Tag: joints in the human body

Vertebral column is part of the axial skeleton. It is the flexible column extending from neck to tail.

The sacrum is a part of the vertebral column. It is formed by the fusion of 5 bones. It is a large, triangular bone at the base of the spine. The main function of the sacrum is to connect the spine to the hip bones (iliac). The sacrum is a very strong bone that supports the weight of the upper body as it is spread across the pelvis and into the legs. Thus, the correct answer is option A.

The upward movement of ribs due to contraction of intercostal muscles which in turn increases the anteroposterior diameter of the chest is called as pump handle movement. The outward and upward movement of ribs to increase the transverse diameter of the thorax is termed as bucket handle movement.  Upper ribs show more pump handle activity as they have a transverse axis of motion between costovertebral and costotransverse articulation which makes options A and B incorrect. 

At the spinal column, the rib starts with the rib head (caput costae or capitulum). The rib bone progresses backwards via the rib neck (collum costae) to the rib tubercle (tuberculum costae). This is where the rib body (corpus costae) begins, which curves round to the front with the rib angle (angulus costae).

In human beings, the cervical vertebrae comprise of the vertebrae of the neck, immediately below the skull. This is the smallest of the true vertebrae, and the distinguishing feature is the presence of a foramen or hole in each transverse process and through which the vertebral artery passes.

• The cervical spine is made up of 7 vertebrae. The first 2, C1 and C2, are highly specialized and are given unique names: atlas and axis, respectively. C3-C7 are more classic vertebrae, having a body, pedicles, laminae, spinous processes, and facet joints.
• The typical cervical vertebrae are $C3, C4, C5, and C6$. The atypical cervical vertebrae are C1 – Atlas, C2 – Axis, and C7 – vertebra. The key difference between typical and atypical vertebrae is that typical vertebrae consist of all basic components of a vertebra while atypical vertebrae are the vertebrae that have modified structure due to their position and function.
  
• Hence 3, 4, 5, 6 are typical cervical vertebrae.
• So,the correct answer is '3,4,5,6'.

• Urostyle is a long bone formed from fused vertebrae at the base of the vertebral column in some lower vertebrates, especially frogs and toads.
• In frog Eighth vertebra is amphicoelous and the 9th vertebra is biconvex and is attached to urostyle on the posterior side.
• Hence the Last vertebra of the frog is Urosyyle.
• So, the correct answer is 'Urostyle'.

• Bone is the rigid part that constitutes the vertebral skeleton. It is a connective tissue largely composed of organic protein collagen and the inorganic mineral hydroxyapatite.
• Mineral hydroxyapatite is chemically Calcium phosphate.
  
• Hence the major constituent of vertebrate bone is calcium phosphate.
• So, the correct answer is 'Calcium phosphate'.

• Osteoporosis is a bone disease that occurs when the body loses too much bone, makes too little bone, or both. As a result, bones become weak and may break from a fall or, in serious cases, from sneezing or minor bumps. Osteoporosis means “porous bone.”
  
• Osteoporosis can be caused due to deficiency of vitamin D, while osteomalacia is caused by a deficiency in calcium and phosphorus. 
• Hence Osteoporosis is characterized by deterioration of the bone due to deficiency of phosphorous is an incorrect statement.
• So, the correct answer is 'III alone is incorrect'.

• The spinous process extends posteriorly, or rearward, from the laminae of the vertebra, and is a point of attachment for several muscles, ligaments, and fasciae. 
  
• In cervical vertebrae C2 through C6, there exists a common variation of bifurcation. A spinous process is considered bifurcated when a small 'split' occurs at the distal end.
• ​The bifurcation allows for the nuchal ligament to fall centrally which allows the cervical musculature to attach jointly to this strong ligament, as well as the spinous process without interference at the bony insertion.
  
• Hence the Bifurcated spinous process is present in second and Sixth cervical vertebrae.
• So, the correct answer is 'Second and Sixth cervical vertebrae'.