Post on 03-Dec-2015
description
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