Histology Flashcards
what are the 4 types of tissues? And their functions?
- Epithelial- covers
- Connective- connects
- Muscular- contracts
- Nervous- conducts
What are the two main divisions of Epithelial Tissue?
- Covers surfaces, lines cavities and tubes
- glandular tissue with secreting cells
What are the characteristics of Epithelial tissue?(3)
- Found in continuous sheets
- Increased mitotic rate- divides rapidly for regeneration of cell
- Avascular- no blood vessels
Functions of epithelial tissue? (4)
- Physical protection
- Control Permeability
- provide sensation
- Produces specialized secretions
Describe epithelial physical protection
protection from abrasion, dehydration, toxins and pathogens
Describe Permeability control (epithelial)
1 .Many epithelia are basically impermeable, or have regulated permeability
2. Junctions between cells can prevent substances from passing between adjacent cells
Where are simple squamous epithelium found?
- capillaries
- air sacs (lungs)
- internal membranes
where are stratified squamous epithelium found?
- skin
- mouth
- throat
where are simple cuboidal epithelium found?
- glands
- ducts
- kidney tubules
where are stratified cuboidal epithelium found?
- lining ducts
where are simple columnar epithelium found?
- lining the digestive tract
where are pseudostratified ciliated columnar epithelium found?
- lining trachea and bronchi
where is transitional epithelium found?
- lining urinary bladder
- lining uterus
what are the two glandular epithelium? Describe them
- Exocrine glands- have ducts
a. products secreted into duct then emptied onto the epithelial surface - Endocrine glands- don’t have ducts
a. products are secreted into extracellular fluid
b. diffuses into blood stream then transported to organs/cells
What are the characteristics of connective tissues? (4)
- functions to support bind and attach other tissue types
- has specialized connective tissue cells, surrounded by an abundance of extracellular matrix
a. collagen, elastic, reticular - Highly vascular
- good nerve supply and lymphatic supply
What are the functions of connective tissues?(6)
- Form Structural framework of body
a. skeleton(includes bones,cartilage) - Transports fluid and dissolved material throughout the body
a. blood/lymph - Provide Protection for body organs
a. Cranium, thoracic cage, pelvis, spinal cavity - Supporting surrounding and connecting tissues
a. Fascia, tendons, ligaments - Energy storage and blood cell formation
a. Fat, red bone marrow - Defense from microorganisms
a. White Blood cells
List the specialized cells of connective tissues(5)
- Fibroblasts
- Adipocytes
- Blood cells
- Chondrocytes
- Osteocytes
List the fibers of connective tissues(3)
- Collagen
- Elastic
- Reticular
Describe collagen
Collagen- (ex. Tendons and ligaments)
1. Largest fibers (long, straight, non-branching)
2. Flexible yet resist pulling(great tensile strength)
3. 3 protein subunits twisted like a rope
Describe Elastic fibers
- Contains elastin protein
- Branching, wavy
- Can stretch up to 150% of original length, then recoil
- Ligaments attaching vertebrae
Describe Reticular Fibers
- A very thin type of collagen
- Interacts to form a 3d branching network of fibers
- Forms supporting framework for cells of organs
Describe the 2 types of connective tissue
Loose CT
-Fibers create loose, open framework
-Areolar tissue, adipose tissue, reticular tissue
Dense CT
-Fibers are densely packed
-Dense regular, dense irregular, elastic
What are the different types of Supporting Connective tissue
- Hyaline Cartilage
- Fibrocartilage
- Elastic cartilage
- Bone
What are the fluid connective tissues
- Blood
- Lymph
What are the 4 types of membranes
- Mucous Membranes
- Serous
- Cutaneous
- Synovial
Describe Mucous membranes
Found lining hollow organs and tubes with opening to external environment
Describe the Serous membranes
Found covering organs and lining cavities within the anterior body cavities
Describe the cutaneous membrane
Dry membrane covering external body surface( epidermis and dermis)
Describe the synovial membrane
found lining the synovial joints- knee, shoulder, elbow
Describe Muscle tissue
- elongated cells
- cells packed with contrile proteins
- highly contractile
- sensitive to external environment changes
What are the types of muscle tissue
- skeletal
- smooth
- cardiac
Describe Skeletal Muscle tissue
- straited
- large cylindrical fibers
- voluntary control
- cannot divide
- peripherally located nuclei
Describe smooth muscle
- non striated
- spindle shaped
- centrally located nuclei
- involuntary
- can divide
Describe Cardiac muscle
- striated
- branching fibers
- centrally located nuclei
- involuntary
- cannot divide
function of skeletal muscle
moves and stabilizes the skeleton
function of cardiac muscles
generates forceful contractions of the heart
function of smooth muscle
surrounds blood vessels and walls of organs
Describe Nervous Tissue
- impulse transmitting cells
- star like appearance
- highly sensitive to external stimuli
- longest cells in the body
- incapable of cell reproduction
two types of cells that make nervous tissue
- neurons
- neuroglia
Describe extracellular matrix
- produced by spcialized connective tissue cells
- can vary from fluid(blood), gel(CT proper), to solid(bone)
