connective tissue Flashcards
characteristics of connective tissue
-known for having a matrix
-can be widely scattered or loosely arranged but not bound to each other
Fibers
-a protein (non-living) made by a cell and dumped into the matrix
-things you add to the matrix change the type/quality
-can be found in muscle
what cell makes fibers?
fibroblast
collagen fibers
-in its natural state its white, fiber adds tensile strength, ability to bind
-parallel collagen is stronger
-ex: tendons, bones, ligaments
elastin fibers
-yellow and rubber like bands (needs ATP) to stretch and not let go, good healthy blood tissue has this. Damaged arteries and lungs do not have this
-found in lungs, skin, blood vessel walls
reticulin fibers
immature collagen, kind of strong, they connect to coarse collagen fibers but branch out forming networks that surround blood vessels and support soft tissue of organs
-found in basement membrane of epithelial tissue and around capillaries, testis and spleen
functions of connective tissue
-function depends on location in the body
-does more than just connect
1. binding and supporting
2.protecting
3.insulating
4. storing reserve fuel
5.transporting substances
Classification of connective tissue
1.Blood
2. Connective tissue (proper)
3. Bone
4. Cartilage
Type of matrix for blood
Fluid
Type of matrix for connective tissue proper
Fluid gel
Type of matrix for cartilage
Solid gel
Type of matrix for bone
Solid (mineralized, calcified)
Breakdown of connective tissue proper
-these are separated based on matrix (matrix based on cell)
1. loose fibrous connective tissue (areolar)
2. Adipose
3. dense fibrous connective tissue (collagenous)
4. elastic connective tissue
5. reticular connective tissue
Breakdown of cartilage tissue
- hyaline cartilage
- fibrocartilage
3.elastic cartilage
Blood Characteristics
Fluid, connective tissue with fluid matrix
-has a variety of cells most are RBC’s who lose their nucleus to make room for more oxygen. But some are also white blood cells and platelets
-white blood cells help to fight pathogens
Function of blood
-transport oxygen and material from one place or another
Location of blood
blood vessels
Loose fibrous connective tissue (areolar) Characteristics
-LFCT
-Fluid gel with cells, fibers found everywhere. Has elastin fibers and binds one thing to another and allows WBC chance to move
- summer = more LFCT
Loose fibrous connective tissue (areolar) Function
-serves as packing material between other tissues, binds body parts and allows them to freely move
-epithelial rest on this due to their blood supply
Loose fibrous connective tissue (areolar) Location
-All over the body, used as a filler. underneath the skin
- holding body fluids
-supporting and binding other tissues
- defending against infection
Adipose Tissue (Characteristics)
-dynamic, matrix moves in and out, cells are tightly packed together
-they change size with the amount of fat they are storing
-highly vascular tissue
- Winter = more adipose tissue
Adipose Tissue Function
-greater nutrient storage capabilities than loose connective tissue
- holding body fluids
-supporting and binding other tissues
-defending against infection
-Insulation/ shock absorber/ energy storage
Adipose Tissue Location
accumulates in subcutaneous tissue
Adipocytes
-cell that holds fat, in a fat vacuole
Dense Fibrous Connective Tissue (Collagenous)
-bundles of closely packed collagen fibers running in the same direction and parallel to each other (still have fluid gel matrix there -resting)
-has great resistance to tension
-no room for blood vessels (hard to heal a tendon b/c of this)
-forms tendons, ligaments
Fibroblast
manufacture fibers and small amount of ground substances
ligaments
-bone to bone connection
tendons
-muscle to bone connection
Dense Fibrous Connective Tissue (Collagenous) Function
to form ligaments and tendons
Elastic connective tissue characteristics
-elastin fibers make this up, dense regular connective tissue
Elastic connective tissue Function
forms a few ligaments that are elastic, additionally much of the large arteries
Elastic connective tissue location
-blood vessels and lungs
Reticular connective tissue characteristics
-has reticular fiber, matrix is a combination of fluid gel
-reticular cells are a type of fibroblast
Reticular connective tissue function
-filler in, so organs do not collapse
-forms internal framework that supports many free blood cells
Reticular connective tissue location
-Soft organs (lymph nodes, spleen, bone marrow)
Hyaline cartilage characteristics
-has a solid gel matrix (flexible)
-most abundant cartilage
-gets replaced by bone when you age
-babies have this when first born (easy to push out)
Hyaline cartilage function
-provides structural support
cartilage
-a type of connective tissue that is tough but flexible, providing rigidity to structure it supports
-lacks nerve fibers and is avascular
-receives nutrients by diffusion from blood vessels located in connective tissue
chrondroblast
-cell that grows cartilage
chondrocytes
-mature cartilage cells
-sits in a lacunae, more than one can fit inside a lacunae
Hyaline cartilage location
-connects ribs to the sternum
- tip of nose(framework)
- ends of bones (shock absorbers)
-supports most of respiratory system passages
