BIOL1003 Lecture 4: Lecture 4 BIOL - Skeletal System
9 Aug 2018
School
Department
Course
Professor
13th March
Human Biology – Lecture 4
Lecture
Skeletal System
• Bone is living tissue
206 bones in the human body and are categorized according to
their shape:
- Long: femur
- Short
- Flat: bones of the skull, scapula
- Irregular
3 cell types part of the bone and all arise from osteogenic stem
cells
- osteoblasts – build bone
- osteocytes – maintain
- osteoclasts – break down
Composition:
- 25% organic matter- collagen
- 50% Inorganic matter – calcium and phosphate
- 25% water
Structure:
- Epiphysis
- Centre of the long bone: diaphysis or shaft
• Bone Compact (compact bone has rigidity and strength so it doesn’t
shatter when impacted)
Solid matrix: strength, rigid
Haversian system:
- In the centre: central canal contains blood vessels, vain and
arteries.
- Canaliculi
- Lacunae (within the lacunae you have osteocytes)
Periosteum and endosteum: both have osteogenic stem cells and
have veins and arteries
- There are pain receptors in the periosteum
• Cancellous or spongy bone
Honey comb matrix allows it to absorb shock – e.g. when you
stamp your foot, the shockwave doesn’t reverberate throughout
the body, it is contained in the femur.
Trabeculae
- Surrounded by endosteum
Bone marrow
- Red marrow contains: red, white cells and blood elements
- Yellow marrow: replaces the red marrow through maturity
and contains fat cells
• Bone formation (ossification):
Embryo (3 months)
Modelled on connective tissue:
Document Summary
206 bones in the human body and are categorized according to their shape: 3 cell types part of the bone and all arise from osteogenic stem cells. 50% inorganic matter calcium and phosphate: bone compact (compact bone has rigidity and strength so it doesn"t. Centre of the long bone: diaphysis or shaft shatter when impacted) In the centre: central canal contains blood vessels, vain and arteries. Lacunae (within the lacunae you have osteocytes) Periosteum and endosteum: both have osteogenic stem cells and have veins and arteries. There are pain receptors in the periosteum: cancellous or spongy bone. Honey comb matrix allows it to absorb shock e. g. when you stamp your foot, the shockwave doesn"t reverberate throughout the body, it is contained in the femur. Red marrow contains: red, white cells and blood elements. Yellow marrow: replaces the red marrow through maturity: bone formation (ossification): and contains fat cells. Intramembranous ossification membrane is used as a.
