Tissues (3) Flashcards
what are tissues?
Groups of cells with similar structure and function
What is Histology?
The study of normal tissues
What is Pathology?
The study of abnormal tissues
What are the 4 primary types of tissues?
- Epithelial
- Connective
- Muscle
- Nervous
What is a Membrane?
A sheet of tissues
Locations of Epithelial tissues
-Body coverings
-Body linings
-glandular tissue
Functions of Epithelial tissues
-Protection
-Absorption
-Filtration
-Secretion
What are the characteristics of Epithelial tissue
-Versatility
-Continuity
-Regenerate
-Secretion
Secretion
All substances either secreted or absorbed must pass through epithelial tissues; many are capable of secretion. May be called GLANDULAR EPITHELIUM or SIMPLY GLANDS
Epithelial membranes have a free ______ exposed either to body’s exterior or to cavity of an internal organ, and a lower surface resting on a structure-less ______
- Apical surface
- basement membrane
Simple Epithelium
Single layer of flat cells
Stratified Epithelium
Many layers of mostly flat cells
Squamous epithelium
Flat, very thin, and smooth
Cuboidal epithelium
Cube-shaped like dice
Columnar epithelium
Shaped like columns
Simple squamous epithelium
single layer of FLAT cells
location of squamous epithelium
-Lines ventral body cavities and covers organs in those cavities
-Lines the lungs and capillaries where diffusion or filtration of substances occur
-Lines arteries, veins, and the heart
functions of simple squamous epithelium
diffusion, filtration, and secretion in membranes
simple cuboidal epithelium
Single layer of CUBE-SHAPED cells
location of simple cuboidal epithelium
- common in glands and their ducts.
ex: salivary glands, thyroid glands, and pancreas (glandular epithelium)
-found in walls of kidney tubules where they have microvilli-for reabsorption of substances
-ciliated types are found in the fallopian tubes
functions of simple cuboidal epithelium
-secretion, re-absorption, and in some instances propulsion
simple columnar epitherlium
single layer cells shaped like COLUMNS they are taller than they are wide
location of simple columnar epithelium
entire length of digestive tract (stomach to anus)
function of simple columnar epithelium
secretion of digestive enzymes, and absorption of end products of digestion into blood and lymph
Microvilli ( columnar epithelium)
for efficient absorption, columnar cells of small intestines have microvilli that increase the surface area for absorption
Goblet Cell (columnar epithelium)
A type of columnar cell found in intestinal and respiratory linings
-secretes mucus
Goblet cell is also known as
a unicellular gland
Ciliated epithelium
columnar cells with cilia on their free surface
-sweeps materials across cell surface
-lines nasal cavities, larynx, trachea, etc
Stratified cuboidal
two layers of cuboidal cells
- functions in protection
stratified columnar
surface cells are columnar. Cells underneath vary in size and shape
-functions in protection
stratified squamous epithelium
cells become flater as they are pushed toward the surface
Pseudostratified Columnar
single layer, but some cells are shorter than others giving the false (pseudo) impression of being stratified
Location of pseudostratified columnar
respiratory tract where it is ciliated (pseudostratified ciliated columnar epithelium)
Mucus from ___ traps dust and debris and the___ propel the mucus upward and away from the lungs
- goblet cells
- cilia
function of pseudostratified columnar
protection, absorption, or secretion
Transitional Epithelium
The surface change shape from round to squamous
- Lines the urinary bladder
- allows it to stretch without tearing
Glands
Epithelial cells or organs that synthesize and secrete a particular product that has a function either at that site or at a more distant sight
Unicellular glands
- goblet cells
- found in the lining of the respiratory and digestive tracts
- their secretion is mucus
Multicellular glands
-made of many similar cells or a variety with their products mixed into a collective secretion
