Skeletal System ● Endoskeleton- Inside, made of bones and
cartilage as the human grows it also grows
Key Functions of the Skeletal System: (INTERNAL). Mostly in humans, dogs, birds,
1. Support and fish.
- The skeleton acts as the structural framework of ● Exoskeleton- Hard outer part that protects
the body. and supports the body, located outside the
- It forms a base for muscles and soft tissues to body (EXTERNAL). Mostly in insects.
attach, enabling posture and movement.
- The vertebral column (backbone) is crucial for Axial skeleton- consists of 80 bones arranged in the
upright posture; without it, the body would longitudinal axis of the body. Supports the head and
collapse. different vital organs, and provides attachment
2. Protection points for muscles. (UPPER EXTREMITIES)
- The skeleton safeguards vital organs and soft E.g Skull, vertebral column, spine, ribcage, breast
tissues. bone, laryngeal skeleton.
- Cranium (skull) and spine protect the central Appendicular skeleton- Consists of 126 bones that
nervous system. make up the upper and lower extremities as well as
- The rib cage protects the heart, lungs, and other the girdles that attach the limbs to the axial
thoracic organs. skeleton.
- Protection extends to all bodily systems through E.G shoulder girdle, upper limbs, pelvic girdle, lower
structural barriers. limbs
3. Production of Blood Cells
- Bone marrow inside many bones produces red I. Axial Skeleton
and white blood cells.
- Red blood cells transport oxygen throughout the The axial skeleton comprises bones along the body’s
body. central axis, primarily supporting and protecting
- White blood cells are essential for immune internal organs.
defense against pathogens.
4. Mineral Storage 1. Skull
- Bones act as reservoirs for minerals crucial for
Composed of cranial and facial bones protecting the
biochemical processes.
brain and features of the face.
- Bone is composed of minerals such as calcium
and phosphorus, these minerals account for 2/3 of A. Cranial Bones
the weight of bone
- 95% of calcium and 90% of phosphorus are stored ● 8 bones that form the cranial cavity,
in bones and teeth enclosing the brain.
5. Triglyceride Storage 1. Parietal bones
- Yellow bone marrow contains adipose cells ○ Two cranial bones forming the roof
storing triglycerides(fat), and is found in the hollow of the skull.
center of long bones(femur). The purpose of this is 2. Temporal bones
to provide or prolong energy in the body. ○ Bones at the sides and base of the
- Red bone marrow produces blood cells and skull.
Yellow bone marrow produces or primarily stores 3. Occipital bone
fat. ○ Forms the back and base of the
Lipids- stores fat skull, allowing passage of the spinal
Types of Skeleton: cord.
4. Sphenoid bone
cartilage as the human grows it also grows
Key Functions of the Skeletal System: (INTERNAL). Mostly in humans, dogs, birds,
1. Support and fish.
- The skeleton acts as the structural framework of ● Exoskeleton- Hard outer part that protects
the body. and supports the body, located outside the
- It forms a base for muscles and soft tissues to body (EXTERNAL). Mostly in insects.
attach, enabling posture and movement.
- The vertebral column (backbone) is crucial for Axial skeleton- consists of 80 bones arranged in the
upright posture; without it, the body would longitudinal axis of the body. Supports the head and
collapse. different vital organs, and provides attachment
2. Protection points for muscles. (UPPER EXTREMITIES)
- The skeleton safeguards vital organs and soft E.g Skull, vertebral column, spine, ribcage, breast
tissues. bone, laryngeal skeleton.
- Cranium (skull) and spine protect the central Appendicular skeleton- Consists of 126 bones that
nervous system. make up the upper and lower extremities as well as
- The rib cage protects the heart, lungs, and other the girdles that attach the limbs to the axial
thoracic organs. skeleton.
- Protection extends to all bodily systems through E.G shoulder girdle, upper limbs, pelvic girdle, lower
structural barriers. limbs
3. Production of Blood Cells
- Bone marrow inside many bones produces red I. Axial Skeleton
and white blood cells.
- Red blood cells transport oxygen throughout the The axial skeleton comprises bones along the body’s
body. central axis, primarily supporting and protecting
- White blood cells are essential for immune internal organs.
defense against pathogens.
4. Mineral Storage 1. Skull
- Bones act as reservoirs for minerals crucial for
Composed of cranial and facial bones protecting the
biochemical processes.
brain and features of the face.
- Bone is composed of minerals such as calcium
and phosphorus, these minerals account for 2/3 of A. Cranial Bones
the weight of bone
- 95% of calcium and 90% of phosphorus are stored ● 8 bones that form the cranial cavity,
in bones and teeth enclosing the brain.
5. Triglyceride Storage 1. Parietal bones
- Yellow bone marrow contains adipose cells ○ Two cranial bones forming the roof
storing triglycerides(fat), and is found in the hollow of the skull.
center of long bones(femur). The purpose of this is 2. Temporal bones
to provide or prolong energy in the body. ○ Bones at the sides and base of the
- Red bone marrow produces blood cells and skull.
Yellow bone marrow produces or primarily stores 3. Occipital bone
fat. ○ Forms the back and base of the
Lipids- stores fat skull, allowing passage of the spinal
Types of Skeleton: cord.
4. Sphenoid bone
