Connective Tissue: Types and Composition

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which characteristic distinguishes connective tissue from epithelia?

  • Connective tissue is typically found on body surfaces.
  • Connective tissue is generally avascular.
  • Connective tissue is not supplied by nerves.
  • Connective tissue is rarely found on body surfaces. (correct)

What primary components constitute connective tissue?

  • Ground substance and blood vessels
  • Extracellular matrix and cells (correct)
  • Epithelial cells and ground substance
  • Muscle fibers and nervous tissue

What determines the qualities of different connective tissues?

  • The ratio of cells to extracellular matrix
  • The structure of the extracellular matrix (correct)
  • The type of blood vessels present
  • The number of nerves innervating the tissue

Which components does the ground substance of connective tissue extracellular matrix (ECM) consist of?

<p>Water, proteins, and polysaccharides (D)</p> Signup and view all the answers

What happens when glycosaminoglycans (GAGS) join with core proteins?

<p>They form proteoglycans. (C)</p> Signup and view all the answers

What is one unique property of hyaluronic acid among the glycosaminoglycans (GAGs)?

<p>It is not sulphated and does not covalently bind to a core protein. (C)</p> Signup and view all the answers

What is a function of hyaluronidase?

<p>It makes ground substance more liquid. (D)</p> Signup and view all the answers

Which of the following describes the role of chondroitin sulfate in the body?

<p>Providing support and adhesive features to cartilage, bone, skin, and blood vessels (A)</p> Signup and view all the answers

What causes periorbital ECM deposition and thyroid eye disease (Exophthalmos)?

<p>Increased deposition of glycosaminoglycans and water influx in the orbital contents (C)</p> Signup and view all the answers

What are the two main types of components in the extracellular matrix (ECM)?

<p>Ground substance and protein fibers (B)</p> Signup and view all the answers

What is a key characteristic of collagen fibers?

<p>They are very strong but flexible to resist pulling forces. (C)</p> Signup and view all the answers

Which of the following describes reticular fibers?

<p>Collagen fibers with a coating of glycoprotein, providing strength and support (B)</p> Signup and view all the answers

What function does fibrillin serve in elastic fibers?

<p>It increases the strength and stability of elastin. (A)</p> Signup and view all the answers

What is the underlying cause of Marfan Syndrome?

<p>A genetic defect in a gene coding for fibrillin (B)</p> Signup and view all the answers

What is the role of fibroblasts in connective tissue?

<p>To secrete components of the matrix. (B)</p> Signup and view all the answers

What is the primary function of adipocytes?

<p>To store fat. (D)</p> Signup and view all the answers

Which cells are responsible for producing histamine and dilating blood vessels?

<p>Mast cells (C)</p> Signup and view all the answers

Which major classification best describes embryonic connective tissues?

<p>Embryonic or Mature (D)</p> Signup and view all the answers

What is the key characteristic of mesenchyme, an embryonic connective tissue?

<p>It gives rise to all other connective tissues. (B)</p> Signup and view all the answers

In what type of tissue are the fibroblasts widely scattered and embedded in a jelly-like ground substance?

<p>Mucous connective tissue (B)</p> Signup and view all the answers

Which of the following is characteristic of loose connective tissue?

<p>An open framework with many cells and fewer fibers (B)</p> Signup and view all the answers

Which type of loose connective tissue is characterized by adipocytes and functions in insulation, energy storage and temperature control?

<p>Adipose connective tissue (B)</p> Signup and view all the answers

What is a distinguishing feature of dense regular connective tissue?

<p>Regularly arranged collagen fibers (B)</p> Signup and view all the answers

What is the main functional role of tendons?

<p>Connecting muscle to bone (D)</p> Signup and view all the answers

What describes the key characteristics of hyaline cartilage?

<p>A weak and resilient gel with few obvious fibers (A)</p> Signup and view all the answers

What are the names of the rod-shaped units that constitute and compose compact bone?

<p>Osteons (C)</p> Signup and view all the answers

What is the primary difference between compact and spongy bone?

