A&P Chapter 4 Study Guide

Tissues

Group of cells similar in structure that perform common or related functions

Histology

Study of cells

Epithelial tissue

Connective tissue

Muscle tissue

Nervous tissue

4 basic tissue types

Nervous tissue

Internal communication

• Brain

• Spinal cord

• Nerves

Muscle tissue

Contracts to cause movement (shortens to produce movement)

Epithelial tissue

Forms boundaries between different environments, protects, secrets, absorbs, filters

Connective tissue

Supports, protects, binds other tissue together

Epithelial tissue (epithelium)

Is a sheet of cells that covers a body surface or lines a body cavity

Coverings and lining epithelium

Glandular epithelium

Epithelial tissues 2 main forms

Coverings and lining epithelium

Forms the outer layer of skin, lines open cavities, and covers walls and organs of ventral body cavity

Glandular epithelium

Forms glands of the body that secrete substances

• Salivary glands

Polarity

Specialized contacts

Supported by connective tissue

Avascular but innervated

Regenerative

Epithelial tissue has 5 distinguishing characteristics

Polarity

Cells may have top and bottom

Apical

Borders open (hollow) space

Basal surface

Next to underlying connective tissue

• Faces inward towards body organ

Specialized contacts

Epithelial tissues need to fit close together

Supported by connective tissue

All epithelial sheets are —

Reticular lamina

Deep to basal lamina

Consist of network of collagen fibers

Basement membrane

Basal and reticular lamina make up basement membrane

Resist stretching and tearing

Avascular but innervated

No blood vessels are found in epithelial tissues, however its supplied by nerve fibers

Regeneration

Self-repairing shield when it gets damaged, it can quickly make new cells to replace old ones

Number of cells

Shape of cells

All epithelial tissue have two names

Simple epithelia

Stratified epithelia

Number of cells

Squamous

Cuboidal

Columnar

Shape of cells

Simple epithelia

Consist of a single cell layer

Stratified epithelia

Consist of two or more cell layers

Squamous

Flattened and scale like

Cuboidal

Box like, cube

Columnar

Tall, column like

Simple squamous epithelia

Cells single layered and are flattened

Endothelium

Lining of lymphatic vessels, blood vessels, and heart

Mesothelium

Serous membranes in ventral body cavity

Simple cuboidal epithelium

Single cell layer

Secretion and absorption

Forms walls of smallest ducts of glands and many kidney tubules

Digestive tact; gallbladder; ducts of some glands; bronchi; and uterine tubes

Simple cuboidal epithelium locaiton

Simple columnar epithelium

Single layer of tall, closely packed cells

Absorption and secretion of mucus, enzymes, and other substance

Kidney tubules; ducts and secretary portions of small glands; ovary surface

Simple columnar epithelium location

Pseudostratified columnar epithelium

Looks like a lot of layers (like stratified epithelium) but it has just one layer

Simple epithelium tissues

Involved in absorption, secretion, filtration

Stratified epithelium tissues

Two or more layers of cells

More durable than simple because protection is major role

Stratified squamous epithelium

Multilayered, flattened

• Located in area of wear and tear (skin)

• Protects underlying tissues in area subject to abrasions

Stratified cuboidal epithelium

Typically only two layers think, quite rare

Found in sweat and mammary glands

Stratified columnar epithelium

Also very limited, small amounts found in pharynx, in male urethra, and lining some glandular ducts

Transitional epithelium

Forms lining of hollow urinary organs (bladder, urethra, and ureters)

Gland

One or more cells that make and secrete an aqueous fluid called a secretion

Endocrine

Ductless glands that produce hormones

• Secretions arent released into a duct, into surrounding interstitial fluid, which is picked up by circulatory system

• Secrete hormones, messenger chemical that travel through lymph or blood to their specific targets

Exocrine

Secrete products onto body surfaces or into body cavities

• Sweat glands, salivary glands

• Secretions are released onto body surfaces, or body cavities

Unicellular exocrine glands

Mucus cells and goblets cells (the only important part)

