Ch 5 Test Yourself Flashcards
What are the four primary types of tissue?
Epithelial, connective, muscle, and nervous
What is histology?
Histology is the study of the microscopic structures of tissues and organs.
List seven functions performed by epithelial cells.
- Protect, cover, and line other tissues
- Filter biochemical substances
- Absorb nutrients
- Provide sensory input
- Manufacture secretions
- Manufacture excretions
- Act as an interface layer that separates and defines the beginning and ending of different types of tissues.
What four attributes characterize epithelial tissue in general?
- Epithelial cells are polar
- Lateral surfaces are connected by junctional complexes
- All epithelial cells lack blood vessels or capillaries
- Most epithelial cells are innervated
What are the four types of cellular junctions?
How does the basement membrane act as a partial barrier between the epithelial cell and the underlying connective tissue?
Oxygen and nutrient molecules diffuse through the basement membrane from capillaries in the underlying connective tissue.
Why do some epithelial cells have cilia and microvilli?
Microvilli increase surface area for absorption and secretion; cilia facilitate movement of materials.
What does it mean if epithelial tissue is classified as simple, stratified, or pseudostratified?
- Simple: single layer of cells
- Stratified: more than one layer of cells
- Pseudostratified: appears stratified but is a single layer with nuclei at different levels
What are the three basic shapes of epithelial cell?
Squamous, cuboidal, and columnar
Where can simple squamous epithelium be found?
Inner lining of the lung and filtration membranes of kidneys
Where can simple cuboidal epithelium be found?
On the surface of ovaries and in the secretory portions of glands
Where can simple columnar epithelium be found?
Lining the length of the gastrointestinal tract
Where can stratified squamous epithelium be found?
Lining the mouth, esophagus, vagina, and rectum
Where can pseudostratified columnar epithelium be found?
In the respiratory tract and portions of the male reproductive tract
Where can transitional epithelium be found?
In portions of the urinary tract
What is a gland?
A gland is a cell or group of cells that has the ability to manufacture and discharge a secretion.
How do glands develop embryologically?
Multicellular glands form from the infolding of a layer of epithelial cells.
What is the difference between endocrine and exocrine glands?
- Endocrine: no ducts, secrete hormones into bloodstream
- Exocrine: possess ducts, secrete locally
Where are goblet cells found?
Interspersed among columnar cells of the respiratory and digestive tracts
What do goblet cells secrete?
Mucin, which becomes mucus when combined with water.
How are multicellular exocrine glands constructed?
They consist of a secretory unit and a duct carrying the secretion.
Describe merocrine, apocrine, and holocrine glands.
- Merocrine: secrete via exocytosis without damaging cells
- Apocrine: lose apex of cell during secretion
- Holocrine: entire cell is destroyed during secretion
How are serous and mucous secretions different?
- Serous: watery, high enzyme concentration
- Mucous: thick, viscous, composed of glycoproteins
How are connective tissue and epithelial tissue similar?
Both may form membranes in the body.
What are the three basic constituents of connective tissue?
Extracellular fibers, ground substance, and cells
List seven functions of connective tissue.
- Forms metabolic and structural connections
- Forms a protective sheath around organs
- Helps insulate the body
- Acts as a reserve for energy
- Provides support
- Transports substances
- Plays a role in healing and immune response
What are GAGs?
Glycosaminoglycans, which are the ground substance in soft connective tissue.
What role do GAGs play in connective tissue?
They help orient fiber formation during healing.
Compare collagenous, reticular, and elastic fibers.
- Collagenous: strong, thick, provide tensile strength
- Reticular: thin, branched, support cellular organs
- Elastic: branched, allow stretching
What are fibroblasts?
Large, irregularly shaped cells that manufacture and secrete fibers and ground substance.
Can you give three examples of transient cells in connective tissue?
- Leukocytes
- Mast cells
- Macrophages
What are the two broad categories of connective tissue?
Connective tissue proper and specialized connective tissue.
What are the components of areolar tissue?
Randomly placed fibers and cells in a thick, translucent ground substance.
