Connective Tissue Flashcards
What is the function of connective tissue?
- comprises much of the body and is the most abundant type of tissue by weight
- Binds structures
- Provides support and protection
- Serves as frameworks
- fills spaces
- Stores fat
- Produces blood cells
- Protects against infection and repairs tissue damage
What are the general characteristics of connective tissue?
- Cells are farther apart and have an abundant extracellular matrix between them
What is an extracellular matrix?
- Is composed of protein fibers and a ground substance consisting of nonferrous protein and other molecules and fluid
- Binds supports, and provides a medium thru with substances may be transferred between blood and cells of tissue
What’s the consistency of the extracellular matrix?
Varies from fluid/semisolid to solid
What are the major cell types in CT?
- Fibroblasts
- Macrophages
- Mast cells
What are the general characteristics of fibroblasts?
- The most common type of fixed cells in CT.
- Large/star-shaped cells
- Produce fibers by secreting proteins into the extracellular matrix
- Respond rapidly to injury by increasing # of fiber production
- Help repair tissue
What are the general characteristics of macrophages?
- Histiocytes
- Usually attached to fibers but can detach and actively move about
- Specialized to carry on phagocytosis (the exocytosis of large particles/viruses/microorganisms_
- Clear foreign particles from tissues, provides defense against infection
- Plays role in immunity
What are the general characteristics of mast cells?
- Widely distributed in CT
- Usually are near blood vessels
- Derived from white blood cells
- Release heparin (compound that prevents blood clotting)
Which cell releases histamine?
- Mast cells release histamine.
- Stimulates inflammation by dilating the small arterioles that feed the capillaries
- Is inhospitable to infections, bacteria and viruses
- also dilutes toxins
WHAT ARE THE SIX COMPONENTS OF CONNECTIVE TISSUE?!
CELLULAR: - Fibroblasts, macrophages, mast cells EXTRACELLULAR: - Collagen, elastic, reticular fibers - Ground substance
What is the function of Collagen fibers?
- Thick, threadlike structures
- The body’s main structural protein
- Great tensile strength; slightly elastic
- Found in ligaments and tendons
What is the function of Elastic fibers?
- Bundles of microfibrils embedded in elastin
- Provides elastic quality to parts that stretch
- Not as strong as collagen fibers
- Found in vocal cords, respiratory air passages
What is the function of reticular fibers?
- Thin fibers of collagen
- Forms delicate supportive networks within tissues
- Found in the spleen/liver
What is the function of ground substance?
- nonfibrous protein and other molecules, and varying amounts of fluid
- Fills spaces around cells and fibers
WHAT ARE THE TWO MAJOR CATEGORIES OF CT?
- Ct proper
- Specialized CT
What is CT proper?
- Includes loose CT tissue
(Areolar, adipose, reticular) - and DENSE CT
(Dense regular, irregular, and elastic)
What are the general characteristics of dense CT? and loose CT?
Dense CT: - Contains abundant collagen fibers - Appears white Loose CT: - Has fewer collagen fibers
General characteristics of Areolar CT
- Forms delicate, thin membranes thru-out the body
- Mainly fibroblasts that are located some distance apart and are separated by a gel-like ground substance that contains collagen and elastic fibers
- binds skin to underlying organs
- Beneath most epithelium layers/nourishes blood vessels near epithelial cells
General characteristics of adipose
- adipocytes store fat
- push their nuclei to one side
- crowd out other cell types
- protects/cushions/insulates
- Beneath skin
- Behind eyeballs
- Around kidney/heart
- spaces between muscles
Two types of adipose tissue
White adipocytes:
- store nutrients for nearby cells to use in production of energy
- Brown fats have many mitochondria that can break down nutrients to generate heat to warm the body.
What are the general characteristics of Reticular CT?
- composed of thin reticular fibers in a 3D network.
- Provides the framework of certain internal organs such as the liver/spleen
What are the general characteristics of dense CT?
- Densely packed collagenous fibers; a fine network of elastic fibers; and few cells, mostly fibroblasts
- Very strong/withstand pulling forces
- Binds body parts together
- Tendons/ligaments/dermis
- POOR BLOOD SUPPLY; slow to heal
What are the general characteristics of dense irregular CT?
- are thicker, interwove, and more randomly distributed than fibers of dense regular CT.