• Produce mucus

Merocrine

Holocrine

Apocrine

Mode of secretion

Merocrine

Secrete products by exocytosis as secretions are produced

Holocrine

Accumulate products within until rupture

(explode)

Apocrine

Accumulate products within, but only apex ruptures

• Cell repairs damage and repeats

Connective tissue proper

Cartilage

Blood

Bone

Connective tissue 4 main classes

Extracellular matrix

Of nonliving portion of connective tissues in which the living cells are suspended in

Ground substance

Fibers

Cells

All connective tissue have 3 main components

Ground substance

Unstructured gel like material that fills space between cells

Connective tissue fibers

Provide structure

Collagen fibers

(physical support) Strongest, most abundant

Elastic fibers

(like rubber bands) long, thin, elastin fibers that allow for stretch and recoil

Reticular fibers

(are flexible) short, fine, highly branched collagenous fibers

Connective tissue cells

Immature and mature forms of many cell types

Fibroblasts

In connective tissue proper become fibrocytes

Chondroblasts

In cartilage become chrondocytes

Osteoblasts

In bone becomes osteocytes (manage and protect)

Hematopoietic stem cells

Are the immature form of blood cells

• “Hemocytoblast” maker of hemo cells

“blasts”

Cells are immature form of cell that secretes ground substance and matrix fibers

“cytes”

Cells are mature form of cells that maintain health of the matrix, can revert to “blasts”

Adipocytes

Store energy fats

Leukocytes (white blood cells)

Responds to tissue injury

Mast cells

Detect foreign microorganisms and initiate local inflammatory response (only in connective tissues)

Hesparin

An anticogulant

Histamine

Makes capillaries leaky

Proteases

Enzymes that degrade proteins

Macrophages

Breaks down foreign materials and dead cells

Connective tissue proper

Consist of all connective tissues. Except bone, cartilage, and blood

Areolar

Adipose

Reticular

Connective tissue proper : loose connective tissue

Dense regular

Dense irregular

Elastic

Connective tissue proper : dense connective tissue

Areolar

Supports and binds other tissues

Universal packing material between other tissues

Adipose

• White fats

Adipocytes

Functions in shock absorption, insulation, energy storage

• Brown fats

Use lipid fuels to heat bloodstreams rather than to produce ATP

Tendon

Connects muscle to bone

Ligaments

Connects bone to bone

Aponeuroses

Connects to muscle to muscle

Dense regular

Very high tensile strength

Closely packed bundles of thick collagen fibers

Manufactures collagen fibers and ground substance

Dense irregular

Bundles of collagen thicker and irregularly arranged

Forms sheets rather than bundles

Resists tension from any direction

Elastic

Some ligaments are very elastic

Found in the walls of many large arteries

Cartilage

Matrix secreted from chondroblasts (during growth) and chondrocytes (adults)

Hyline cartilage

Elastic cartilage

Fibrocartilage

3 types of cartilage

Hyline cartilage

Most abundant

Found at tips of long bones, nose, trachea, larynx, and cartilage of ribs

Elastic cartilage

Similar to hyline but more elastic fibers

Ears and epigolottis

Fibrocartilage

Properties between hyline and dense regular tissue

Strong, found in areas as intervertebral discovered and knee

Bone, or osseous tissue

Support and protects body structures

Stores fat and synthesizes blood cells in cavities

Osteoblasts produce matrix

Osteocytes maintains matrix

Blood

(transport mechanism) most typical connective tissue because its fluid

Muscle tissue

Responsible for most types of movement

• Chemical energy to mechanical energy

Skeletal muscle

Cardiac muscle

Smooth muscle

3 types of muscle tissue

Skeletal muscle tissue

Attached to and causes movement

Cardiac muscle tissue

Found only on the walls of the heart

Intercalated disc

Are specialized joints where cardiac cells are joined

Smooth muscle tissue

Mainly found in the walls of hollow organs

Nervous tissue

Main components : spinal cord, brain, nerves

Neurons

Respond to stimuli via processes called dendrites

Membranes

Organs of more than one type of tissue that cover and line