Supporting Systems Flashcards
Name and explain the three types of skeletons
- Hydro skeleton - consists of fluid filled, closed chambers within an organism
- Exoskeleton- surrounds the body of an organism
- Endoskeleton - occur within the body of an organism
how do animals with a hydrostatic skeleton move
the fluid filled closed chambers provide support against which muscles can contact to bring about movement, the contracting creates pressure that causes a change in shape of the animal, this causes movements such as crawling, burrowing or swimming
give examples of animals that have hydrostatic skeletons
- coelenterates, eg. jellyfish
- annelids eg. earthworms
- nematodes eg. roundworms
What are the disadvantages of an hydrostatic skeleton
- they like well-developed skeletal depends mechanisms
- have a restricted range of movement
- are confined to areas near or in water
- cannot reach any great size
Give examples of animals that have exoskeletons
• Tortoises • coral • starfish • molluscs but Mainly found in arthropod
In arthropods what is the exoskeleton made from
it is made from the polysaccharide, chitin, which is a substance similar to the cellulose found in plant walls. it is light and strong
What are the advantages of an arthropod exoskeleton
- It’s an external structure that supports the animal and protect internal organs
- It has muscles attached to knobs and plates to allow for movement
- It has joints where the exoskeleton is thin and flexible which enables the animal to move more easily
- It is often covered with a layer of wax called a cuticle that reduces loss of water from the body which prevents the animal from drying out
What are the disadvantages of exoskeletons
- Limited mobility due to their rigidity
* Limited growth as a large animal would need a large exoskeleton that would be very heavy and restrict movement
How are the growth disadvantages of exoskeletons overcome
- arthropod shed their exoskeletons to allow them to grow this is called moulting or ecdysis. A new exoskeleton is generated by the underlying epidermis. after the exoskeleton is shed, the arthropod pumps up its body by the intake of air or water in order to expand the new exoskeleton to a larger size. Dehydration of the cuticle then takes place which causes it to harden into an exoskeleton
- many mollusks have calcareous shells and as the grow the diameter of shell is added to and enlarged without altering shape
How are the mobility disadvantages of exoskeletons overcome
- the arthropod exoskeleton is divided into functional units. egg the head, thorax and abdomen of insects
- arthropoda have jointed limbs where the exoskeleton is thin which enables the leg to move
what are vertebrate endoskeletons made of
either bone or cartilage
What are the advantages of an endoskeleton
- supports the body giving it shape
- is made of living tissue which can grow as the animal increases in size
- protects the internal organs such as the brain, lungs and heart
- provides anchors for muscles which work with bones to allow movement
What two things make up the endoskeleton
Bone and cartilage
Where it does Cartlidge occur
In isolated areas of the body such as in parts of the ribs, the nose, pinna of the ear, between vertebra and in the lining of joints
What is the difference between cartilage and bone
Cartilage is much softer than bone because it contains less minerals it has a few blood vessels and no nerves
What three types of Cartilage are there
Hyaline, elastic and fibrous
What are the basic components of Cartilage
- chondrocytes which are mature cartilage cells in the lacunae (cavities) surrounded by
- a matrix made up of a jelly like substance in which both collagen fibers (for flexibility and strength) and elastic fibers (for elasticity) are deposited
- a large amount of tissue fluid (80% of cartilage is water)
Why is cartilage important
- It lines many joints facilitating smooth movement
- it acts as a shock absorber between vertebra
- it forms flexible structures such as the Eppy glottis and Hannah of the ear
What must a bone tissue be supplied by
Blood vessels, nerves and lymph vessels
How is bone tissue made up
Bone tissue is made up of osteocyte in lacunae set in a matrix made up of the following:
• collagen fibres (made up of complex proteins) that stick to each other in a criss-cross pattern giving bone its flexibility, making it strong and durable, they have a glistening white appearance and are also called white fibres
• Minerals, including calcium salts that are incorporated into the matrix in a process called mineralisation
What are the two types of bone tissue
Compact bone and spongy cancellus bone
Explain compact bone
- Found on the surface of phones and the shaft of the limb bones
- Very hard and dense and looks smooth and homogenous
- made up of many Haversian systems or osteons
- provide strength and support to the body
explain spongy (cancellous) bone
- lighter in weight and has a more open structure
- made up of small thin plates of bone called trabeculae which form an irregular network
- able to resist stress as the plates of trabeculae are precisely arranged alone lines of stress
- able to form red (erythrocytes) and white (leukocytes) blood cells in the red marrow found in the spaces between trabeculae
what is the difference between osteocytes and osteoblasts and osteoclasts
osteocytes are inactive mature bones cells. if more bone is needed then they’re stimulated and they form osteoblasts which lay down the new bone tissue. osteoclasts (formed in the lacunae) break down bone
what four groups are bones classified in
- long bones
- short bones
- flat bones
- irregular bones
Explain long bones
they are much longer than they are wide. They are made up of a shaft, the diaphysis and two head (epiphyses)
Except for the patella, and the bones of the wrists and ankles, all the bones of the limbs are long bones
these bones provide support for the limbs and for the attachment of muscles, which enable the limbs to bring about movement
explain short bones
They are cube shaped bones which are nearly equal in length and width
they are made up of spongy bone, except at the surface where there is a thin layer of compact bone
examples are the carpals of the wrist and the tarsals of the ankles, the movement of these bones enable the wrists and ankles to rotate and move in many directions
Explain flat bones
They are thin, flattened and usually slightly curved bones
they’re made up of two parallel layers of compact bone with spongy bone between
flat bones protect parts of the body and provide large areas for the attachment of muscles
eg. cranial bones, sternum, ribs, scapulae
Explain irrregular bones
bones that can’t fit into any of the other categories
they have complicated shapes and are mainly made up of spongy bone enclosed by a thin layer of compact bone
eg. vertebrae and hip bones
name explain the three different types of fractures
- a bone fracture - break of crack in a bone
- a stress fracture - a small crack in a bone that occurs as a result of repeated pressure on the bone due to prolonged activities such as walking or running
- green stick fracture - an incomplete break of the bone (common in children as bones are softer)
what causes a fracture
when a bone cannot withstand the physical forces exerted on it. eg. injuries from falls or sport, physical abuse, diseases that weaken bones
how are different fractures described
- complete - broken into two pieces
- incomplete - cracks but doesn’t break (green stick)
- simple - bone breaks cleanly but does not penetrate the skin
- compound or open - the broken ends of the bone stick through the skin
- comminuted - bone fragments into many pieces
hoe can fractures be treated
- first an x-ray may be needed to see what type of fracture it is
- The broken pieces may need to be put back together in place
- The bones must be immobilised by a cast or by pins until they heal as new bone forms around break
What are the six functions of the human skeleton
- supper - help the body stay upright and keep its shape
- protection - for the internal organs and tissues of the body such as the heart lungs and brain
- movement - by the muscles which are attached to the bones
- blood cells - formed in the red marrow of bone
- mineral salts - calcium and phosphorus form part of the bones and are stored in them
- hearing - the ossicles in the middle ear transmit sound waves to the inner ear and enable us to hear
how many bones make up the human skeleton
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LABEL THE HAVERSIAN SYSTEM
PAGE 40
LABEL THE TYPICAL STRUCTURE OF LONG BONE
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LABEL THE DIFFERENT FRACTURES
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LABEL THE FULL SKELETON
PAGE 46
