Biology Form 5 Chapter 2 - Locomotion & support : 2.1 Part 1

1. BIOLOGY FORM 5
CHAPTER 2
LOCOMOTION & SUPPORT
PART 1

2. The Necessity for Support & Locomotion
in Humans & Animals
WHY DO HUMANS & ANIMALS NEED
SUPPORT?
1. To find the food
2. To find partner for mating
3. To protect/escape from their
predator
4. To shelter from bad environment

3. Type of skeletons
A) HYDROSTATIC SKELETONS,
EXOSKELETONS AND ENDOSKELETONS

4. Three types of skeletons in animals:
Hydrostatic Exoskeletons
Endoskeletons

5. Hydrostatic skeleton / hydroskeleton is
ideal for:
Burrowing

6. A hydrostatic skeleton is :
a volume of fluid enclosed in a body cavity
surrounded by muscle
Longitudinal muscle
Fluid-filled cavity
Circular muscle
chaetae
TS Earthworm

7. A hydrostatic skeleton is found in:
primarily in soft-bodied invertebrates, both
terrestrial and aquatic
Earthworm
Cnidarians

8. Hydrostatic skeleton:
consists of internal fluids (held under
pressure in compartments surrounded by
muscles)
since the liquid cannot escape, it forms a
skeleton which cannot be compressed
this makes a soft-walled structure like an
earthworm’s rigid so that muscles can act
against it

9. What happens when:
The longitudinal muscles of a segment
contract:
The compartment shortens and bulges
The circular muscles in a segment contract:
The compartment in that segment
elongates

10. Alternating contractions of the circular & longitudinal
muscles create :
waves of narrowing and widening, lengthening and
shortening, that travel down the body

11. An earthworm uses its hydrostatic skeleton to crawl

12. Chaetae :
 anchor earthworm while it pushes
itself forwards

13. EXOSKELETONS

15. What is an ‘Exoskeleton’?
A hardened outer surface to which muscles
attach
Exoskeletons occur in:
molluscs, arthropods

16. An exoskeleton:
protects all the soft tissues of the animal
BUT

17. is itself subject to damage by:
Abrasion
Crushing
Around 50,000 Spider crabs
invaded an Australian coast [2005]

18. What is the greatest drawback of the
arthropod exoskeleton?
Exoskeleton cannot grow
What must the animal do to become larger?
MOULT

19. Arthropods are the only non-vertebrate
group to possess:
jointed appendages
Chitin:
- the hard, composite
material that shields
insects from harm - is
light, strong
- can be both:
 hard (as in exoskeleton)
 flexible (as in joints)

20. The Joints are hinges
the levers on either side are operated
by:
Flexor muscles
Extensor muscles

21. Contractions of the muscles cause:
jointed segments of the exoskeleton to move
relative to each other

22. In which direction does the limb move
when:
Flexor muscles
contract:
Towards the body
Extensor muscles
contract:
Away from the body

23. The hollow tubular form of the exoskeleton:
is very efficient for:
 support &locomotion
in small animals e.g.
arthropods
can support a much greater weight without
giving way than a solid cylinder strut (like a
bone) of the same mass
bone

24. HOWEVER, the exoskeleton:
loses this efficiency when organisms:
 become greater
 their mass increases

25. Endoskeleton
Dolphin

26. The Endoskeleton of vertebrates:
is an internal scaffolding to which muscles
attach and against which they can pull

27. Functions of the mammalian endoskeleton:
1. provides a rigid framework that supports the body
and protects the internal organs e.g. rib cage
protects lungs and heart
2. important for locomotion – although muscle
contractions provide the power, skeletal structures
actually bring about movement

28. My skull…
protects
my
brain.

29. My rib cage…
…protects
my
heart
and
lungs.

30. muscles can only contract and relax
without something rigid to pull against, a
muscle would just be a formless mass

31. What would you look like
without bones?
Without bones
inside you
to give you shape,
you would be a
BLOB!

32. skeletal systems provide rigid support against
which muscles can pull, creating directed
movements
Look at the flashes of red
when the legs walk
forward. These are the
working muscles as they
contract;
the muscles in yellow are
at rest

33. Functions of the mammalian endoskeleton:
3. in adults, the bone marrow produces blood cells
and platelets – the red bone marrow produced red
blood cells

