Skeletal System Flashcards
1
Q
Organisms first evolved in
A
water
2
Q
What did water provide for early organisms?
A
support against the pull of the earths gravity
3
Q
What did land organisms need to avoid being a non-motile jelly-like mass of cells?
A
a support system
4
Q
Why was a support system even more essential for complex land animals?
A
for active movement in search of food and to escape danger
5
Q
What is closely linked in complex animals?
A
support and body movement
6
Q
How is body movement achieved in complex animals?
A
by muscles pulling on some kind of support
7
Q
Do active multicellular animals in water need a support system?
A
Yes to succeed in their hunt for food
8
Q
What have most complex animals evolved for support and movement?
A
supporting structures or skeletons
9
Q
What do skeletons provide?
A
support against gravity and flexibility for movement
10
Q
What are the main types of materials in animal skeletons?
A
chitin cartilage and bone
11
Q
What is chitin?
A
a tough light and flexible material
12
Q
What is chitin a major component of?
A
the skeletons of arthropods
13
Q
What kind of substance is chitin?
A
a carbohydrate
14
Q
What is chitin similar to?
A
cellulose
15
Q
What is cellulose?
A
the cell wall material of plants
16
Q
Is chitin permeable to water?
A
Yes
17
Q
How is chitin often strengthened?
A
by deposits of hardened proteins and minerals
18
Q
Where is cartilage found?
A
in the skeletons of complex vertebrates
19
Q
What does cartilage consist of?
A
living cells (chondroblasts) and carbohydrate and protein fibres
20
Q
Describe cartilage
A
a tough and flexible tissue with great tensile strength
21
Q
What does cartilage act as?
A
a shock absorber
22
Q
What does cartilage cushion?
A
the effect of bones moving against bones
23
Q
What forms the entire skeletal system of sharks and rays?
A
Cartilage
24
Q
What are the three types of cartilage in mammals?
A
hyaline cartilage fibro-cartilage and elastic cartilage
25
What does hyaline cartilage make up?
the rings supporting the trachea and bronchi the surfaces of movable joints and the protruding part of the nose
26
Where is fibro-cartilage found?
in the discs between the vertebrae of the vertebral column
27
How does fibro-cartilage compare to hyaline cartilage?
it is tougher
28
Where is elastic cartilage found?
in the external ear the epiglottis the Eustachian tube and the external ear canal
29
Does cartilage have its own blood supply?
No
30
How does cartilage get oxygen and nutrients?
they diffuse across from nearby tissues
31
What is the major component of the vertebral skeleton?
Bone
32
What does bone consist of?
living bone cells (osteocytes) protein fibres (collagen) and minerals
33
What are the main minerals in bone?
calcium phosphate and calcium carbonate
34
What proportion of bone mass do minerals make up?
two-thirds
35
How does bone compare to cartilage?
stronger and more rigid
36
Does bone have its own blood supply?
Yes
37
What is the skeleton of a young vertebrate embryo made of?
cartilage
38
What happens to cartilage as the embryo grows?
bone cells replace cartilage cells
39
What is ossification?
the process of cartilage hardening into bone through the addition of minerals
40
Where does the embryo get calcium compounds?
from the mothers blood
41
Why is a balanced diet with calcium important for expectant mothers?
for proper bone development in the embryo
42
Why do young children need calcium compounds?
for continued bone growth after birth
43
What is an excellent source of calcium compounds?
Milk
44
What vitamin is needed for proper bone development?
Vitamin D
45
What does the shape and size of a bone depend on?
its position and function in the vertebrates body
46
Describe limb bones
big and long
47
Describe ossicles in the middle ear
small and shaped like a hammer an anvil and a stirrup
48
Describe the thigh bone of a human
a long bone with a hollow shaft expanded into a head at each end
49
What is the shaft of the thigh bone made of?
hard or compact bone
50
What are the heads of the thigh bone made of?
spongy bone covered by a thin layer of compact bone
51
Describe spongy bone
honeycomb-like appearance due to numerous bony struts
52
What is the hollow shaft of the thigh bone filled with?
