Chapter Seven : Support and Movement

 

 

The amin concept of chapter 5
Support and movement in living organisms

1- In plants there are two main types of support:
a- physiological support e.g cell turgidity.
b- Structural support, [by deposition of hard substances such as cellulose lignin, cutin, subrin on or in the cellwalls].

2- The cell wall becomes stronger if cellulose or lignin are deposited.

3- The human skeletal system consists of bones and cartilages [206 bones].

4- Bones form about 18% of the total body weight.
5- The bone is hollow and covered by periosteum rough membrane.

6- The bone marrow inside the bone cavity contains blood capillaries and nerves, it forms new blood cells.

7- Bones which perform the same function are identical in structure.

8- Ligaments which are rough tissues attache between bones, they exist in movable joints.

9- The tips of articulated bones are covered with cartilage.
10- The synovial fluid prevents or reduces friction between bones.

11- The skeletal system in man consists of:
a- Axial skeletal system:
[ vertebral column - rib cage - skull]
B- Apendicular skeletal system:
[ The upper limbs - the lower limbs the pectoral girdle - the pelvic girdle]
12- The vertebral column consists of 33 vertebrae which differ in shape and size in different regions of the body:
a- 7 cervical.
b - 12 thoracic.
c- 5 lumber.
d- 5 sacral. Fused"
e- 4 coccyx "fused"

13- Each vertebra has a neural canal or arch through which the spinal cord passes.

14- The skull consists of two main parts the cranium which is made up of 8 serrated bones, and the facial part which includes face bones, jaws and dense orbits of ears, eyes and nose.

15- At the base of the cranium there is a large hole known as the foramen magnum through which the spinal cord passes.

16- The thoraic cage consists of :
12 thoracic vertebrae, the sternum and 12 pairs of ribs.

17- The last two pairs of ribs are short and do not reach the sternum and are known as floating ribs.

18- Ribs can move anteriorly and laterally to increase the thoracic cavity.

19- The pectoral girdle or shoulder bones consists of the scapula and clavical.

20 - Bones of the upper limb are:
Humerus - radius and ulna - carpals meta carpals - phalanges.

21- The lower limb consists of :
femur - tibia - fibula - tarsals - metatarsals - phalanges.

The pelvic girdle and the sacrum together form the pelvis in the region of the hips.

23- Each pelvic girdle consists of 3 bones which are ilium ischium , and pubis.
24- The main types of movement in living organisms:
a- cytoplasmic streaming
b- Positional movement of some organs e.g peristalsis
c- The movement of insectivorous plant leaves.
d- The movement of animals from one place to another.
25- The skeleton may be endoskeleton or exoskeleton.

26- Some plant leaves respond to touch and move e.g mimosa.
27- Leaves of legumes and mimosa move as a response to light and darkenss.
28- Different plant parts repsond to different stimuli like light, water and gravity this is called tropism.
29- Haptotropism is responding to a support which is seen in tendrils of peas.

30- If the tendrils do not meet a support they will welt and die.

31 - The pull movement is seen in subterranean stems and bulbs, the pulling roots contract pulling them downwards.

32- The body parts move as a system of levers:
a- Nodding of the head represents a lever of the first order.
b - Movement of foot on the ankle represents a lever of the second order.
c- Bending your hand upward represents a lever of the third order.