physiology, digestion life on earth

Question 1

cell differentiation

Answer 1

the development of cells with specialised structure and function from unspecialised precursor cells

Question 2

intestinal cells

Answer 2

villi present, absorption takes place

Question 3

muscle cells

Answer 3

smooth and skeletal muscle

Question 4

red blood cells

Answer 4

no nucleus, biconcave disc shape

Question 5

paranecium

Answer 5

a protist found in fresh water, moving by the coordinated beating of the cilia that cover its body

Question 6

amoeba

Answer 6

a protist that lives in fresh water and moves by amoeboid movement

Question 7

epithelial cells

Answer 7

a tissue that covers the outside of the body (eg skin) or lines an organ or cavity within the body

have a basal side that closely interacts with other cells and an apical side that is exposed to the lumen

some epithelial cells are polar

Question 8

epithelial cell types

Answer 8

simple squamous, cuboidal, simple columnar, stratified squamous, pseudo stratified columnar

Question 9

simple squamous epithelium

Answer 9

thin one layer thick to allow transport of gas, flat cells, line the alveoli and blood vessels

Question 10

cuboidal epithelium

Answer 10

cube shaped, line the kidney and glands, can secrete and absorb

Question 11

simple columnar epithelium

Answer 11

line the villi of the small intestine, absorbing, many mitochondria for absorption energy, taller than they are wide

Question 12

stratified squamous epithelium

Answer 12

lots of layers of epithelial cells, linings of the mouth, top layers can be replaced from the basal layer

Question 13

pseudo stratified columnar epithelium

Answer 13

cilia, looks like there’s different layers but there’s not, found in the trachea

Question 14

occluding junctions

Answer 14

tight junctions and anchoring junctions

Question 15

communicating junctions

Answer 15

gap junctions which allow molecules to pass through from one cell to the other

Question 16

connective tissue

Answer 16

cells are sparsely distributed within an extra cellular matrix that may be solid, jelly like or even liquid

contains a web of protein fibres, collagen, elastic and reticular

Question 17

collagen

Answer 17

strong and non elastic

Question 18

elastic

Answer 18

made of elastin

Question 19

reticular

Answer 19

thin and highly branched, reticular fibres serve to join connective tissue to adjacent tissues

Question 20

blood

Answer 20

liquid plasma contains platelets, red and white blood cells

Question 21

types of connective tissue

Answer 21

loose, fibrous, bone, adipose and cartilage

Question 22

loose connective tissue

Answer 22

3 fibre types (collagen, elastic and reticular)

fibroblasts - cells that secrete both matrix and protein

macrophage cells

attaches skin to tissues

forms mesenteries that hold the internal organs in place

Question 23

adipose connective tissue

Answer 23

stores fat - energy storage

hormones regulate the levels

found surrounding tissue and organs and gives protection to blood vessels

marine mammals adipose tissue is called blubber and this stores energy, insulates, gives buoyancy and protection

Question 24

fibrous connective tissue

Answer 24

contains collagen (a glycoprotein)

found in tendons and ligaments
tendons attach muscles to bones and ligaments link joints

fibroblasts synthesise extra cellular mixture and collagen

Question 25

cartilage

Answer 25

collagen fibres in rubbery matrix of chondroitin sulphate (a protein carbohydrate complex)

secreted by cells called chondrocytes

resists compression (shock absorbing)

Question 26

bone

Answer 26

a mineralised matrix of collagen fibres impregnated by salts

secreted by cells called osteoblasts (these become osteocytes in fully formed bone)

more rigid that cartilage but not brittle

each bone has a central canal for nerves and blood vessels, bone marrow is found here, red bone marrow is where bloods made and yellow contains mostly fat

Question 27

compact bone

Answer 27

gives strength and is found on the outer surface of bones

Question 28

spongy bone

Answer 28

more delicate and found in the centre and at the end of bones