Non-striated or smooth muscles, Biology

Assignment Help:

NONSTRIATED (= SMOOTH) MUSCLES -

  1. Non-striated muscles are found in the posterior part of oesophagus, stomach, intestine, lungs, urinogenital tract, urinary bladder, blood vessels, iris of eye, dermis of skin and arrector pili muscle of hair. Smooth muscles never connect with skeleton.
  2. These muscle fibres or cells are elongated and spindle shaped.
  3. Each fibre contains a single oval nucleus surrounded by the cytoplasm (sarcoplasm). In the cytoplasm the myo- fibrils are arranged longitudinally.
  4. There is no sarcolemma, however, the fibre is enclosed by plasma membrane.

1574_non striated muscles.png

 

FUNCTION -

These muscles help in peristalsis which happens in tubular viscera.

Action of these muscles is controlled by autonomic nervous system and hence they are not under the control of the animal's will.

 

TYPES -

Functionally smooth muscles are of two types : single-unit smooth muscles and multi-unit smooth muscles.

(i)       Single-unit smooth muscles are composed of muscle fibres closely joined together. All the fibres of the single smooth muscle contract together as a single unit. These muscles are found in the walls of hollow visceral organs like gastrointestinal tract and urinary bladder.

(ii)      Multi-unit smooth muscles are composed of independent muscle fibres and are not closely joined together. Their fibres contract as separate units. Arrector pili muscles of skin dermis, ciliary and iris muscles in the eyes, and muscles of the walls of the large blood vessels are some examples of multi-unit smooth muscles.


Related Discussions:- Non-striated or smooth muscles

Define the rehabilitation phase of spinal trauma disease, Define the Rehabi...

Define the Rehabilitation Phase of spinal trauma disease? Once the patient s condition stabilizes, individualized diets need to be recommended, based on the energy and nutrient

Define the drug and drug effect, Define the Drug and Drug Effect? In th...

Define the Drug and Drug Effect? In the discussions above, we reviewed the effect of food on drug metabolism. Interestingly, not only can drugs interact with food and alcohol,

Endoplasm and ectoplasm, Normal 0 false false false EN-...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Lab: 7 Osmosis, Tonicity and the plant cell. Table 3: Amount of water displ...

Tonicity and the plant cell. Table 3: Amount of water displaced by potato samples before and after experiment?

What are the tissues that form the skin in vertebrates, Q. What are the tis...

Q. What are the tissues that form the skin in vertebrates? The skin of vertebrates is made of epidermis is an external layer of epithelial tissue and dermis a layer of connecti

Pathophysiology of cardiac tamponade, Q. Pathophysiology of Cardiac tampona...

Q. Pathophysiology of Cardiac tamponade? Progressive increase in pericardial fluid results in progressive increase in intrapericardial pressure, till a critical volume is reach

Meal planning and nutrient needs of fast-growing infants, Define meal plann...

Define meal planning and nutrient needs of fast-growing infants? We just got to know the meal planning and nutrient needs of fast-growing infants and preschoolers in the previo

Short-day plants (sdp) - plant responses to light-dark cycle, Short-Day Pla...

Short-Day Plants (SDP) - Plant Responses to Light-Dark Cycles These plants only flower or flower more profusely and rapidly when given less than a certain (critical) number of

What is the general chemical equation of photosynthesis, What is the genera...

What is the general chemical equation of photosynthesis? Why doesn't that equation clearly show the real origin of the molecular oxygen liberated? The general equation of photo

Classification of Protozoan parasite , how to make question on classificati...

how to make question on classification of Protozoan parasite

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd