What are parapodia used for?
What are parapodia used for?
The fleshy protrusions on the sides of some marine gastropods are also called parapodia. They are particularly well-developed in sea butterflies. Some sea hares use their parapodia to swim. Parapodia can even be used for respiration (similar to gills) or for locomotion.
Where are most Polychaetes found?
Polychaetes are multi-segmented worms living in all environments in the world’s oceans, present from abyssal depths to shallow estuaries and rocky shores, and even free swimming in open water. They are strictly aquatic annelids, but are the most abundant and diverse group of Phylum Annelida.
How do Polychaetes move?
Locomotion in free-moving polychaetes is accomplished by circular, longitudinal, and parapodial muscles and by coelomic fluid. Body undulations, which help the worm to move rapidly, are produced by the contraction of longitudinal muscles stimulated by the backward stroke of parapodium of a particular segment.
Which ligaments are cut during a hysterectomy?
The sacrouterine ligament is cut and ligated, and the ligature is gripped and retracted. The remaining ligaments adhering to the uterus are the vesicouterine ligament and anterior half of the cardinal ligament.
What are parapodia made of?
Parapodia are biramous. They have a dorsal notopodium and a ventral neuropodium. These lobes usually have chaetae (notochaetae or neurochaetae), which are bristles made of chitin and protein. The notopodium can have a dorsal outgrowth called a dorsal cirrus while the neuropodium can have a ventral cirrus.
Which is correct about parapodia?
(i) Parapodia are lateral appendages in arthropods used for swimming. Parapodia are present in some annelid worms. These are a pair of flattened flesh lobes bearing numerous bristles. Radula (rasping organ) in molluscs is a structure involved in feeding.
What are the salient features of Polychaetes?
The following are the salient feature exhibited by Polychaetes:
- They are dioecious and multi-portioned.
- They possess separate sexes.
- Fertilization is external.
- It exhibits metamerism and segmentation.
- It possess closed vascular system.
- It has chain type of nervous system.
Is Errantia a class?
Polychaete
Errantia/Class
Why is the cervix removed during hysterectomy?
During a total hysterectomy, your womb and cervix (neck of the womb) is removed. A total hysterectomy is usually the preferred option over a subtotal hysterectomy, as removing the cervix means there’s no risk of you developing cervical cancer at a later date.
How do Polychaetes operate parapodia?
Polychaetes’ locomotion traits, which involve extension/retraction of parapodia and chaetae, are burrowing, slow creeping (six to eight segments in one ‘wavelength’), fast crawling (14 segments), and swimming. Some Aeolosoma species swim with the aid of beating the cilia at the head end of the body.
What is the procedure to remove the cervix called?
Cervix Removal Surgery. Surgical removal of the cervix is called a radical trachelectomy (RT), or a cervicectomy. It involves removing the cervix and some surrounding tissue as well as the upper one-third of the vagina and pelvic lymph nodes. The cervix is commonly removed through the vagina (called an RVT) or sometimes through the abdomen (RAT).
What are the treatment options for cervical intraepithelial neoplasia (CIN)?
Another way to treat cervical intraepithelial neoplasia (CIN) is with excisional surgery called conization. The doctor removes a cone-shaped piece of tissue from the cervix. The tissue removed in the cone includes the transformation zone where cervical pre-cancers and cancers are most likely to start.
What are the treatment options for invasive cervical cancer?
Procedures to treat invasive cervical cancer are: A simple hysterectomy removes the uterus (both the body of the uterus and the cervix) but not the structures next to the uterus (parametria and uterosacral ligaments). The vagina and pelvic lymph nodes are not removed.
What is the difference between cryosurgery and excisional surgery for cervical cancer?
Excisional surgery (conization) cuts out and removes the pre-cancer. Cryosurgery is a type of ablation where a very cold metal probe is placed directly on the cervix. This kills the abnormal cells by freezing them.
