Tissue structure

Question 1

what are the three germ cell layers ?

Answer 1

• endoderm (inner)
• mesoderm (middle)
• ectoderm (outer)

Question 2

which tissue develops from the mesoderm ?

Answer 2

• muscle tissue
• connective tissue

Question 3

which tissue is formed form all three germ cell layers ?

Answer 3

• epithelial tissue

Question 4

what tissue develops from ectoderm layer ?

Answer 4

• skin tissue
• nervous tissue

Question 5

what tissue develops from ectoderm layer ?

Answer 5

• skin tissue
• nervous tissue

Question 6

what are 3 main function of epithelial tissue ?

Answer 6

• protective layer
  -secrete substances
• absorption of substances

Question 7

Structure of epithelial tissue

Answer 7

• basement membrane
• apical surfaces
• blood vessels
• nucleus

Question 8

Structure of epithelial tissue

Answer 8

• basement membrane
• apical surfaces
• blood vessels
• nucleus

Question 9

what is the basement membrane made of ?

Answer 9

• basal lamina (selectively permeable) and reticular lamina

Question 10

what is apical surface ?

Answer 10

• top
• lined with microvilli to inc surface area for absorption eg. small intestine
• cilia to waft mucus in one direction eg. in trachea

Question 11

what is the function of basement membrane ?

Answer 11

• attaches epithelium to connective tissue

Question 12

what are the 3 types of layers of epithelia tissue ?

Answer 12

• simple
• stratified
• pseudostratified

Question 13

what is simple epithelia ?

Answer 13

• one layer

Question 14

what is stratified epithelia?

Answer 14

• more than one layer, only bottom layer in contact with basement membrane (like bricks)

Question 15

what is pseudostratified epithelia ?

Answer 15

• appear to be arranged in layers but only one layer

Question 16

what are the 4 different shapes of epithelia cells ?

Answer 16

• squamous
• columnar
• cuboidal
• transitional

Question 17

what shape are squamous epithelial cells?

Answer 17

• flat like paving stones

Question 18

what shape are columnar epithelial cells ?

Answer 18

• taller than they are wider

Question 19

what shape are cuboidal epithelial cells ?

Answer 19

• similar height, depth and width
• cube like

Question 20

what are transitional epithelial cells ?

Answer 20

• layers which change shape when they are stretched

Question 21

function of simple squamous cells ?

Answer 21

• lines blood vessels
• lines alveoli in lungs

Question 22

function of simple cuboidal epithelial cells ?

Answer 22

• lines kidney tubules
• reabsorbs+ secretes water and small molecules

Question 23

function of simple columnar cells ?

Answer 23

• lines digestive organs eg. small intestine
• can have cillia + goblet cells that secretes mucus

Question 24

function of stratified squamous epithelium ?

Answer 24

• protects outer layer of skin from infection etc

Question 25

function of stratified cuboidal epithelium?

Answer 25

- lines ducts and sweat glands

Question 26

function of stratified columnar epithelium ?

Answer 26

- lines mammary glands + epididymus ( sperm )

Question 27

what are the three types of junctions on the surface on epithelial cells ?

Answer 27

- adhesion junctions - tight junctions - gap junctions

Question 28

what are gap junctions ?

Answer 28

- spot like junctions allowing small molecules to pass

Question 29

what are tight junctions ?

Answer 29

- adjacent apical plasma membranes fuse, preventing substances from passing

Question 30

what are adhesion junctions ?

Answer 30

- desmosomes create adhesion's involving cadherin proteins

Question 31

what is an endocrine gland ?

Answer 31

- secrete into empty tissue spaces then goes to blood

Question 32

what is an exocrine gland ?

Answer 32

- secretes products into ducts

Question 33

what are the 3 secretory mechanisms for exocrine glands ?

Answer 33

- merocrine - apocrine - holocrine

Question 34

what is merocrine secretion ?

Answer 34

- secretion passes via exocytosis - no damage to plasma membrane - eg. salivary gland

Question 35

what is apocrine secretion ?

Answer 35

-apical end pinched off to release product into duct - eg. mammary gland

Question 36

what is holocrine secretion ?

Answer 36

- death of cells releases its contents - eg. sebaceous gland

Question 37

what does an epithelial membrane contain ?

Answer 37

- contains an epithelium and an underlying connective tissue

Question 38

what are the 4 types of epithelial membranes ?

Answer 38

- mucous (small intestine, nose) - cutaneous (skin) - synovial (lines joints, secretes synovial fluid ) - serous (lines body cavities , secrete serous fluid )