Support systems in animals - the human skeleton Flashcards
(120 cards)
1
Q
Which animals have hydrostatic skeletons
A
Snails (mollusca) and earthworms (anelida)
2
Q
What is a hydrostatic skeleton
A
It is when animals have fluid filled bodies and that give them their structure and support. These organisms secrete watery fluid (coelomic fluid) that is trapped inside the body cavity (coelom)
3
Q
Which animals have exoskeletons
A
Arthropoda (crabs, millipedes, insects)
4
Q
What kind of skeletons can vertebraes have
A
They can have cartilaginous skeletons (sharks and rays) or bony skeletons (endoskeletons) because they are internal
5
Q
What are the advantages of the human skeleton
A
- support
- protect
- point of attachment for muscles and movement
- allows growth
6
Q
How many bones does the adult human skeleton have
A
206
7
Q
What parts of the skeleton are the axial skeleton
A
vertebral column, rib cage, skull and sternum
8
Q
What parts of the skeleton are the appendicular skeleton
A
shoulder girdle, pelvic girdle and lower and upper limbs
9
Q
How does the skull start off
A
It starts off as 29 bones during embryonic development (excluding teeth) which later on are connected through fibrous cartilage. The lines that the joints form disappear at ages 30 to 40
10
Q
How many bones does the cranium have
A
8
11
Q
What does the cranium do
A
It protects the brain and sensory organs
12
Q
How many facial bones are there
A
14
13
Q
What are the names of the upper and lower jaw and how many bones do they each have
A
upper jaw: maxilla; 2 bones on each side
lower jaw: mandible; 1 bone on each side
14
Q
What are the smallest bones in the body
A
The 6 auditory ossicles in the ear; hammer, stirrup and anvil at each side
15
Q
What is the foramen magnum
A
a large opening at the base of the skull through which the spinal chord passes.
On either side of it is a projection which articulates with the first vertebra (atlas) to allow nodding movements
16
Q
How many teeth does the adult human have
A
32
17
Q
How many milk teeth do children have
A
20
18
Q
What type of teeth do humans have, how many of them do they have and what do they do
A
incisors: 4,bite
canines: 2, tear and grip
premolars: 4
molars: 6, chew and grind
19
Q
What are heterodont and homodont mammals and why
A
Heterodont: humans, they have different teeth which perform different functions
Homodont: dolphins, teeth have the same basic structure
20
Q
What is the hardest substance in the body
A
tooth enamel
21
Q
What are teeth embedded in
A
tooth sockets
22
Q
What is another word for dental bone
A
dentine
23
Q
What is the vertebral column
A
The vertical support of the body and the true axis that allows movements
24
Q
What are the first two cervical vertebrae
A
atlas and axis
25
Describe the atlas
1. Supports the skull and allows nodding movements
2. Does not have a centrum or spinal processes
3. Transverse processes are short and thick
4. Transverse processes form articulation facets on which the condyles of the skull can rest
26
Describe the axis
1. Centrum is shaped into an odontoid process that forms around the axis around which the atlas can rotate
2. Odontoid process is kept in position by a strong ligament. The transverse processes are small to allow rotations of the head
3. Axis allows rotation of skull
27
True or False
| The thoracic vertebrae are the vertebrae with a structure closest to that of typical vertebrae
true
28
Why are the thoracic vertebrae slightly larger than the cervical vertebrae
to lend more support
29
Where are articulation facets found on thoracic vertebrae
at each side and against the transverse processes of the first 10 vertebrae articulating with the ribs, these joints move slightly when we breathe
30
Why are the lumbar vertebrae large and solid and prominent
to carry the weight of the body and anchor muscles used to bend and rotate the lower back. The cartilage discs in this area are under a lot of pressure
31
Which part of the vertebral column has no function in the human body
the coccyx
32
What do the vertebrae of the sacrum fuse to form
a strong triangular bone that articulates with the hip bones
33
How many pairs of ribs does the rib cage have
12
34
What is the front of the ribs attached to
sternum (breast bone)
35
What does the sternum do
serves as extra protection for the heart and lungs
36
What attaches the ribs and sternum
elastic cartilage
37
What are true ribs and how many are there
They are attached directly to the sternum and there are 7 pairs
38
What are false ribs
They are attached to the cartilage of the previous ribs with cartilage
39
What are the last two ribs called and why
They are floating ribs because they are not attached to anything
40
What are the two layers of muscle that cover the ribcage
external and internal intercostal muscles
41
What happens to the external and internal intercostal muscles when you inhale
They contract to lift the ribcage up and outwards. They also relax to let you exhale
Internal intercostal muscles contract to decrease the volume of the thorax and put more pressure on the lungs so air is forced out of the lungs
42
What is the scapula
a flat triangular bone with a prominent ridge on the back for the attachment of muscles, that moves over the ribs at the back and assists movement and is not attached to the axial skeleton
43
Explain what the shallow socket that the scapula has is
It is an articular facet known as the glenoid cavity into which the humerus fits to form a ball and socket joint
44
What is the clavicle
An s shaped bone that articulates with the scapula one one side and the sternum on the other side. It is most frequently broken because it takes the full impact of falls on outstreched arms
45
How many bones are there in the wrist joint
8 irregular carpal bones
46
How many metacarpal bones are in the palm of the hand
5
47
How many phalanges do humans have
14
48
What does the pelvic girdle consist of
2 hip bones that form a strong girdle with the sacrum
49
What are the 3 parts of the hip bones and why are these bones fused
ilium, ischium and the pubic bone/pubis; they are fused for strength
50
What are the pubic bones joined by
fibrous cartilage that allows small movement in women during birth, this joint is called the pubic symphysis
51
What is another word for tibia
shin bone
52
What is another word for fibula
calf bone
53
How many bones does the ankle have
7
54
How many metatarsal bones are there
5
55
What is a joint
A junction where two or more bones are joined by ligaments or cartilage
56
How can joints be classified
1. immovable joints: eg. sutures between skull bones
2. semi movable joints: usually connected by elastic cartilage eg. the ribs and breastbone
3. movable joints: Also called synovial joints eg. shoulder or elbow where bones are connected by ligaments.
