bio exam #2

tissue

a collection of cells of the same type that perform a common function

4 types of tissue

connective, muscular, nervous, epithelial

connective tissue

binds and supports tissue parts

muscular tissue

moves the body and its parts

nervous tissue

conducts nerve impulses

epithelial tissue

covers body surfaces; lines body cavities

three components of connective tissue

specialized cells, ground substance, and protein fibers

ground substance

noncellular material between the cells

three types of protein fibers

collagen, reticular, and elastic fibers

collagen fibers

flexible and strong

reticular fibers

thin, highly branched collagen fibers

elastic fibers

contain elastin, a protein that stretches and recoils

three types of connective tissue

fibrous, supportive, and fluid

fibrous connective tissue; two forms

loose and dense

loose fibrous connective tissue

includes areolar connective tissue, reticular connective tissue, and adipose tissue

dense fibrous connective tissue

found in tendons and ligaments

t/f loose fibrous connective tissue supports epithelium and many internal organs

true

two major types of supportive connective tissue

cartilage and bone

3 cartilage types

hyaline, elastic, and fibrocartilage

hyaline cartilage

fine collagen fibers; found in the tip of the nose, ends of long bones and the fetal skeleton

elastic cartilage

lots of elastic fibers; found in the outer ear

fibrocartilage

strong collagen fibers; found in the disks between vertebrae

t/f bone is the most rigid connective tissue

true

two types of bone tissue

compact and spongy

compact bone

makes up the shafts of long bones; bone cells are located in lacunae

spongy bone

inside the ends of long bones; lighter than compact bone, but strong

two types of fluid connective tissue

blood and lymph

blood

made of a fluid matrix called plasma and cellular components called formed elements

red blood cells (erythrocytes)

cells that carry oxygen

white blood cells (leukocytes)

cells that fight infection

platelets (thrombocytes)

pieces of cells that clot blood

lymph

derived from the fluid surrounding the tissues; contains white blood cells

t/f muscular tissue isn't specialized to contract

false

three types of muscular tissue

skeletal, smooth, and cardiac

skeletal muscle

attached to the skeleton by tendons; voluntarily controlled

t/f muscle fibers have multiple nuclei

true

are muscle fibers striated (striped) or dotted in appearance

striated

smooth muscle

no striations, spindle-shaped cells with one nucleus; involuntarily controlled

cardiac muscle

found only in the walls of the heart; striated; involuntary; single nucleus; connected by intercalated disks

nervous tissue is made of what

neurons nad neuroglia

three primary functions of nervous tissue

sensory input, integration, and motor output

neuron parts

dendrites, a cell body, and an axon

what do dendrites do in a neuron

carry information toward the cell body

what does the cell body do in a neuron

contains the nucleus and other organelles

what does the axon do in a neuron

conducts nerve impulses away from the cell body

nerves

bundles of axons traveling to and from the brain and spinal cord

neuroglia

outnumber neurons 9:1; take up more than half the volume of the brain

what is the neuroglia's main function

support and nourish neurons

why are neuroglia important

help with learning and memory

epithelium

made of tightly packed cells; either simple or stratified

simple epithelium

single layer of cells

stratified epithelium

multiple layers of cells

simple squamous epithelium

single layer of flattened cells; found in the lungs

simple cuboidal epithelium

single layer of cube-shaped cells

simple columnar epithelium

single layer of column-shaped cells

pseudostratified columnar epithelium

appears stratified but every cell touches the basement membrane

stratified epithelia

several layers of cells

stratified squamous epithelia

forms the outer layer of the skin and lines the mouth & esophagus

transitional epithelia

cells change shape in response to tension

glands

one or more cells that make and secrete a product

two types of glands

exocrine and endocrine

exocrine glands

secrete into ducts

endocrine glands

secrete into the bloodstream; have no ducts

integumentary system

includes the skin and accessory organs such as hair, nails, and glands

functions of the integumentary system

protects underlying tissues from trauma, pathogen invasion, and water loss; helps regulate body temperature; contains sensory receptors; makes us aware of our surroundings

t/f the integumentary system only includes two types of tissues

false

what are the two main regions of skin

epidermis and dermis

what layer is under the skin

subcutaneous layer (hypodermis)

epidermis

thin, outermost layer of the skin; made of stratified squamous epithelium

autograft

skin from another area of the body

allograft

skin from another person

what are the cells of the epidermis

keratinocytes, langerhans cells, melanocytes

keratinocytes

upper layer of epidermis; dead and filled with keratin; waterproof barrier

langerhans cells

a type of white blood cell

melanocytes

produce melanin; produces skin color and protects from UV light

skin cancer

caused by ultraviolet rays from the sun

basal cell carcinoma

cancer of the epidermal stem cells; most common type of skin cancer

melanoma

cancer of melanocytes; extremely serious

dermis

thick, inner layer of the skin; made of dense fibrous connective tissue

subcutaneous layer

includes hypodermis; composed of loose connective tissue and adipose tissue to store energy, insulate and protect

t/f the subcutaneous layer is technically not part of the skin

true

accessory organs of the skin

nails, hair, and glands

nails

offer a protective covering; grow from the nail root to cover the nail bed; cuticle covers the nail root

hair

follicles & shaft; color comes from melanin

hair follicles

epidermal structures that surround the hair itself

hair shaft

the portion of hair protruding from the skin

arrector pili muscles

attached to the hair follicle

t/f goosebumps come from the arrector pili muscles contracting

true

oil glands

produce sebum; acne

sweat glands (sudoriferous glands)

in the dermis; help regulate body tempurature

organ

a group of tissues performing a common function

groups of organs with a similar function form an...

organ system

two types of body cavities

ventral and dorsal

ventral cavity

contains the thoracic, abdominal, and pelvic cavities; thoracic and abdominal are separated by the diaphragm

dorsal cavity

contains the cranial and vertebral cavity

body membranes

line cavities and the internal spaces of organs and tubes that open to the outside

four types of body membranes

mucous, serous, synovial membranes, and the meninges

mucous membranes

line the tubes of the digestive, respiratory, urinary, and reproductive systems; composed of epithelium overlying loose fibrous connective tissue

what do mucous membranes do

protect from bacteria; protect stomach from burning; secrete mucus

serous membranes

line closed cavities and cover the surface of the organs contained within; pleurae, pericardium, peritoneum