Module 6

Question 1

organism hierarchy

Answer 1

cells
tissue
organs
body systems
organisms

Question 2

cell junctions

Answer 2

type of membrane protein facilitating cell to cell attachments

Question 3

endothelial cells

Answer 3

cells that line the inside of blood vessels

protective barrier

Question 4

epithelial cells

Answer 4

cells that line the cavities and surfaces of organs

rest on basement membrane (specialized extracellular matrix that separates them from connective tissue)

Question 5

types of junction proteins

Answer 5

tight junctions
adherens junctions
desmosomes

all part of junctional complex

Question 6

tight junctions

Answer 6

structurally and functionally dived the plasma membrane into two domains (apical surface - top, basal surface - bottom)

phospholipids cant move across tight junctions

proteins in tight junction connect to cell cytoskeleton

regulate paracellular transport

Question 7

adherens junctions

Answer 7

use transmembrane receptor proteins (cadherins) that bind to other cadherins on neighbouring cells

overlap of cadherins is proportional to bond strength

found in neural synapses and cardiac muscles

Question 8

desmosomes

Answer 8

provide structural integrity to cell

function like snaps to eachother

link cytoskeleton of cell

found in cells exposes to physical stress (skin and cardiac muscles)

Question 9

gap junctions

Answer 9

built of two halves, connect to cross intercellular gap

cells connected by gap junctions use channel gating to move ions sugars nucleotides and other molecules

important in cardiac muscles contraction

Question 10

extracellular matrix (ECM)

Answer 10

network of molecules that fill space between cells

proteins formed by cells to provide external structure and support of the cells and tissues of the body

without tissues cant hold together properly

Question 11

basement membrane

Answer 11

special matrix below epithelial cells and on outside of tissues

consist of special sheet of collagen and other proteins that is a structure foundation and barrier for epithelial cells and a network to stabilize tissue

Question 12

types of ECM proteins

Answer 12

collagen
fibronectin
elastin
laminins
proteoglycans

Question 13

collagen

Answer 13

main structural protein of ECM

exists as triple helix which crosslink to form fibrils which form collagen fibers

multiple types specific to different tissues

Question 14

fibronectin

Answer 14

glycoproteins that connect cells to collagen matrices, cell adhesion

expressed as dimers and bind to integrins

interactions with cytoskeleton cause dimers to straighten and associate with other fibronectins resulting in fibrils at the cell surface

Question 15

elastin

Answer 15

give elasticity to tissues allowing them to return back to original shape after being distorted by external force

have hydrophobic and hydrophilic regions allowing them to return

Question 16

laminins

Answer 16

provide adhesive substrate for cells and strengthen ECM

forms triple helical coils, forms cross like structure w multiple binding sites for ECM proteins

each end of T forms a connection with neighbouring molecule

can handle tension in multiple directions

Question 17

proteoglycans

Answer 17

hydrated gel resistant to compressive forces

important for cartilage in joints

consist of protein polypeptide core and attached sugar residues

Question 18

types of tissues

Answer 18

epithelial
nervous
muscle
connective

Question 19

epithelial tissues + types

Answer 19

protects inside of body from environment

there is specialization
- skin epithelial tissues
- gland epithelial tissue
- digestive tract epithelial tissue

Question 20

gland epithelial tissue

Answer 20

epithelial cells specialize to form glands

cells organize forming pocket like structures where they release secretions via ducts

exocrine glands
- release secretion outside body

endocrine glands (dont have ducts)
- release secretions internally into bloodstream

Question 21

digestive tract epithelial tissue

Answer 21

line entire digestive system

different types functions
- produce and excrete glycosylated proteins (exocytosis), mucus protecting cells
- form digestive glands that produce and release digestive enzymes and hydrochloric acid (exocrine gland)
- facilitate transportation, nutrients transport across cells to enter body

Question 22

nervous tissues

Answer 22

use electrical communication to carry information over long distances

composed of nerve cells and glial cells

Question 23

mechanisms of nervous tissues

Answer 23

differences in ion concentration across membrane creates electrical potential

changes in electrical potential are used as a signal allowing for rapid communication

Question 24

muscle tissue

Answer 24

convert chemical and electrical signals into mechanical movement

types of muscles
- skeletal (moves skeleton)
- smooth (lines digestive system, larger blood vessels and anywhere requiring contractile activity)
- cardiac (found in heart, pump blood)

Question 25

connective tissues

Answer 25

fill space between cells to provide mechanical strength and cushioning for protection make up the ECM different types with different characteristics - lungs, ECM rich in elastin - bone, ECM rigid common cell type fibroblast

Question 26

organs

Answer 26

when two or more tissue types come together to form a function

Question 27

stomach

Answer 27

epithelial tissues line it, protect from digestive proteins and acids outside lined with smooth muscles cells to contract to mix contents and propel them into the intestine nervous tissues control and coordinate contractions and some gland secretion connective tissue, hold everything together and provide shape

Question 28

body systems

Answer 28

formed when two or more organs come together with a coordinated purpose (11 total)

Question 29

cardiovascular system

Answer 29

heart (pump), blood vessels (routes of transport) and blood (carries nutrients to cells and removes their wastes)

Question 30

homeostasis

Answer 30

ability of a cell of organism to regulate and maintain is internal environment regardless of the influences of the external environment

Question 31

homeostatic control system

Answer 31

sensor - detects environmental variable integrator - compares the variable to its set point effector - if value is different from set point effector initiates changes to restore set point can be intrinsically or extrinsically controlled

Question 32

body temperature control

Answer 32

body set point 37 C sensor - temperature monitoring nerve cells, always sensing and sending information to thermoregulation center integrator - thermoregulation checks information and compares it to set point, if different signals effector effector - blood vessels in the skin contract (minimize heat loss) and skeletal muscles rapidly contract, shivering (generate heat)

Question 33

intrinsically controlled

Answer 33

sensor, integrator and effect all located within a tissue exercising skeletal muscle that needs oxygen to produce ATP - oxygen drops, sensed by blood vessels, muscles dilate to increase oxygen

Question 34

extrinsically controlled

Answer 34

regulatory mechanisms outside of the tissue or organ

Question 35

negative feedback loop

Answer 35

effect initiate response in opposite direction thus restoring set point once reached effector actions stop

Question 36

positive feedback loop

Answer 36

effector amplify initial signal not homeostatic breastfeeding stimulates more milk production