57
What characterises synovial joints
Bones are joined by ligaments
The whole joint is enclosed in a tough joint capsule
Friction during movement is decreased by synovial fluid
58
What makes the bodies of animals with hydrostatic skeletons firm
The pressure of the coelomic fluid against the muscles which can also contract to enable movement
59
What qualities does water have that makes it suitable to a skeleton
It cant be compressed and distributes changes in pressure evenly
60
What re the advantages of a hydrostatic skeleton
1. Watery environment keeps surfaces moist and prevents desiccation
2. Water supplies extra support
61
What are the disadvantages of a hydrostatic skeleton
1. Inefficient movement
2. Not protected against mechanical injuries
3. Sensitive to temperature changes
62
What are the advantages of an exoskeleton
1. Support
2. Point of attachment for muscles
3. Mobile seams enhance movement
4. Fair resistance to temperature changes
5. Protection against injury, toxins and desiccation
6. Camouflage
63
What are the disadvantages of an exoskeleton
1. Restricts growth and vulnerable during molting
| 2. Relatively mobile
64
What is an endoskeleton
An internal framework of bone and cartilage
65
What are the disadvantages of an endoskeleton
Bones may break or crack due to pressure exerted on them
66
True or False
| The bones of the skeleton lower the resistance that the muscles collaborate against to produce movement.
False
| The bones supply the resistance
67
What are the functions of the human skeleton
1. Movement
2. Protection
3. Support
4. Mineral storage (calcium and phosphates)
5. Hearing (auditory ossicles)
6. Blood cell formation (red bone marrow)
68
What two groups of bones does the skull consist of
the cranium and facial bones
69
What joins the bones in the cranium
immovable joints; sutures
70
What does the vertebral column consist of
24 articulating vertebrae and 9 fused vertebrae in sacrum and coccyx
71
What is fibrocartilage
discs found between the vertebrae to prevent friction and act as shock absorbers during movement
72
How do spinal nerves enter and leave the spinal cord
small gaps between adjacent vertebrae
73
What stabilises the vertebrae and helps to help control movement
Strong ligaments and muscles areound the spine
74
What is the basic structure of all vertebrae
1. consists of a centrum, neural arch and processes for attachment of muscles/ligaments
2. Between the neural arch and centrum a spinal canal (Foramen) is formed. It surrounds and protects the spinal cord (attached to foramen magnum)
75
What outgrowths are visible in the vertebrae
1. neural spin
2. two transverse processes
3. articular surfaces (occur for articulation with the previous and successive vertebrae and articulation with the ribs and thoracic vertebrae
76
What are the functions of the vertebral column
1. Supports the skull
2. Surrounds and protects the spinal cord
3. Separate vertebrae and s shaped curvature provide flexibility allowing humans to bend backwards, forwards and sideways
4. Fibrocartilage discs between vertebrae act as shock absorbers
77
What does a typical ribcage consist of
12 pairs of ribs, sternum, costal cartilages and 12 thoracic vertebrae
78
What does the pectoral girdle consist of
two scapulae and two clavicles
79
How is the pectoral girdle connected and why
It is connected to the back of the thorax by muscles to enable it to have a supporting structure as well as giving the shoulders greater freedom of movement for greater arm mobility
80
What provides limit of movement in the pectoral girdle
the clavicle
81
What are the functions of the pectoral girdle
1. Forms a strong support structure for the attachments of the arms
2. Provides large area of bone for the attachment of muscles
3. Forms ball and socket joints with the arms which allows the arms to move freely
82
What kind of joint do the bones of the forearm form in the elbow
a hinge joint
83
Describe the shape/position of the ulna
1. largest bone of the forearm situated on the pinky finger
| 2. c shaped articular facet that articulates with the humerus to form the elbow joint
84
Describe the shape/position of the radius
1. thinner bone of the forearm situated on the thumb side
| 2. Lower end is wider than upper end and articulates with carpals to form wrist joint
85
Why are carpal bones one of the most flexible bones in the body
They can slide over each other to allow high degree of movement
86
What does the pelvic girdle consist of
Two hip bones joined in the middle by a semi movable joint called the pubic symphysis
87
What is the deep socket that occurs where the 3 fused hip bones are found
acetabulum
88
What kind of joint does the head of the femur and the acetabulum form
a ball and socket joint
89
Name and describe the two types of bone
1. Compact bone: hard, dense bone tissue
Forms the surface of bones and shafts of long bones
Provides strength and support
