SKELETAL SYSTEM AND SUPPORTING TISSUES, Introduction to the skeletal system in living organisms
Living 0rganisms including plants and animals need tissues and other supporting systems to enable them carry out life’s processes such as movement, respiration, feeding and reproduction.
Here is a typical example of what I am saying, without the various bones and tissues, vertebrates will not be able to stand, respire, move and carry out other life’s processes Many multi-cellular organisms, mostly plants and animals needs to support themselves in some way to enable them to maintain their shape. It is also worthy of note that without the skeletal system, we as humans will not be able to stand upright, move about in search of food, carry loads, raise our heads and other parts of the body. As a result of the above stated facts about the skeletal system of living organisms, we have no choice than to devote ample time to study one of the essential parts of living organisms.
THE SKELETAL SYSTEM AND THE SUPPORTING TISSUES IN ANIMALS
What is skeleton? Why do we have skeleton in our body as living things?
The question will not be complete if we don’t ask how many bines are there in the human body or how can we count the number of bones in the body of humans. So here is a compact definition of the skeletal system
WHAT IS SKELETON?
Skeleton is the bony framework of the body which provides support, shape and protection of the soft tissues and organs in animals. Without the skeletal system, animals may not be able to carry out most of life’s processes such as movement, respiration and feeding. One of the most important functions of the skeletal system is that it enables animals to move from place to place
The skeletal system helps to determine the advancement and development of organisms, for instance, man is able to stand erects/upright because of our sophisticated skeletal system.
THE COMPONENT OF SKELETAL MATERIALS AND THEIR VARIOUS FORMS
This is most confusing in trying to understand and name the various forms of the skeletal system. The issue here is what are materials the creator of living organisms used in making the skeleton? Does the skeleton have components? So join me as I take deeper into the study of skeletal system of living organisms.
There are three forms of skeletal materials found in animals. These are cuticles, bones and cartilages
The cuticles as a material of the skeletal system, is composed of chitin and a thin of water proof layer of wax. The chitin is non-living substance, therefore animals with this type of skeletal material can only grow by moulting. In this process of growth called moulting, an organism only shed off it old skeletal system and put on a new one. In order words, any organism with this type of skeleton will have put off the old skin.
The cuticle is an exoskeleton which is located externally on the body of the organism. An example of organism with the cuticle as its skeletal material system are mainly arthropods which are insects, crabs, scorpion and prawns
The bones as part of the skeletal system of organisms, is a tissue and a major component of the vertebral skeleton. It consists of living bone cells called osteocytes, protein fibres called collagen and minerals which is mainly calcium-phosphate and calcium-carbonate
The minerals, which is the non-living component of the bone is made up of the mass of a bone. As a result, bone is stronger and more rigid tissue than the cartilage.
A bone consists of a hard outer layer-shaft and a spongy or hollow cavity filled with bone marrow. A typical example of organisms which have bones are mainly vertebrates, which are bony fishes, toads, lizards, snakes, birds and mammals.
The cartilage, as form of material found in the skeletal system, is a tissue found in the skeleton of complex vertebrates. The cartilage consist of living cells called chondroblasts, carbohydrates and protein fibres. The cartilage is a flexible and tough tissue that has great tensile strength.
The cartilage acts as a shock absorber, cushioning the effects of bone moving against bone during movement. Examples of organisms with cartilages are mainly cartilaginous fishes like wales, sharks and mammals generally.
TYPES OF CARTILAGES
In mammals mostly, there are three types of cartilages. They are
i. Hyaline cartilages
This type of cartilages is found in bronchi and trachea, surfaces of movable joints, the protruding part of the nose which supports it
This types of cartilages is tougher than hyaline cartilages and it is found in the discs between the small bones of the vertebral column
iii. Elastic cartilages
This type of cartilages is found in the external ear called pinnae and the epiglottis
THE VITAMINS AND MINERALS ELEMENTS NECESSARY FOR HEALTHY BONE DEVELOPMENT
Generally it is said that growth is effective and consistent if certain activities which are supposed to propel it is in proportion to it. So these vitamins and mineral elements are
i. Vitamin-D Calciferol, Vitamin-C all form the cement of bone
ii. Mineral elements are calcium/phosphorus/magnesium
The difference between bones and cartilages
I. Bone is made up of living and non-living cells
II. Bones are flexible especially in adults
III. Bone is made up of hard substance
IV. Bone can never be replaced by a cartilage
V. Bone is made up of mineral salts
VI. Bone is stronger, and it is a more rigid tissue
CARTILAGE Cartilage is made up of mainly living cells
ii. Cartilage is very flexible both in young and the adult
iii. Cartilage is made up of soft materials or substance
iv. Cartilage is not as strong as the bone but it is a flexible tissue
TYPES OF SKELETON
TYPES OF BONE
PLEASE READ MY PREVIOUS ARTICLE ON FORMS OF SKELETAL MATERIALS AND BONES TO FULLY UNDERSTAND WHAT IS SKELETON
As I highlighted in my previous post, here I will be treating the various types of skeleton in more advanced detail. As you read, if there is any topic or subject, or whatever question you would like me to clarify please don’t hesitate to use our comment box or search this blog using the search box.
