A&P Chapter 4 Flashcards
What is epithelial tissue?
A sheet of cells that covers body surfaces or cavities
What are the two main forms of epithelial tissue and where are they located?
- Covering and lining epithelia, located on external and internal surfaces (like skin)
- Glandular epithelia, located in secretory tissues in glands (like salivary glands)
What are the main functions of epithelial tissue?
Protection, absorption, filtration, excretion, and sensory reception
What are the special characteristics of epithelial tissues?
Polarity, apical surface, basal surface, specialized contacts, avascularity, innervated, regeneration, and specialized contacts
What is the polarity (top and bottom) of epithelial tissues?
- The apical surface, upper free side, is exposed to the surface or cavity
- The basal surface, lower attached side, faces inward towards the body
What is the apical surface’s texture?
Most apical surfaces are smooth, but some have specialized fingerlike projections called microvilli
What does the basal surface attach to?
The basal lamina, an adhesive sheet that holds the basal surface of epithelial cells to underlying cells
The apical and basal surfaces differ in ______?
Structure and function
What are the specialized contacts of epithelial tissues?
Epithelial tissues have tightly packed cells, and had desmosomes and tight junctions
Epithelial tissue is _____ by underlying tissue
Nourished
What is regeneration?
Abundant cell division
What are the two names of all epithelial tissues?
First name indicated the number of cell layers, and the second name indicated the shape of the cells
What is the tip to identifying the shape of the cells?
Look at the apical (top) surface to determine cell shape
What are the names for the cell layers?
Simple = one layer and stratified = more than one layer
What are the names for the cell shapes?
Squamous = flat, cuboidal = cube-like, and columnar = taller than it is wide
What is simple squamous epithelium?
A single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm. It is the simplest of epithelia
What is the function of simple squamous epithelium?
Allows materials to pass by diffusion and filtration in sites where protection is not important. It also secretes lubricating substances in serosae
What is serosae?
Linings of the ventral body cavity
What is the location of simple squamous epithelium?
Kidney glomeruli, air sacs of lungs, the lining of the heart, blood vessels and lymphatic vessels, and serosae
What is simple cuboidal epithelium?
Single layer of cube-like cells with large, spherical central nuclei
What is the function of simple cuboidal epithelium?
Secretion and absorption
Where is the location of simple cuboidal epithelium?
Kidney tubules, ducts and secretory portions of small glands, and the ovary surface
What is simple columnar epithelium?
Single layer of tall cells with round to oval nuclei, many cells have microvilli, some have cilia, this tissue may contain goblet cells
What are goblet cells?
Mucus-secreting unicellular glands
What is the function of simple columnar epithelium?
Absorption, secretion of mucus, enzymes, and other substances. The ciliated type propels mucus or reproductive cells by ciliary action
What is the location of simple columnar epithelium?
Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands. The ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus
What are pseudostratified columnar epithelium?
Single layer of cells of differing heights, some not reaching the free surface, nuclei seen at different levels, may contain goblet cells and cilia
What is the function of pseudostratified columnar epithelium?
Secretes substances, particularly mucus, propulsion of mucus by ciliary action
What is the location of pseudostratified columnar epithelium?
Ciliated variety lines the trachea and most of the upper respiratory tract. Nonciliated variety is in males’ sperm-carrying ducts and ducts of large glands
What are stratified squamous epithelium?
Thick epithelium composed of several cell layers, basal cells are cuboidal or columnar and metabolically active, surface cells are flattened (squamous). In the keratinized type, the surface cells are full of keratin and are dead. Basal cells are active in mitosis and produce the cells of the more superficial layers
What is the function of stratified squamous epithelium?
Protects underlying tissues in areas subjected to abrasion
What is the location of stratified squamous epithelium?
Nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina. Keratinized type forms the epidermis of the skin, a dry epithelium
What are stratified cuboidal epithelium?
Two or more layers of cells, cells at the apical surface are about as tall as they are wide
What is the function of stratified cuboidal epithelium?
pROTE
What is the function of stratified cuboidal epithelium?
Protection and secretion
What are stratified columnar epithelium?
Two or more layers of cells, cells at the apical surface are taller than they are wide
What is the function of stratified columnar epithelium?
Protection and secretion
What is the location of stratified columnar epithelium?
Large ducts of salivary glands, male urethra, and pharynx
What is transitional epithelium?
Resembles both stratified squamous and stratified cuboidal, basal cells are cuboidal or columnar, surface cells are dome shaped or squamous-like, depending on the degree of organ stretch
What is the function of transitional epithelium?
Stretches readily, permits stored urine to distend urinary organ
What is the location of transitional epithelium?
Lines the urethra, bladder, and part of the urethra
What is a gland?
One or more cells that makes and secretes an aqueous fluid called a secretion
What are glands classified by?
The site of product release and the relative number of cells forming the gland
What are the sites of product releases in glands?