<p>Compact bone forms the outer layer of bones, while spongy bone lies underneath (C)</p> Signup and view all the answers

What feature describes spongy bone?

<p>It lays underneath compact bone. (D)</p> Signup and view all the answers

Which of the following cell types is responsible for breaking down bone?

<p>Osteoclasts (C)</p> Signup and view all the answers

What is the central (Haversian) canal in bone osteons?

<p>A canal containing blood, lymph, and nerves (D)</p> Signup and view all the answers

What causes the hardness of bone?

<p>Concentric rings of mineral salts (D)</p> Signup and view all the answers

What describes liquid connective tissue?

<p>Consists of blood plasma and formed elements (D)</p> Signup and view all the answers

What is the primary function of erythrocytes in liquid connective tissue?

<p>To transport oxygen and carbon dioxide. (A)</p> Signup and view all the answers

How do neutrophils and monocytes combat disease?

<p>Through phagocytosis. (A)</p> Signup and view all the answers

Which formed elements are involved in clotting?

<p>Platelets. (A)</p> Signup and view all the answers

What is one of the main functions of the glycosaminoglycan glucosamine?

<p>It supports cells and fibers, binds them together (D)</p> Signup and view all the answers

Name a function of a plasma cell?

<p>It develop from B lymphocytes (D)</p> Signup and view all the answers

Flashcards

Functions of Connective Tissue

Binds, supports, strengthens other body tissues. Transports substances (e.g., blood). Stores energy reserves (e.g., fat/adipose tissue).

Where is connective tissue NOT found?

Connective tissue is NOT found on body surfaces, unlike epithelia. Most connective tissues are highly vascular, except cartilage.

Connective Tissue Composition

Extracellular Matrix (ECM) and Cells.

Composition of Extracellular Matrix (ECM)

Ground Substance (GS) and Protein Fibres

Signup and view all the flashcards

Source of ECM protein fibres

Secreted by cells within the ECM/CT.

Signup and view all the flashcards

Ground Substance Composition

Water, proteins (like gelatin), and polysaccharides (sugars).

Signup and view all the flashcards

Glycosaminoglycans (GAGS)

Long, unbranched polysaccharides.

Signup and view all the flashcards

Hyaluronic Acid Function

Viscous, slippery substance that binds cells, lubricates joints, and maintains eyeball shape.

Signup and view all the flashcards

Chondroitin Sulphate

Support and adhesive features in cartilage, bone, skin, and blood vessels.

Signup and view all the flashcards

Keratan Sulphate Location

Found in bone, cartilage, and cornea of the eye.

Signup and view all the flashcards

Dermatan Sulphate Location

Found in skin, tendons, blood vessels, and heart valves.

Signup and view all the flashcards

Main cause of orbital swelling

Deposition of Glycosaminoglycans and influx of water

Signup and view all the flashcards

Three Types of Protein Fibres in ECM

Collagen fibres, Reticular fibres, and Elastic fibres.

Signup and view all the flashcards

Collagen Fibres Function

Collagen fibres are strong but flexible to resist pulling forces.

Signup and view all the flashcards

Common Location of Collagen

Bone, cartilage, tendons, and ligaments.

Signup and view all the flashcards

Reticular Fibres

Composed of collagen with glycoprotein, providing strength and support.

Signup and view all the flashcards

Location of Reticular Fibres

Adipose tissue, nerve fibres, and smooth muscle tissues.

Signup and view all the flashcards

Elastic Fibres

Elastin surrounded by fibrillin, allowing stretch without breaking.

Signup and view all the flashcards

Elastic Fibres Location

Skin, blood vessels, and lung.

Signup and view all the flashcards

Cause of Marfan Syndrome

Mutation in gene on chromosome 15 which codes for fibrillin.

Signup and view all the flashcards

Symptoms of Marfan Syndrome

Tall, long-limbed, chest deformity. Weakened heart valves and arterial walls.

Signup and view all the flashcards

Two Common Connective Tissue Cell Types

Fibroblasts and Adipocytes (fat cells).

Signup and view all the flashcards

Fibroblasts Function

Secrete components of the matrix (fibres and ground substance).