There are three main types of skeleton.
1. Hydrostatic skeleton
2. Exoskeleton and
The Hydrostatic fluid skeleton
The hydrostatic skeleton is the type of skeleton possessed by soft-bodied animals. They have fluid pressure to provide support. The fluid is secreted to fill the spaces in the body. The fluid presses against the body wall, causing the muscles to contract, exerting pressure against the fluid.
This helps to maintain the shape and form of the animal. Example of organisms with this type of skeleton is the earthworm and anemones
Exoskeleton is the type that is found in outside or the external part of the body of some animals. Most vertebrates also possess cuticle which is composed of chitin.
The Chitin is non-living substance commonly found covering the outer parts of the body of some animals. Such external skeletal tissues encloses, supports, gives shape, protects and enable the animals to move about from place to place.
Here is a skeletal system of human
Examples of organisms with exoskeleton are invertebrates like Euglena, Paramecium, Hydra, Tapeworm, Snails, Prawn, Crabs, Spiders, Crayfish, millipedes and earthworms.
Organisms with this type of skeleton can only grow by a process called moulting or ecdysis. In this process, an organism sheds off its old skeleton, and is covered with a new one as it grows.
An endoskeleton is the type of skeletal system that is found in the body of the animal. Endoskeleton exists in bony or cartilaginous skeleton of fishes, toad, lizards, birds and mammals. The endoskeleton in vertebrates is made up of cartilages and bones. Endoskeleton in mammals are the skull, vertebral column or backbone, ribs and the bones of the fore-limbs and hind-limbs
THE BONES OF AXIAL AND APPENDICULAR SKELETON
The skeletal system or bones in mammals like that of rabbit are grouped into two major parts. These are the Axial and Appendicular skeleton which are the main part of the skeletal system
1. Axial skeleton
The Axial skeleton is made up of the skull, vertebral column or backbone, the ribs, sternum/breastbone
2. Appendicular skeleton
The Appendicular skeleton is made up of the limb girdles (pectoral and pelvic girdle) and the limbs (forelimbs and hind limbs)
The mammalian skull is made up of several flat bones which are joined together by means of joints called sutures
There are three major parts of the skull
i. The cranium which is often called the brain box. This part of the skull houses the brain
ii. The facial skeleton, supports the nose, eyes and the muscles of the cheek.
iii. The jaw. This part of the skull is made up of the upper jaw called MAXILLA and the lower jaw known as mandible in the teeth is also fixed.
The functions of the skull as part of the skeletal system
i. The skull gives protection to the brain
ii. The skull gives shape to the head
iii. The skull protects vital organs like eyes, nose and ears
iv. The skull bears the teeth which is used for the grinding of food
THE VERTEBRAL COLUMN OF THE SKELETAL SYSTEM
The vertebral column, also known as the backbone or spinal column, is the central supporting structural system of the skeleton. The vertebral column forms the backbone of the vertebrate animals and houses the spinal cord.
It is made up of five group of bones known as the vertebrae=== singular vertebra. In humans, it consists of 33 vertebrae while in rabbit it consists of 46 vertebrae. The vertebrae are held one the other with a strong ligament having compressible cartilage pads called INVERTEBRAL DISC between consecutive vertebrae.
In mammals, the five different vertebrae are
1. Cervical vertebrae===== this found in the neck region
2. Thoracic vertebrae=====this type of vertebra is found in the chest region
3. Lumber vertebrae====this type of vertebrae is found along the upper abdomen
4. Sacral vertebrae=== this type of vertebrae is found around the lower abdomen
5. Caudal vertebrae=-==== this type of vertebrae is found around the tail region.
The features of typical vertebrae as part of the skeletal systems
All vertebrae, even though they have different functions, have certain features in common. So a typical vertebrae has the following features in common
this is for the passage of the spinal cord
this projects upwards dorsally for the attachment of muscles
they projects from each sides of the vertebrae for the attachment of muscles and ligaments
it is a solid piece of bone below the neural canal
v. Facet: this a small, smooth and slight depressed area on a bone that is usually a point of contact with another bone.
vi. Zygapophysis: these are articular surfaces for the articulation of successive vertebrae. They are grouped into two parts. Pre-zygopaphysis facing inward and upwards while the post-zygapophysis faces outward and downward
Don’t get tired friend, read about the various types of vertebrae here
Types of vertebrae and their functions
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