34. Functions of the mammalian endoskeleton:
4. bone serves as a storage site for:
 calcium & phosphorus
– bone contains 90% of the
phosphorus in the human body
 Yellow bone marrow, dominated
by fat cells, also stores energy
reserves

35. Functions of the mammalian endoskeleton:
5. the skeleton participates in sensory transduction –
three tiny bones in the middle ear transmit sound
vibrations between the eardrum and the cochlea
[not in syllabus]
Cochlea [send
impulses to brain]

36. The endoskeleton can heal itself
Can this happen in the exoskeleton?
NO

37. Question: [SEP, 2004]
The endoskeleton of vertebrates is made of bone, which
is a cellular, living tissue capable of growth, self-repair,
and remodelling in response to physical stress.
An exoskeleton made of chitin is not capable to carry
out any of these functions.
Moulting is required if the animal is to grow, rendering
it susceptible to infections and vulnerable to
predators during the time when a new exoskeleton is
being formed. These disadvantages are not
associated with an endoskeleton.
The exoskeleton limits the size of the animal. The
exoskeleton would have to become thicker and
heavier in order to prevent collapse as the animal
grows bigger. This would make movement difficult.

38. RECAP : SKELETAL SUPPORT
 Skeletons have 5 major functions
 Support & Shape
 Movement
 Protection of internal organs
 Produce blood cells
 Store materials

39. Human Endoskeleton
A) STRUCTURE OF SKELETON

40. THE AXIAL SKELETON

41. STRUCTURE OF SKELETON
 There are about 206 bones found in an adult skeleton.
 The bones are divided into two main groups
(1) AXIAL SKELETON
(2) APPENDICULAR SKELETON

42. AXIAL SKELETON
 The axial skeleton forms
the basic structure
supporting the rest of
the skeleton.
 It consists of:
 Skull
 Vertebral column
 Rib cage

43. APPENDICULAR SKELETON
 Forms mainly the
extremities of the
body and their
connections to the
axial skeleton
 Consists of
- limbs (arms &
legs)
- shoulder and pelvic
girdles

44. OVERVIEW
THE VERTEBRAL COLUMN

45. The Vertebral Column consists of:
a series of vertebrae, separated by
intervertebral discs made of cartilage
Intervertebral
discs

46. Intervertebral disc acts as a shock absorber
Flexion (Bending
Forward)
Extension (Bending
Backward)

47. Vertebrae protect the Spinal cord
Spinal cord
Spinal
nerve

48. Intervertebral disc may protrude & compress nerves

49. The Vertebral Column has an "S"-like
curve :
when looking at it from the side
 this allows for an even
distribution of weight
the "S" curve helps a
healthy spine
withstand all kinds of
stress

50. The vertebrae are
held together by ligaments which:
– prevent their dislocation
– permit a degree of movement so that the
vertebral column as a whole is flexible

51. AXIAL SKELETON
 The axial skeleton forms
the basic structure
supporting the rest of
the skeleton.
 It consists of:
 Skull
 Vertebral column
 Rib cage

52. AXIAL SKELETON
SKULL
Cranium consists of 8
bones fused
together.
Face has 14 bones.
Most are fused,
whilst others like the
mandible (lower jaw
bone) can move
independently

53. Fusion of the human skull

54. AXIAL SKELETON
VERTEBRAL COLUMN
Divided into 5 main regions
(1) Cervical spine (7)
(2) Thoracic spine (12)
(3) Lumbar spine (5)
(4) Sacrum (5)
(5) Coccyx (4)
The 5 sacrum vertebrae
and 4 coccyx vertebrae are
fused to form one solid
bone.

55. ANATOMICAL TERMINOLOGY
TERM DEFINITION
Superior Toward the Head
Inferior Toward the feet
Anterior (ventral) Front
Posterior (dorsal) Back
Medial Toward the midline (inside)
Lateral Toward the side (outside)
Proximal Nearer the trunk
Distal Further from the trunk
Prone Face down (on stomach)
Supine Face up (on back)

56. Spinous process
Neural canal
centrum
TERM FUNCTION
Centrum Absorb shock and provide
support
Neural canal Spinal cord goes to it
Spinous process Points of attachment for
muscles and ligaments
Transverse process Points of attachment for
muscles and ligaments
Transverse process