- Allow tissue to sustain tension exerted from many different directions.
- Dermis of skin
- around skeletal muscles
- (periosteum, which covers the bones)
- (Within the perichondrium - which covers cartilage; in some capsules of some organs)
What are the general characteristics of elastic CT?
- Abundant yellow elastic fibers in parallel strands or branching networks
- Between the fibers are collagen/fibroblasts
- Found in the attachments between bones of the spinal column
- Walls of hollow organs, arteries, and airways
- elastic quality
What are specialized CT?
- include cartilage, bone and blood
- Each have unique extracellular matrix with highly specialized cells not found in other CT
What are the general characteristics of cartilage?
- A rigid, specialized CT
- Support, frameworks, and attachments; protects underlying tissues
- Forms structural models for many developing bones
- Extracellular matrix is abundant and largely composed of collagen fibers embedded in a gel-like ground substance
What is a chondrocytes?
- Cartilage cells
- occupy small chambers called lacunae and lie completely within the extracellular matrix
What is perichondrium?
- Cartilage structure is enclosed in perichondrium (a CT covering)
- Blood vessels surround the perichondrium and obtain nutrients from the vessels via diffusion
What are the general characteristics of hyaline cartilage?
- Fine collagen fibers
- is the most common type of cartilage
- found at the ends of bones and in many joints
- In the soft part of the nose, and the supporting rings of the respiratory passages
- Protects, supports, and provides framework for the development of bones
What are the general characteristics of elastic cartilage?
- flexible due to elastic fibers in the matrix
- located in the external ear, and the larynx
- provides framework for the ears, and the parts of the larynx
What are the general Characteristics of fibrocartilage?
- very tough tissue due to many collagenous fibers
- shock absorber for structures subjected to pressure
- cushions the knees and the pelvic girdle
- is also located in the intervertebral discs)
What are the 3 types of cartilage?
- hyaline
- elastic
- fibrocartilage
What are the general characteristics of bone?
- most rigid CT
- Hardens due to large amounts of mineral salts such as calcium phosphate and calcium carbonate between cells
What is the function of bone?
- supports the body structures
- Protects vital structures in the cranial/thoracic cavities and is the attachment for muscles
- Contains red marrow, which forms blood cells
- Stores and releases inorganic chemicals such as calcium and phosphorus
What are the two types of bone tissue?
- compact
- spongy
What are the main characteristics of bone (osseous) CT?
- most rigid tissue
- solid matrix composed ot calcium and collagen
- supports structures
- produces blood cells
- Contains osteocytes in lacunae
Characteristics of compact bone?
- cells are called osteoblasts
- deposit bony matrix in thin layers called lamellae
- Forms concentric patterns around tubes called central, or Haversian canals (which contain blood vessels)
What are the functions of blood CT?
- composed of formed elements suspended in a fluid extracellular matrix called PLASMA
- formed elements include: red/white bloods cells, and cellular fragments called platelets
What are the functions of the formed elements within blood?
Red blood cells: transport gases
White blood cells: fight infections
platelets: involved in blood clotting
WHAT ARE THE SIX TYPES OF CT PROPER?
- areolar CT
- adipose CT
- reticular CT
- dense regular CT
- dense irregular CT
- Elastic CT
WHAT ARE THE FIVE TYPES OF SPECIALIZED CT?
- hyaline cartilage
- elastic cartilage
- fibrocartilage
- blood
- bone
What are membranes?
Membranes are sheets of cells
What are epithelial membranes?
- Are thin structures that are composed of epithelium and underlying CT
- Cover body surfaces and line cavities
What are the 3 major types of epithelial membranes?
- serous
- mucus
- cutaneous
What are the functions of serous membrane?
- line body cavities that do not open to outside of body
- inner lining of thorax, abdomen, and covers organs
- consists of a layer of simple squamous epithelium + a thin layer of areolar CT
- secrete serous fluid for lubrication
What are the functions of the mucus membrane?
- lines cavities/tubes that open to the outside of the body
- lining of digestive, respiratory, urinary, and reproductive tracts
- consists of epithelium laying over a layer of areolar CT
- goblet cells within mucus membrane secrete mucus
What are the functions of the cutaneous membrane?
- skin
- part of the integumary system
What are the functions of the synovial membrane?
- different from epithelial membrane
- composed entirely of CT
- lines joint cavities