fatty yellow marrow
53
What do the spaces in spongy bone contain?
red marrow
54
What do many small openings in bone allow?
blood vessels and nerves to enter the bony tissue
55
Describe the structure of bone
strong and light often called living concrete
56
How does bone compare to concrete?
stronger and much lighter
57
What do protein fibers in bone tissue act as?
flexible reinforcing rods
58
What do calcium salts in bone act as?
cement
59
What does the hollow structure of long bones do?
makes them light without decreasing strength
60
How does a hollow bone compare in strength to a solid bone?
nearly as strong
61
What does the arrangement of bony struts in spongy bone enable?
the bone to withstand great compression
62
How is bone ideally constructed?
to act as skeletal material
63
What are the main types of skeletons in animals?
hydrostatic skeleton exoskeleton and endoskeleton
64
What animals use a hydrostatic skeleton?
soft-bodied animals like the earthworm
65
How does a hydrostatic skeleton provide support?
fluid pressure
66
Describe hydrostatic skeleton animals
tubular with a muscular body wall
67
What happens to fluid in a hydrostatic skeleton?
it is secreted to fill the space in the body and presses against the muscular body wall
68
What does the muscular body wall do in a hydrostatic skeleton?
it contracts exerting a force against the fluid
69
What is an exoskeleton?
a skeleton of non-living material that forms on the outside of arthropods bodies
70
What secretes the exoskeleton?
cells covering the body of the animal
71
What is the main component of the exoskeleton?
chitin
72
How is the exoskeleton strengthened?
by deposits of protein and minerals especially calcium carbonate
73
Describe calcareous exoskeletons
common in aquatic crustaceans like crabs and prawns hard and heavy
74
What is the exoskeleton made up of?
a series of plates or tubes attached at joints by sheets of unhardened chitin
75
What does unhardened chitin make the exoskeleton?
flexible
76
How is the animal attached to the exoskeleton?
by muscles
77
What does the exoskeleton support the animal against?
gravity
78
What does the exoskeleton enable the animal to do?
move about
79
What do animals with exoskeletons do periodically?
moult
80
What happens during moulting?
they shed their old exoskeletons and grow rapidly in size while the new exoskeletons are still soft and extensible
81
What is moulting also known as?
ecdysis
82
What animals have an endoskeleton?
all vertebrates
83
Of what material are endoskeletons mainly composed?
bones
84
Are bones living or non-living?
living tissues
85
Do bones grow?
Yes steadily as the animal grows
86
Is moulting necessary for animals with endoskeletons?
No
87
What are bones attached together by?
movable joints and tough flexible fibers called ligaments
88
What do ligaments make the skeleton?
flexible
89
What are attached to bones?
muscles
90
What do muscles and bones bring about?
body movements and locomotion
91
What is the basic plan of vertebrate skeletons?
Each skeleton has an axial skeleton and an appendicular skeleton
92
What does the axial skeleton form?
the main central axis
93
What does the appendicular skeleton consist of?
parts that articulate with the axial skeleton
94
What bones form the axial skeleton?
the skull vertebral column breastbone or sternum and ribs
95
What bones form the appendicular skeleton?
the limb girdles (shoulders and hips) and limbs
96
What is the mammalian skull made up of?
several flat bones joined together
97
What does the mammalian skull form?
the brain box or cranium the snout or face and a lower jaw or mandible
98
What does the snout or face consist of?
the upper jaw or maxilla and cavities for the main sense organs
99
Describe the mandible
a single curved bone that hinges with the rest of the skull
100
What do the upper and lower jaws bear?
teeth for chewing food
101
What does the base of the skull pivot on?
the top vertebra of the vertebral column
102
What does the pivoting of the skull allow?
nodding and rotation of the head
103
What is the vertebral column also known as?
the backbone or spinal column
104
What is the vertebral column?
the central supporting structure of the skeleton
105
How many vertebrae are in the human vertebral column?
33
106
What do vertebrae form?
a flexible column with a central canal for the spinal cord
107
What separates vertebrae?
discs of fibro-cartilage
108
What holds vertebrae together?
ligaments
109
What do intervertebral discs allow the vertebral column to do?
bend backwards and forwards and sideways
110
What leaves the spinal cord through openings between adjacent vertebrae?