What are the 2 major groups Multicellular glands are divided into
Exocrine and Endocrine
Exocrine Glands
Secretions empty through ducts
- includes sweat and sebaceous glands(external), liver and pancreas (internal)
- mostly secrete ENZYMES
Endocrine Glands
Ductless, secretions directly diffuse into capillaries
- all secretions are HORMONES
What are the types of connective tissue
- Loose connective tissue
-Dense connective tissue
-Specialized connective tissue
What are the types of loose connective tissue
-Areolar
-Adipose
What are the types of dense connective tissue
-Fibrous
-Elastic
What are the types of specialized connective tissue
-Blood and hemopoietic
-Bone
-Cartilage
-Lymphoid and reticuloendothelial
-synovial tissue and bursae
Functions of the connective tissue
-Binds body tissues together
-supports the body
-provides protection
What is a typical characteristic of all connective tissues
The presence of Matrix
What is Matrix
A structural network of NON-LIVING intracellular material
- each connective tissue has its own specific kind of matrix
A characteristic of connective tissue is living cells which are
responsible for producing the matrix
-each connective tissue has different types of cells
A characteristic of connective tissue is variations in blood supply
Most connective tissues are well vascularized (good blood supply)
- tendons, ligaments, and cartilages have poor blood supply and heal very slowly
Extracellular Matrix has
Ground substance and fibers
Ground substance in extracellular matrix
mostly water along with proteins and polysaccharide molecules
Fibers in extracellular matrix
- produced and secreted by LIVING CELLS
what are the 3 types of fibers
Collagen(white), Elastic(yellow), and Reticular fibers
Areolar tissue
Have fibroblasts, collagen, elastic fibers, and fluid that make up the matrix
what are fibroblasts
the cells that produce all protein fiber types
The matrix contain mast cells that release
Histmine and macrophages
What are the functions of the areolar tissue
-packaging tissue
-intercepts pathogens
-participates in inflammation
-phagocytosis
what is phagocytosis
Process by which white blood cells engulf and destroy microbes
Adipose Tissue
There are two kinds and both are called ADIPOCYTES
White Adipose tissue
Matrix is small, consists of tissue fluid and a FEW COLLAGEN FIBERS
Brown adipose tissue “brown fat”
Adipocytes contain iron
Reticular Connective Tissue
delicate network of interwoven RETICULAR FIBERS forming stroma or internal framework of certain organs
-These fibers are synthesized RETICULAR CELLS
Location of reticular connective tissue
lymph nodes, spleen, liver, and bone marrow
Dense connective tissue
The main matrix element is COLLAGEN FIBERS
- crowded between collagen fibers are parallel rows of FIBROBLASTS that synthesize them
Locations of FIBROUS dense connective tissue
-outer layer of arterial walls
-tendons
-ligaments
-between skin and muscles
Locations of Elastic dense connective tissue
-middle layers of arterial walls
-surrounding alveoli of lungs
Bone also known as
Osseous tissue
Bone cells are
osteocytes
Matrix of bone is made of
Calcium Salts and abundant collagen fibers
In long bones the osteocytes, matrix, and blood vessels are in very precise arrangements called
Haversian systems or osteons
What are the functions of Bone (special connective tissue)
support the body, protect internal organs from mechanical injury, storage for calcium,
Blood vessels go through
the central canal
Osteocytes are
Inside the lacunae
Lamella are
The lines
Cartilage is
less hard, smooth, and more flexible than the bone
Characteristics of cartilage
- Matrix is a protein-carbohydrate mix, does not contain calcium salts, but contains ABUNDANT WATER
what is the major cell type of cartilage
chondrocyte
what does cartilage contain
abundant collagen fibers
Locations of cartilage
larynx, rib attachments to sternum, epiphyses of long bones, entire fetal skeleton prior to birth
What are the types of cartilage
