lec 7 skeletons, muscle and movement

Question 1

what are 3 challenges faced by humans (multicellular) that are not faced by bacteria/ameobas

Answer 1

1. after reproduction, multicellular organisms must undergo development

2.must have transport system for sending materials to other cells

3. cells must coordinate+communicate activities w/ other cells

Question 2

t/f cells in multicellular organisms are specialized

Answer 2

true

Question 3

explain the difference between a single-celled organism and multicellular organism in terms of cell functions.

Answer 3

single-celled: all fxns of life occur in single cell

multicellular: cells specialized to perform one fxn

Question 4

t/f specialized cells can survive as individuals

Answer 4

false

Question 5

for multicellular organisms, what is an advantage of having specialized cells?

Answer 5

more control over env. where cells reside

Question 6

what are organs?

Answer 6

collection of specialized cells that perform shared fxn.

Question 7

what are organs made of?

Answer 7

tissue

Question 8

what is tissue made of?

Answer 8

specific cell types

Question 9

what are the 4 basic tissue types in animals?

Answer 9

epithelial
connective
muscle
nerve

Question 10

what type of cell is epithelial tissue made of? what are 2 fxns of them?

Answer 10

epithelial cells

-form the surface of animals
-line body cavities

Question 11

what type of cell is connective tissue made of? what is their fxn?

Answer 11

connective cells
-connect+support other cells

Question 12

what type of cell is muscle tissue made of? what is their fxn?

Answer 12

muscle cells

-contract to give animals ability to move

Question 13

what type of cell is nerve tissue made of? what is their fxn?

Answer 13

nerve cells

-transmit nerve signals thru body

Question 14

what is the purpose of a skeleton?

Answer 14

-supports body
-gives it shape

Question 15

what is a major component in the skeleton?

Answer 15

bone tissue

Question 16

what is bone tissue made of?

Answer 16

connective cells surrounded by calcium+collegen matrix

Question 17

what is the purpose of calcium minerals in bones?

Answer 17

provide rigidity+strength

Question 18

what is the purpose of collegen in bones?

Answer 18

provides resistance to tension
reduces brittleness

Question 19

what produces collegen in the bone?

Answer 19

connective cells called osteocytes (bone cell)

Question 20

what is the purpose of marrow in the bone?

Answer 20

source of blood cells + other important cells (osteocytes)

Question 21

what is bone remodelling? what are 2 reasons it occurs?

Answer 21

bone changes in thickness

response to: exercise, hormones (estrogen)

Question 22

how much calcium do adults require for remodelling?

Answer 22

large amt

1000mg/day

Question 23

what is cartilage? what is it’s main fxn?

Answer 23

-cells that prod. collegen
-support+supplement bone

Question 24

t/f cartilage is more flexible than bone

Answer 24

true

Question 25

where are 3 places in the body where cartilage is found?

Answer 25

nose ears rib cage

Question 26

what are ligiments? what is the main fxn?

Answer 26

-flexible sheets of tissue -join bone to bone

Question 27

what are hydrostatic skeletons?

Answer 27

use fluid pressure to become rigid

Question 28

where is hydrostatic skeleton used in humans? what other animals use it?

Answer 28

-tounge -soft bodied animals (worms, jellyfish)

Question 29

what part of our skeleton allows us to move?

Answer 29

joints-bends and breaks in the skeleton

Question 30

what do tendons do?

Answer 30

connect bone to muscle

Question 31

what do cartliage discs do?

Answer 31

shock absorbers

Question 32

what are synovial sacs?

Answer 32

provide lubrication to joints

Question 33

what is Osteoarthritis?

Answer 33

progressive degenerative condition that wears down cartilage

Question 34

give example of ligiment injury, and why it occurs

Answer 34

ACL tear- football player quickly changing direction while running torsion on ligaments in knee, under high pressure, ligament will snap

Question 35

what is an ACL tear?

Answer 35

femur (thigh) twists one way and tibia/fibula (calve) twist another way -Results in a torn ligament

Question 36

what are the 5 components of muscle tissue?

Answer 36

muscle fibers myofibrils (iniv. cylinders) sarcomere (contractile unit) actin myosin

Question 37

explain how sacomeres work when contracting a muscle

Answer 37

-myosin heads attatch/detatch ('walk') along actin filaments -this pulls z discs (ends of sarcomere) closer together -sarcomere and therefore, muscle gets shorter

Question 38

what happens to sarcomeres when a muscle relaxes?

Answer 38

myosic completely released from actin, sarcomere elongates again