Supporting systems (ANIMALS BONES) pages 37 - 45 Flashcards
Name + Explain the three types of skeletons
Hydrostatic skeletons- consist of fluid filled closed chambers inside the body, that provide support, against which muscles can contract to bring about movement. “Cushion” internal parts from shock.
Exoskeletons- SURROUND the BODY of an organism.
Endoskeletons- Found WITHIN the BODY of an animal
Which animals have a hydrostatic skeleton, exoskeleton and endoskeleton?
hydrostatic- soft-bodied INVERTEBRATES
exo- in many groups of animals, mainly ARTHROPODS (exo is made of “chitin”).
endo- all VERTABRATES (made of bone and or cartilage)
What are the advantages of of exo and endoskeletons
Arthropod exoskeleton:
*{{External structure}} that- supports animal and protects internal organs from injury.
*Has {{muscles}} attached knobs and plates so it allows for movement.
*Has {{joints}} where exo is thin + flexible = enables animal to MOVE easily.
*Covered in {{cuticle}} = reduces loss of water from body = prevents animal from drying out.
Endoskeleton:
* {SUPPORTS} body by giving it shape
* Made up of {LIVING TISSUE} that can grow as animal increases size
* {PROTECT} internal organs e.g. brain, lungs, ❤️
* {PROVIDES ANCHORS} for muscles which work with bones to allow movement.
What are the disadvantages of hydrostatic and exo,
and
How can exo overcome disadvantages
soft bodied animals:
~Restricted range of movement
~Cant reach great size, whether they live in 💧 or on 🏝️
~Confined to areas near or in 💧, cause they lose water so readily.
Exo:
~ Rigid= limits mobility
how to overcome:
~ allowing flexibility by ➗ into different functional units OR
~ Arthropods have joined limbs where exo is thin at the joints = enables leg to move
~ Limit growth, large animal need large exo which is heavy + restricts movement.
how to overcome:
~ they moult/ecdysis- process where Arthropods shed their exo to enable them to grow.
After exo is SHED Arthropod PUMPS up body by the INTAKE of air or water to EXPAND new exo to a large size.
DEHYRATION of cuticle takes place causing it to harden into exo.
(easy prey when moulting)
How does the jellyfish and earthworm move?
JELLYFISH: move by CONTARCTING their bell-shaped form = FORCES water out of the bell = PROPELS the jellyfish forward.
Earthworms: Use hydrostatic skeleton to change body shape as they move forward by PERISTALSIS.
{Circular and longitudinal} muscles produces movement through waves of {contraction and relaxation}.
When lengthwise muscles contract, segments of the body shorten, when circular muscles contract segments of the body elongate.
CHAEATE {press} into the ground to ensure that earthworm moves forward.
Name + Explain what tissues made up an endoskeleton
What are they supplied with?
- Cartilage- occurs in isolated areas in body e.eg. ribs, 👃
*Less minerals = softer than bone.
*Few blood vessels + NO nerves
2.Bone- Bulk of skeleton.
*Hardest tissue in body
*Needs to be light to reduce weight for animal to move around
*Supplied with: blood vessels, nerves and lymph vessels
How is cartilage and bone tissue made up
Cartilage
3 types: Hyaline, Elastic, Fibrous Cartilage
Components of above:
~Chondrocytes in lacunae
~Matrix- surround Chondrocytes, made of jelly-like substances in which both collagen fibres and elastic fibres= deposited
~Tissue fluid- 80% of cartilage = 💧
Bone
Made of Osteocytes in lacunae, set in matrix, made up of:
~Collagen fibres AKA white fibres (stick in criss cross pattern)- give bone flexibility, making it strong + durable, cause the fibres stick together in criss-cross pattern.
~Minerals- Account for hardness of the bone.
How is bone tissue classified?
2 types:
*Compact bone
Found: Surface of bones and shafts of limbs
Are: Very hard + dense
Look: Smooth + Homogenous
Made up of: Many Haversian systems or osteons
Provide: Strength + Support
*Spongy Bone
Lighter in weight and has more open structure
Made of: Trabeculae
Able to: Resist stress as the plates of trabeculae are arranged along lines of stress
Able to: Form red and white blood cells in red marrow.
How are bones classified
- Long bone
*Made of: Shaft, diaphysis, two heads and epiphyses.
*All bones of limbs = long, except patella, wrists, and ankles
*Provide: Support for limbs and for attachment of muscles, which enables limbs to bring about movement
2.Short bones
3.Flat bones } Read through
4.Irregular bones
Why is bone and cartilage so N.B
Bone- ~Compact bone gives STRENGHT + SUPPORT to body
~Spongy bone helps skeleton REDUCE SRESS and
MANUFACTURES RED AND WHITE BLOOD CELLS
Cartilage- ~LINES many joints, facilitating smooth movement
~Acts as SHOCK ABSORBER between vertebrae
~Forms FLEXIBLE structure.
Diagram of typical long bone
Check One Note
Differentiate between bone fracture, stress fracture and greenstick fracture
*Bone fracture = Break/crack in bone
*Stress fracture = Small crack in bone, result of repeated pressure on the bone due to prolonged activities
*Greenstick fracture = Incomplete break of bone. Cracks on one side.
What causes a fracture, and why are older women more likely to break a bone?
Caused by trauma:
~ Physical abuse 🤦
~ Injuries from falls or sports ⚽️
~ Diseases that weaken bone i.e. OSTEOPOROSIS 🤕
Osteoporosis = more common in women after middle age
How are different fractures are described? (5)
Complete = bone broken into TWO pieces
Incomplete/greenstick = bone CRACKS but doesn’t break
Simple = bone breaks CLEANLY but DOESNT penetrate skin
Compound/open = Bone penetrates skin, and stick through the skin
Comminuted = Bone fragments into many pieces
VIEW PICTURES ON ONE NOTE
How can fracture be treated? (3)
- X-ray to 👓 type of fracture
- Broken pieces need to be realigned
- Bone must be IMMOBILIZED by cast/pins till they heal, as new bone forms around break