What is the common term for adipose tissue?
Fat
How is brown fat different from white fat?
Brown fat is specialized for heat generation while white fat is used for energy storage.
What happens to adipocytes as they fill with lipid?
The organelles and nuclei are pushed to one side, and the cells become large spheres with eccentrically placed nuclei. The cytosol is compressed into a thin rim surrounding the lipid droplet.
What appearance does adipose tissue have microscopically due to its lipid content?
A ‘chicken wire’ appearance.
What is brown adipose fat and its role?
A specialized form of adipose tissue found in newborns and hibernating animals that plays an important part in temperature regulation and heat production.
How is lipid stored in brown fat compared to white fat?
In brown fat, lipid is stored in multiple small vesicles rather than in a single large droplet.
Why does brown fat have a high number of mitochondria?
Because it dissipates energy derived from lipid oxidation as heat instead of adenosine triphosphate (ATP).
What is the histological appearance of brown fat?
It looks glandular and is sometimes called the hibernating gland.
What are three subtypes of dense connective tissue?
- Dense regular
- Dense irregular
- Elastic
Give three examples of specialized connective tissue.
- Cartilage
- Bone
- Blood
How is cartilage similar to connective tissue proper?
It is composed of cells, fibers, and matrix.
What is a key difference between cartilage and dense connective tissue?
Cartilage is more rigid than dense connective tissue.
What limits the thickness of cartilage?
Nutrients diffuse from the surrounding perichondrium through the matrix to the chondrocytes.
Why is cartilage slow to heal?
Because it is avascular.
Describe hyaline cartilage.
The most common type, composed of closely packed collagen fibers, tough but more flexible than bone, resembling blue-white, frosted ground glass.
What characterizes elastic cartilage?
Contains an abundance of elastic fibers forming dense branching bundles, found in the epiglottis and external ears.
What is fibrocartilage and where is it found?
Contains thick bundles of collagen fibers, fewer chondrocytes, lacks a perichondrium, found in vertebrae, pelvic girdle, and knee joint.
Why are blood and bone both considered types of connective tissue?
Both contain cells, a matrix, and extracellular fibers.
What two tissue types are membranes composed of?
- Epithelial
- Connective tissue
Where are mucous membranes found?
Lining the organs with connections to the outside environment, including digestive, respiratory, urinary, and reproductive tracts.
What functions do mucous membranes perform?
- Produce protective and lubricating mucus
- Assist with the passage of food or waste
- Help trap pathogens and foreign particles
What portion of a serous membrane covers the outer surface of organs?
The visceral layer.
What is effusion?
The escape of fluid from its normal vessels into a body cavity.
What is ascites?
The presence of an effusion in the peritoneal space.
What is another name for cutaneous membrane?
Integument or skin.
Where are synovial membranes found?
Lining the cavities of joints.
How are synovial membranes different from other membrane types?
They have no epithelium and are composed completely of connective tissue.
What are muscle fibers adapted for?
Contraction, composed of specialized proteins actin and myosin.
List three types of muscle.
- Skeletal
- Smooth
- Cardiac
What is a key feature of skeletal muscle?
It is striated and generally under voluntary control.
What characterizes smooth muscle?
It is nonstriated and involuntary.
What is unique about cardiac muscle?
It contracts involuntarily and has specialized pacemaker cells.
What are the two basic cell types that make up neural tissue?
- Neurons
- Supporting neuroglial cells
What is the most important function of neural tissue?
To receive and transmit electrical and chemical signals throughout the body.
What initiates the process of inflammation?
A period of vasoconstriction followed by vasodilation.
What causes the clinical signs of heat, swelling, redness, and tenderness during inflammation?
- Increased blood flow
- Plasma fluid accumulation
- Irritation of nerve endings
What is granulation tissue?
A bright pink tissue formed as macrophages clear debris, composed of collagen fibers and small capillaries.
What is the difference between first- and second-intention wound repair?
- First intention: Edges held in close apposition without significant scarring.
- Second intention: Edges separated, granulation tissue forms, resulting in scar formation.
