Answer
Verified
423.3k+ views
Hint: The vertebral column is differentiated into cervical, thoracic, lumbar, sacral and coccygeal regions, starting from the skull. The number of cervical vertebrae are seven in almost all mammals including human beings.
Complete answer:
The cervical vertebrae is the specific feature of mammals. It is typically the smallest vertebrae which is located below the neck and offers stability and mobility to the head. It is connected to the thoracic spine which is relatively immobile. The 7 vertebrae are labelled as $C_1 – C_7$ where $C_1$ is Atlas which articulates with the occipital condyles of the skull. The foramen of this vertebrae divides into two parts by a ligament.
In the upper part of the ligament, the spinal cord is present. $C_2$ is known as Axis. Centrum is present in $C_2$. Anterior surface of the centrum consists of a long odontoid process of dens which fits into the odontoid fossa of Atlas to make a pivot joint. Vertebrae from $C_3 – C_6$ are typical vertebrae. $C_7$ is the largest cervical vertebrae consisting of a long spinous process which projects posteriorly towards the skin. The number of cervical vertebrae shows no variation and in fact remains constant in all mammals except Manatees and sloths. Manatees also known as sea cows are large slow moving aquatic mammals which are famous for possessing only six cervical vertebrae instead of seven.
Hence, the correct answer is option (D).
Note: All cervical vertebrae have apertures in their transverse forms called as Foramina Transversarium which shapes Vertebrarterial canal. Through this canal vertebral artery passes. This artery supplies blood in brain and spinal cord. Spinous process of cervical vertebrae is bifid except $C_7$. Only $C_7$ has demifacets where upper part of head of first rib articulates.
Complete answer:
The cervical vertebrae is the specific feature of mammals. It is typically the smallest vertebrae which is located below the neck and offers stability and mobility to the head. It is connected to the thoracic spine which is relatively immobile. The 7 vertebrae are labelled as $C_1 – C_7$ where $C_1$ is Atlas which articulates with the occipital condyles of the skull. The foramen of this vertebrae divides into two parts by a ligament.
In the upper part of the ligament, the spinal cord is present. $C_2$ is known as Axis. Centrum is present in $C_2$. Anterior surface of the centrum consists of a long odontoid process of dens which fits into the odontoid fossa of Atlas to make a pivot joint. Vertebrae from $C_3 – C_6$ are typical vertebrae. $C_7$ is the largest cervical vertebrae consisting of a long spinous process which projects posteriorly towards the skin. The number of cervical vertebrae shows no variation and in fact remains constant in all mammals except Manatees and sloths. Manatees also known as sea cows are large slow moving aquatic mammals which are famous for possessing only six cervical vertebrae instead of seven.
Hence, the correct answer is option (D).
Note: All cervical vertebrae have apertures in their transverse forms called as Foramina Transversarium which shapes Vertebrarterial canal. Through this canal vertebral artery passes. This artery supplies blood in brain and spinal cord. Spinous process of cervical vertebrae is bifid except $C_7$. Only $C_7$ has demifacets where upper part of head of first rib articulates.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
Mark and label the given geoinformation on the outline class 11 social science CBSE
When people say No pun intended what does that mea class 8 english CBSE
Name the states which share their boundary with Indias class 9 social science CBSE
Give an account of the Northern Plains of India class 9 social science CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Trending doubts
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE
Which are the Top 10 Largest Countries of the World?
Difference Between Plant Cell and Animal Cell
The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths
Give 10 examples for herbs , shrubs , climbers , creepers
Change the following sentences into negative and interrogative class 10 english CBSE
Write a letter to the principal requesting him to grant class 10 english CBSE