Spinal nerves
111
What does a typical vertebra have?
a neural canal a neural spine transverse processes a centrum and smooth surfaces or facets
112
What is the neural canal for?
passage of the spinal cord
113
What is the neural spine?
a projection upwards dorsally
114
What are transverse processes?
projections from the sides of each vertebra
115
What is the centrum?
a solid piece of bone below the neural canal
116
What are facets?
smooth surfaces at the front and back that fit into the adjacent vertebrae
117
What are the first and second vertebrae of the column?
the atlas and the axis
118
What type of vertebrae are the atlas and axis?
cervical vertebrae
119
Describe the atlas
a ring of bone with a very large neural canal and no centrum
120
What does the atlas have?
a pair of large hollow facets
121
What do the facets of the atlas fit into?
two bulging surfaces of the skull
122
What movement does the atlas allow?
nodding movements of the head
123
How is the axis different from the atlas?
the axis has a large centrum which projects forward as the odontoid process
124
What does the odontoid process of the axis fit into?
the ventral portion of the neural canal of the atlas
125
What movement does the axis allow?
rotation of the head from side to side
126
What vertebrae make up the cervical vertebrae?
the atlas the axis and the next five vertebrae
127
How many thoracic vertebrae are there?
twelve
128
What are thoracic vertebrae attached to?
the ribs
129
How many lumbar vertebrae are there?
five
130
What do lumbar vertebrae support?
most of the bodys weight
131
What are sacral vertebrae fused to form?
a sacrum
132
What does the sacrum articulate with?
the pelvic girdle
133
How many caudal vertebrae do humans have?
four
134
What are human caudal vertebrae fused to form?
the coccyx
135
Are caudal vertebrae fused in most other mammals?
No
136
How many caudal vertebrae does a rabbit have?
about sixteen
137
How many caudal vertebrae does a rat have?
between twenty-seven and thirty
138
What do twelve pairs of ribs and the sternum form?
the rib cage
139
How many bones make up the human sternum?
a single bone
140
How many bones make up the rabbit sternum?
seven small bones
141
Where do ribs articulate?
with the thoracic vertebrae at the back
142
How do ribs attach to the sternum?
by means of elastic cartilage
143
How many pairs of ribs are attached to the sternum in humans?
the first ten pairs
144
What are the last two pairs of ribs in humans called?
floating ribs
145
How many pairs of floating ribs do rabbits have?
the last three pairs
146
What does the pectoral girdle hold?
the upper limbs or arms to the axial skeleton
147
How many bones make up the human pectoral girdle?
four
148
What are the bones of the pectoral girdle?
two scapulae and two clavicles
149
What are scapulae?
large flat triangular shoulder-blades at the back
150
What are clavicles?
small slender collar-bones in front
151
How are scapulae attached?
to the vertebral column by muscles
152
What is the glenoid cavity?
a depression in the scapula
153
What fits into the glenoid cavity?
the head of the humerus
154
What joint does the humerus and glenoid cavity form?
the shoulder joint
155
What are clavicles attached to?
a scapula at one end and the sternum at the other end
156
Is the pectoral girdle rigid?
No
157
What does the flexibility of the pectoral girdle enable?
free movement of the arms and shoulders
158
How many bones make up the adult human pelvic girdle?
two the right and left pelvis
159
What are the pelvic bones joined to?
the sacrum at the back
160
How are the pelvic bones held together in front?
by fibro-cartilage at the facets
161
What do the pelvic bones form?
a complete rigid girdle
162
What is the acetabulum?
a deep cavity on the outer edge of each pelvis
163
What fits into the acetabulum?
the head of the femur
164
What joint does the femur and acetabulum form?
the hip joint
165
What is the pelvic girdle designed to do?
receive the weight of the upper body and pass it on to the legs or the surface on which you are sitting
166
Does the pelvic girdle restrict movement?