-makes up embryonic skeleton before bones form
Fibrocartilage characteristics
-like hyaline cartilage but with collagen
-rows of chondrocytes alternate with rows of collagen fibers
Fibrocartilage function
-hold body erect with flexibility
Fibrocartilage location
-pubic area (pubic region of each coxal bone)
-skeletal backbone
-spongey cartilage of knee
Fibrocartilage location
-pubic area (pubic region of each coxal bone)
-skeletal backbone
-spongey cartilage of knee
Elastin cartilage characteristics
-identical to hyaline cartilage but has more elastin fibers
Elastin cartilage function
provide strength and flexibility (stretchability)
Elastin cartilage location
-forms the skeleton of the external ear and the epiglottis
Osseous Tissue (bone)
-ability to protect body structures and support
-provide cavities for storing fat and making blood cells
-matrix similar to cartilage but mineralized
-bone is vascular
osteoblast
bone building cell
-there for growth and repair of bone tissue
osteocytes
mature bone cells
-reside in the lacunae within the matrix
-cannot reproduce (mitosis) in lacunae, b/c so ridged
-only one per lacunae
compact bone
-porous, room for blood vessels
-made of haversian structures
Haversian system
-the structural unit of compact bone
-also called osteon
Periosteum
glistening white double membrane, covers the external surface of the entire bone except the joints
- the outer layer of the periosteum is dense connective fibrous tissue (DFCT) (irregular version)
-the inner layer is the osteogenic layer containing osteoblast
-has rich supply of nerve fibers and blood vessels
peri = around
osteo= bone
Volkmann’s canal
-lie at right angles to the long axis of the bone and connect the blood and nerve supply of the medullary cavity to the haversian canals
Haversian canal
-canal in the center of each osteon contains small blood vessels and nerve fibers that serve the osteocytes needs
lamella
-each ring of matrix (ex:onion)
canaliculi
-hairlike canals that radiate from the lacunae, connecting them to each other and the central canal
-provide intracellular communication and nutrient delivery
lacuna
-a small space, cavity, or depression
-osteocytes are found in these
spongy (cancellous) bone
- honeycomb of needle like or flat pieces that contain open spaces filled with red or yellow marrow
-also called trabecula
diaphysis
-shaft of bone (compact bone predominate)
epiphysis
-are the bone ends
-outer shell of compact bone forms the exterior while a spongy bone is in the interior
-a thin layer of hyaline cartilage covers the joints of the epiphysis
compact bone
-external layer of bone
medullary cavity
-central cavity of a long bone, full of yellow marrow (in adults) that have adipose tissue
-in infants the marrow is red
-some red marrow present in spongy bone cavities
endosteum
-lining of the medullary cavity , where osteoclast predominate
articular cartilage
hyaline cartilage covering bones at end of moveable joints
epiphyseal line
-is a remnant of the epiphyseal plate (growth plate) which is a disc of hyaline cartilage that grows during childhood to lengthen the bone
osteoclast
destroy the matrix to get calcium
What do we need calcium for?
- for every part of blood clotting
- for muscle contractions
- nerve impulses
* you dietary intake of calcium allows osteoblasts to make more
osteogenesis
Formation of bone
* the precursor before osseous tissue is DFCT and hyaline cartilage
- in embryos this leads to the formation of a bony skeleton ( but they start out with the two precursors)
-in adult hood used when the body increases in size
ossification
-used in adults for bone remodeling and repair
Intramembranous ossification
- this is dense fibrous connective tissue (DFCT)
-Osteoblast come in to lay down calcium to make matrix to make the bone
-bone develops form fibrous membrane
-forms the cranial bones of the skull
-most bones formed by this process are flat bones
Name two places where hyaline cartilage is still located on a bone?
- on the epiphyseal surfaces called articular cartilage
2.at the junction of the diaphysis and epiphyseal called the epiphyseal plate
Endochondral ossification
-a bone develops by replacing hyaline cartilage
-all bones below the base of the skull except clavicle form by this way
Endochondral ossification process
- starts out a cartilage model, where a bone collar forms around the diaphysis
*cartilage model surrounded by perichondrium (eventually called periosteum) - cartilage destroyed makes room for osteoblast (primary ossification center)
3.secondary ossification center, blood vessels go to epiphysis - Remains of cartilage are at the top of the epiphysis called articular cartilage (used as shock absorbers)
*each bone has a genetic time
* only long bones have epiphysis and diaphysis
Bone growth- length
Diaphysis gets longer because rows of cartilage on the side gets destroyed and replaced with bone. While the epiphysis stays the same. This only occurs up to a point until your diaphysis and epiphysis fuses forming the plate
Bone growth- width
-the medullary cavity needs to grow by destroying bone
-osteoblast and osteoclast are apart of bone growth for width
-involves laying down of more bony matrix on outside which is accompanied by bone destruction on inside by osteoclast