Endocrine = Ductless and internally secreting (hormones), and Exocrine = have ducts and externally secreting (sweat)
What is the relative numbers of cells forming the gland?
Unicellular (goblet cells) or multicellular (salivary)
Multicellular epithelial glands form by ________?
Invagination (inward growth) of an epithelial sheet
What do exocrine glands retain?
Connecting cells, which forms a duct that transports secretions to the epithelial surface
What do endocrine glands lose?
Their ducts during development
Where do endocrine glands secrete hormones?
Into the interstitial fluid, which then enters the blood
What do mucous and goblet cells produce?
Mucin
What is mucin?
A sugar-protein that can dissolve in water to form mucus, a slimy, protective, lubricating coating
Where are mucous cells and goblet cells found?
In epithelial linings of intestinal and respiratory tracts
What are mucous cells and goblet cells considered?
Unicellular
What is the most abundant and widely distributed of the primary tissues?
Connective tissue
What are the major functions of connective tissues?
Binding and support, protecting, insulating, storing reserve fuel, and transporting substances (blood)
What are the four main classes of connective tissue?
- Connective tissue proper
- Cartilage
- Bone
- Blood
What are the three components of connective tissue?
Ground substances, fibers, cells
What are the cell types in connective tissue?
Blast cells, cyte cells, fat cells, white blood cells, mast cells, and macrophages
What are blast cells?
The immature form of the cell that actively secretes ground substance and fibers
What are examples of blast cells?
Fibroblasts found in connective tissue proper, chondroblasts found in cartilage, osteoblasts found in bone, and hematopoietic stem cells found in bone marrow
What are cyte cells?
Mature, less active form of blast cells that now becomes part of and helps maintain health of the matrix
What are adipocytes?
Fat cells that store nutrients
What are neutrophils, eosinophils, and lymphocytes?
White blood cells that are the tissue’s response to injury
What are mast cells?
They initiate the local inflammatory response against foreign microorganisms they detect
What are macrophages?
Phagocytic cells that eat dead cells, microorganisms, and function in the immune system
What does connective tissue proper consists of?
All connective tissues except bone, cartilage, and blood
What are the two subclasses of connective tissue proper?
Loose connective tissues, and dense connective tissues
What are loose connective tissues?
They have fewer cells and protein fibers than dense connective tissue. Has an abundant ground substance
What are the three types of loose connective tissue?
Areolar, adipose, and reticular
What are dense connective tissues?
Mostly protein fibers, less ground substance
What are the three types of dense connective tissue?
Dense regular, dense irregular, and elastic
What is Proper –> Loose –> Areolar tissue?
Gel-like matrix with all three fiber types, cells, fibroblasts, macrophages, mast cells, and some white blood cells
What is the function of Proper –> Loose –> Areolar tissue?
Wraps and cushions organs, its macrophages phagocytize bacteria, plays important role in inflammation, holds and conveys tissue fluid
What is the location of Proper –> Loose –> Areolar tissue?
Widely distributed under the epithelia of the body. Forms lamina propria of mucous membranes, packages organs, surrounds capillaries
What is Proper –> Loose –> Adipose tissue?
Has a matrix as in areolar, but vary sparse, closely packed adipocytes, has a nucleus pushed to the side by large fat droplets
What is the function of Proper –> Loose –> Adipose tissue?
Provides reserve food fuel, insulates against head loss, supports and protects organs
What is the location of Proper –> Loose –> Adipose tissue?
Under the skin in SubQ tissue, around the kidneys and eyeballs, within abdomen, and in breasts
What is Proper –> Loose –> Reticular tissue?
Loose network of reticular fibers in a gel-like ground substance, reticular cells lie on the fibers
What is the function of Proper –> Loose –> Reticular tissue?
Fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages
What is the location of Proper –> Loose –> Reticular tissue?
Lymphoid organs (lymph nodes, bone marrow, and spleen)
What is Proper –> Dense –> Regular tissue?
Primarily parallel collagen fibers, a few elastic fibers, major cell type is the fibroblast
What is the function of Proper –> Dense –> Regular tissue?
Attaches muscles to bones or to muscles, attaches bones to bones, withstands great tensile stress when pulling force is applied in one direction
What is the location of Proper –> Dense –> Regular tissue?
Tendons, most ligaments, aponeuroses
What is Proper –> Dense –> Irregular tissue?
Primarily irregularly arranged collagen fibers, some elastic fibers, fibroblasts are the major cell type
What is the function of Proper –> Dense –> Irregular tissue?
Withstands tension excreted in many directions, provides structural strength
What is the location of Proper –> Dense –> Irregular tissue?
Fibrous capsules of organs and joints, dermis of the skin, submucosa of digestive tract
What is Proper –> Dense –> Elastic tissue?
Dense regular connective tissue containing a high proportion of elastic fibers
What is the function of Proper –> Dense –> Elastic tissue?