2. Spongy bone: softer, light bone tissue
Form head of long bones and contains red marrow
Exert resistance against forces that act on bones
90
Briefly describe what cartilage is
It is semi transparent, tough elastic connective tissue
91
Briefly describe what tendons are
inelastic, white fibrous connective tissue that attach muscle to bone
92
Describe what ligaments are
1. Tough yellow elastic connective tissue that attach bone to bone
2. Stretch only enough to control movement in a joint
3. Hold bones in position (stabilise joints)
93
What covers the ends of two bones in a synovial joint
hyaline cartilage
94
Name and explain the types of synovial joints
1. Ball and socket joint
One bone fits into the other; movement in any direction eg. Shoulder and hip joint
2. Hinge joint
Movement in one plane eg. elbow and knee joint
3. Pivot joint
One bone rotates around the other eg. atlas around the axis
4. Gliding joint
Flat articular surface of one bone slides over another eg. wrist bones/ ankle joint
95
Name and explain the types of bones in the skeleton
1. Long bones
Consist of a shaft (diaphysis) and head (epiphysis) eg. humerus and femur
2. Short bones
Have a shaft but no head g. ribs and rapal bones
3. Flat bones
eg. scapula and hip bones
4. Irregular bones
no specific shape eg. vertebrae and auditory ossicles
96
What is the epiphysis
The head of each end of a long bone which consists largely of spongy bone and is covered with hyaline cartilage
97
What is spongy bone
Found in the epiphysis of long bones and contains red marrow
98
What is red bone marrow
Found in the spaces between trabeculae in spongy bone and the is the area where white and red blood cells are made
99
What are trabeculae
The struts in the network of irregular bony plates in the epiphysis of bones which transfer stresses from the epiphysis to the diaphysis which has a much thicker layer of compact bone and resists stress better
100
What is the diaphysis
Cylindrical shaft of a long bone composed of hard compact bone on the outside
101
What is the periosteum
Membrane of dense fibrous connective tissue which surrounds the outside surface of the shaft of a long bone
It has blood vessels to nourish bone and repair injuries
Provides surface of attachment for muscles through tendons/ligaments
102
Endosteum
The delicate connective tissue layer lining the inside surface of compact bone
103
Marrow cavity
This is filled with yellow marrow which consists largely of fat
104
What is a lever
a rigid rod that rotates around a specific point
105
What are the 3 main components of a lever
Fulcrum (turning point) F
Effort (where the force must be exerted) E
Load (where teh load has to be moved) L
106
Explain and give an example of what a class 1 lever is
LFE/EFL
The load at one end is balanced by the effort on the other side; the fulcrum is found between the two
When one pushes down on one side the other will lift vice versa
eg. nodding your head
107
Explain what a class 2 lever is
FLE/ELF
Has the load and the effort on the same side as the fulcrum and the fulcrum is always at one end of the lever; force must be exerted in the same direction as load must be moved
eg. ankle
108
Explain what a class 3 lever is
FEL/LEF
The effort and the load are on the same side on the fulcrum but the effort is exerted closer to the fulcrum than the load
eg. during a biceps curl
109
What are antagonistic muscles
Muscles that work opposite to one other (in pairs) when one contracts the other relaxes eg. biceps (flexor muscle) and triceps (extensor muscles)
110
Briefly describe the position of the biceps
On one end two tendons are attached to the pectoral girdle while the other end is attached to the radius
111
Describe the position of the triceps
One end is attached to the pectoral girdle with three tendons while the other is attached to the ulna
112
What muscles are involved during muscle contraction for movement
skeletal muscles (cross striated, voluntary muscles)
113
What causes striations in skeletal muscles
The arrangement of longitudinal, contractile myofibrils in the cylindrical muscles cells
114
What are the characteristics of skeletal muscles
1. Attached to the skeleton by inelastic tendons
2. Striations
3. Voluntary
115
What is osteoarthristis
The most common form of arthritis, which is caused by an inflammation of the joints. It is usually accompanied with pain and swelling
116
What is osteochondritis
An inflammation of the cartilage and bone; it leads to defective growth and deformity
117
What is osteogenesis impefecta
A hereditary condition in which a baby is born with very fragile bones
118
What is osteomalacia
A softening of the bones, caused by a deficiency of vitamin D
119
What is osteomyelitis
A bacterial infection of the bone marrow
120
What is osteoporosis
A change in the mass or texture of bone, caused by a depletion in the level of calcium it contains; as a result the bones become weak
