Semester Exam: histology connective tissue Flashcards
Fibrocartilage description
Matrix similar, but less firm than hyaline cartilage
Thick collagen fibers predominate
lacunae smaller, squished, big collagen fibers
Fibrocartilage function
Tensile strength and ability to absorb compressive shock
Fibrocartilage location
Intervertebral discs
Pubic symphysis
Discs of knee joint (miniscus)
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
bone tissue location
bones
Blood Tissue description
red and white blood cells in a fluid matrix
Blood Tissue function
transport of respiratory gases, nutrients, and wastes
Blood Tissue location
within blood vessels
Blood Tissue characteristics
An atypical connective tissue
Consists of cells surrounded by fluid matrix
Reticular Connective Tissue description
network of reticular fibers in loose ground substance
Reticular Connective Tissue function
form a soft, internal skeleton (stroma) – supports other cell types
Reticular Connective Tissue location
lymph nodes, bone, marrow, spleen
Dense Irregular Connective Tissue description
Primarily irregularly arranged collagen fibers
Some elastic fibers and fibroblasts
Dense Irregular Connective Tissue location
Dermis of skin
Submucosa of digestive tract
Fibrous capsules of joints and organs
Dense Irregular Connective Tissue function
Withstands tension (from multiple directions) Provides structural strength
Dense Regular Connective Tissue description
Primarily parallel collagen fibers (same direction)
Fibroblasts and some elastic fibers
Poorly vascularized (long time to heal)
Dense Regular Connective Tissue function
Attaches muscle to bone (tendon)
Attaches bone to bone (ligament)
Withstands great stress in one direction
Dense Regular Connective Tissue location
Tendons and ligaments
Aponeuroses (sheet of tendons/dense regular)
Fascia around muscles
elastic connective tissue
rare, in aorta, a lot of elastic tissue
Cartilage characteristics
Firm, flexible tissue
Contains no blood vessels or nerves
Matrix contains up to 80% water
Cell type – chondrocyte
Cartilage types
Hyaline (nose, joints)
Elastic (flexible, ear)
Fibrocartilage (least flexible, discs between vertebra)
Hyaline Cartilage description
Imperceptible (cant see) collagen fibers (hyaline = glassy)
Chodroblasts produce matrix
Chondrocytes lie in lacunae
Hyaline Cartilage function
Supports and reinforces
Resilient cushion
Resists repetitive stress
Hyaline Cartilage location
Ends of long bones
Costal cartilage of ribs
Cartilages of nose, trachea, and larynx Location
Elastic Cartilage description
Similar to hyaline cartilage
More elastic fibers in matrix
big lacunae
Elastic Cartilage function
Maintains shape of structure
Allows great flexibility
Elastic Cartilage location
Supports external ear
Epiglottis
Areolar Connective Tissue description
Gel-like matrix with:
all three fiber types (collagen, reticular, elastic) for support
Ground substance is made up by glycoproteins also made and secreted by the fibroblasts.
Cells – fibroblasts, macrophages, mast cells, white blood cells, adipocytes
Highly vascular tissue
areolar connective tissue function
Wraps and cushions organs
Holds and conveys tissue fluid
Important role in inflammation
Main battlefield in fight against infection
areolar connective tissue location
Widely distributed under epithelia
Packages organs
Surrounds capillaries
Adipose Tissue description
Closely packed adipocytes
Have nucleus pushed to one side by fat droplet
Adipose tissue function
Function
Provides reserve food fuel
Insulates against heat loss
Supports and protects organs
Adipose Tissue location
Under skin
Around kidneys
Behind eyeballs, within abdomen and in breasts
Connective Tissue
Most diverse and abundant tissue
Main classes of connective tissues
Connective tissue proper
Blood – Fluid connective tissue
Cartilage and Bone tissue (both supporting connective tissues)
Components of connective tissue:
Cells (varies according to tissue)
Matrix (which is made up of Protein fibers and Ground substance )
Common embryonic origin
mesenchyme
connective tissue proper
Variety of cells, fibers & grounds substances
Types of cells depend on use
Cells found in connective tissue proper
Fibroblasts (build collagen) Macrophages, lymphocytes (antibody producing cells) Adipocytes (fat cells) Mast cells (swollen response) Stem cells (turn into anything)
Fibers found in connective tissue proper
collagen
elastic
reticular
collagen
Collagen – very strong & abundant, long & straight
thicker pink
elastic
Elastic – branching fibers with a wavy appearance (when relaxed)
thin, purple or black (dark colored)
reticular
Reticular – form a network of fibers that form a supportive framwork in soft organs (i.e. Spleen & liver) mesh, spider web with reticular, and collagen
matrix
each connective tissue has its own unique matrix, made of fibers and ground substances
ground substance
Along with fibers, fills the extracellular space
Ground substance helps determine functionality of tissue
Connective Tissue Proper - Classifications
loose and dense connective tissue
loose connective tissue
Areolar
Reticular
Adipose
(more cells less fibers, loosely packer)
dense connective tissue
Regular
Irregular
Elastic
(more fibers, less cells)
Covering and Lining Membranes
Combine epithelial tissues and connective tissues
Cover broad areas within body
Consist of epithelial sheet plus underlying connective tissue
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
Synovial membranes
lining joint cavities Loose connective (areolar) + simple squamous epithelium Secretes fluid (synovial fluid) which lubricates, protects & cushions joint structures
muscle tissue types
Skeletal muscle tissue
Cardiac muscle tissue
Smooth muscle tissue
Skeletal Muscle Tissue characteristics
Long, cylindrical cells
Multinucleate
Obvious striations
Skeletal Muscle Tissue function
Voluntary movement
Manipulation of environment
Facial expression
Skeletal Muscle Tissue location
Skeletal muscles attached to bones (occasionally to skin)
Cardiac Muscle Tissue function
Contracts to propel blood into circulatory system
Cardiac Muscle Tissue characteristics
Branching cells
Uni-nucleate
Intercalated discs
Cardiac Muscle Tissue location
Occurs in walls of heart
Smooth Muscle Tissue characteristics
Spindle-shaped cells with central nuclei
Arranged closely to form sheets
No striations
Smooth Muscle Tissue function
Propels substances along internal passageways
Involuntary control
Smooth Muscle Tissue location
Mostly walls of hollow organs
Nervous Tissue function
Transmit electrical signals from sensory receptors to effectors
Nervous Tissue location
Brain, spinal cord, and nerves
Nervous Tissue description
Main components are brain, spinal cord, and nerves
Contains two types of cells
Neurons – excitatory cells
Supporting cells (neuroglial cells)
steps in tissue repair
inflammation
organization
regeneration and fibrosis
inflammation
Release of inflammatory chemicals
Dilation of blood vessels
Increase in vessel permeability (white blood cells and clotting proteins leak to area)
Clotting occurs (scab)
Organization and restored blood supply
begins while inflammation starts
The blood clot is replaced with granulation tissue
Epithelium begins to regenerate
Fibroblasts produce collagen fibers to bridge the gap
Debris is phagocytized
Regeneration and fibrosis
The scab detaches
Fibrous tissue matures; epithelium thickens and begins to resemble adjacent tissue
Results in a fully regenerated epithelium with underlying scar tissue
inflammatory response
nonspecific reaction develops quickly where tissue is injured
immune response
extremely specific but takes longer to act
granulation tissue
delicate pink tissue composed of capillaries (fragile bleed freely)
primary germ layers
ectoderm, mesoderm, and endoderm
Nerve tissue arises
ectoderm
Muscle and connective tissues arise from
mesoderm
Epithelial tissues arise from
all three germ layers
