Upload
others
View
6
Download
0
Embed Size (px)
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 1
SESSION 8: SUPPORT SYSTEMS IN ANIMALS PART 1 KEY CONCEPTS
hydrostatic skeleton, exoskeleton, endoskeleton – examples, advantages & disadvantages
human skeleton – parts of axial & appendicular skeleton
functions of skeleton
structure of a long bone X-PLANATION Skeletons have three major functions:
1. Support 2. Movement 3. Protection of internal organs
HYDROSTATIC SKELETON:
Consists of fluid held under pressure in a closed body compartment
Protects body parts by cushioning them from shock
Provides body shape, which can be changed by contracting muscles in the body wall
Provides resistance for muscle action
Earthworms, hydras, are examples of organisms with hydrostatic skeletons
TYPES
ENDOSKELETON
HYDROSTATICEXOSKELETON
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 2
Hydra:
Earthworm:
EXOSKELETON:
- Rigid external skeleton which can be hard or leathery
The exoskeleton of arthropods is made of chitin.
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 3
ENDOSKELETON (INSIDE THE BODY):
Consists of hard or leathery supporting elements situated among a variety of tissues
Most echinoderms, including sea stars and sea urchins, have an endoskeleton of hard plates beneath their skin
Vertebrate endoskeletons consist of cartilage or a combination of cartilage and bone
Sea Urchin:
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 4
Starfish:
TYPE OF SKELETON ADVANTAGES DISDAVANTAGES
HYDROSTATIC No need for specialised structures or tissues. Very little energy needed for locomotion as it is aided by water or moist land environment
Size is limited Must have moist habitat to survive Speed of locomotion limited
EXOSKELETON Protects animal Good body support Reduces water loss Provides good leverage for muscle action
Animal has to moult in order to grow Growth limited Movement limited to joints
ENDOSKELETON Greater flexibility Can grow much larger than other types Good body support and shape Protects internal organs Provides more positions for muscle attachment – more power to muscles
No outside protection Does not prevent dehydration Movement limited to joints
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 5
HUMAN SKELETAL SYSTEM
AXIAL APPENDICULAR
AXIAL SKELETON
Consists of the bones that lie around the longitudinal axis of the human body Skull bones, auditory ossicles
(ear bones), hyoid bone, ribs,
sternum (breastbone), and
bones of the vertebral column
*** Hyoid bone - U-shaped bone in the neck to which the tongue is attached.
Consists of the bones of the upper and lower limbs (extremities), plus the bones forming the girdles that connect the limbs to the axial skeleton
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 6
The Skull
The Vertebral Column
Cervical Vertebrae (7)
Thoracic Vertebrae (12)
Lumbar Vertebrae (5)
Sacrum 5 (fused)
Coccyx 4 (fused)
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 7
The Thorax
The Rib Cage and Sternum
Sternum - Manubrium, body, xiphoid process True Ribs (7) False Ribs (3) Floating Ribs (2)
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 8
THE APPENDICULAR SKELETON
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 9
The Pelvic Girdle
Comparing male and female pelvic girdles:
General Functions:
• Support - framework that supports body and cradles its soft organs
• Protection - for delicate organs, heart, lungs, brain
• Movement - bones act as levers for muscles
• Mineral storage - calcium & phosphate
• Blood cell formation - from bone marrow
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 10
Types of bones making up the skeletal system:
• Long Bones - metacarpals, metatarsals, phalanges, humerus, ulna, radius, tibia, fibula
• Short Bones - carpals, tarsals
• Flat Bones - rib, scapula, skull, sternum
• Irregular Bones - vertebrae, some facial bones
X-AMPLE QUESTIONS Question 1: Explain 3 functions of the skeletal system.
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 11
Question 2: Complete the table below:
Bones of Skeletal System
Axial or Appendicular Skeleton
Tarsals 1
Vertebrae 2
Ribcage 3
Scapula 4
Pelvis 5
Mandible 6
Question 3: Study the diagrams and answer the questions:
Life Sciences Grade 10
www.learnxtra.co.za
Brought to you by Page 12
3.1 Identify parts labelled 2, 4 and 5. 3.2 What is the function of structure labelled 8? 3.3 Why are parts labelled 10 referred to as false ribs? 3.4 Provide the numbers of the following parts: a) floating ribs b) sternum Question 4: Study the following diagram and answer the questions:
4.1 Provide labels for parts A,B,C and D. 4.2 In which region (1 or 2) would you find the little toe. Provide a reason for your
answer.
A
B C
D
1
2