Yes
167
What does the pelvic girdles rigid structure restrict?
movements of the hips and legs
168
What are the fore and hindlimbs of all terrestrial vertebrates built on?
a basic pentadactyl plan
169
What was the evolution of pentadactyl limbs?
one of the major adaptations that arose in connection with terrestrial life
170
What does a pentadactyl limb consist of?
a long bone a pair of long bones side by side a set of nine small bones in three rows five thin long bones and five digits
171
What are phalanges?
individual bones of the digits
172
What are the parts of the forelimb or arm?
the upper arm the lower arm the wrist and the hand
173
What are the bones of the lower arm?
the ulna and radius
174
What movement do the bones of the lower arm allow?
partial rotation of the hand
175
What other movement is possible with the human hand?
rotation of the thumb to a position opposite the fingers
176
What does the opposable thumb allow?
grasping and manipulating objects precisely
177
What is the importance of the opposable thumb?
it was important in the evolution of humans
178
What are the parts of the hindlimb or leg?
the thigh the shank the ankle and the foot
179
What is the largest and strongest bone in the body?
the thigh bone
180
How do the bones of the foot compare to those of the hand?
they are not as dextrous
181
What do the bones of the foot form?
an arch
182
What does the arch of the foot enable?
the foot to withstand tremendous forces
183
What is a joint?
the place where two or more bones meet or articulate
184
What do joints allow?
movement
185
What holds bones together at a joint?
strong ligaments
186
What do ligaments prevent?
dislocation during movement
187
Does the degree of movement vary at a joint?
Yes
188
What is the most mobile joint in the body?
the shoulder joint
189
What joints are immovable?
the joints of the bones that form the cranium
190
What is a slightly movable joint?
the one between the hip-bones
191
What can martial arts exercises and childbirth do to the hip-bone joint?
make it flexible
192
What are the weak spots of the skeleton?
freely mobile joints
193
What is a common injury among athletes?
shoulder dislocation
194
What are the four main kinds of movable joints?
ball-and-socket joint hinge joint gliding or sliding joint and pivot joint
195
What joints are ball-and-socket joints?
the shoulder joint and hip joint
196
What is the ball-like structure that fits into the glenoid cavity of the scapula?
the head of the humerus
197
What directions of movement does the ball-and-socket joint allow?
several directions
198
What is the freely articulating joint formed by the round head of the femur?
the acetabulum of the pelvis
199
Where do hinge joints occur?
at the elbow and knee
200
What type of movement do hinge joints allow?
movement in one direction only
201
How do the bones in a hinge joint function?
like one half of a hinge
202
Where do gliding or sliding joints occur?
at the wrist and ankle
203
What movement do gliding joints allow?
sliding of bones over one another and movement of the hand and foot up and down or rotated slightly
204
What do pivot joints allow?
rotation of one part of the body on another
205
Where is a pivot joint found?
between the atlas and axis vertebrae
206
What acts as a pivot in the pivot joint?
the odontoid process of the axis
207
What does the odontoid process of the axis allow?
rotation of the head on the vertebral column
208
What is a joint usually enclosed in?
a capsule made of ligament
209
What covers the articulating surfaces of bones?
smooth cartilage
210
What does cartilage prevent?
the surfaces of the bones from being worn out
211
What is between the surfaces of the articular cartilage?
a sac lined by synovial membrane
212
What is the sac filled with?
synovial fluid
213
Describe synovial fluid
a thick viscous fluid
214
What does synovial fluid serve as?
a lubricant during movement
215
What does the structure of a joint allow?
free movement of the bones
216
Do plants have a highly developed skeletal system like animals?
No
217
Why dont plants need a highly developed skeletal system?
they do not have to move about to obtain food
218
What kind of tissues do plants need?
supporting tissues
219
What functions do supporting tissues perform in plants?
remain upright spread out their branches and hold their leaves in the best positions for trapping sunlight
220
What are the important types of supporting tissues in plants?
turgid parenchyma collenchyma sclerenchyma and xylem (wood)
221
What are the two main systems in most terrestrial plants?
an aerial shoot system and an underground root system
222
What surrounds the roots?
soil
223
What do roots do?
grip the soil
224
What does the soil do to roots?
press
