chapter 39: locomotion and support systems

Question 1

how does the diversity of skeletons make for good support systems

Answer 1

Rigidity, protection, surfaces for muscle attachment

Question 2

what is a hydrostatic skeleton

Answer 2

-Fluid-fill gastrovascular cavity or coelom
-utilizes fluid pressure to offer support & resistance to the contraction of muscles so that mobility results
-manipulates and uses fluid for contractions, pull and push
-earthworms,, planarians, jellyfish, analids,

Question 3

characteristics of the use of muscular hydrostats

Answer 3

-Fluid contained within individual cells that comprise a muscle assists with movement
-Human tongues & elephant trunks!

Question 4

what are the characteristics of a mollusk exoskeleton?

Answer 4

-Thick & nonmobile calcium carbonate shell
-Protection against predators
-Can grow as animal grows

Question 5

what are the characteristics of an arthropod exoskeleton?

Answer 5

-Composed of chitin
-Jointed & movable, allows for appendages
-Protect against predators & desiccation (drying out)
-Must molt to grow

Question 6

what is an endoskeleton and what are they made of in different organisms (echinoderms, sharks&rays, bony fishes&amphibians&reptiles&birds&mammals

Answer 6

-True bones
-Echinoderms
-Spicules & plates of calcium carbonate
-Sharks & Rays
-Cartilage
-Bony fishes, amphibians, reptiles, birds, & mammals
-Bone & cartilage

Question 7

what are the advantages of an endoskeleton?

Answer 7

1. Grows with the animal
2. Supports the weight of large animals
3. Protects vital internal organs
4. Protected by outer tissues
5. Allows flexible & more complex movements

Question 8

characteristics of mammal skeletons

Answer 8

-Aquatic animals streamlined torpedo-shaped skeleton
-Animals that jump compact skeleton & elongated hindlimbs
-Carnivores walk on their toes
-Hoofed mammals elongated legs
-Humans bipedal

Question 9

functions of the human skeletal system

Answer 9

1. Support of the body
2. Protection of vital internal organs
3. Sites for muscle attachment
4. Storage reservoir for ions
5. Production of blood cells
   -HOMEOSTASIS

Question 10

what are the processes of bone growth and renewal?

Answer 10

-Prenatal - Cartilaginous structures shaped like future bones
-Calcium deposits Converted into bones by cartilage cells & osteoblasts: bone-forming cells
-Endochondral ossification: conversion of cartilaginous models to bones

Question 11

what are the steps of endochondral ossification

Answer 11

-conversion of cartilaginous models to bones
1. Blood vessel invades cartilaginous structures
2. Primary ossification center forms
3. Osteoblasts from and develop secondary ossification centers
4. Growth plates form
5. Fuses end to long bone

Question 12

what happens to adult bones?

Answer 12

-Adults bone continuously broken down & built up again
-Bone is active, growing tissue with extensive blood supply
-needs constant blood supply

Question 13

what are osteoclasts

Answer 13

cell responsible for bone resorption

Question 14

what are osteocytes?

Answer 14

mature bone cell located within lacunae of bone
own individual pocket/chamber

Question 15

what is the anatomy of a long bone

Answer 15

Cavity bounded at sides by compact bone & ends by spongy bone (red blood cells)

Question 16

what are compact bones

Answer 16

-contains osteons, consisting of concentric layers of matrix, & osteocytes in lacunae (middle)
-very densely packed
-blood vessel only living part
-flexible enough to allow for movement

Question 17

what is spongy bone?

Answer 17

irregular, mesh-like arrangement of thin plates of bone

Question 18

what are joints

Answer 18

articulation between two bones of a skeleton
Bones connect at joints

Question 19

what are the 3 types of joints

Answer 19

1. Fibrous Joints - immovable, skull, ribcage
2. Cartilaginous Joints - slightly movable, still rigid, spine-between vertebrae
3. Synovial Joints - freely mobile, ligaments, elbow, knee

Question 20

characteristics of the muscular system

Answer 20

-Composed of contractile tissue
-Changing its length by contracting & relaxing
-Most animals rely on muscles for movement!

