Tissues - Anatomy and Physiology Lecture Flashcards
are collections of structurally similar cells with related functions
Tissues
The four primary tissues are
__________, _________,
__________, and _________ tissues.
epithelial, connective, muscle, nervous
Function of Nervous tissue
Internal communication
Location of Nervous Tissue
Brain, spinal cord, and nerves
Function of Muscle Tissue
Contracts to cause movement
Location of Muscle Tissue
- Muscles attached to bones (skeletal)
- Muscles of heart (cardiac)
- Muscles of walls of hollow organs (smooth)
Function of Epithelial Tissue
Forms boundaries between different environments, protects, secretes, absorbs, filters
Location of Epithelial tissue
- Skin surface (epidermis)
- Lining of GI tract organs and other hollow organs
Function of Connective Tissue
Supports, protects, binds other tissues together
Location of Connective Tissue
- Bones
- Tendons
- Fat and other soft padding tissue
Epithelial tissue is the ________, _______, and ________ tissue of
the body.
covering, lining and glandular
Two main types of Epithelium (by location)
- Covering and lining epithelia
- Glandular epithelia
where to find Covering and lining epithelia
On external and internal surfaces
where to find Glandular epithelia
Secretory tissue in glands
Cells have ____________.
polarity
Special characteristics of Epithelial Tissue
- Cells have polarity
- Are composed of closely packed cells
- Supported by a connective tissue reticular lamina
- avascular but innervated
- high rate of regenaration
2 surfaces of epithelial tissue
- apical (upper, free) surface
- basal (lower, attached) surface
may bear microvilli (e.g., brush border of intestinal lining) or cilia (e.g., lining of trachea)
apical surface
faces the lumen (inside of a hollow organ)
apical surface
is adjacent to the underlying tissue.
basal surface
How many layers does simple epithelium have?
1
How many layers does stratified epithelium have?
2 or more
Classification of Epithelia
- Squamous
- Cuboidal
- Columnar
single layer of flattened cells with disc-shaped central nuclei
and sparse cytoplasm; the simplest of the epithelia.
Simple squamous epithelium
function of Simple squamous epithelium
allows passage of materials by diffusion and filtration
in sites where protection is not nimportant; secretes lubricating substances in serosae.
location of Simple squamous epithelium
Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity (serosae).
description of simple squamous epithelium
single layer of flattened cells with disc-shaped central nuclei
and sparse cytoplasm; the simplest of the epithelia.
Description of Simple cuboidal epithelium
single layer of cubelike cells with large, spherical central nuclei
function of simple cuboidal epithelium
secretion and absorption
location of simple cuboidal epithelium
Kidney tubules; ducts and secretory portions of small glands; ovary surface.
description of simple columnar epithelium
single layer of tall cells with round to oval nuclei; some cells
bear cilia; layer may contain mucus secreting unicellular glands (goblet cells).
function of simple columnar epithelium
Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action.
location of simple columnar epithelium
Nonciliated type lines most of the digestive tract (stomach to anal canal), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus
Description of Pseudostratified columnar epithelium
single layer of cells with differing heights some not reaching
the free surface; nuclei seen at different levels; may contain mucussecreting cells and bear cilia.
Function of Pseudostratified columnar epithelium
secretion, particularly of mucus; propulsion of mucus by
ciliary action.
Location of Pseudostratified columnar epithelium
Nonciliated type in male’s sperm-carrying ducts and ducts of
large glands; ciliated variety lines the trachea, most of the upper respiratory tract.
Description of Stratified squamous epithelium
thick membrane 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 dead; basal cells are active in mitosis and produce the cells of the more superficial layers.
Function of Stratified squamous epithelium
protects underlying tissues in areas subjected to abrasion
Location of Stratified squamous epithelium
Nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina; keratinized variety
forms the epidermis of the skin, a dry membrane
Stratified Cuboidal Epithelia
- Quite rare in body
- Found in some sweat and mammary glands
- Typically two cell layers thick
Stratified Columnar Epithelium
- Limited distribution in body
- Small amounts in pharynx, male urethra, and lining some glandular ducts
- Also occurs at transition areas between two other types of epithelia
Description of Transitional epithelium
resembles of stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamouslike, depending on degree of organ stretch.
Function of Transitional epithelium
stretches readily and permits distension of urinary organ
by contained urine.
Location of Transitional epithelium
Lines the ureters, urinary bladder, and part of the urethra.
Connective tissue is the most ______________and ______________ distributed tissue type.
abundant; widely
Four classes of connective tissue
- connectice tissue proper
- cartilage
- bone tissue
- blood
subclasses of connective tissue proper
- loose connective tissue
- dense connective tissue
types of loose connective tissue
- areolar
- adipore
- reticular
types of dense connective tissue
- regular
- irregular
- elastic
types of bone tissue
- compact bone
- spongy bone
Major Functions of Connective Tissue
- binding and support
- protection
- insulation
- transportation (blood)
Characteristics of Connective Tissue
Connective tissues have:
- varying degrees of vascularity
- Cells separated by non-living extracellular matrix
Structural Elements of Connective Tissue
- ground substance
- cells
- fibers
Medium through which solutes diffuse between blood capillaries and cells
Ground substance
component of ground substance
- Interstitial fluid
- Adhesion proteins (“glue”)
- Proteoglycans
Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid)
Proteoglycans
Trap water in varying amounts, affecting the viscosity of the
ground substance
Proteoglycans
Three types of fibers
Collagen, Elastic, Reticular
(white fibers)
- Strongest and most abundant type
- Provides high tensile strength
collagen fibers
Networks of long, thin, elastin fibers that allow for stretch
elastic fibers
Short, fine, highly branched collagenous fibers
reticular fibers
Mitotically active and secretory cells
“blasts”
Mature cells
“cytes”
cells in connective tissue proper
fibroblasts
cells in cartilage
chondroblasts and chondrocytes
cells in bone
osteoblast and osteocytes
cells in bone marrow
hematopoietic stem cells
Description of loose connective tissue
gel-like matrix with all three fiber types; cells: fibroblasts,
macrophages, mast cells, and some white blood cells.
