Connective Tissue Cells - Mrs. Dearden`s Classes
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Transcript Connective Tissue Cells - Mrs. Dearden`s Classes
Bell Work
What is connective tissue?
Where can it be found?
Connective Tissue
Most
diverse and
abundant tissue
Main classes:
Connective tissue
proper
Cartilage
Bone tissue
Blood
Connective Tissue- General Features
Components of connective tissue:
Cells (varies according to tissue)
Extracellular Matrix (in btw. Cells)
○ Protein Fibers
○ Ground substance
Other
Characteristics:
Not on body surfaces
Highly vascular (except cartilage)
Connective Tissue Cells
1.
“Blast” Cells
Immature class of cells- blast cells have
ability to divide & secrete extracellular
matrix
Called:
○
Fibroblasts in loose & dense connective tissue
○ Chondroblasts in cartilage
Once EC matrix is
○ Osteoblasts in bone
produced, “blast” cells
become “cyte” cells &
maintain the matrix
Connective Tissue Cells
2. Fibroblasts- found in most connective
tissue,large/flat & branching; secrete fibers and
EC matrix
3. Adipocytes- fat cells (deep to skin)
4. Mast cells- help in the body’s reaction to injury &
infection (alongside blood vessels)
Produce histamine which dilates vessels
5. WBCs- fight pathogen invasion & inflammation
Macrophages- engulf bacteria
Plasma Cells- develop from a WBC & they secrete
antibodies (neutralize foreign substances)
Connective Tissue Cells
Extracellular Matrix
Definition: material btw cells
Functions:
Supports cells/ binds cells together
Stores water
Provides a medium for exchange of substances
btw. cells & blood
Components:
Fibers & Ground Substance
ECM Fibers- strengthen & support
connective tissue
Collagen
1.
strong & resist pulling forces
Not stiff thus flexible
Found in cartilage, tendons, ligaments & bone
Elastic
2.
Provides strength & stretching
Found in skin, blood vessels & lungs
Reticular
3.
Primary support & strength tissue
Thinner than collagen fibers; branching networks
Covers many organs (spleen, liver, lymph nodes)
Collagen Fibers
Elastic Fibers
Reticular Fibers
Ground Substance- connective tissue
btw. cells
Characteristics:
May be fluid, semifluid, gelatinous, or calcified
Composed of Glycosaminoglycans (GAGs)
Polysaccharides
Attract water
Lubricate/support
Types:
Chondroitin Sulfate- supports/adheres skin,
cartilage, tendons, bone & blood vessels
Hyaluronic Acid- slippery & binds cells together,
lubricates joints, & maintains structure shape
Do Now:
What components make up
extracellular matrix? Describe
each component.
Entrance Slip
1.
2.
3.
Name three cells found in connective
tissue?
What type of fiber has characteristics of
strength and flexibility?
What is ground substance? Give a
characteristic of it.
Connective Tissue Proper
Loose
Connective Tissue- loosely
intertwined fibers btw. cells
Areolar
Reticular
Adipose
Dense
Connective Tissue- thicker, denser
fibers btw. fewer cells
Regular
Irregular
Elastic
Areolar Connective Tissue
Description
Gel-like matrix w/:
○ 3 Fibers: collagen, reticular, & elastic for support
○ Ground substance is made up by many GAGs
Cells – fibroblasts, macrophages, mast cells, white
blood cells, adipocytes
Function
Wraps & cushions organs
Binds the skin to underlying organs & fills space
between muscles
Important role in inflammation main battlefield in fight
against infection
Areolar Connective Tissue
Location
Widely distributed under epithelia (has many blood
vessels so it nourishes epithelial cells)
Packages organs
Surrounds capillaries
Adipose Tissue
Description
Closely packed adipocytes
Nucleus pushed to one side
by fat droplet
Function
Provides reserve food fuel
Insulates against heat loss
Supports & protects organs
Location
Found by areolar tissue
Under skin- insulates the body
& protects organs
Cushions joints
Around kidneys, between
muscles, behind eyeballs,
within abdomen and in breasts
Reticular Connective Tissue
Description – network
of reticular fibers in
loose ground substance
Function – form a soft,
internal skeleton
(stroma- covers soft
organs)
Location – lymphoid
organs
Lymph nodes, bone
marrow, and spleen
Dense Regular Connective Tissue
Description
Parallel collagen fibers
Fibroblasts and some elastic fibers
Poorly vascularized
Function
Attaches muscle to bone
Attaches bone to bone
Withstands great stress in
one direction
Location
Tendons and ligaments
Fascia around muscles
Dense Irregular Connective Tissue
Description
Irregularly arranged collagen
fibers
Some elastic fibers and
fibroblasts
Function
Withstands tension
Provides structural strength
Location
Dermis of skin
Heart valves
Surrounds cartilage & bone
Submucosa of digestive tract
Fibrous capsules of joints and
organs
Elastic Connective Tissue
Description
Branching elastic fibers
Some fibroblasts
Function
Very elastic
Can recoil to its original shape
after being stretched
Location
Lung tissue
Elastic arteries
Vocal chords
Ligament btw. vertebrae
Connective Tissue Catch Phrase
Set the timer. Give the stack of cards to
someone on Team 1. One person from Team 1
will try to give their team mates clues to their
phrase. If Team 1 guesses the phrase, Team 2
gets the stack of cards and tries to guess their
phrase.
