The sternum (pl. “sterna”) is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external.
What is sternum and terga?
In crustaceans, the tergum is known as a pleuron when it overhangs the insertion of the limb on each side as a free plate. In contrast to the tergum, the ventral portion of a segment is called the sternum. The sternum or breastbone is a long flat bone located in the center of the chest.
What are Tergites and Sternites?
Tergite: It is a sclerite (plates that form exoskeleton) present on dorsal side of an abdominal segment in an arthropod. Sternite: It is a chitinous plate present on the dorsal side of an abdominal segment in an arthropod.
What is tergum in insect?
A tergum (Latin for “the back”; plural terga, associated adjective tergal) is the dorsal (‘upper’) portion of an arthropod segment other than the head. The anterior edge is called the ‘base’ and posterior edge is called the ‘apex’ or ‘margin’.
What is sternal anatomy?
Sternum. The sternum is the bone that lies in the anterior midline of our thorax. It forms part of the rib cage and the anterior-most part of the thorax. Its functions are to protect the thoracic organs from trauma and also form the bony attachment for various muscles.
Where is the sternum?
The sternum is a partially T-shaped vertical bone that forms the anterior portion of the chest wall centrally. The sternum is divided anatomically into three segments: manubrium, body, and xiphoid process. The sternum connects the ribs via the costal cartilages forming the anterior rib cage.
What is Tergum and sternum in cockroach?
Tergum is the covering each segment of the cockroach on the dorsal side. Sternum: The sternum is the covering of each segment of the cockroach on the ventral side.
What is pleura of cockroach?
Cockroaches also have a brown colored exoskeleton and segmented body. There are three segments into which the cockroach body is divided. … Each segment is further divided into four plates called terga, sterna, and two lateral pleura. These divisions are joined together by the Arthrodial membrane.
What is dorsal and ventral?
In general, ventral refers to the front of the body, and dorsal refers to the back. These terms are also known as anterior and posterior, respectively. … Similarly, for the feet, the dorsal side is the top of the foot, or the area facing upwards when standing upright.
Where are sclerites present in cockroach?
It is present in the lining of the pharynx and buccal cavity.
Which sternum is absent in the abdomen of cockroach?
(b) There are 10 terga and nine sterna in the abdomen of cockroach . Tenth sternum is absent.
What is Pronotum in cockroach?
The pronotum is a prominent plate-like structure that covers all or part of the thorax of some insects. The pronotum covers the dorsal surface of the thorax. The American Cockroach (Periplaneta americana) is a common pest species found in the home.
Which wing is present in beetle?
Beetle wings are composed of a forewing (also known as elytron) and a hind wing. The elytra are rigid. A beetle’s functional wings, which allow flying, are the hind wings.
What is pleural sulcus in insects?
The pleuron (pl. pleura, from Greek side, rib) is a lateral sclerite of thoracic segment of an insect between the tergum and the sternum. The terms pro-, meso- and metapleuron are used respectively for the pleura of the first, second and third thoracic segments.
What are abdominal appendages?
The number of appendages on the thorax and abdomen vary greatly among large taxonomic groups. Malacostracans (such as decapods and amphipods) generally possess five to eight pairs of thoracic appendages (sometimes called thoracopods or pereiopods) and six pairs of abdominal appendages (pleopods and terminal uropods).
What is the sternum made of?
The sternum is composed of highly vascular tissue, covered by a thin layer of compact bone which is thickest in the manubrium between the articular facets for the clavicles. The inferior sternopericardial ligament attaches the pericardium to the posterior xiphoid process.
What is the structure and function of sternum?
The Anatomy of the Sternum
The sternum is a long, flat bone that protects the underlying muscles, organs, and important arteries within the chest. This includes the lungs, heart, and stomach, along with all of their intricate blood vessels, muscles, and cartilage.
Is sternum axial or appendicular?
The 80 bones of the axial skeleton form the vertical axis of the body. They include the bones of the head, vertebral column, ribs and breastbone or sternum. The appendicular skeleton consists of 126 bones and includes the free appendages and their attachments to the axial skeleton.
What type of bone is sternum?
1. Flat Bones Protect Internal Organs. There are flat bones in the skull (occipital, parietal, frontal, nasal, lacrimal, and vomer), the thoracic cage (sternum and ribs), and the pelvis (ilium, ischium, and pubis). The function of flat bones is to protect internal organs such as the brain, heart, and pelvic organs.
What organs are under the sternum?
- The medulla is the inside part of the thymus.
- The cortex is the layer that surrounds the medulla.