Function of loose connective tissue
wraps and cushions organs; its macrophages phagocytize
bacteria; plays important role in inflammation; holds and conveys tissue fluid.
Location of loose connective tissue, areolar
Widely distributed under epithelia of body, e.g., forms lamina propria of mucous membranes; packages organs; surrounds capillaries.
Description of adipose tissue
Matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet.
Function of adipose tissue
provides reserve food fuel; insulate against heat loss; supports and protects organs.
Location of adipose tissue
Under skin in the hypodermis; around kidneys and
eyeballs; within abdomen; in breasts.
Description of Reticular Tissue
Network of reticular fibers in a typical loose ground substance; reticular cells lie on the network
Function of Reticular Tissue
Fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages.
Location of Reticular Tissue
Lymphoid organs (lymph nodes, bone marrow, and spleen).
Description of dense regular connective tissue
primarily parallel collagen fibers; a few elastic fibers;
major cell type is the fibroblast.
Function of dense regular connective tissue
Attaches muscles to bones or to muscles; attaches bones
to bones; withstands great tensile stress when pulling force is applied in one direction.
Location of dense regular connective tissue
Tendons, most ligaments, aponeuroses.
description of dense irregular connective tissue
primarily irregularly arranged collagen fibers; some elastic fibers; major cell type is the fibroblast.
function of dense irregular connective tissue
Able to withstand tension exerted in many directions; provides structural strength.
location of dense irregular connective tissue
Fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract.
description of elastic connective tissue
Dense regular connective tissue containing a high
proportion of elastic fibers
function of elastic connective tissue
Allows recoil of tissue following stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration
location of elastic connective tissue
Walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes.
3 types of cartilage
hyaline cartilage, elastic cartilage, fibrocartilage
description of hyaline cartilage
Amorphous but firm matrix; collagen fibers form an
imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae.
function of hyaline cartilage
supports and reinforces; has resilient cushioning properties;
resists compressive stress.
location of hyaline cartilage
Forms most of the embryonic skeleton; covers the ends
of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx.
description of elastic cartilage
Similar to hyaline cartilage, but with more elastic fibers in matrix
function of elastic cartilage
Maintains the shape of a structure while allowing great flexibility
location of elastic cartilage
Supports the external ear (pinna); epiglottis.
Description of fibrocartilage
Matrix similar to but less firm than that in hyaline cartilage; thick collagen fibers predominate.
Function of fibrocartilage
Tensile strength with the ability to absorb compressive shock
Location of fibrocartilage
Intervertebral discs; pubic symphysis; discs of knee
joint.
Description of bone (osseous tissue)
hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae. Very well vascularized.
Function of bone (osseous tissue)
Bone 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).
Location of bone (osseous tissue)
Bones
Description of Blood
Red and white blood cells in a fluid matrix (plasma).
Function of Blood
transport of respiratory gases, nutrients, wastes, and other substances
Location of blood
Contained within blood vessels.
recieve electrical and chemical messages from other neurons
dendrites
processess incoming signals and generates outgoing signals
cell body
sends outgoing signals to axon terminals
axons
make contact with nearby cells and transmit signals to them
axon terminals
a single glial cells wraps itself around an axon to form a segment of the ___________________
myelin sheath
Nervous Tissue is made up of
neurons and neuroglial cells
Description of 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 nonirritable supporting cells
Function of Nervous Tissue
transmits electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity
3 types of Muscle Tissue
Skeletal, Smooth, Cardiac
Location of Nervous Tissue
Brain, spinal cord, and nerves
Description of Skeletal Muscle Tissue
Long, cylindrical, multinucleate cells; obvious striations
Function of Skeletal Muscle Tissue
Voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control.
Location of Skeletal Muscle Tissue
In skeletal muscles attached to bones or occasionally to skin
Description of Cardiac Muscle Tissue
branching, striated, generally uninucleate cells that interdigitate at specialized junctions (intercalated discs).
Function of Cardiac Muscle Tissue
As it contracts, it propels blood into the circulation; involuntary control.
Location of Cardiac Muscle Tissue
The walls of the heart.
Description of Smooth Muscle Tissue
Spindle-shaped cells with central nuclei; no striations; cells arranged closely to form sheets.
Function of Smooth Muscle Tissue
Propels substances or objects (foodstuffs, urine, a baby) along internal passageways; involuntary control.
Location of Smooth Muscle Tissue
Mostly in the walls of hollow organs
continuous multicellular sheets composed of atleast two primary tissue types:
1) epithelium bound to an underlying layer of
2) connective tissue proper
line all body cavities that open to the outside of the body
such as the hollow organs of the digestive, respiratory and urogenital tracts
Mucous Membranes
they are “wet,” or moist, membranes bathed by secretions or, in the case of the urinary mucosa, urine
Mucous Membranes
moist membranes found in closed ventral body cavities
Serous Membranes
Types of Serous Membranes
Pleurae
Pericardium
Peritoneum
line the thoracic wall and cover the lungs
Pleurae
encloses the heart
Pericardium
encloses the abdominopelvic viscer
Peritoneum
requires that cells divide and migrate activities that are initiated by growth factors (wound hormones) released by injured cells.
Tissue Repair
Repair occurs in two major ways:
Regeneration and Fibrosis
replaces destroyed tissue with the same kind of tissue
Regeneration
fibrous connective tissue proliferates to form scar tissue
Fibrosis