Signup and view all the flashcards

Adipocytes (fat cells) Function

Store fat (triglycerides).

Signup and view all the flashcards

Macrophages

Phagocytic cells fixed or wandering, that engulf bacteria.

Signup and view all the flashcards

Plasma cells

Produce antibodies.

Signup and view all the flashcards

Mast cells

Produce histamine that dilates vessels.

Signup and view all the flashcards

Leucocytes

White blood cells that migrate to infection sites.

Signup and view all the flashcards

Classification of Connective Tissue

Embryonic and Mature.

Signup and view all the flashcards

Function of Mesenchyme (embryonic)

Gives rise to all other connective tissues.

Signup and view all the flashcards

Function of Mucous CT

Supports umbilical cord of foetus.

Signup and view all the flashcards

Categories of Mature Connective tissues

Loose, Dense, Fluid, and Supporting.

Signup and view all the flashcards

Types of Loose Connective Tissue

Areolar, Adipose, and Reticular.

Signup and view all the flashcards

Fibres in Areolar Connective Tissue

Collagen, Reticular, and Elastic.

Signup and view all the flashcards

Function of Areolar CT

Strength, elasticity, support. Like a packing material, found around almost every body structure

Signup and view all the flashcards

Adipose Tissue characteristics

Adipocytes dominant, stores fat.

Signup and view all the flashcards

Adipose Function

Insulation, energy source, temperature control.

Signup and view all the flashcards

Dense regular CT

Tendons (muscle to bone) and Ligaments (bone to bone)

Signup and view all the flashcards

Cartilage sub-types

Hyaline, Elastic and Fibro.

Signup and view all the flashcards

Hyaline Cartilage

Abundant, relatively fragile. Provides flexibility and movement.

Signup and view all the flashcards

Two different types of bone tissues

Compact and cancellous (spongy)

Signup and view all the flashcards

Study Notes

  • Connective tissue binds, supports, and strengthens body tissues
  • It is a major transport system with blood and a site for energy reserves like fat or adipose tissue

Features of Connective Tissues Contrast with Epithelia

  • Connective tissue isn't on body surfaces, unlike epithelia
  • Cartilage and tendons show exceptions - cartilage is avascular, while tendons have minimal blood supply
  • Connective tissue is usually highly vascular
  • Connective tissue, like epithelia, is supplied by nerves, but cartilage is an exception

Connective Tissue Composition

  • Connective tissue is composed of extracellular matrix (ECM) and cells
  • CT = ECM + Cells

Extracellular Matrix Composition

  • ECM consists of ground substance (GS) and protein fibers
  • ECM = GS + Fibres
  • Protein fibers in the ECM are secreted by the cells in the ECM/CT
  • ECM structure dictates connective tissue qualities
  • Cartilage has a firm and rubbery ECM, while bone has a hard and inflexible ECM

Ground Substance

  • Ground substance, a component of the ECM, is a mixture containing: water, proteins (like gelatin), and polysaccharides (sugars)
  • GS = H2O + proteins + polysaccharides
  • The sugars consists of Glycosaminoglycans (GAGS or mucopolysaccharides)
  • GAGS join with core proteins, which forms proteoglycans

Glycosaminoglycans (GAGS)

  • Glycosaminoglycans (GAGS) "mucopolysaccharides" are long, unbranched polysaccharides with repeating disaccharide units
  • N acetylglucosamine is an example of an amino sugar
  • glucuronic acid is an example of a Uronic sugar

GAG Examples

  • Sulfated GAGs like dermatan sulfate, heparin sulfate, keratan sulfate, and chondroitin sulfate bind to core proteins to form proteoglycans (PGs)
  • Hyaluronic acid is a non-sulphated GAG example
  • Hyaluronic acid does not bind directly to the protein backbone but links to various PGs

Hyaluronic Acid

  • Hyaluronic acid is unusual because it is not sulphated or covalently bound to a core protein
  • Due to its polar nature to collectively trap water, creating a jelly-like ground substance

