Portage Learning Pathophysiology NURS 231 Unit 10 Exam
It forms the structural framework for our bodies, a site of attachment for muscles, a
means of protection for vital organs and soft tissue structures, a storage site for calcium
and other minerals and finally, the site of blood cell production. *note - only 4 are
needed.
Name 4 functions of the skeleton.
The axial skeleton consists of the bones in the skull, thorax, and the vertebral column.
The appendicular skeleton includes all the bones of the upper and lower extremities, as
well as the pectoral and pelvic girdles.
Name the 2 major skeletal divisions and the bones that comprise each.
Cortical bone provides the hard outer shell of bone and the cancellous bone forms the
interior aspect of bone. Cortical bone has a tightly packed extracellular matrix that
provides its rigidity while the cancellous bone has a spongy appearance with trabeculae
and bone marrow.
Compare and contrast cortical bone and cancellous bone.
Long bones – femur or humerus
short bones – carpals or tarsal bones
flat bones – scapula or bones of the skull
,irregular bones – vertebrae
Name the 4 shapes of bone and give an example of each.
The extracellular matrix of osseous or bone tissue is calcified or hardened. This feature
provides bone with its strength to support body weight and to serve as a shield for the
soft tissue structures that it surrounds. The extracellular matrix can be further
subdivided into the organic matrix and the inorganic matrix. Organic matrix, in most of
the types of connective tissues including bone is made up of collagen fibers and ground
substance. Ground substance is a gel like material containing minute amounts of
proteins and polysaccharides. This ground substance plays a very important role in the
metabolic functions which are necessary for the growth and repair of the bone. The
inorganic matrix is made up mainly of calcium phosphate. In addition, it has carbonate,
magnesium, sodium, and other heavy metals such as lead that might have been
removed from the circulation.
Describe the structure and function of the extracellular matrix of osseous tissue.
osteoprogenitor- undifferentiated, differentiate into osteoblasts, help heal fractures
osteoblasts- bone building cells, ossification and calcification, growth factor and tumor
necrosis factor, secrete alkaline phosphate for bone growth and repair
osteocytes- mature bone cells, housed in lacunae, death leads to breakdown of bony
matrix, reabsorbed by osteoclasts and repaired by osteblasts
osteoclasts - bone chewing cells, reabsorb bone, PTH increases osteoclasts, Calcitonin
decreases osteoclasts
Be able to name and describe the function of the 4 bones cells.
Parathyroid hormone (PTH) is released from the parathyroid glands, which has the
effect of maintaining blood calcium and phosphate levels. If blood calcium levels are
, below the normal level, then the parathyroid glands will release PTH in order to raise
blood calcium back to the normal level. Normally, when the levels are attained or if the
blood calcium increases to elevated levels due to negative feedback, the release of PTH
will stop. PTH is going to regulate the levels of calcium in one of the following four ways:
It's going to stimulate the release of calcium from the bone, increase renal reabsorption
of calcium while at the same time increasing renal excretion of phosphate. Activate
vitamin D, which will increase intestinal absorption of calcium, and finally, reduce blood
phosphate levels.
Explain what PTH does, but include where it is produced, what triggers its secretion.
Calcitonin is synthesized by the parafollicular cells of the thyroid gland. It opposes the
effects of parathyroid hormone by lowering blood calcium levels. Calcitonin prevents
the release of calcium from bones and restricts tubular reabsorption of calcium and
phosphate. The primary stimulus for calcitonin synthesis and secretion is an increased
blood calcium level.
Explain what Calcitonin does - include where it is produced and what stimulates its
secretion.
The pathway of Vitamin D activation starts in the liver when the precursor form of
Vitamin D undergoes hydroxylation to produce 25hydroxyvitamin D After that it is
carried to the kidneys and is further transformed to any of the active forms,
1,25-dihydroxyvitamin D3 or 24,25-dihydroxyvitamin D3. Vitamin D can enter the body in
one of two ways. It can enter the intestines through dietary intake (best sources include
fatty fish, cheese, beef liver and egg yolks), or it can enter the skin through the action of
ultraviolet radiation from the sun. Refer to Figure 10.5.
Be familiar with Figure 10.5 and be able to describe the activation pathways of Vitamin
D.