- The capsule is the thin covering over the outside of the thymus.
How does the sternum develop?
The sternum develops from left and right bars of mesenchyme that migrate to the midline and eventually fuse. The fully developed sternum is composed of a manubrium, body, and xiphoid process. The superior aspect of the manubrium is at the level of the T2-3 IVD.
What is Arthrodial membrane in cockroach?
Note: Arthrodial membrane particularly is a tough membrane occurring as a cuticle layer over the body of cockroaches. They are formed as skeletal elements occurring in insects and functions by providing relative movement because of their flexible nature.
Which sternum is boat shaped in female cockroach?
The 7th sternum is boat-shaped and an 8th and 9th sternum together forms a genital pouch.
What is Arthrodial membrane?
Arthrodial membrane is the tough flexible cuticle that occurrs between skeletal elements in insects and help in relative movement.
What is tergum sternum and pleura?
The dorsal plate is named tergum or tergite or notum, the ventral plate sternum or sternite, the lateral pleura. … Here, the endoskeleton forms internal dorsal processes called phragmata, to which the extrinsic muscles of wings attach.
Which of the following segments constitute the thorax of the cockroach?
Thorax of a cockroach has three segments- prothorax, mesothorax and metathorax.
How is oxygen transported in cockroach?
Complete answer:Cockroach’s respiration occurs through spiracles which are the small openings that are situated on the sides of the body. … When the oxygen-rich air goes into the body of a cockroach through spiracles it then enters the tracheal tubes and then diffuses to various tissues and the body cells.
What is dorsal foot?
Description. The dorsum of foot is the area facing upwards while standing.
What is dorsal anatomy?
Posterior or dorsal – back (example, the shoulder blades are located on the posterior side of the body). Medial – toward the midline of the body (example, the middle toe is located at the medial side of the foot).
What is caudal and rostral?
Rostral/Caudal: Rostral — directed toward the nose (beak) [head]. Caudal — directed toward the tail (& beyond) [head, neck, trunk, tail, limbs]. (View Veterinary vs Human Head Directions)
Which membrane helps join the sclerites in cockroach?
The cockroach’s whole body is enclosed by a chitinous, rigid exoskeleton. The exoskeleton has hardened plates in each segment, called sclerites, which are joined by a thin and flexible articular membrane known as the arthrodial membrane. So, the correct answer is, ‘Arthrodial membrane’.
What is the role of Alary muscles in cockroach?
(d) 7. Hint: Alary muscle in cockroaches occurs in the heart wall and it helps in blood circulation. Alary muscles are associated with the blood vascular system of cockroaches.
Which is the tongue of cockroach?
Hypopharynx is considered as tongue in cockroach because it helps in movement of food in the pre oral cavity of cockroach. The hypopharynx is found medially to the mandibles and the maxillae.
How many sternum do male cockroaches have?
Hint: In cockroaches, both male and female abdomen consists of 10 segments. In males, accessory reproductive glands are called mushroom glands present on the sixth and seventh segment. The number of visible sterna in male cockroaches is two more than that of the female cockroaches.
Which terga is invisible in male cockroach?
EXPLANATION: The 8th tergum in a male and 9th and 10th terga in female are not visible as they are overlapped by the 7th terga.
Is pronotum and prothorax are same?
As nouns the difference between prothorax and pronotum
is that prothorax is (entomology) the anterior part of the insect thorax; it carries the first pair of legs while pronotum is the dorsal plate of the prothorax in insects.
What is the function of the prothorax?
The prothorax bears the first pair of legs and a pair of respiratory openings (spiracles). The much larger mesothorax bears the second pair of legs, a second pair of spiracles, and the pair of forewings.
What is the function of the pronotum?
The pronotum is the most important area for of the thorax for hopper identification. A ridge running along the mid-line of the dorsal (top) surface, anteriad to posteriad (front to back) is the median carina.
What insect has 4 wings?
We would run around in the fields and spend hours in vain trying to catch these elusive insects. As it turns out, dragonflies have four wings instead of the conventional two wings that other flying animals have. These wings allow the dragonfly to hover and accelerate in any direction they wish.
Are insect wings appendages or not?
Insect wings are not segmental appendages as are the legs. The paired wings arise as lateral folds of the integument, one pair above each of the last two pairs of legs. Each wing thus consists of an upper and lower sheet of exoskeleton closely applied to each other.
What insect has 2 sets of wings?
Butterflies and moths have two pairs of wings, usually quite large compared to the size of their bodies. They constantly change direction as they flutter about, making them harder for predators to catch.