Chapter 4: Tissues - the living fabric Flashcards
Tissues
Groups of cells that are similar in structure and function
4 types of tissue
Epithelial, Connective, Muscle, Nerve (MNCE)
Characteristics of Epithelial Tissues
Highly Cellular: most mass comes from nerves
Special Contacts: form continuous sheets held together by tight junctions and desmosomes
Polarity: apical and basal surfaces
Supported by connective tissue: reticular and basal laminae
Avascular but innervated: no blood vessels, but supplied by nerve fibers
Highly regenerative: rapidly replaces lost cells by mitosis
Simple Squamous
Single layer of flattened cells found in lining of heart and blood vessels, lungs, serosae
Simple Cuboidal
single layer of cube-like cells with large central nuclei found in kidney tubules, secretory glands, ovarian surfaces
Simple columnar
single layer of tall cells with oval nuclei, many with cilia
nonciliated: lines digestive tract and gallbladder
ciliated: lines small bronchi, uterine tubes and regions of uterus
Pseudostratified Columnar
single layer of cells with different heights, function in secretion and propulsion of mucus
sperm-carrying male reproductive ducts (nonciliated) and trachea (ciliated)
Stratified Squamous
thick tissue composed of several layers of cells
protect underlying areas subjected to abrasion
external skin’s epidermis (keratinized), linings of esophagus, mouth and vagina (nonkeratinized)
Transitional Epithelium
several cell layers, stretches to permit dissension of urinary bladder
lines urinary bladder, ureters, part of urethra
Epithelial membranes
Cutaneous (toughest), Mucous, Serous (least tough)
Cutaneous
skin (integument)
Mucous
lines body cavities open to exterior (digestive and respiratory tracts)
Serous
moist membranes found in closed ventral body cavities
Glandular
1 or more cells that makes and secretes a fluid
classified by product release
Endocrine: released inside
Exocrine: released outside
Number of cells: unicellular or multicellular
Endocrine glands
Ductless glands that produce hormones
secretions include amino acids, proteins, glycoproteins or steroids
Exocrine Glands
secrete their products onto body surfaces or into body cavities
mucous, sweat, oil and salivary glands
Merocrine
products are secreted by exocytosis (pancreas, sweat and salivary glands)
Holocrine
products are secreted by the rupture of gland cells (sebaceous glands)
Connective tissue
found throughout the body
most abundant and widely distributed
4 types of connective tissue
connective tissue
cartilage
bone
blood
Connective tissue functions
binding and support
protection
insulation
transportation
Cellular component
each category of connective tissue has a different connective tissue cell type
Ground substance
unstructured gel-like protein/glycoprotein material that fills the space between cells
Collagen Protein fiber
tough, inelastic fibers that provide tensile strength
Elastic Protein fiber
long, thin spring-like fibers
Reticular Protein fiber
short, branched fibers that form networks that support soft tissues
Connective cells
originate from an embryonic tissue called mesenchyme
Fibroblast
connective tissue proper
chondroblasts
cartilage
osteoblasts
bones
hematopoietic stem cells
blood (red blood cells, white blood cells, plasma cells, macrophages, and mast cells, platelets)
Areolar connective tissue
gel-like matrix with all 3 connective tissue fiber types
fibroblasts,
wraps and cushions organs
Adipose connective tissue
matrix similiar to areolar connective tissue, with closely packed adipocytes
acts as fuel stores, insulates against heat loss and supports and protects
found under skins, around kidneys, within abdomen and in breasts
Reticular connective tissue
loose ground substance w/ reticular fibers, reticular cells lie in a fiber network that supports immune cells,
found in lymph nodes, bone marrow and spleen
Dense regular tissue
parallel collagen fibers w/ few elastic fibers
fibroblasts
attaches to bone or other muscles (tendons) and bone to bone (ligaments) provides great strength in the direction parallel to the fibers
Dense irregular tissue
irregularly arranged collagen fibers with some elastic fibers, fibroblasts
withstands tension in many directions providing great structural strength
found in dermis, submucosa of digestive tract and fibrous organ capsules
Hyaline cartilage
amorphous, firm matrix w/ very sparse network of collagen fibers,
chondrocytes lie in lacunae (cavities)
supports, reinforces, cushions and resists compression
found in embryonic skeleton, the end of long bones, costal cartilages, nose, trachea and larynx
Elastic cartilage
similiar to hyaline but with more elastic,
maintains shape and strict while allowing flexibility
supports external ear and the epiglottis
Fibrocartilage cartilage
matrix similiar to hyaline, but less firm w/ thick collagen fibers
provides tensile strength and absorbs compression shock
found in intervertebral discs, the pubic symphysis, and in discs of the knee joint
Bone (Osseous Tissue)
hard, calcified matrix with collagen fibers found in bone
osteocytes founding lacunae
supports, protects, and provides levers for muscular action
stores calcium and minerals (“hard” bone) and fat (yellow bone)
hematopoiesis
performed in red marrow inside bones, creating new blood cells in the body
Blood
Red and white cells in a fluid matrix (plasma)
cells originate from red bone marrow
functions in the transport of respiratory gases, nutrients, and wastes and the immune system
Nervous tissue
branched neurons and support cells
transmits electrical signals from sensory receptors to effectors
found in the brain, spinal cord and peripheral nerves
Skeleton muscle
long, cylindrical, multinucleate cells with obvious striations
initiates and controls voluntary movement
found in muscles that attach to bones or skin
Cardiac muscle
branching, striated, uninucleate cells interlocking at intercalate discs
propels blood through the circulatory system
found in the walls of the heart
Smooth muscle
sheets of spindle-shaped cells with central nuclei that have no striations
propels substances along internal passageways
founding the walls of hollow organs
control of contradiction is involuntary
Tissue Trauma
inflammation
dilation of blood vessels (redness, heat)
increase in blood vessel permeability (swelling, edema)
Pain due to damages nerve endings and pressure from swelling
Tissue Repair
initial clotting of blood
reorganization and restoration of blood supply (blood clot replaced by granulation)
regeneration and fibrosis (surface epithelium regenerates and the scab detaches)
fibrous tissue matures and begins to resemble the adjacent tissue
results in fully regenerated epithelium with underlying scar tissue