Hyaline Cartilage, Elastic Cartilage, and Fibrocartilage
Hyaline Cartilage
Has ABUNDANT COLLAGEN FIBERS hidden by a rubbery matrix with glassy BLUE-WHITE appearance
- chondrocyte is its major cell type
Locations of Hyaline cartilage
Nasal septum, larynx. articular surfaces of the joints
Elastic cartilage
possesses WEB-LIKE MESH OF ELASTIC FIBERS amongst lacunae containing CHONDROCYTES
- Always has a PERICHONDRIUM
Location of Elastic cartilage
External ear, nose, epiglottis
Fibrocartilage
highly compressible forms cushion-like discs between vertebrae
Blood is
The only connective tissue in fluid state
52%-62% total blood volume
is surrounded by fluid matrix called blood plasma
Fibers are
the soluble protein MOLECULES-PROTHROMBIN AND FIBRINOGEN that become visible during blood clotting
Blood cells are
Erythrocytes, Leukocytes, and thrombocytes
What is unique about blood
It is the only connective tissue in fluid state
What are Erythrocytes
Red blood cells
What are Leukocytes
White blood cells
What are Thrombocytes
Platelets
Muscle cells is also known as
muscle fiber and MYCOCYTE
Muscle fibers are
embedded into an EXTRACELLULAR MATRIX consisting if a mesh of COLLAGENOUS components
what are the types of muscles
skeletal
smooth
cardiac
Skeletal muscle
- CYLINDRICAL cells, MULTINUCLEATED, STRIATED
Striations are
due to precise arrangement of alternating light ACTIN and dark MYOSIN FILAMENTS IN THE MUSCLE FIBERS
Skeletal muscles are
voluntary
what are the functions of the skeletal muscle
-move the skeletal bones to which they are attached
-generate significant amount of body head to maintain temp constant
-help in respiration
Cardiac Muscle cells are only found in the
Heart, called MYOCARDIUM as a whole
Cardiac muscle cells are
Branches, uninucleated and faintly striated
Cell membranes are extensively folded and fit into matching interlocking folds called
Intercalated discs
cardiac muscles are
involuntary
functions of the cardiac muscles
pump blood
maintain blood pressure
keep blood in circulation
Smooth/ Visceral muscles are
spindle-shapes cells, uninucleated, with no striations
smooth/visceral muscles are
involuntary
Functions for smooth/visceral muscles
the functions of the organs in which they are found
Smooth visceral muscles are found in
The stomach and intestines, contractions are in waves called PERISTALSIS
Nervous tissue
composed of NEURONS THE NERVE CELLS, and specialized NERVE SUPPORT CELLS CALLED NEUROGLIA
Neurons are capable of
generating and transmitting electrochemical impulses through chemicals called Neurotransmitters
Neuroglia
Insulate, protect, and support neurons
Major characteristics of neurons
-irritability
-conductivity
functions of nervous tissue
feeling an interpreting sensations, initiation of movements, learning and memory
What are the tissues that regenerate easily
-epithelial
-blood-forming tissues
-bone
What are the tissues that regenerate weakly
-Smooth muscle
-dense regular connective tissue
Tissues that regenerate poorly
-skeletal muscle
-cartilage
Tissues that do not regenerate but replaced largely with scar tissue
-cardiac muscle
-nervous tissue within the brain and spinal chord
What are the 3 types of reactions that occur
-regeneration
-healing
-fibrosis
what is regeneration
tissue replaced damaged components and returns to a normal state
what is healing
damaged tissues incapable of complete restitution and or supporting structures of tissues are severely damaged
what is fibrosis
heavy deposition of collagen in organs such as lungs, liver, kidneys following chronic inflammatory processes
Skin and aging
loses elasticity and collagen becomes less flexible, develop wrinkles
arteries and aging
reduced capacity to expand become hardened
- render less blood supply, lowered metabolism, decline in hormone levels and slow healing
tendons, ligaments and aging
stopped posture and joint instability
bones and aging
lose calcium, become brittle, prone to fractures(osteoporosis)
muscles in aging
atrophy (loss cells)
