A&P Test 2

What is a tissue?

a group of similar specialized cells that perform a specific function

What are the 4 major types of tissues?

Epithelial, Connective, Nervous, Muscular

What is epithelial tissue?

Covers external & internal surfaces; forms most glands

Functions of Epithelial Tissue

• Protection

• Forms Barrier

• Regulates the passage of O2 and CO2

• Secretion

• absorption

Subtypes of tissue are named by:

number of cell layers and shape of cells

What are the different layers of cells?

Simple and stratified

What are the shapes of cells?

squamous, cuboidal, columnar

Simple Squamous (Epithelial Tissue Subtype)

very thin so that substances easily move through

Simple Squamous forms lining of:

Lung air sacs (Alveoli) and Small Blood Vessels (capillaries)

Simple Cuboidal (Epithelial Tissue Subtype)

Kidney tubules excrete & reabsorb materials to form urine

Simple Columnar (Epithelial Tissue Subtype)

The lining of the stomach and intestine produce enzymes and absorbs digested food

Pseudostratified Columnar (Epithelial Tissue Subtype)

Mucous membranes of respiratory airways, has cilia, and secrete mucus

Stratified Squamous (Epithelial Tissue Subtype)

resistant to abrasion, grows fast for the replacement of dead cells

Where can you find Keratinized Stratified Squamous tissue?

 In the epidermis

Where can you find Nonkeratinized Stratified Squamous tissue?

In the mouth, esophagus, vagina, and anus

Stratified Cuboidal (Epithelial Tissue Subtype)

ducts of sweat and mammary glands

Transitional (Epithelial Tissue Subtype)

stratified cuboidal or columnar tissue that stretches

Where can you find Transitional Tissue?

in the urinary bladder and ureters

Connective tissue

cells scattered within the extracellular matrix

What are the 3 general cell types in connective tissue?

Osteoblast, Osteocytes, Osteoclasts

Blasts

produce matrix

Cyte

maintain matrix

Clast

Break down matrix

Functions of Connective Tissue

1. enclose and separate

2. connect

3. support movement

4. storage

5. transport

6. protection

Areolar tissue (Connective Tissue Subtype)

binds epithelia to underlying tissues

What does Areolar tissue do?

Binds skin to muscle

Adipose tissue  (Connective Tissue Subtype)

(fat)- function to insulate, cushion, and store energy

Reticular tissue (Connective Tissue Subtype)

A framework for lymphatic organs

Dense Regular tissue (Connective Tissue Subtype)

support and movement

Dense Irregular tissue  (Connective Tissue Subtype)

withstands stress

Dense elastic tissue (Connective Tissue Subtype)

allows recoil after stretch

Cartilage (Connective Tissue Subtype)

support and flexibility

What are the 3 subtypes of cartilage

• Hyaline Cartilage

• Elastic Cartilage

  • Fibrocartilage

Hyaline Cartilage

ends of bone at joints, trachea, nose

Elastic Cartilage 

external ear 

Fibrocartilage

intervertebral disks

Bone (Connective Tissue Subtype)

support, movement, protection

Blood  (Connective Tissue Subtype)

functions in transport and immunity

Nervous Tissue

functions as a communication system that senses & responds to stimuli

What is Nervous tissue composed of?

neurons and supporting cells

How does information travel quickly through nervous tissue?

within neurons as an electrical impulse and between neurons as a chemical signal

What do dendrites do?

receive information

What does the cell body (soma) do?

contains nucleus & most organelles

What does the axon hillock do?

generates signal

What does the axon do?

Conveys a signal away from the cell body

What does neuroglia do?

protect and assist neurons

Skeletal Tissue (Muscle Tissue Subtype)

• voluntary control, strained

• Cells are multinucleate & unbranched

• moves bones

Cardiac Tissue (Muscle Tissue Subtype)

• involuntary control, striated

• Cells are branched and interconnected (intercalated discs join cells via gap junctions)

• Cells contract as a unit, contracts heart

Smooth Tissue (Muscle Tissue Subtype)

• involuntary control, not straited

• Cells are fusiform and overlapping

• moves the walls of the digestive tract, small arteries, bronchioles, and the uterus

• controls pupil size, piloerection

The two types of glands formed from epithelial tissue

• Endocrine

• Exocrine

Endocrine

• Glands without ducts

• secrete hormones into the blood

Exocrine

• glands with ducts

• secrete into a surface or into an organ

Two types of Exocrine glands:

• unicellular

• multicellular

Unicellular Exocrine Gland

mucous cells & goblet cells

Multicellular Exocrine Gland

Classified by structure & mode of secretion

Simple Duct Structure

duct does not branch

Compound Duct structure

duct branches

3 modes of secretion of multicellular exocrine glands

• merocrine

• holocrine

• apocrine

Merocrine

Secrete via exocytosis

Examples of Merocrine

sweat, salivary, mammary, pancreas, and gastric glands

Holocrine

secrete via cell rupture

Examples of holocrine

sebaceous (oil) glands of skin

cell apex pinches off for secretion

Apocrine

The types of exocrine gland secretions

Serous, Mucous, and Mixed

secrete thin fluid 

Serous Glands 

mucous cells and goblet cells that secrete thick mucus with mucin glycoprotein; occur in areas of respiratory tubules and digestive track

Mucous Glands

Secrete a combination of thin fluid and mucus

Mixed Glands

Membranes formed from epithelial and connective tissue

cutaneous, mucous, serous

Where is Cutaneous found?

the skin

Where is Mucous found?

In the respiratory and digestive

Where is serous found?

Pleural, pericardial, and peritoneal

The two layers of serous membranes

Parietal layer and visceral layer

Parietal layer

lines the cavity

visceral layer

covers organ surface