Difference and silmarities between frog pectoral girdle and rabbit pectoral girdle
Answers
Answer:
Explanation:
FROG:
1. Pectoral girdle is present in the anterior part ot the trunk.
2. It is connected to the axial skeleton (vertebral column) dorsally with muscles & ligaments and formed mostly with bone tissues.
3. Same as in shark.
4. The os innominatum has the dorsal scapular part and ventral coracoid part. Stouter scapula on the lateral side and the supra scapula formed of calcified cartilage which is a* thin, broad present on the dorsal side. The clavicle membrane bone is present antero-ventral to the pectoral girdle.
5. The coracoid part possess, proper stout uralid, infront of it calcified cartilaginous pre coracoid along with another strip cartilaginous epicoracoid bones. The two epicoracoids are closely associated with each other in the mid ventral line.
6. At the junction of scapular & coracoid bones on the posterior side, the depression of glenoid cavity is present.
7. The sternum lies in the mid ventral line of the chest part. It has two portions. The anterior presternum attached to the anterior part of the girdle. It possess a X - shaped omosternumand at its distal end a small carlilaginous episternum. The posterior purt sternum is present behind the girdle. It consists of a stout bone mesosternum and flat plate xiphisternum at the distal end.
8. The forelimb bones are articulating with pectoral girdle.
9. Coracoid fenestrae are present.
10. It not only helps the movements of the fore limbs but also protects the heart and lungs.
RABBIT:
(i) The axial skeleton is present along the longitudinal axis of the body and consists of the bones of skull, the vertebral column, the ribs and the sternum;
(ii) The appendicular skeleton lies at right angle to the longitudinal axis of the body and consists of the bones of limbs and the girdles.
Axial Skeleton:
Characteristics of Skull:
Some important characteristic points in the mammalian skull are as follows:
1. Since there is a general tendency to increase in the size of the brain, the skull has a short posterior cranial part for lodging the brain and the long anterior facial part comprising mainly the jaws. In higher mammals the facial part lies below the cranial part.
2. The number of bones in the skull is much reduced, many of them are fused intimately so that their separating boundaries are marked only by the sutures.
3. Skull is dicondylic, i.e., 2 occipital condyles. Each exoccipital bears an occipital condyle.
4. Tropibasic skull-a vertical interorbital septum is present in between two orbits. Cranium does not extend into orbital region.
5. The food passage is well separated from the nasal passage due to the development of palate which is formed of premaxillae, maxillae and palatines.
6. A zygomatic arch on either side of the skull is formed by squamosal, jugal and maxillary bones.
7. The auditory capsules are formed by the union of periotic and tympanic forming a swollen tympanic bulla.
8. The articular and quadrate of the jaws become separated and free, and form malleus and incus respectively (two ear-ossicles of the three). Stapes forms the columella.
9. Otic bones, prootic, epiotic and opisthotic, are fused to form a single periotic.
10. Turbinal bones are much folded and, thus, increases the olfactory surface of nasal chambers.