57. Cervical, Thoracic, Lumbar, Sacrum
and Coccyx

58. AXIAL SKELETON
 ATLAS – first cervical
vertebra
 AXIS – second cervical
vertebra
 Spinal chord runs down the
canal formed by the
vertebra being stacked on
top of one another.
 Intervertebral Discs are
found between each
vertebrae and keep spine
flexible and they absorb
shock
CERVIX

59. Cervical Vertebrae
transverse foramen
Dens
(odontoid process)
Atlas (C1) Axis (C2)
bifid
spinous
process
centrum
transverse Neural canal
process
All have transverse foramen for blood
vessel and nerve to pass through

61. THORAX

62. centrum
spinous process
Neural
canal
transverse process
lamina
Articular
facet
rib facet
THORACIC
spinous process
Spinous process long
and directed downwards
Spinous and transverse
process for attachment of
muscles and ligaments.

63. LUMBAR

64. Thoracic
& Lumbar
Vertebrae
Transverse
process
lumbar
vertebrae
thoracic
vertebrae
Spinous process
Neural
canal
centrum

65. SACRUM

66. Sacrum (5 fused
vertebrae)
sacral articular surface
Transverse
ridges
sacral foramen
4 pairs of openings for
passage of nerves and
blood vessels.

67. Coccyx

68. Vertebral Column
intervertebral
foramen
intervertebral
disk

69. AXIAL SKELETON
THORAX
 12 pairs of ribs
 Joined to thoracic
vertebrae
 Top 10 ribs joined to
sternum
 Remaining two have
“free” ends – ‘floating’

70. Thorax
True Ribs (7 pairs)
False Ribs (5 pairs)
1
2
3
4
5
6
7
1
2
3
4
5
Floating

71. Rib
neck
tubercle
costal
groove
shaft
head

72. Sternum
manubriu
m
clavicular
notch
sternal
notch
body
xiphoid
process
sternal
angle
intercostal
space

73. The end!

74. Label the lumbar vertebrum:
1. Neural spine
2. Articular
process
3. Transverse
process
4. Neural canal
5. Centrum

76. APPENDICULAR SKELETON
 Forms mainly the
extremities of the
body and their
connections to the
axial skeleton
 Consists of
- limbs (arms & legs)
- shoulder and
pelvic girdles

77. Pectoral Girdle
scapula
clavicle
humerus

78. Clavicle
acromial end sternal end

79. coracoid process
acromion
process
glenoid cavity
superior angle
inferior angle
Anterior Scapula
subscapular fossa

80. Posterior
Scapula
lateral border
supraspinous fossa
spine
medial border
infraspinous fossa
acromion process

81. APPENDICULAR SKELETON
THE ARM AND HAND

82. Humerus
head neck olecranon fossa

83. Anterior Humerus
medial epicondyle
trochlea
capitulum
lateral epicondyle
deltoid
tuberosity
lesser
tubercle
greater
tubercle
intertubercular
groove
coronoid fossa

84. Ulna
trochlear notch
head
styloid process
coronoid process
radial notch
olecranon process
Ulna larger than radius

85. Radius
radial tuberosity
head
styloid process

87. Manus (Hand)
Carpals (8)
Metacarpals (5)
Digits (5)
3
1 pollex

88. Appendicular Skeleton
Pelvic Girdle
and
Lower Limb

89. Sacrum
Pelvic Girdle
ilium
pubis
ischium
pubic symphysis
sacroiliac joint
iliac
fossa
acetabulum
obturator
foramen

90. iliac crest
greater sciatic
notch
ischial spine
HIP BONE
ischial tuberosity
lesser sciatic
notch
anterior
superior iliac
spine

91. Anterior Femur
head
neck
fovea capitis
patellar surface

92. lesser trochanter
gluteal tuberosity
greater trochanter
medial epicondyle
medial condyle
linea aspera
lateral condyle
Posterior Femur
lateral epicondyle
Intercondylar fossa

93. Tibia
medial condyle
lateral condyle
anterior crest
tibial tuberosity
medial malleolus
Tibia larger than fibula

94. Fibula
head lateral malleolus
Patella

95. Foot
Tarsals (7)
Metatarsals (5)
Calcaneus
Talus
Digits (5)

96. Name the
Individual Phalanx
Hallux (Great Toe)
1
3

97. THE END
PART 1