Tissues and Intigmentary Flashcards
what is the definition of tissue
group of similar cells that function together
Define histology
study of tissues
List the different types of tissues in the body give a brief description of their roles in the body
- epithelial: covers, lines, forms glands
- Connective: protects, supports, binds, provides immunity
- muscle: contracts and regulates volume or creates movement
- nervous: electrical communication
Describe epithelial tissues
- consist of tightly joined cells arranged in continuous sheets
- single /multilayer
- free surface called apical surface
- adheres to connective tissue via basement membrane at the basal surface
What is the function of epithelial tissue?
-Protection
-absorption
-filtration
-lubrication
sensory reception
What are the 2 types of major epithelium?
- Cover and Linings
- Glandular
What are cover and lining epithelium
- Cover surface area of skin (epidermis)
- lines internal organs; stomach bladder, lunges
- inner lining of blood vessels, ducts, body cavities
What are glandular epithelium? what are some examples?
- secreting portion of glands (endocrine and exocrine)
- sweat glands, salivary, thyroid
How are epithelial tissues classified
- number of layers
- shape of the tissues
List the layer of tissues in epithelial cells
- Simple: single layers of cells
- Stratified - 2 or more layers
- pseudo-stratified - single layer but appears stratified
What are the characteristics of simple epithelial tissues?
- single layer of cells.
- thin to incleare membrane transport like diffusion
What are the characteristics of stratified epithelial cells?
- 2 or more layers of cells
- thicker for protection from wear and tear
What are the characteristics of pseudo-stratified epithelial cells?
- “falsely stratified “
- looks multilayered but only has one layer
- nuclei at different hight in the row of cells.
List of shape classification of epithelial cells
- Squamous
- Cuboidal
- Columnar
- Transitional
what are the characteristics of squamous epithelial cells?
- Flattened, scale like cells
- thin for increasing membrane transport (filtration, diffusion, osmosis)
What are the characteristics of cuboidal epithelial tissues
- cube-shaped with central, round nucleus
- membrane transporter (secretion, absorption)
What are the characteristics of columnar epithelial tissues?
- Tall, cylindrical cells, rectangular
- Oval nuclei appear at same height in the cells.
- Functions to protect, membrane transport (secretion, absorption, can be ciliated)
What are the characteristics of transitional epithelial tissue
-cells that are able to change shape and stretch
List the additional features of epithelial tissue
- Keratinized
- glandular
- cilia
- microvilli or brush boarder
What is keratinized epithelial tissue
- dead cells full of tough, fibrous protein
- mechanical protection
What are goblet cells and what is their function?
- modified columnar cell
- contain goblet cells which secrete mucus, a sticky fluid
- mucus acts as a lubricant, traps particles, and protects the epithelium of stomach lining
What is cilia epithelial tissue?
thin, hair-like microtubule structures on surface of cells that sweeps mucus trapped particles away
What is the microvilli or brush boarder
-very small tiny, finger like projections of the plasma membrane of a cell that increase surface area of the cell for absorption
List the types of epithelial tissues in the body
- Simple Squamous Epithelium
- Simple ciliated, glandular epithelium
- Stratified squamous epithelium
Describe simple Squamous Epithelial tissue
- found in low wear and tear areas
- associated with blood capillaries and respiratory surface of lung alveoli
- thin to increase the rate of diffusion for gas and fluid exchange
Describe Simple ciliated, glandular epithelial tissue
- found lining upper respiratory track, filopian tubes, uterus, sinuses
- adapted to move across fluids or particles along a passage by ciliation action
Describe Stratified squamous epithelial tissue. Where is this tissue found?
- found lining wet surfaces where it is non-keratinized stratified squamous and all the cells in the layers are living
- found in the outer layer of skin where it is keratinized providing a dead thick layer adapted for protection
Define Glandular epithelium
highly specialized epithelial cell or group of cells that secretes substances onto a surface, into ducts or into the blood
What are the two types of glandular epithelium?
- endocrine
- Exocrine
What are the characteristics of endocrine glands?
- secretes hormones into extracellular fluid and then usually into the blood
- ductless glands
- ex: human growth hormone produced by pituitary gland
What are the characteristics of exocrine glands?