Allows tissue to recoil after stretching, maintains pulsatile flow of blood through arteries, aids passive recoil of lungs following inspiration
What is the location of Proper –> Dense –> Elastic tissue?
Walls of large arteries, within certain ligaments associated with the vertebral column, within the walls of the bronchial tubes
What is the matrix in cartilage?
The matrix is secreted from chondroblasts (during growth) and chondrocytes (adults). Chondrocytes are found in cavities called lacunae. The matrix is 80% water with packed collagen fibers and sugar proteins
Cartilage is ______ yet _______ material that ________ fibers
Tough yet flexible material that lacks nerve fibers
Cartilage is considered to be _______?
Avascular, it receives nutrients from the membrane surrounding it
What is Proper –> Cartilage –> Hylaine tissue?
Amorphous but firm matrix, collagen fibers from an imperceptible network, chondroblasts produce the matrix and when mature (as chondrocytes) lie in lacunae
What is the function of Proper –> Cartilage –> Hyaline tissue?
Supports and reinforces serves as a resilient cushion, resists compressive stress
What is the location of Proper –> Cartilage –> Hyaline tissue?
Forms most of the embryonic skeleton, covers the ends of long bones in joint cavities, forms costal cartilages of the ribs, and forms cartilages of the nose, trachea, and larynx
What is Proper –> Cartilage –> Elastic tissue?
Similar to hyaline cartilage but has more elastic fibers in the matrix
What is the function of Proper –> Cartilage –> Elastic tissue?
Maintains the shape of a structure while allowing great flexibility
What is the location of Proper –> Cartilage –> Elastic tissue?
Supports the external ear (pinna), epiglottis
What is Proper –> Cartilage –> Fibrocartilage?
The matrix is similar to but less firm than in hyaline cartilage, thick collagen fibers predominate
What is the function of Proper –> Cartilage –> Fibrocartilage tissue?
Tensile strength allows it to absorb compressive shock
What is the location of Proper –> Cartilage –> Fibrocartilage tissue?
Intervertebral discs, pubic symphysis, discs of knee joint
What is Proper –> Cartilage –> Bone tissue?
Hard, calcified matrix, containing many collagen fibers, osteocytes lie in lacunae. Very well vascularized
What is the function of Proper –> Cartilage –> Bone tissue?
Supports and protects (by enclosing), provides levers for the muscles to act on, stores calcium and other minerals and fat, marrow inside bones is the site for blood cell formation (hematopoiesis)
What is Proper –> Cartilage –> Blood tissue?
Red and white blood cells in a fluid matrix (plasma)
What is the function of Proper –> Cartilage –> Blood tissue?
Transports respiratory gases, nutrients, wastes, and other substances
What is the location of Proper –> Cartilage –> Blood tissue?
Contained within blood vessels
What is muscle tissue considered?
Highly vascularized
What is muscle tissue responsible for?
Most types of movement
What are the three types of muscle tissue?
- Skeletal muscle
- Cardiac muscle
- Smooth muscle
What is skeletal muscle?
Long, cylindrical, multinucleate cells, obvious striations
What is the function of skeletal muscle?
Locomotion, manipulation of the environment, facial expression
What is the location of skeletal muscle?
In skeletal muscles attached to bones or occasionally to skin
What is cardiac muscle?
Branching, striated, generally uninucleate cells that connect at specialized junctions (intercalated discs)
What is the function of cardiac muscle?
As it contracts, it propels blood into the circulation
What is the location of cardiac tissue?
The walls of the heart
What is smooth muscle?
Cells are spindle shaped (tapered on both ends) with central nuclei, no striations, cells arranged closely ot form sheets
What is the function of smooth muscle?
Propels substances or objects (food, urine, a baby), along internal passageways
What is the location of smooth muscle?
Mostly in the walls of hollow organs
What control is smooth muscle under?
Involuntary
What control is cardiac muscle under?
Involuntary
What control is skeletal muscle under?
Voluntary
What are glial cells?
Supporting cells that support, insulate, and protect neurons
What is nervous tissue?
Neurons are branching cells, cell processes that may be quite long extend from the nucleus-containing cell body, also contributing to nervous tissue are nonexcitable supporting cells
What is the function of nervous tissue?
Neurons transmit electrical signals from sensory receptors and to effectors (muscles and glands), supporting cells support and protect neurons
What is the location of nervous tissue?
Brain, spinal cord, and nerves
What tissues regenerate extremely well?
Epithelial tissue, bone, areolar connective tissue, dense irregular connective tissue, blood-forming tissue
What tissues regenerate moderately?
Smooth muscle and dense regular connective tissue
What tissues have virtually no functional regenerative capacity?
Cardiac muscle and nervous tissue of brain and spinal cord. New research shows cell division does occur, and efforts are underway to coax them to regenerate better