Synarthroses-no joint cavity, little or
no movement
It forms the structural framework for our bodies, a site of attachment for muscles, a
means of protection for vital organs and soft tissue structures, a storage site for calcium
and other minerals and finally, the site of blood cell production. *note - only 4 are
needed.
Name 4 functions of the skeleton.
The axial skeleton consists of the bones in the skull, thorax, and the vertebral column.
The appendicular skeleton includes all the bones of the upper and lower extremities, as
well as the pectoral and pelvic girdles.
Name the 2 major skeletal divisions and the bones that comprise each.
Cortical bone provides the hard outer shell of bone and the cancellous bone forms the
interior aspect of bone. Cortical bone has a tightly packed extracellular matrix that
provides its rigidity while the cancellous bone has a spongy appearance with trabeculae
and bone marrow.
Compare and contrast cortical bone and cancellous bone.
Long bones – femur or humerus
short bones – carpals or tarsal bones
flat bones – scapula or bones of the skull
,irregular bones – vertebrae
Name the 4 shapes of bone and give an example of each.
The extracellular matrix of osseous or bone tissue is calcified or hardened. This feature
provides bone with its strength to support body weight and to serve as a shield for the
soft tissue structures that it surrounds. The extracellular matrix can be further
subdivided into the organic matrix and the inorganic matrix. Organic matrix, in most of
the types of connective tissues including bone is made up of collagen fibers and ground
substance. Ground substance is a gel like material containing minute amounts of
proteins and polysaccharides. This ground substance plays a very important role in the
metabolic functions which are necessary for the growth and repair of the bone. The
inorganic matrix is made up mainly of calcium phosphate. In addition, it has carbonate,
magnesium, sodium, and other heavy metals such as lead that might have been
removed from the circulation.
Describe the structure and function of the extracellular matrix of osseous tissue.
osteoprogenitor- undifferentiated, differentiate into osteoblasts, help heal fractures
osteoblasts- bone building cells, ossification and calcification, growth factor and tumor
necrosis factor, secrete alkaline phosphate for bone growth and repair
osteocytes- mature bone cells, housed in lacunae, death leads to breakdown of bony
matrix, reabsorbed by osteoclasts and repaired by osteblasts
osteoclasts - bone chewing cells, reabsorb bone, PTH increases osteoclasts, Calcitonin
decreases osteoclasts
Be able to name and describe the function of the 4 bones cells.
Parathyroid hormone (PTH) is released from the parathyroid glands, which has the
effect of maintaining blood calcium and phosphate levels. If blood calcium levels are
, below the normal level, then the parathyroid glands will release PTH in order to raise
blood calcium back to the normal level. Normally, when the levels are attained or if the
blood calcium increases to elevated levels due to negative feedback, the release of PTH
will stop. PTH is going to regulate the levels of calcium in one of the following four ways:
It's going to stimulate the release of calcium from the bone, increase renal reabsorption
of calcium while at the same time increasing renal excretion of phosphate. Activate
vitamin D, which will increase intestinal absorption of calcium, and finally, reduce blood
phosphate levels.
Explain what PTH does, but include where it is produced, what triggers its secretion.
Calcitonin is synthesized by the parafollicular cells of the thyroid gland. It opposes the
effects of parathyroid hormone by lowering blood calcium levels. Calcitonin prevents
the release of calcium from bones and restricts tubular reabsorption of calcium and
phosphate. The primary stimulus for calcitonin synthesis and secretion is an increased
blood calcium level.
Explain what Calcitonin does - include where it is produced and what stimulates its
secretion.
The pathway of Vitamin D activation starts in the liver when the precursor form of
Vitamin D undergoes hydroxylation to produce 25hydroxyvitamin D After that it is
carried to the kidneys and is further transformed to any of the active forms,
1,25-dihydroxyvitamin D3 or 24,25-dihydroxyvitamin D3. Vitamin D can enter the body in
one of two ways. It can enter the intestines through dietary intake (best sources include
fatty fish, cheese, beef liver and egg yolks), or it can enter the skin through the action of
ultraviolet radiation from the sun. Refer to Figure 10.5.
Be familiar with Figure 10.5 and be able to describe the activation pathways of Vitamin
D.
Synarthroses-no joint cavity, little or
no movement