- secretes substances onto the free surface of coverings or lining epithelia
- secretions reach free surface through ducts (tubes)
- Ex: sweat glands, oil glands, salary glands
What are connective tissues?
- consist of a few cells and a matrix composed of ground substance and fibres
- most abundant and widely distributed tissue in the body
what are the types of cells found in connective tissue
- fibroblasts
- osteocytes
- chondrocytes
- erythrocytes
- leukocytes
What are the types of fibers found in connective tissue
- collagen
- elastic fibers
- reticular fibers
What is the functions of connective tissue?
- gluing tissue together
- storing energy
- structural support
- transport
- insulation
What are some examples of connective tissue?
- dermis of skin
- cartilage, tendons, ligaments, and bone
- blood and lymph
What is ground substance?
the components of a connective tissue between the cells and fibers.
What is the function of ground substance?
- Supports cells
- binds cells together
- provides a medium through which substances are exchanged between blood and cells
What are the types of connective tissue?
- Areolar tissue
- Adipose tissue
- Dense regular connective tissue
- dense irregular connective tissue
- Hyaline Cartilage
- Bone or osseous Tissue
- Blood
- Lymph
Describe areolar tissue; where is it found?
- widely distributed throughout the body
- filter type of connective tissue that glues tissue together
- found in subcutaneous layer of skin
- found in walls of organs
Describe Adipose tissue;
- contains large amounts of adipocytes which store fat or triglycerides
- white fat functions in protection, insulation, and energy storage
Describe dense regular connective tissue; where is it found?
- collagen fibers irregularly arranged in bundles
- very strong (against pulling in 1 direction) yet pliable
- found in tendons and ligaments
Describe dense irregular connective tissue
- contains collagen fibres that have no regular arrangement
- occurs in sheets in places of the body where forces are exerted in more than 1 direction
Where is dense irregular connective tissue found
- facia coverings,
- muscles,
- dermis of skin,
- heart valves,
- joint capsules
Describe hyaline cartilage
- Chondrocytes are embedded in a pliable matrix of fine fibres and gel-like ground substance
- provides flexibility, support, reduces friction and absorbs shock
- capable of enduring more stress than dense connective tissue
What is the name for cartilage cells?
Chondrocytes
Where is hyaline cartilage found>
- ends of long bone
- rib cartilage
- nose
- larynx
- trachea
- embryonic skeleton
Describe bone or osseous tissue
- located in a matrix composed of collagen fibres and minerals
- classified as compact (dense) or spongy (cancalous)
what are bone cells called?
Osteocytes
Where is the role of minerals and collagen fibers in bone tissue?
- convey hardness
- provide tensile strength
What is the function of bone tissue?
- provide protection
- support
- attachment for muscle
- contains red bone marrow for blood cell formation
- acts in mineral storage (calcium)
Describe blood connective tissue
- transports gasses, nutrients, vits, minerals, hormones, and other substances through the body
- plays role in immunity
Why is blood considered to be connective tissue
-composed widely of scattered cells in a matrix
What is the name for the liquid matrix of blood?
Plasma
What substances are suspended in blood plasma
- formed elements
- cells
- cell fragments
What are the cells found in the blood?
- erythrocytes - red blood cells
- leukocytes - white blood cells
- thrombocytes - platelets
Describe lymph
- composed of excessive tissue fluid (interstitial fluid) that flows into lymphatic vessels in be retuned to blood
- lymph fluid is similar to blood plasma but has less protein and no red blood cells
What is the function of lymph?
-returns excessive tissue build to the blood,
-transports absorbed dietary fats
provides immunity
Describe Skeletal muscle
- striated, light and dark regions alternating (actin and myosin)
- voluntary contraction
- multinucleate, large cells
What is the function of skeletal muscle tissue
- locomotion
- posture
- heat production
Describe cardiac muscle tissue
- muscle of the heart
- striated and branched
- involuntary control
- autorhythmic, can contract on own and without nervous system input
Describe smooth muscle tissue
- non striated (smooth look)
- involuntary control
Where is smooth muscle located?
- walls of blood vessels
- airways
- stomach
- intestines
- urinary bladder
What is the function of smooth muscle
- contract to constrict the lumen of a hollow structure
- mixes food
- propels foodstuff
- vary the volume of a structure
