epithelial tissue

Question 1

define tissues

Answer 1

Groups of cells (can be different) with a common role

Question 2

whats the 4 basic types of tissue

Answer 2

Epithelial
– covers and lines body surface and cavities, they serve to protect organs

Connective
– protects & supports

Muscular (very specific type of tissue)
– generates physical force for movement

Nervous (is found in nervous system)
– coordinates body activities – by generating and transferring info through nerve impulses. They also respond to chemical stimuli

Question 3

what are the common features of epithelial tissue

Answer 3

Cells close together – continuous sheets, so provides protection and separation of organs and body cavities

Cover surfaces & line cavities - always a free surface associated with epithelial tissue = Apical surface = uppermost surface, eg may be the covering of the outermost layer of the skin

Have a Basement membrane of connective tissue

No blood vessels – so referred to as avascular

Have a nerve supply – so highly innervation

High capacity for cell division. Due to where are in body and their lining nature

Question 4

what are the 2 epithelial cell categories

Answer 4

simple and stratified

Question 5

whats Simple Epithelium

Answer 5

1 layer of cells

Question 6

whats stratified epithelium

Answer 6

more than 1 layer of cells

Question 7

what are the cell shapes of simple and stratified epithelium

Answer 7

squamous – flat cell type

cuboidal – shape that name suggests

columnar – shape that name suggests

transitional (able to change shape)

Question 8

explain squamous simple epithelium

Answer 8

Squamous= single layer of flat cells. – polygonal appearance (many sides) when viewed from above

Important role for filtration (kidneys) or diffusion (lungs & capillaries)

They turn over and replace themselves every few weeks

Question 9

squamous simple epithelium are called endothelium when….

Answer 9

Called endothelium (type of simple epithelium that lines the interior surface of blood vessels and lymphatics) when lining heart, blood and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and rest of vessel wall

Question 10

squamous simple epithelium are called mesothelium when …

Answer 10

Called mesothelium ( membrane composed of simple squamous epithelial cells) when in serous (watery) membranes – line a body cavity that does not open to the exterior e.g. pleura, pericardium and peritoneum (sac that surrounds the heart).

They produce a lubrication fluid that’s released between layers providing slippery non adhesive and protective surface facilitating movement and reduce friction

Question 11

what does the connective tissue form

Answer 11

forms the basement membrane and helps to anchor

Question 12

the many sides to a simple squamous epithelial cell is referred to what

Answer 12

polygon

Question 13

give ex of where find simple squamous epithelial

Answer 13

peritoneum
small intestine

Question 14

describe simple cuboidal epithelium

Answer 14

cube shaped cells, rounded nuclei

single layer

Found on surface of many diff organs

In pancreases and overies

Provide protection

And pump material in and out of lumen

Question 15

describe simple columnar epithelium

Answer 15

May be ciliated or non-ciliated

Elongated shape

found in Stomach, small intestine and large intestine will be lined with this including uterus as well

Question 16

where is non ciliated simple columnar epithelial cells found

Answer 16

found in GI tract, and may be brush bordered as opposed to ciliated

Question 17

where is ciliated simple columnar epithelial cells found

Answer 17

Ciliated are involved with movement of mucus and other substances via cilia found there, particularly in the upper respiratory tract , fallopian tubes and uterus and centeral part of spinal cord

Transports egg from follicle its moved towards uterus by cilia

Question 18

describe pseudostratified columnar

Answer 18

appears stratified: nuclei at various levels

Although only a single layer of cells it suggests there is a stratified structure due to cell nuclei position.

It rarely occurs a squamous or cuboidal, its usually considered synonymous with term pseudo stratified columnar

Question 19

explain stratified squamous epithelial

Answer 19

Stratified = multiple layers

Apical (top) layer of cells are flat

Deep layers vary from cuboidal to columnar

Cells in the basal layer divide and move upward toward apical surface –to help repair surface wear & tear

Found mostly in organs and areas of body where lots of physical wear and tear, removing the top layers of the cell

Found in skin, mouth, vagina, and oesophagus

Question 20

describe Stratified Cuboidal Epithelium

Answer 20

Rare but Found in gland like sweat gland, salivary glands

Lumen of the duct as associated with glands

Question 21

describe Stratified Columnar Epithelium

Answer 21

rare

also associated with ducts – like esophagus, parts of the eye, and male urethra, salivary glands

Function is secretion and protection

Cell shape change in the layers

Question 22

describe Transitional Epithelium

Answer 22

variable in appearance — cells can stretch

Gets its name from fact that its variable in appearance as stretches and expands

Its found in organs or vessels that expand and contract like urinary bladder the ureters, and gland ducts of the prostate

Appearance of cells change in appearance as( bladder) expands and stretches

Question 23

describe glandular epithelium (endocrine)

Answer 23

Endocrine glands = collection of glands that secrete hormones directly into the circulatory system, so these will be deposited into the blood so help blood vessels very close to them

Ex, thyroid gland

Question 24

describe glandular epithelium (exocrine)

Answer 24

Ex, of exocrine - sweat gland in skin produce sweat that’s deposited onto surface of the skin