Continue the game by going back and forth,
as each team guesses the correct phrases. If
the buzzer sounds during your turn, the other
team gets a point and has the chance to earn
a bonus point if they guess your phrase.
Bell Work
What are the three types of
loose and dense
connective tissue?
Cartilage
Characteristics:
Firm, flexible tissue
Contains no blood vessels or nerves
Matrix contains up to 80% water
Mainly collagen & elastic fibers
Cell type – chondrocyte
Types:
Hyaline
Fibrocartilage
Elastic
Hyaline Cartilage
Description
Collagen fibers not in the matrix (hyaline =
glassy)
Chodroblasts produce matrix
Chondrocytes lie in lacunae (space in mature
cartilage)
Function
Supports and reinforces
Resilient cushion/ Resists repetitive stress
Reduces friction
Hyaline Cartilage
Location
Fetal skeleton
Ends of long bones
Costal cartilage of ribs
Cartilages of nose tip,
trachea, and larynx
Joints
*weakest of the 3 cartilages
Fibrocartilage
Description
Matrix similar, but less firm
than hyaline cartilage
Thick collagen fibers
predominate in matrix w/
scattered chondrocytes
Function
Tensile strength w/ ability
to absorb compressive
shock
Location
Intervertebral discs
Pubic symphysis (where
hips join)
Discs of knee joint
*strongest type of cartilage
Elastic Cartilage
Description
More elastic fibers in
matrix w/ chondrocytes
Function
Maintains shape of
structure
Allows great flexibility
Location
Supports external ear
Epiglottis
Bone Tissue
Function
Supports and protects
organs
Provides levers and
attachment site for muscles
Stores calcium and other
minerals
Stores fat
Marrow is site for blood cell
formation
Characteristics
ETC matrix= lamellae rings
of mineral salts
Lacunae- spaces in lamellae
containing osteocytes
Location
Bones
Blood Tissue
Description
red and white blood cells
in a fluid matrix
Function
transport of respiratory
gases, nutrients, and wastes
Location
within blood vessels
Characteristics
An atypical connective
tissue
Consists of cells surrounded
by nonliving matrix (blood
plasma- mainly water &
dissolved nutrients)
Do Now:
What is the proper name of a
bone cell, and what is the
name of the space in which
a bone cell lies?
Do Now:
What are the three types of
dense connective tissue?
Muscle Tissue
Types
Skeletal muscle tissue
Cardiac muscle tissue
Smooth muscle tissue
Skeletal Muscle Tissue
Characteristics
Long, cylindrical cells
Multinucleate
Obvious striations
Function
Voluntary movement
Manipulation of
environment
Facial expression
Location
Skeletal muscles
attached to bones
(occasionally to skin)
Long, cylindrical cells that tend to have
more than one nuclei.
Cardiac Muscle Tissue
Function
Contracts to propel blood into circulatory
system
Characteristics
Branching cells
Uninucleate
Intercalated discs
Location
Occurs in walls of heart
Long, cylindrical cells that are shorter than
skeletal muscle cells.
They have only one nucleus per cell.
Smooth Muscle Tissue
Characteristics
Spindle-shaped cells with
central nuclei
Arranged closely to form
sheets
No striations
Function
Propels substances along
internal passageways
Involuntary control
Location
Mostly walls of hollow organs
These cells are tapered at the ends, giving
them a spindle appearance. They have one
nucleus and are not striated.
Nervous Tissue
Function
Transmit electrical signals
from sensory receptors to
effectors
Location
Brain, spinal cord, and
nerves
Description
Main components of brain,
spinal cord, & nerves
Contains two types of cells
○ Neurons – excitatory cells
○ Supporting cells (neuroglial
cells)
Neurons consist of the cell body, which does basic cell
activities, and dendrites (which receive impulses) and
axons (one per cell, conducting impulses away from cell
body).
Tissue Response to Injury
Inflammatory response – non-specific,
local response
Limits damage to injury site
Immune response – takes longer to
develop and very specific
Destroys particular microorganisms at site of
infection
The Tissues Throughout Life
At the end of second month of development:
Primary tissue types have appeared
Major organs are in place
Adulthood
Only a few tissues regenerate
Many tissues still retain populations of stem cells
○ Stem cells- divide/ differentiate into specialized cell types
With increasing age:
Epithelia thin
Collagen decreases
Bones, muscles, and nervous tissue begin to atrophy
Poor nutrition and poor circulation – poor health of tissues
Covering and Lining Membranes
Combine
epithelial tissues and
connective tissues
Cover broad areas within body
Consist of epithelial sheet plus
underlying connective tissue
Three Types of Membranes
Cutaneous membrane – skin
Mucous membrane
Lines hollow organs that open to surface of body
An epithelial sheet underlain with layer of lamina
propria
Serous membrane – slippery membranes
Simple squamous epithelium lying on areolar
connective tissue
Line closed cavities
○ Pleural, peritoneal, and pericardial cavities