GAG functions

  • Hyaluronic Acid binds cells, lubricates joints, and maintains the shape of the eyeball
  • Hyaluronidase breaks down ground substance, making it more liquid and is produced by white blood cells, sperm, and some bacteria to facilitate sperm access to the egg

GAGs Application

  • Chondroitin Sulphate supports and provides adhesive features in cartilage, bone, skin, and blood vessels
  • Keratan Sulphate exists Found in bone, cartilage, and the cornea of the eye
  • Dermatan Sulphate exists Found in skin, tendons, blood vessels, and heart valves
  • Abnormal ECM ground substance leads to the deposition of glycosaminoglycans and the influx of water increasing the orbital contents

Abnormal Periorbital ECM

  • Abnormal Periorbital ECM and Thyroid Disease (Exophthalmos) is more common in younger women
  • Goitre and swelling of the thyroid gland occurs
  • Autoimmune over-activation of thyroid causes Goitre
  • Autoimmune action on fibroblasts in ECM of eye causes exophthalmos
  • The deposition of glycosaminoglycans and the influx of water increase the orbital contents

ECM Composition

  • ECM is composed of ground substance and protein fibers

Types of Connective Tissue Fibres

  • There are 3 different types of connective tissue fibres in the extracellular matrix (ECM): collagen fibers, reticular fibres and elastic fibres
  • Proteins secreted by the cells in ECM are made of protein fibers

Collagen

  • Composed of thick collagen fibers, connective tissue is strong but flexible to resist pulling forces
  • Collagen features vary, such as in cartilage where there is more water content compared to bone
  • Collagen makes up 25% of abundant protein of the body
  • It's found in bone, cartilages, tendons, and ligaments and is arranged in parallel bundles

Reticular fibres

  • Consists of composed of coating Glycoprotein collagen, in fine bundles with glycoprotein
  • Made by fibroblasts
  • Gives support and strength
  • Forms part of the basement membrane
  • Thinner, branching spreads through tissue and adipose tissue, nerve fibres, and smooth muscle tissues

Elastic fibres

  • Elastic fibres are thinner than collagen fibres, are made of Fibrous network
  • The protein elastin is covered by the glycoprotein fibrillin, this gives more strength and stability
  • It can be stretched to 150% without breaking, and is found in skin, blood vessels, and lung

Marfan Syndrome: Genetic Connective Tissue Disorder

  • The disease stems from a dominant mutation on chromosome 15, impacting the fibrillin gene
  • Fibrillin, a glycoprotein (350 kDa), provides structural support for elastin
  • The body produces Transforming Growth Factor beta(TGFb) which increasing growth because it does not bind normally to fibrillin to keep it inactive (theory)
  • This condition occurs in 1 in 20,000 live births

Marfan Features

  • Usually tall, long limbed, and often with a chest deformity (e.g. protruding or collapsed sternum)
  • With medical vigilance to control blood pressure patients will hopefully have a normal life span
  • Weakened heart valves and arterial walls

Connective Tissue Cells

  • Two common types are fibroblasts and adipocytes

Fibroblasts

  • Key Functions: secretes the matrix with fibers and ground substance
  • Primary Location: widely distributed in connective tissues; migratory

Adipocytes

  • Key Functions: store fat (triglycerides)
  • Primary Location: under the skin and around organs

Other cells found in Solid CT

  • Macrophages (Histiocytes); phagocytic cells fixed and wandering forms in connective tissues (CT), Wandering in CT: sites of infection/inflammation/ injury
  • Plasma cells; From B-lymphocyte produce antibodies
  • Mast cells; Produce histamine that dilates vessels
  • Leukocytes; migrate out from blood

Classification of Connective Tissue

  • Classification:
    • Embryonic
    • Mature

Embryonic Connective Tissues

  • Mesenchyme embryonic Tissue consists of connective tissue cells (mesenchymal cells) in a semi-fluid ground substance containing reticular fibres
  • Mucous CT is a Tissue with widely scattered fibroblasts embedded in jelly-like ground substance that supports the umbilical cord of foetus.

