fibres
that are interwoven without regular orientation, fibres are not arranged in
parallel bundles.
Thick bundle fibers are arranged randomly in tough, resilient
meshwork that can be stretched in more than one direction as in the dermis of the skin.
Location
Covering sheath of-
1. Nerve, tendons, brain, and spinal cord
2. Covering of muscles
3. Covering of dermis of the skin
4. Capsule of many visceral organs; like kidney, liver
Function
1. Provide strength
2. Provide durable
C. Elastic Connective Tissue
Elastic connective tissue contains a high concentration of
elastic fibers.
It is found in organs where stretching or alteration of
shape is required. It has characteristics, capable of considerable extension
and recoil. It can be stretched and will back (rebound) into shape.
Fibroblasts are present in the space between fibres.
Location
1. In large blood vessel wall
2. Trachea and bronchi and lungs
3. Wall of elastic arteries
4. True vocal cords
5. Ligaments between vertebrae
Function
Allow stretching of various organs
Also,
Get details on types of
muscle tissue, and types of
nervous tissue.
2. Specialized Connective Tissue
Specialized connective tissue includes; Cartilage, Bone, and Blood.
Check out types of specialized connective tissue.
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