Anatomy 1.1B Flashcards
What are the two types of ossification?
Intramembranous ossification and endochondral ossification
What clinical conditions are associated with bone growth alterations?
Dwarfism, Marfan’s Syndrome, Rickets, Osteomalacia, Osteoporosis
What is intramembranous ossification?
Ossification that takes place inside the membrane, occurring in cranial bones and the sternum
What is endochondral ossification?
Ossification that occurs inside the cartilage, such as in long bones like the femur and humerus
What are the four major steps in intramembranous ossification?
- Stem cells differentiate into osteoblasts
- Osteoblasts secrete osteoid which calcifies
- Formation of woven bone
- Lamellar bone replaces woven bone
What are fontanelles and their function?
Ossified remnants of fibrous membranes in an infant’s skull that allow for compression during birth and brain growth
What is hydrocephalus?
A condition known as ‘water on the brain’ caused by a blockage in the ventricular system
What occurs during endochondral ossification?
Hyaline cartilage patterns are used for bone construction, which becomes calcified and replaced by bone
What is the role of the epiphyseal plate in bone growth?
It allows for longitudinal growth of long bones through zones of cartilage cells
What are the zones of the epiphyseal plate?
- Proliferation zone
- Hypertrophic zone
- Calcification zone
- Ossification zone
What is appositional growth?
The process where osteoblasts secrete bone matrix on the external surface to widen bones
What happens to bone remodeling as we age?
Osteoclastic activity outweighs osteoblastic activity, leading to thinner, lighter bones
What are some examples of conditions that alter bone growth?
- Marfan’s syndrome
- Achondroplastic dwarfism
- Pituitary dwarfism
What regulates bone remodeling?
Hormonal control loops and mechanical/gravitational forces
What is the normal range for blood calcium levels?
9-11 mg/100ml of blood
What hormone is released when blood calcium levels decline?
Parathyroid hormone
What is Wolff’s Law?
A bone grows and remodels in response to the demands placed on it
What are the stages of the physiological healing process after a fracture?
- Formation of a haematoma
- Growth of new blood vessels
- Formation of a soft callus
- Replacement with a spongy bone callus
- Bony union occurs
What are the categories of bone markings?
- Projections for muscle and ligament attachment
- Surfaces that help form joints
What is a tuberosity in bone markings?
A large rounded projection
What is a crest in bone markings?
A narrow ridge of bone, usually quite prominent
What is a trochanter?
A large blunt irregularly shaped process seen on the femur
What is the function of the head in bone markings?
A bony expansion of a narrow neck
What is a facet in bone markings?
A smooth fairly flat articular surface
What is a trochanter?
A large blunt irregularly shaped process found on the femur
The greater and lesser trochanters are specific examples found only on the femur.
What is the term for a bony expansion of a narrow neck?
Head
What is a facet in anatomical terms?
A smooth fairly flat articular surface
Facets are seen where the ribs attach to the vertebral bones of the thoracic spine.
What defines a condyle?
A rounded articular projection found at the end of long bones
Examples include the condyles of the femur and humerus.
What is a ramus?
A projection, such as that seen in the mandible of the jaw.
What is a fissure?
A narrow slit-like opening.
Fill in the blank: A _______ is a round or oval opening.
Foramen
What is a notch or meatus?
A canal or passageway.
What defines a sinus in anatomical terminology?
A cavity within a bone.
What is a fossa?
A shallow basin.
What are the sites for muscle attachment on the femur?
- Trochanter
- Tuberosity
- Tubercle
- Crest
- Line
- Epicondyles
What is the head of the femur?
An expansion on the narrow neck that provides the ball of the ‘ball and socket’ joint at the hip.
What are the medial and lateral condyles of the femur?
Rounded projections forming part of the knee joint.
What is the intercondylar fossa?
A shallow depression between the condyles.
What are the two processes for ossification?
- Intramembranous
- Endochondral
What hormones coordinate long bone growth?
- Growth hormone
- Sex hormones
What regulates the release of calcium into blood?
Parathyroid hormone (PTH)
What role do osteocytes play in bone remodeling?
They monitor and maintain bone matrix and release biochemical signals in response to physical stress.
What are the three categories of bone markings?
- Projections that form attachment sites for tendons and ligaments
- Projections that form joints
- Depressions or openings to allow passage of neurovascular bundles
