Different Elementary Tissue in Human Body

Elementary tissue

Different Elementary Tissue in Human Body

Bundles of cells prepare tissue which provide shape of organ and have specialized function.

Classification of tissue.

Tissues divided into four type:

Epithelial tissue

Epithelial tissue is arranged in single and multiple layers of cells. Epithelial tissues are lining and cover throughout the body. Epithelial tissue forms the outer covering of the skin and it also form the inner lining of blood vessels, body cavity, ducts, respiratory, digestive, urinary and reproductive systems. Some epithelial tissues have glandular like structure that makes up thee secretion portion of glands such as sweat gland, adrenal gland and thyroid gland. 

     

Classification of epithelial cells

• Simple epithelial tissue 
• Stratified epithelial

Simple epithelial tissue: structurally and functionally simple epithelial tissue further classified into four types:

• a) Simple squamous epithelium
• b) Simple cuboidal epithelium
• c) Simple columnar epithelium (nonciliated and ciliated)

•    Nonciliated simple columnar epithelium
•    Ciliated simple columnar epithelium

• d) Pseudostratified columnar epithelium

•    Pseudostratified nonciliated columnar epithelium
•    Pseudostratified ciliated columnar epithelium

Stratified epithelial

Stratified squamous epithelium 

• Keratinized stratified squamous epithelium 
• Nonkeratinized stratified squamous epithelium

Stratified cuboidal epithelium.

Stratified columnar epithelium.

Transitional epithelium.

Glandular epithelium

Endocrine glands.

Exocrine glands.

 

Simple squamous epithelium

Simple squamous epithelium composed with multiple flat cells and make Single layer. Viewed from apical surface of Stratified epithelial resembles like a tiled floor. Nucleus present in central that is oval shaped. 

Location: lining on the heart, blood vessels and lymphatic vessels.

Functions

1. Present at the site of filtration in kidney.
2. Present at diffusion site such as lungs and blood vessels.
3. Present in serous membrane.

Simple cuboidal epithelium

Simple cuboidal epithelium is composed with single layer of cube shaped cells. Nucleus is centrally located.

Location

 
Surface Lining on ovary, kidney tubules. Make up secretion of some glands, such as thyroid gland.

Function

 
Secretion and absorption.

Nonciliated simple columnar epithelium

Nonciliated simple columnar epithelium is composed with column shape, single layer and nonciliated cells. 

Location  

Lining on gastrointestinal tract and gallbladder.

Functions

 
Secretion and absorption.
Secreted mucus lubricating lining of respiratory, digestive and reproductive system.

Ciliated simple columnar epithelium

Ciliated simple columnar epithelium is composed with column shape, single layer and ciliated cells. Oval shape nuclei present near base of cells.

Location

 
Lining of fallopian tube (uterine), uterus, bronchioles of respiratory tract. 

Functions

 
Cilia help moving mucus and foreign particles toward throat.
Sneezing and coughing speed up movement of cilia and mucus.

Pseudostratified columnar epithelium

Several layers of column cells shaped are composed pseudostratified columnar epithelium. Multiple nuclei are present at various levels. All cells are attached to basement membrane.

Pseudostratified ciliated columnar epithelium

Pseudostratified ciliated columnar epithelium contains goblet cell which secrets mucus. These cells are bear cilia.  

Pseudostratified nonciliated columnar epithelium

Pseudostratified nonciliated columnar epithelium contains cells without cilia and lacks of secrets mucus.

Location 

 
Pseudostratified ciliated columnar epithelium lines of upper respiratory tract.
Pseudostratified nonciliated columnar epithelium lines of larger ducts of glands.

Function

 
Pseudostratified ciliated columnar epithelium secretes mucus that traps foreign particles and sweep away mucus for elimination from body.
Pseudostratified nonciliated columnar epithelium functions in protection and absorption.

Stratified squamous epithelium

Two or more layer of cells.
Few cells in apical layer and several layers are deep to squamous.

Keratinized stratified squamous epithelium

Keratinized stratified squamous epithelium develops tough layer of keratin in both apical and deep layer. Keratin protein is helps protect skin from heat, chemicals and microbes.

Nonkeratinized stratified squamous epithelium

Nonkeratinized stratified squamous epithelium does not contain huge amount of keratin protein in apical and deep layers.

Location

 
Nonkeratinized stratified squamous epithelium are lining of mouth, esophagus, epiglottis and vagina.
Keratinized stratified squamous epithelium are forms superficial layer of skin.

Function

 
Protect against water loss, ultraviolet radiation, abrasion and foreign invasion. 

Stratified cuboidal epithelium

Two or more layer of cells.
Cells in apical layer are cube shaped.

Location

 
Sweat gland.
Esophagus.
Male urethra.

Function

 
Protection.
Secretion.
Absorption. 

Stratified columnar epithelium

Basal layer consist irregularly shaped cells.
Apical layer has column shaped cells.

Location

 
Urethra.
Esophageal glands.
Conjunctiva of eyes.

Function

 
Protection.
Secretion.  

Transitional epithelium

Looks similar as stratified cuboidal epithelium
Apical layer cells are large and rounded.
Tissue is stretched, cells become flatter. 

Location

 
Urinary bladder.
Urethra.
Ureters.

Function

 
Allow urinary organ to stretch. 

Glandular epithelium

Endocrine glands
Secretions (hormones) directly enter into bloodstream, without though any duct like structure.

