Skeletal System Flashcards
1
Q
Invertebrates Skeletons
A
- Either lack a hard skeleton (E.g., Worms)
- Or have an exoskeleton (insects)
2
Q
Hydrostatic Skeleton
A
- Skeleton that uses fluid pressure in body cavity to support an organism’s shape and movement
- E.g., Earthworms, sea anemones
3
Q
Exoskeleton
A
- Muscles work against a rigid external shell. Lack a hard skeleton.
- Exo = on the outside
- E.g., Insects, clams, crabs, snails
4
Q
Endoskeleton
A
- Vertebrates have this
- Muscles work against internal body parts
- Endo = on the inside
- E.g., Fish, amphibians, reptiles, birds, mammals (including humans)
5
Q
Axial Skeleton
A
- Consists of the spine, ribs, head, and tail (80 bones)
- One of the two major parts of the vertebrates skeleton
- Well conserved – spine rib cage and head are easily distinguished between most vertebrates
- Linear bilateral symmetry – vertebrates have a line down the middle (spine) and two similar sides (left and right)
6
Q
Appendicular Skeleton
A
- Consists of the appendages (arms, hands, legs, feet, shoulder girdle, and pelvic girdle) (126 bones)
- One of the two major parts of the vertebrates skeleton
- Fits to its environment – E.g.:
- Humans: hands, arms, legs
- Dogs: paws, legs
- Birds: wings, legs
- Fish: fins
7
Q
Functions of the vertebrae skeleton
A
- Mineral storage
- Blood cell formation
- Support
- Protection
- Movement
8
Q
Store Minerals
A
- Calcium – necessary for muscle contraction, including heartbeat
- Phosphorus: DNA backbone, needed for ATP
- Bones store 99% of body’s calcium, 85% of body’s phosphorus
9
Q
Blood cell formation
A
- Bone marrow contains stem cells: undifferentiated cells that become specific cell types
- Red and yellow bone marrow
- Red bone marrow stem cells become blood cells
10
Q
Support
A
- The skeleton supports body shape and orientation
- Humans: tall, upright, versatile
- Fish: long, thin, streamlined
- Frogs: low center of gravity for jumping
11
Q
Protection
A
- Rigid structure protects soft vital organs
- Rib cage protects heart, lungs, digestive tract
- Skull protects brain
12
Q
Movement
A
- Skeletal system works with the muscular system
- Flexible ligaments hold bones together
- Allows the skeleton to move
13
Q
Cells that make up bones
A
- Osteoblasts
- Osteocytes
- Osteoclasts
14
Q
Osteoblasts
A
- Create bone by producing the extracellular matrix and mineralizing it
15
Q
Osteocytes
A
- Mature osteoblasts that are trapped within the bone matrix
16
Q
Osteoclasts
A
- Break down old bone tissue
17
Q
Types of Vertebrate Bone Tissue
A
- Periosteum
- Compact Bone
- Spongey Bone
- Others
18
Q
Periosteum
A
- Layer of connective tissue around the outside of the bone.
- Important for bone growth, repair, and nourishment
19
Q
Compact Bone Tissue
A
- Around the outer edges of bone
- Hard outer layer
20
Q
Spongey Bone
A
- Inside the bone
- Less dense
- Make bones lighter and more flexible
- Primarily found at the ends of long bones – within the pelvic bones, ribs, skull, and vertebrae
21
Q
Other Types of Bone
A
- Contain blood vessels and nerves
- Bone Marrow – produce blood cells in the centre of some bones
22
Q
Bone and Mineral Storage
A
- Every bone in the vertebrate body is an organ
- Bones are living organs
o Can heal after they are broken
o Remodelled throughout life - Bones are important storehouses for two minerals:
o Calcium is necessary for muscle contraction, including the heart, and nerve function
o Phosphorous is important in ATP and DNA - When there is not enough Ca+2 in the body, the body obtains it by dissolving bone tissue
- It is important to maintain bone density by:
o Eating a diet high in calcium - Dairy products, broccoli, sea food
o Doing weight-bearing exercise - Running, walking, lifting weights - When the body has enough calcium and there is stress on the bones, the body will build the bones and make them stronger.
- Smoking increases the rate of decrease in bone density as a person ages.
- The efficacy of dietary supplements is unclear and do not seem to work as well as dietary calcium. When the bones become thin, it can lead to fractures, including fractures in the spine that can lead to back problems and reduced mobility.
