Tissues

simple squamous epithelia (lymphatic)

description:

-single layer of flat, disc-like cells

-flattened nuclei

-functions as surface for filtration and diffusion

Location:

-air sacs of lungs→alveoli

-glomeruli

-blood vessel and capillary lumens

-body cavity linings

simple cuboidal epithelia

description:

-single layer of cube-like cells

-large, round nuclei

-responsible for secretion and absorption

location:

-ducts and glands

-kidney tubules

-ovary

-thyroid

simple columnar epithelia (intestinal)

description:

-single layer of tall, rectangular cells

-elongated nuclei

-microvilli (absorption) and cilia (propulsion) common on apical surface

-function in absorption (digestive tract) and secretion (mucous, reproduction)

location:

-digestive tract lining

-respiratory tract lining

psuedostratified columnar epithelia

description:

-single layer of columnar cells of different heights

-nuclei appear at different heights

-have appearance of multiple layers

-function in secretion and propulsion (can be ciliated)

location:

-male sperm duct

-respiratory tract

-large glands

stratified squamous epithelia (keratinized and nonkeratinized)

description:

-multiple layers of squamous cells on a basement membrane

-surface cells are dead, flat and keratinized

-basal cells are cube-shaped and mitotically active

-form protection against abrasion and damage for tissue underneath

location:

-skin (keratinized)

-lining of esophagus

-lining of vagina

-lining of mouth

stratified cuboidal epithelia

description:

-generally two layers of cubelike cells

-protection

location:

-largest ducts of sweat glands, mammary glands, and salivary glands

stratified columnar epithelia

description:

-several cell layers, basal cells usually cuboidal

-superficial cells elongated and columnar

-protection; secretion

location:

-rare in the body; small amounts in the male urethra

-in large ducts of some glands

transitional epithelia

description:

-appears to be stratified squamous or cuboidal

-basal cells are cuboidal

-surface cells are rounded/squamous

-stretch permitted, enabling storage of urine

location:

-lining of urinary tracts such as:

-ureter

-bladder

-urethra

areolar loose connective tissue

description:

-loosely-packed assembly of all fiber types, fibroblasts, and immune cells

-main function: cushions organs

-also contains key immune mediators to fight off infections

location:

-supporting under epithelial layers and surrounding organs

adipose loose connective tissue

description:

-matrix crowded by tightly-packed adipocytes

-serves to insulate and protect organs

-provides energy storage depot

location:

-around major organs

-within subcutaneous layer of skin (under dermis)

reticular loose connective tissue

description:

-meshwork of reticular fibers loosely-organized

-forms a flexible meshwork

-supports tissue and immune cells

location:

-lymph nodes

-bone marrow

-splenic pulp

regular dense connective tissue

description:

-fibroblasts embedded within a regularly-ordered assembly of collagen fibers

-functions to resist pulling stress

location:

-attaches muscle to bone (tendon)

-attaches bone to bone (ligament)

irregular dense connective tissue

description:

-irregularly-arranged collagen fibers with fibroblasts embedded within

-resists force in many directions

location:

-dermis

-joint capsules

-underlying epithelial linings such as in the digestive tract

elastic dense connective tissue

description:

-dense regular connective tissue enriched with elastin fibers

-ordered arrangement of elastin

-allows for stretch and recoil of tissue

location:

-walls of arteries

-walls of bronchial tubes

-some ligaments

hyaline cartilage connective tissue

description:

-flexible, firm gel matrix secreted by chondroblasts

-this becomes embedded in lacunae (chondrocytes)

-functions to cushion, support and reinforce other tissues and organs

location:

-nose

-trachea

-ribs

-ends of long bones

-embryonic skeleton

elastic cartilage connective tissue

description:

-same organization as hyaline cartilage

-enriched with elastin fibers

-has greater degree of flexibility and stretch

-allows for tissue to return to original shape

location:

-outer ear

-epiglottis

fibrocartilage connective tissue

description:

-firm hyaline matrix, with more organized collagen fibers

-resists compressive force

location:

-components of joints with limited flexibility, like intervertebral discs

-menisci

-pubic symphysis

blood connective tissue

description:

-erythrocytes, leukocytes, and platelets within a plasma matrix

-primary function: transport of oxygen and carbon dioxide, nutrients and other dissolved molecules throughout the body

location:

-contained within arteries, veins and capillaries

bone connective tissue

description:

-calcified collagen matrix embedded osteocytes

-cross talk among osteocytes

-high degree of vascularity

-functions in calcium storage, attachment for muscles

-spongy bone contains marrow, stem cells for blood formation

location:

-skeleton

skeletal muscle tissue

description:

-elongated myotubes formed from fused cells

-multinucleated

-striations visible

-function in voluntary skeletal movement

location:

-attached to bones

cardiac muscle tissue

description:

-elongated myotubes with greater degree of branching

-specialized cell junctions (intercalated discs) seen as deep red margins between cells

-individual nuclei evident

-striations visible

-ensure flow of blood to all body tissues

location:

-heart wall only

smooth muscle tissue

description:

-spindle-shaped cells with central nucleus

-found in layers that form sheets

-can provide force (e.g. during uterine contractions)

-can accommodate stretch (e.g. digestive system)

location:

-walls of hollow organs

nervous tissue

description:

-neurons receive sensory information and carry it to the brain, transmit motor impulses from brain to effector organs, and form synapses with one another

-glial cells provide structural support, protection and nourishment for neurons in the brain and spinal cord

location:

-brain

-spinal cord

-cranial and peripheral nerves