BIOL 221 - Lecture 2 Exam

What are the 4 basic types of tissues?

epithelial, connective, muscle, nervous(nerve)

Definition of Tissue?

cells with similar structures and functions organized in groups/layers

Characteristics of Epithelial Tissues?

tightly packed cells

apical (free) surface

basal surface

basement membrane

have rapid regeneration

are avascular

Epithelial Tissue

covers or lines the body surfaces (inside and out)
controls exchange and provides protection

Connective Tissue

cartilage, tendons, ligaments
binds and supports body parts

Muscle tissue

for movement of the body

Nervous Tissue

detects changes and transmits information rapidly

Apical (Free Surface)

exposed to spaces, no attachment to anthing

Basal Surface

attaches the cell to the basement membrane

Basement Membrane

attaches to the underlying connective tissue

Surface Epithelium

Covers body surfaces and lines internal spaces with organs

Glandular Epithelium (Exocrine/Endocrine Glands)

produce secretion

Exocrine glands

they are ducts that are open externally
secrete products onto epithelial surface (salivary glands, mucous glands)

Endocrine Glands

they have no duct
secrete hormones back into the bloodstream (circulates around the body)

Simple Epithelial

1 layer, best for exchange
(diffusion, absorption, secretion)

Stratified Epithelial

more than 1 layer, good for protection

squamous cell shape

flat and is the fastest for diffusion

cuboidal cell shape

cubelike, good for secretion and absorption

columnar cell shape

columnlike
good for absorption and transportation

Transitional cell shape

shape varies
good for stretching

Connective tissue characteristics

few loosely arranged cells
large amount of matrix
can be fibrous, solid, semi solid, fluid
is vascular (except cartilage)

are usually covered by epithelium, not exposed to external environment

CT - extracellular matrix

matrix = ground substance + protein fibers

CT - Ground substance

water and dissolved substances
can be fluid, gel like, or solid

CT - Protein Fibers

Collagen - tensile strength
Elastic - stretching
Reticular - provides framework

Connective tissue Categories

loose
dense
specialize

Loose CT Type
(Areolar and Adipose)

loose fibers, more ground substance, softer, more flexible

Areolar CT

under the epithelium, binds skin to muscles
(falls under Loose)

Adipose CT

in places of fat (hips/breasts)
energy storage and insulation
(falls under Loose)

Dense Irregular CT

on the dermis of the skin
dense collagen fibers, resists pulling

Dense Regular CT

on the tendons and ligaments
dense collagen fibers, resists pulling

Specialize Connective Tissue - highly modified matrix
What are the 3 types

cartilage (firm gel)
blood (fluid matrix)

bone (mineralized)

Skeletal Muscle Tissue

attached to bones; voluntary movement;
cells are called muscle fibers

Cardiac Muscle Tissue

heart; moves blood; involuntary
muscle cells

Smooth Muscle Tissue

moves substances through hollow organs, involuntary
muscle cells

Muscle Tissue

use protein fibers for contraction
allows for movement and generating heat

Nerve Tissue

found in brain, spinal cords, nerves (embedded in connective tissue)
regulates body functions

Neuron (nerve cell)

functional units of nerve tissue
specialized to form and transmit nerve impulses in response to environmental changes

Neuroglia (nerve glue)

nourish, insulate, protect neurons

body membranes

thin sheets of tissue that line cavities, cover surfaces, or separate tissues and organs

Epithelial Tissue MEMBRANE

epithelium + underlying areolar connective tissue

Serous Membrane (Epithelial)

line closed body cavities (thoracic and abdominopelvic)
pericardium, pleura, peritoneum

secretes serous fluid, reducing friction

Mucous Membranes (Epithelial)

line cavities open to the external environment
secretes mucus, for lubrication and trapping pathogens

Cutaneous Membrane (Epithelial)

the skin
keratinized (dry surface)

Connective Tissue MEMBRANE

formed only of connective tissue
protect, stabilize, lubricate organs and structures

meninges, perichondrium, periosteum, synovial membranes

Meninges

brain

Perichondrium

lines the cartilage

Periosteum

lines the bones

Synovial membranes

surrounds joints, keep joint in place

Skin is a organ

there are multiple tissues that work together (the integumentary system)

What does skin do?

prevents fluid loss
regulates heat

senses environment
barrier to pathogens
Vitamin D regulation

Epidermis

1st layer of skin - epithelium
only lipid soluble substances can cross epidermis

Dermis

2nd layer of skin - dense irregular connective tissue
stops our skin from being pulled in different directions

Hypodermis

3rd layer of skin - adipose tissue