Histology Lab

main tissue types

epithelial, connective, muscle, neural

epithelial tissue main functions

covers exposed surfaces, lines internal passageways and chambers, produces glandular secretions

connective tissue main functions

fills internal space, provides structural support, stores energy

muscle tissue main functions

contracts to produce movement

neural tissue main functions

conducts electrical impulses, carries information

epithelial tissue characteristics

cells bound closely together, free (apical) surface

attached to underlying connective tissue by basement membrane

avascular (lacks blood vessels)

continual replacement or regeneration of cells

classification of epithelia

number of layers of cells (simple vs stratified vs pseudostratified) and shape of exposed cells (squamous, cuboidal, columnar)

connective tissue components

ground substance, fibers, cells

connective tissue types

proper (loose vs dense), fluid (blood, lymph), supporting (cartilage, bone)

types of cartilage

hyaline, elastic, fibrocartilage

hyaline cartilage

most common

matrix is closely packed with collagen

tough but flexible

reduces friction between bones

elastic cartilage

resilient and flexible

contains elastic fibers

fibrocartilage

little ground substance

matrix made up of densely woven collagen fibers

durable and tough: resists compression, absorbs shock

muscle tissue types

skeletal, cardiac, smooth

components of skeletal muscle tissue

striations, nuclei, muscle fibers

produces voluntary movement

cardiac muscle tissue components

nuclei, cardiac muscle, intercalated discs, striations

produces involuntary movement

smooth muscle tissue components

nuclei, smooth muscle cells

nerve tissue components

neurons and neuroglia

neuron components

cell body, dendrites, axon

bone tissue components

osteon (whole tree), osteocytes (cells), lamella (rings of a tree), central canal (middle)

integumentary system

largest organ, includes skin and associated structures (i.e. hair and nails)

the layers of the skin

epidermis, dermis, hypodermis

epidermis

outer layer of skin

avascular, superficial epithelium

made of stratum corneum, lucidum, granulosum, spinosum, basale

dermis

middle layer of skin, underlying connective tissue

made of papillary layer and reticular layer

papillary layer

superficial dermis

contains tactile receptors

reticular layer

deep dermis, contains lamellated receptors that sense pressure and sweat glands

hypodermis

subcutaneous layer of superficial fascia

not normally considered a part of the integument

mostly functions in fat storage, adipose tissue

contains subcutaneous plexus

subcutaneous plexus

network of blood vessels in the hypodermis

thick skin contains

no hair, no sebaceous glands, all 5 layers

thin skin contains

hair, sebaceous glands, smooth muscle, 4 layers (no stratum lucidum)