Question 21

what are tendons

Answer 21

bands of fibrous connective tissue that attach muscles to skeleton

Question 22

characteristics of muscles

Answer 22

-When muscles contract shorten
-Muscles only pull; cannot push
-Antagonistic pairs

Question 23

what is tone?

Answer 23

continuous, partial contraction of the muscle

Question 24

characteristics of muscle fibers

Answer 24

Muscle contains many bundles of muscle fibers
Muscle fibers have many myofibrils: contractile portion of muscle fiber

Question 25

what is a sarcolemma

Answer 25

plasma membrane of myofibril
involved in T-tubule system
good at getting things to sarcoplasmic reticulum

Question 26

what is the sarcoplasmic reticulum

Answer 26

modified endoplasmic reticulum of myofibril
looks like nets
serves as storage site for calcium ions (Ca2+)
ion is essential for muscle contraction

Question 27

what is a sarcomere

Answer 27

One of many units, arranged linearly within a myofibril, whose contraction produces muscle contraction
one sarcomere is made up of myosin filaments and actin filaments

Question 28

what is myosin

Answer 28

Muscle protein making up thick filaments in a sarcomere; it pulls actin to shorten sarcomere, yielding muscle contraction

Question 29

what is actin

Answer 29

One of two major proteins of muscle, along with myosin, make up thin filaments in myofibrils of muscle fibers

Question 30

what are antagonistic pairs?

Answer 30

pairs of muscles where one contracts and the other relaxes
-ex. triceps and biceps

Question 31

what is the sliding filament model?

Answer 31

the process where myosin pulls actin closer

Question 32

Which of the following statements about the insect exoskeleton is not true?

a.
The insect exoskeleton grows with the organism

b.
The exoskeleton protects insects against predators and drying out

c.
The insect exoskeleton is made of a complex form of carbohydrate called chitin

d.
The insect exoskeleton has muscles attached to it from the inside of the body

e.
The insect exoskeleton is jointed and movable

Answer 32

a.
The insect exoskeleton grows with the organism

Question 33

Which of the following functions is not a function of the human skeletal system?

a.
Protects internal organs

b.
Provides the ATP for muscles to use in contraction

c.
Acts as a storage site for calcium and phosphorus ions

d.
Acts as a structure against which muscles can contract

e.
Acts as the site of blood cell production in adults

Answer 33

b.
Provides the ATP for muscles to use in contraction

Question 34

Which of the following statements about the nature of bone is true?

a.
The outer compact bone is nonliving calcium, but the bone marrow is active living tissue

b.
Bone is active and living when formed by osteoblast but dies after it hardens

c.
Bone is nonliving calcium deposits and removing bone is a bloodless operation

d.
Bone is similar to cartilage, nearly inert, and with little blood supply

e.
Bone is active, growing tissue with an extensive blood supply

Answer 34

e.
Bone is active, growing tissue with an extensive blood supply

Question 35

The type of bone tissue that is found along the sides of a long bone and has lacunae arranged in concentric circles around central canals that contain blood vessels and nerves is

a.
Fibrous membrane

b.
Red marrow

c.
Compact bone

d.
Spongy bone

Answer 35

c.
Compact bone

Question 36

What is the correct order that a motor nerve impulse travels when triggering a muscle contraction?

a.
motor nerve-sarcolemma-synaptic cleft-sarcoplasmic reticulum-troponin

b.
motor nerve-synaptic cleft-sarcolemma-sarcoplasmic reticulum-troponin

c.
motor nerve-synaptic cleft-sarcolemma-troponin-sarcoplasmic reticulum

d.
motor nerve-sarcolemma-sarcoplasmic reticulum-synaptic cleft-troponin

e.
motor nerve-sarcoplasmic reticulum-synaptic cleft-sarcolemma-troponin

Answer 36

b.
motor nerve-synaptic cleft-sarcolemma-sarcoplasmic reticulum-troponin