Chapter Five

Tissues

Terms

Tissue Histology: the study of tissue structure Pathology: the study of cells and tissues for

diagnostic purposes

4 tissue types

Epithelial Connective Muscle Nervous

Epithelial

Avascular Has nerve supply Easily renewable Functions: protection, secretion, absorption,

excretion, sensory reception Classified by cell shape and layer

arrangement

Epithelial cell shape

Squamous-flat and thin Cuboidal-cube-shaped Columnar-tall and cylindrical Transitional-cell shape changes

Epithelial layer arrangement

Simple-single layer Stratified- two or more layers Pseudostratified-one layer that appears to

have several layers

Simple Squamous Epithelium

Structure: Single layer of flat thin cells

Function: diffusion

Location: Alveoli of lungs; capillaries; heart lining

Simple Cuboidal Epithelium

Structure: Single layer of cube-shaped cells

Function: Secretion and absorption

Location: Ducts of glands; ovarian surface

Simple Columnar Epithelium

Structure: Nonciliated: single layer of tall & narrow cells without

cilia Ciliated: single layer of tall & narrow cells with cilia

Function: Nonciliated: secretion (Goblet cells) and absorption Ciliated: movement of mucus

Location: Lines tracts with environmental openings

Pseudostratified Epithelium

Structure: 1 layer of tall & narrow cells that appears to be

more than 1--but it is not Ciliated (w/ cilia) and nonciliated (no cilia)

Function: Secretion & movement of mucus

Location: Lines airways of upper respiratory tract

Pseudostratified - ???

Stratified Squamous Epithelium

Structure: 2 or more flat, thin layers

Function: protection

Location: Esophagus, tongue, vaginal lining, epidermis

of the skin

Stratified Cuboidal Epithelium

Structure: 2 or more layers of cube-shaped cells

Function: Protection; limited secretion and absorption

Location: Sweat gland ducts

Stratified Columnar Epithelium

Structure: 2 or more layers of tall & narrow cells

Function: Protection & excretion

Location: Conjunctiva of eye; excretory ducts

Transitional Epithelium

Structure: Appearance of cells ranges from squamous to

cuboidal & columnar Function:

Allows for stretching without tearing (distensibility)

Location: Urinary bladder

Glandular Epithelium a/k/a Glands

Glands: consists of a cell or group of cells that secrete substances into ducts, onto surfaces, or into blood

2 types: Exocrine: secretion goes through a duct

Ex. Sweat, oil, saliva, pancreas Endocrine: secretion goes into blood stream

without passing through a duct Ex. Thyroid, pituitary, & pancreas

Connective Tissue

Most abundant and widely distributed tissue in the body

Consists of cells and a matrix (determines a tissues qualities; may be fluid, gel, fibers)

Has a nerve supply Highly vascular (except cartilage)

**You only need to know the MATURE connective tissues.**

Mature Connective Tissue

Areolar Adipose Dense Regular Dense Irregular Elastic Cartilage Compact Bone Blood

Areolar Connective Tissue

Location Subcutaneous layer of skin

Function Strength Support elasticity

Adipose Connective Tissue

Location Around heart, kidneys, eyes, and in yellow

bone marrow Function

Energy reserve and protection

Dense Regular Connective Tissue

Location Tendons

Muscle to bone Ligaments

Bone to bone

Function attachment

Dense Irregular Connective Tissue

Location Fascia: covers organs Periosteum: covers bones Perichondrium: covers cartilage Pericardium: covers heart

Function Provides strength

Elastic Connective Tissue

Location Lung tissue, trachea, vocal cords, bronchial

tubes Function

stretching

Cartilage

Location Nose, voice box, epiglottis, external ear, pubis

symphysis Function

Support, cushioning, rigidity, flexibility

Compact Bone

Location Bones (osteocytes)

Function Support, protection, storage

Blood

Location Blood vessels, heart

Function Transport gases, immunity, clotting

Nervous Tissue

Tissue of the nervous system Basic functioning unit = neuron

The neuron

Cell body (soma) Dendrites (many) Axon (one)

Muscle Tissue

3 types Skeletal Smooth Cardiac

Skeletal Muscle

Attaches to bones of skeleton Striated (striped) in appearance voluntary

Smooth Muscle

Makes up walls of internal organs Nonstriated Involuntary

Cardiac Muscle

Found in heart Striated with intercalated discs involuntary

Membranes

Tissues that cover or line a part of the body 3 types

Mucous Synovial Serous

Mucous Membranes

Line body cavities that open to the environment

Secrete mucus Ex: digestive system, reproductive system,

respiratory system

Synovial Membranes

Line the cavities of some joints Secrete synovial fluid Lubricates joints to prevent friction during

movement Bursae are often present here as well

bursitis

Serous Membranes Line body cavities that do not open to the environment Secrete serous fluid 2 layers:

Parietal: lines cavity wall Visceral: covers organ(s)

3 locations: Lungs = pleura

pleurisy Heart = pericardium

pericarditis Abdomen = peritoneum

peritonitis

So...

Visceral pleura=covers lungs Parietal pleura=lines thoracic cavity

Visceral pericardium=covers heart Parietal pericardium=lines pericardial cavity

Visceral peritoneum=covers abdominal organs

Parietal peritoneum=lines abdominal cavity

Pleural membranes

Interactive Review

Blood Muscle Tissue