Location 

 
Pituitary gland.
Pineal gland.
Adrenal gland.
Thymus gland.

Function

 
Hormones maintain various physiological activities.
Hormones regulate many metabolic activities.

Exocrine gland

Secretory products released into ducts

Location 

Earwax gland.
Sweat gland.

Oil gland

Function

 
Produce sweat to regulate body temperature.
Produce oil, earwax, saliva and digestive enzymes.  

Connective tissue

Connective tissue
 

Connective tissue support, protect and bind together other tissue. Connective tissue is the diversity of cells which containing large quantity of extracellular matrix. 

Classification of connective tissue 

A) Loose connective tissue
B) Dense connective tissue
C) Cartilage
D) Bone tissue
 

Loose connective tissue

Fibers are loosely arranged between the cells in loose connective tissue. 

Loose connective tissues are three types:

Areolar connective tissue 

It consists of fibers (collagen, elastic and reticular) and several types of cells (Fibroblasts, macrophages, adipocytes, mast cell, plasma cell and other kinds of blood cells). Areolar connective tissues are one of the most distributed connective tissue.

Composition:  

Fibers: 

Collagen, elastic and reticular.

Cells:  

Fibroblasts, macrophages, adipocytes, mast cell, plasma cell and other kinds of blood cells.

Location: 

Subcutaneous deep to skin, around blood vessels, nerve.

Function: 

Areolar connective tissue provide support, elasticity and strength.

Adipose connective tissue

Adipose tissue composed with fibroblast cells (also known as adipocytes cells) that cells are specialized for storage for fats (triglycerides).

Composition

 
Cells: 

Adipocytes or fibroblast 

Location:  

Around the heart kidneys, behind eyeball.

Function 

Protects and supports body organs.

Reduces heat loss through skin.

     In new born, Generate heat to maintain normal body temperature. 

Reticular connective tissue

Composition: 

Fiber: 

Reticular fibers.

Cells: 

Reticular cells 

Location: 

Spleen, lymph nodes, red bone marrow.

Function: 

Help to binds smooth muscle tissue (SMT) cells.

Help to form stroma (shape) organ.  

Help to remove aged blood cells in spleen.

Dense connective tissue

The fibers arranged between the cells are thick and closely packed. 

Dense connective tissues are three types:

Dense regular connective tissue

Composition

 
Fibers:

Mainly collagen fibers are regularly arranged in bundles.  Fibroblast present in rows between bundles.  

Matrix: 

White and shiny.

Location: 

Form tendons (binds muscle to bone), and some ligament (bind bone to bone).

Function: 

Provide strong attachment between many structure such as ligaments and tendons.

Dense irregular connective tissue

Composition: 

 
Fibers: 

Collagen fibers are irregularly arranged in bundles with few fibroblast.

Location: 

Fibrous pericardium of heart, heart valve, joint capsule.

Function

 
Help to pulling strength in many directions.  

  

Elastic connective tissue

Composition: 

Elastic fibers are arranged with fibroblast.

Location:  

Wall of elastic arteries, lung tissue, bronchial tube.

Function:  

Allow stretching of various organs for example; lung- inhale or exhale. 

After stretching recoil to original shape of organ. 

     

Cartilage

Hyaline cartilage

Composition: 

Resilient gel,  fine collagen fibers.

 
Location: 

Nose, trachea, at the end of bones and fetal skeleton etc.

Function: 

Provide surface for support and flexibility. 

It help for movement at joint, hyaline cartilage present at both end of bone, it reduce the fraction.

Fibrocartilage

Composition: 

Thick collagen fibers and perichondrium absent 

Location: 

Cartilage pad of knee, intervertebral disc.

Function: 

Joining and support structures together.

Make it strongest type of cartilage.

Elastic cartilage

Composition: 

Elastic fibers and perichondrium present.

Location: 

External ear, epiglottis.

Function:

 
Help to maintain shape of certain structure of organs of body.

Bone tissue

Liquid connective tissue 

1. Blood tissue 
2. Lymph 

Muscular tissue

Muscular tissues consist of muscle fibers that can use ATP to generate force. Muscular tissues generate heat, produce body movement and maintain body posture. 

Muscular tissues are classified into 3 types:

Skeletal muscle tissue

Skeletal muscle tissues consist of long, cylindrical and striated fibers. Skeletal muscles are voluntary nature because it contract and relax by conscious control.

Location

 
Skeletal muscle tissues are attached to bone by tendons.

Functions

 
Heat production.
Protection.
Body posture.
Body movement. 

Cardiac muscle tissue

Cardiac muscles are consists with branched striated fibers and a centrally located nucleus. Cardiac muscle tissues are involuntary nature because it contract and relax by unconscious control.  

Location

 
Heart wall.

Function 

 
Pump blood to all body parts.

Smooth muscle tissue 

Smooth muscle tissues are consist nonstriated fibers. These fibers are consists with small spindle shaped cells and containing single centrally located nucleus. Smooth muscle tissues are usually involuntary.  

Location 

 
Walls of hollow internal structures such as gall bladder, intestine, stomach, uterus, airway to lungs and blood vessels.

Function

 
Contraction Movement of intestine, stomach, uterus, airway to lungs and blood vessels.

Nervous tissue

Nervous tissues contain neurons and neuroglia. Neurons consist of cell body. Neuroglia do not conduct nerve impulses.

Location

 
Nervous tissue.

Function

 
Converts stimuli into impulses.