Mature Connective Tissues

  • Fluid, Supportive and Proper
  • Five variations will be reviewed

Loose Connective Tissue: Areolar

  • Key Features: presence of collagen, reticular, and elastic fibers
  • Key Functions:Provides strength, Elasticity, and Support
  • Primary Location: widely distributed around almost every structure. Like a “packing material".

Loose Connective Tissue: Adipose

  • Sub-type: Adipose
  • Key Features: Adipocytes , Central triglyceride droplet
  • Insulates and is a temperature control that is an energy source
  • Primary Location: Found with areolar connective tissue (incl. fibroblasts). Buttocks; flanks; abdomen; orbit of eye.
  • White adipose (energy storage) and Brown adipose (heat production)

Dense Regular Connective Tissue

  • Structures formed from them Tendons (muscle to bone); Ligaments (bone to bone); aponeuroses (muscle to muscle)
  • Collagen fibres are not a living tissue.
  • Regularly arranged collagen such as tendons (pulling along the fibre axis) that has Shiny white colour.
  • Slow healing but with good Attachment.
  • Made of many fibres fewer cells

Supporting CT: Hyaline Cartilage

  • Primarily located at anterior ends of ribs; respiratory cartilage – i.e. nose, trachea, bronchi, the Nasal septum, ends of long bones.
  • Abundant. and Relatively weak but with resilient gel in which fibres are present but not obvious
  • Offers good Flexibility and movement.
  • Dense network of collagen and elastic fibres

CT: Bone

  • Compact bone is the Outer layer of bone and forms the shaft of long bones
  • Cortical bone is made of rod-shaped units which are either Osteons or Haversian systems
  • Spongy bone is the Porous inner bone tissue that lies underneath compact bone
  • Bone is also known as Cancellous bone and they Lacks osteons

Compact Bone

  • Has osteons that Store calcium and phosphorous in bone which gives Protection & support
  • Spongy compact bone lacks osteons while and produces blood cells red marrow) and stores triglycerides (yellow marrow).

Bone cells

  • Four cell types are found in bone and is all the detail need to know bone

Osteogenic

  • Mesenchymal stem cells that develop, starts to lay down collagen and becomes Osteoblasts

Osteoblasts

  • Lay down more collagen and mineralization process starts.

Osteocytes

  • Mature bone cells derived from osteoblasts trapped within the extracellular matrix and Involved in exchange of nutrients and wastes. Have gap junctions.

Osteoclasts

  • Large, Multinucleated cells that are Formed from the fusion of blood monocytes and Break-down bone

Osteon (Haversian Systems) Structure

  • Composed of four parts
  • The basic unit of compact bone is the osteon

Structure: Lamellae

  • Made of concentric rings of mineral salts for hardness with calcium phosphate and calcium hydroxide that together form hydroxyapatite
  • Also composed of collagen for tensile strength

Structure: Lacunae

  • They consists of small spaces between lamellae that contain mature bone cells called osteocytes

Structure: Canaliculi

  • "Minute canals" contains EC fluid and minute osteocytic processes that radiate from lacunae which provide routes for oxygen, nutrients and waste

Structure: Central (Haversian) canal

  • Has blood, and nerves

Bone Fracture: Remodeling

  • Osteoclasts reabsorb dead bone
  • Chondroblasts form hyaline cartilage callus
  • Osteoblasts lay down new bone
  • Osteoclasts remodel new bone

5. Liquid Connective Tissue

  • Consists of blood plasma and formed elements, notably the red cells, white cells and platelets
  • (Blood CT=ECM (plasma) + Cells)

Blood: Formed Elements

  • Erythrocytes transport oxygen and carbon dioxide
  • Leukocytes fight off combat disease:
    • Neutrophils and monocytes, phagocytic engulfing bacteria
    • Basophils mobile and Mast cells tissues are released substance’s intensifies it reaction
    • Eosinophils are involved in acute allergic response and are parasitic
    • Leukocytes or Lymphocytes
  • Platelets are involved from megakaryocytes in red marrow with good clotting.
  • Connective tissue has both cells and matrix between them

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

More Like This

Use Quizgecko on...
Browser
Browser