Histology – study of tissuesPathology – study of abnormalities of tissueTissues - group of cells perform related functions and are similar in structure- Cell similar in structure and function- Has 4 fundamental types

CHARAC./TYPES EPITHELIAL CONNECTIVE MUSCULAR NERVOUSFUNCTION Covering

ProtectionAbsorptionSecretionFiltration

- Most abundant primary tissue

- Support- Connects and binds body

parts together- Protect organs- Framework for

movement of muscles- Insulator- Transport substances

- for contraction- movement- termed as fibers

- control- exhibits irritability- conductivity

STRUCTURE

- Exhibits cellularity- Cells fit together to form

compact cells arranged to continuous sheet

- Avascular - Most are capable of regeneration

- Nourished by diffusion(fr. capillaries)

- Membrane: Apical/Free surface

(smooth or may have modification)

Lower surface:- Rests on basement

membrane

- Extracellular matrix Packing material Bear weight Withstand abrasion Absorb large amount

of water- Highly vascularized

- Extensibility- Elastic- Contractility- Highly vascularized and

innervated- cellular

Neurons are branching and non-irritable1. Multipolar Neuron

- have several dendrites coming off the cell body and one axon. Most neurons in the brain and spinal cord are multipolar.2. Bipolar Neuron

- have one dendrite and one axon. They are found in the retina of the eye, inner ear and the olfactory area of the nose.3. Unipolar Neuron

- have only one process extending from the cell body, which then branches into a central branch that functions as an axon and a peripheral branch functions as dendrite . Most sensory neurons are Unipolar.

LOCATION Brain, spinal cord, nervesNO. OF CELL LAYERS 1. simple

2. stratifiedNeurons/nerve cell- react to stimuli/Neuroglia- support cells, insulate and protect neurons

TYPES 1.membranous2.glandular- hormones (exocrine/endocrine)

1.loose-fibroblasts - scattered2.dense – compact3.Cartilage- firm pliable/ tensile strengthchondroblasts/avascular4.bone-osteoblasts - hardest5. blood/vascular -

1. skeletal2.cardiac3.smooth muscle

CLASSIFICATIONS 1. squamous - flat/polyhedral mostly/diffusion/protect lining2. cuboidal – as tall as wide/kidney/ secretion and absorption3. columnar- taller than wide/digestive/absorb4. transitional

2 myofilaments1.Actin2.Myosin

I. Classification of epithelial tissues according to type of cellSIMPLE EPITHELEAL TISSUE

Simple squamous epithelium- Allows passage of materials by

diffusion and filtration- Secretes lubricating material in

serosae

Simple cuboidal epithelium- Secretion and absorption

Simple columnar epithelium- Absorption s- Secretion- Ciliary action

Pseudo stratified ciliated columnar epithelium- Secretion- Propulsion of mucus by

ciliary actionLocation - Air sacs of lungs

- Wall of capillaries (endothelium)- Serious membrane or serosae

- Walls of kidney tubules, glands and ducts

- Surface of ovary

- Lines entire digestive tract- From stomach to anus- Gall bladder

- Respiratory tract- Male’s sperm carrying ducts- Ducts of large glands- trachea

Structure - cells fit closely- like floor tiles- disk shape central nuclei- sparse cytoplasm

- as tall as wide- round to oval central nuclei

- taller than wide- contains goblet cells- round oval nuclei- some cells bear cilia

- not stratified- ciliated

Layers of cell 1 1- rest on basement membrane

1 1 – touch basement membraneNot all touches apex

II. Stratified Epithelial TissueStratified squamous Stratified squamous

keratinizedStratified squamous non keratinized

Stratified cuboidal Stratified columnar

Function - Protection to underlying tissues in areas subjected to abrasion

Water resistant moist protection Protection and secretiom

Location - cells in apical layer- non keratinized

linings- mouth, esophagus,

vagina

Epidermis of skin Lines mouth, esophagus, and vagina

- cells close to basement membrane

- ducts of large glands

- cells close to basement membrane

- ducts of large glands- urethra

Structure - Thick membrane- Basal cells are

cuboidal or columnar,Keratin and dead, active in mitosis

- Metabolically active- Surface cells are

flattened/ squamous

- Cuboidal- Superficial cells

elongated- columnar

Layers of cells - several 2- apical cells are

cuboidal

- basal cells varies in size and shape

- apical cells columnar

III. Transitional cells- highly modified- stratified type that change in shape- forms lining of urinary bladder, ureters and part of urethra- cells

A. basal :cuboidal/columnarB. Apical: varied shape

- when organ is not stretched it is dome like- when stretched it is thin and = large squamous

MUSCULAR TISSUES` Skeletal Cardiac SmoothFunction Locomotion

Facial expressionRapid conduction of electrical impulse across heart

Propels substances

Structure - striated- voluntary- long cylindrical units- multinucleated – along periphery of ^- unbranching

- striated- involuntary- small branching cells- mononucleited- intercalated disks – gap junctions

- non striated- involuntary- spindle/ fusiform shaped cells/nucleus- contracts slowest

location Attached to bones Walls of heart Walls of hallow internal structuresBlood vesselsAirway to lungsVisceral organs

- Highly cellular, well-vascularized tissues- Function is to produce body mvmts- Muscle cells are composed of myofilaments- 2 types of myofilaments: Work together to bring about contraction of muscles

WHITE ADIPOSE CONNECTIVE TISSUE

MAMMAL FIBROCARTILAGE (intervertebral disk)

HUMAN BONE (C-Sec) LOOSE CONNECTIVE TISSUE (Adipose)

GIANT MULTIPOLAR NEURONS SMEAR

HYALINE CARTILAGE ( Trachea) ELASTIC CARTILAGE (Epiglottis)

NERVE CELL (Multipolar)

SMOOTH MUSCLE MAMMAL CARDIAC MUSCLE BONE (C-Sec) ELASTIC CARTILAGE

STRIATED MUSCLE (L-Sec) BONE (L-Sec) LOOSE CONNECTIVE TISSUE (Areolar)

Connective tissues in the book