Exam 2 - BIOS252 / BIOS 252 (Latest 2024 /
2025) : Anatomy And Physiology II With Lab -
Chamberlain
Describe the cells of the bone tissue - ANSWER -Osteogenic
cells
-Osteoblasts
-Osteocytes
-Osteoclasts
What membrane lines the internal canals and the small cavities of the compact and spongy
bones? - ANSWER Endosteum
What is the periosteum composed of? - ANSWER -Dense
irregular connective tissue
-Collagen fibers
-Outer fibrous layer has fibroblasts
-Inner layer has progenitor cells that become osteoblasts
,Describe the matrix of the bone tissue - ANSWER -Stony matter
surrounding osteocytes and lacunae
-1/3 organic (collagen and protein-carb complex) and 2/3 inorganic (CaK, CaCO3...)
-gives bone flexibility and strength
-Minerals resist compression
-Collagen resists tension
Compare the function of the organic and the inorganic material in the bone matrix -
ANSWER -Inorganic (minerals) resist compression
-Organic (protein-carb complex/collagen) resists tension
Why does calcification result in death of chondrocytes, while ossification does not result in
death of osteocytes? - ANSWER Chondroblasts are surrounded
by cartilage matrix and receive oxygen and nutrients by diffusion through the matrix. When the
matrix becomes calcified, diffusion is reduced the the point that the cells die. When osteoblasts
form bone matrix, they connect to one another by their cell processes. Thus, when the matrix is
laid down, canaliculi are formed. Even though the ossified bone matrix is dense and prevents
significant diffusion, the osteocytes can receive gases and nutrients through the canaliculi or by
movement form one osteocyte to another.
Describe the process of endochondral ossification. - ANSWER 1.
Hyaline cartilage is covered with fibrous perichondrium
2. In middle of cartilage (primary oss. center), chondrocytes die, and the thin wall calcify.
Perichondrium cells become osteoblasts and form bony collar-periosteum.
, 3. Blood vessels grow into primary oss. center. Osteoclasts come and hollow out calcified center
(primary marrow cavity). Osteoblasts come and deposit bone, thickening shaft. Second oss.
center develops at ends of bone.
4. Second oss. center hollows out secondary marrow cavity. Dividing line is formed-metaphysis.
5. Epiphyseal plate surrounding by metaphysis exists; enables bones to grow in length and
width.
6. No more cartilage=no more room to grow; only cartilage is articular cartilage, which needs to
stay mushy
What is the effect of inadequate levels of calcium in the diet of an adult on the skeleton? -
ANSWER Since we need calcium for everything, the parathyroid
hormone stimulates osteoclast activity and breaks down bones to release calcium. Bones
become brittle and porous.
The epiphyseal cartilage becomes ossified in our youth. On the other hand, the articular
cartilage does not become ossified. Why is that advantageous? - ANSWER
Growth of articular cartilage results in an increase in the size of the epiphyses. This is only one
of the functions of articular cartilage; it also forms a smooth, resilient covering over the ends of
the epiphyses within joints. Ossified articular cartilage could not perform that function.
A 12 year old girl produces relatively large amount of estrogen, a sex hormone that stimulates
growth of the epiphyseal plate, as well as the rate of ossification. How will that affect her height
in future months? At the age of 25? - ANSWER Her growth for
the next few months increases, and she may be taller than a typical 12-year-old female. Because
the epiphyseal plates ossify earlier than normal, however, her height at age 18 will be less than
otherwise expected.
2025) : Anatomy And Physiology II With Lab -
Chamberlain
Describe the cells of the bone tissue - ANSWER -Osteogenic
cells
-Osteoblasts
-Osteocytes
-Osteoclasts
What membrane lines the internal canals and the small cavities of the compact and spongy
bones? - ANSWER Endosteum
What is the periosteum composed of? - ANSWER -Dense
irregular connective tissue
-Collagen fibers
-Outer fibrous layer has fibroblasts
-Inner layer has progenitor cells that become osteoblasts
,Describe the matrix of the bone tissue - ANSWER -Stony matter
surrounding osteocytes and lacunae
-1/3 organic (collagen and protein-carb complex) and 2/3 inorganic (CaK, CaCO3...)
-gives bone flexibility and strength
-Minerals resist compression
-Collagen resists tension
Compare the function of the organic and the inorganic material in the bone matrix -
ANSWER -Inorganic (minerals) resist compression
-Organic (protein-carb complex/collagen) resists tension
Why does calcification result in death of chondrocytes, while ossification does not result in
death of osteocytes? - ANSWER Chondroblasts are surrounded
by cartilage matrix and receive oxygen and nutrients by diffusion through the matrix. When the
matrix becomes calcified, diffusion is reduced the the point that the cells die. When osteoblasts
form bone matrix, they connect to one another by their cell processes. Thus, when the matrix is
laid down, canaliculi are formed. Even though the ossified bone matrix is dense and prevents
significant diffusion, the osteocytes can receive gases and nutrients through the canaliculi or by
movement form one osteocyte to another.
Describe the process of endochondral ossification. - ANSWER 1.
Hyaline cartilage is covered with fibrous perichondrium
2. In middle of cartilage (primary oss. center), chondrocytes die, and the thin wall calcify.
Perichondrium cells become osteoblasts and form bony collar-periosteum.
, 3. Blood vessels grow into primary oss. center. Osteoclasts come and hollow out calcified center
(primary marrow cavity). Osteoblasts come and deposit bone, thickening shaft. Second oss.
center develops at ends of bone.
4. Second oss. center hollows out secondary marrow cavity. Dividing line is formed-metaphysis.
5. Epiphyseal plate surrounding by metaphysis exists; enables bones to grow in length and
width.
6. No more cartilage=no more room to grow; only cartilage is articular cartilage, which needs to
stay mushy
What is the effect of inadequate levels of calcium in the diet of an adult on the skeleton? -
ANSWER Since we need calcium for everything, the parathyroid
hormone stimulates osteoclast activity and breaks down bones to release calcium. Bones
become brittle and porous.
The epiphyseal cartilage becomes ossified in our youth. On the other hand, the articular
cartilage does not become ossified. Why is that advantageous? - ANSWER
Growth of articular cartilage results in an increase in the size of the epiphyses. This is only one
of the functions of articular cartilage; it also forms a smooth, resilient covering over the ends of
the epiphyses within joints. Ossified articular cartilage could not perform that function.
A 12 year old girl produces relatively large amount of estrogen, a sex hormone that stimulates
growth of the epiphyseal plate, as well as the rate of ossification. How will that affect her height
in future months? At the age of 25? - ANSWER Her growth for
the next few months increases, and she may be taller than a typical 12-year-old female. Because
the epiphyseal plates ossify earlier than normal, however, her height at age 18 will be less than
otherwise expected.
