Bone and Skeletal Flashcards
memorization
What are the functions of the skeletal system?
- Support
- Movement
- Produce Blood cells (Hematopoiesis)
- Mineral storage
- Protects internal organs
What types of marrow are in bone?
Red and yellow
What special function is red marrow associated with?
Hematopoiesis (Production of red blood cells)
Do red blood cells have a nucleus? Why?
No. they eject the nucleus to make room for hemoglobin.
What is yellow marrow’s main component?
Adipose tissue (Fat)
What are the different bone shape classifications? hint (FLISS)
- Flat
- Long
- Irregular
- Sesamoid
- Short
What is the membrane surrounding the outer surface of bone consisting of a dense irregular connective tissue with a cellular inner layer?
Periosteum
What is the membrane lining the medullary cavity?
Endosteum
What is the gross anatomy of a long bone? see book page 221
Proximal Epiphysis(Spongy bone center red marrow)cartilage
Metaphysis(Epiphyseal line)Red marrow
Diaphysis(Yellow bone marrow)
Metaphysis
Distal Epiphysis(spongy bone)cartilage
The Endosteum lines the?
Medullary cavity
What describes an articulation?
A joint: when bone surfaces conform to fit one another
What describes a projection, and what do they do?
An area of bone that is raised, muscle and tendon attachment
What is a foramen?
Opening for blood vessels and nerves to travel through a bone.
What are the cell types found in bone? Which is the stem cell, and which dose not differentiate from this stem cell?
- Osteogenic cell (Stem cell)
- Osteoblast
- Osteocyte
- Osteoclast (not from osteogenic)
What cell would the Osteogenic cell differentiate from, and where are they found?
Mesenchymal cells, Periosteum
What do Osteoclasts do, and where do they come from?
Resorb bone, Myeloid stem cell in red bone marrow
Where would you find an Osteogenic cell, what makes them special?
Deep layers Periosteum, Marrow, only cell in bone that can reproduce
What are Osteoblasts, and where can they be found?
Forms new bone, Periosteum/Endosteum
What are Osteocytes, and where are they found?
Osteoblasts secrete new bone matrix and become encapsulated in Lacuna(e) when matrix calcifies. Once trapped in Lacuna, Osteoblasts differentiate into Osteocytes which maintain the calcified matrix. Found in both compact bone and spongy bone.
Can Osteocytes Replicate themselves?
No
Can an Osteoblast cell Perform replication?
No
What is the space an Osteocyte Occupies?
Lacuna(e)
What are the roles of spongy and compact bone?
The spongy bone helps resist tension forces from a variety of different directions and the compact bone helps resist compression forces parallel to the central canals.
Compact bone is made of?
Osteon
What is an Osteon?
Rings of Concentric Lamella surrounding a central canal
What is Trabeculae?
Branching strut (beam) of osseous tissue found in spongy bone.
What is in the center of each Osteon?
Central canal (Compact bone)
What is the purpose for the central canal?
Blood, Lymph, Nerve Pathway (Compact bone)
Branches off the Central canal?
Perforating canal (Compact bone)
What are Lamellae?
Plates of osseous tissue
Types of Lamellae?
Concentric Lamellae(Osteon) Interstitial Lamellae (Between concentric Lamellae) Circumferential Lamellae (adjacent to periosteum and endosteum)
What are Canaliculi?
Small channels connecting lacunae
Lacuna?
Cavity surrounding an osteocyte
Arteries enter Spongy bone through the?
Nutrient Foramen (Small opening in the Diaphysis)
What is Intramembranous Ossification?
Development of bone from a mesenchymal cells within a fibrous membrane
Osteoblasts secrete?
Osteoid (Collagen fibers)
What is Endochondral Ossification?
Development of bone by replacing a Hyaline cartilage model with osseous tissue.
What is an Epiphyseal plate?
Region containing hyaline cartilage which enables longitudinal (Interstitial) bone growth. Located between the diaphysis and epiphysis in a long bone. At the end of puberty the epiphyseal growth plate completely ossifies leaving an epiphyseal line of compact bone in the adult.
What are the layers of the Epiphyseal plate?
- Reserve zone
- Zone of Proliferative
- Zone of Maturation
- Zone of Ossification
What is the difference between the Epiphyseal plate and the Epiphyseal line?
The plate contains hyaline cartilage allowing the bone to grow. The line consist of compact bone and is a remnant from the growth plate.
What happens in the reserve zone?
Hyaline cartilage matrix production
What happens in the proliferative zone?
Mitosis (cell division) of chondrocytes
What happens in the zone of maturation?
Matrix calcifies and chondrocytes die
What happens in the zone of ossification?
Osteoblasts migrate into the lacunae and secrete osteoid that becomes calcified with hydroxyapatite forming the matrix of osseous tissue.
What is Diploe?
Spongy bone sandwiched between compact bone (Flat bone)
What are the types of fractures? Hint 8 Types
- Closed(not protruding skin)
- Open(Protruding skin)
- Transverse(Across long axis of bone)
- Spiral(twisting)
- Comminuted(multiple breaks)
- Impacted(driven into itself)
- Greenstick(partial fracture)
- Oblique(angle other than 90 degrees i.e. transverse)
What is the process for bone repair?
- Formation of Fracture Hematoma- clotting blood fills the fracture (6 to 8 hrs).
- Formation of Internal and External Calli- osteoblasts and chondroblasts create spongy bone and cartilage respectively to stabilize the fracture (48 hrs).
- Ossification of Cartilage in calli produces spongy bone (Endochondral ossification).
- Remodeling- Osteoclasts remove damaged bone matrix, and osteoblasts produce new osteoid to restore the shape of the bone and form a layer of compact bone replacing spongy bone superficially.
What is hydroxyapatite made from?
Calcium Phosphate Hydroxide (Hydroxide can be replaced with Carbonate, Fluoride, or Chloride)
What hormone secreted by the pituitary gland is essential for bone growth?
GH or Growth hormone (Stimulates Chondrocyte proliferation and Osteoblasts activity) Increases length of bones
Which hormone,secreted by the thyroid gland, promotes osteoblastic activity?
Thyroxine (stimulates bone growth)
What hormones promotes Osteoblastic activity, and the transformation of the epiphyseal plate into the epiphyseal line?
Sex hormones (Estrogen and Testosterone Released in High Levels During Puberty)
What hormone stimulates absorption of calcium and phosphate from the digestive tract?
Calcitriol (speeds up absorption)
What hormone produced by the thyroid gland inhibits Osteoclast (Bone absorption) activity?
Calcitonin (slows bone absorption)
What hormone stimulates Osteoclast proliferation and activation to release calcium from bone? In the kidneys this hormone also promotes reabsorption of calcium and activation of Vitamin D (calcitriol).
Parathyroid hormone (PTH)
