Histology Ch 4 Flashcards
Epithelial tissue
Covers body surface and lines body cavities.
Covering and lining epithelium
covers and lines exterior and interior visceral surfaces
Glandular epithelium
Most or all produce secretions. Discharging them onto the surface of the epithelium or into the interstitial fluid and blood.
5 special characteristics of epithelial tussue
Cellularity (bound together by cell junctions)
Polarity (refers to the structural and functional differences between the apical surface and basal surface)
Attachment (to the basement membrane/basal lamina)
Avascularity (receive nutrients by diffusion/ absorption from exposed or attached epith. surfaces)
Regeneration (damaged and lost cells are replaced by the division of stem cells in the epithelium)
Polarity
Inner and outer surfaces with different structure and function. Called apical-basal polarity
Apical Surface
An upper free surface exposed to the body exterior or the internal organ cavity. Include Microvilli and Cilia
Basal Surface
Lower attached surface.
Microvilli
Finger like extentions of the plasma membrane that greatly increase exposed surface area
Cilia
Tiny hairlike projections that propel substances along their free surfaces
Basal lamina
A line supporting sheet adjacent to the basal surface. Selective barrier and scaffolding for cells to repair wounds
Specialized Contacts
Close lateral connections including tight connections and desmosomes.
Supported by connective tissue
Reticular lamina:beneath the basal lamina, fine network of fibers Basement membrane is formed by the two laminae
Avascular but innervated
no blood vessels but is supplied by nerve fibers.
Regulation
protective covering replaces it’s self rapidly
Epithelial classification by number
Simple: single layer found where absorption, secretion, and filtration occur. Stratified: Two or more layers in high friction areas like lining of the mouth.
Epithelial classification by shape
Squamous: Flat, scale like Cuboidal: boxlike Columnar: tall column shaped.
2 types of glands
Endocrine (ductless) and Endocrine (have ducts)
Where do you find epithelial tissue
Covering, lining and glands
3 Epithelial cell shape
squamous cuboidal columnar
Types of connective tissues
Connective tissue proper: loose and dense Fluid connective tissue: blood and lymph Supporting connective tissue: cartilage and bone
Connective Tissue Proper
- Loose Connective tissue 2. Dense connective tissue
Loose connective tissue
“packing materials” for the body, fill spaces between organs, cushion and stabilize cells in many organs: Areolar Adipose Reticular (mucus connective tissue in embryos)
Dense connective tissue
Collagen fibers are the dominate fiber type Regular Irregular Elastic ie. tendons
Cartilage
Hyaline Cartilage (tough but flexible ie. between ribs & sternum) Fibrocartilage (resists compression and absorbs shock ie. invertebral discs) Elastic cartilage(resilient and flexible ie. ear)
Bone (osseous)
Compact Spongy
Hyaline Cartilage
Most common,tough and somewhat flexible: Articular cartilages Connect ribs to sternum Conducting airways and nasal cartilages
Elastic cartilage
Elastic tissue, extremely resilient and flexible: Outer ear Epiglottis
3 components of connective tissue
Specialized cells Extracellular protein fibers A fluid ground substance
4 membranes in the body
serous cutaneous mucous synovial
2 cell populations that make up neural tissue
Neurons Neuroglia
Similarities in muscle cells
Actin and myosin interactions produce contractions, Calcium ions trigger and sustain contractions
Papillary layer of the dermis
Areolar (lose) tissue and contains capillary, lymphatic vessels and sensory neurons
Reticular layer of the dermis
Lies deep to the papillary, consists of dense irregular connective tissues and bundles of collagen and elastic fibers
4 phases of injury repair
inflammatory: bleeding, swelling redness and pain migratory: scab formation and migrating epithelial cells proliferation: fibroblasts repair tissue under the scab scarring: scab is shed epidermis is complete, fibroblasts create scar tissue
Sensible perspiration
Fluid loss through active sweat glands (merocrine)
Insensible perspiration
Evaporation through the stratum corneum
Areolar tissue
A loose connective tissue that provides support but permits movement due to elastic fibers
Adipose tissue
A loose connective tissue that is similar to areolar but adipocytes account for most of its volume. Provides padding, absorbed shocks, and acts as an insulator. Brown fa and white fat
Reticular tissue
Loose connective tissue that provides a supporting framework. Found in the spleen, liver, bone and lymph nodes.
Dense regular connective tissue
Collagen fibers that run parallel to each other, packed tightly and align with forces applied to the tissue: Tendons: attach muscle to bone Ligaments: attach bone to bone Aponeurosis: tendentious sheet
Cartilage growth
Interstitial: enlarges the cartilage from within Appositional: adds new layers of cartilage to the surface
Fibrocartilage
Extremely durable due to little ground substance and it’s interwoven collagen fibers: Spinal vertebrae Pubic bones
Mucus membrane
Line passageways and chambers that commute to the exterior
Serous membrane
Line the sealed internal cavities of the trunk-not open to the exterior: Pleura Pericardium Peritoneum
Cutaneous membrane
The skin that covers the body surface: Stratified Cubical Columnar
Synovial membrane
Line joint cavity and produce synovial fluid.
Connective tissue provides:
Strength ans stability Maintains relative internal position of organs Supplies route for distribution of blood, lymph and nerves
3 types of muscle
Skeletal: striated, voluentary, multiple nucleus
Cardiac: striated, 1-5 nuclei, involuntary
Smooth: Non-striated, spindle shaped, involuntary, 1 nucleus
Neuroglia
Severalkids of supporting cels that provide:
Physical structure
Repair
Phagocytosis
Provide nutrients
Regulate interstitial fluid
3 modes of gland secretion
Merocrine
Aprocrine
Holocrine
Merocrine glands
The product is released by exocytosis, this is the most common mode of exocrine secretion
Apocrine glands
Involves loss of a portion of the cytoplasm
Example is mammary glands
Holocrine glands
The entire cell becomes packed and bursts, destroying the cell
Example is sebaceous glands in the hair follicules
