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

What is the nonhuman experimental studies, What is the Nonhuman Experimenta...

What is the Nonhuman Experimental Studies How normal brain development proceeds is essential knowledge for professionals concerned with understanding infant and young child dev

Enhancer, The enhancer is the cis-acting nucleotide series to which the tra...

The enhancer is the cis-acting nucleotide series to which the transcription factor(s) bind, and which increases transcription of the gene. It is not part of the promoter; the gener

What are the frequencies of dominant and recessive allele, In a population ...

In a population of 200, 90 are homozygous dominant, 40 are heterozygotes, and 70 are homozygous recessive for a particular trait. What do you expect the frequencies of the dominant

Chronic renal failure , Chronic Renal Failure (CFW) Chronic renal fai...

Chronic Renal Failure (CFW) Chronic renal failure begins when the diseased kidney can no longer maintain the normal chemical structure of body fluids under normal conditio

Clothes , Clothes : The concept of clothes might have started even befo...

Clothes : The concept of clothes might have started even before weaving, as an extension of  the practice of carrying food hd  implements about.  Attachments with a convenient

Reproduction, when pollen tube enters the embryo-sac,it has;

when pollen tube enters the embryo-sac,it has;

Discuss the example of comprehensive neuropsychology, Discuss the example o...

Discuss the example of Comprehensive neuropsychology  Example of these include deficits of visuo-spatial perception hampering performance on construction tasks, poor comprehe

Show the symptoms and treatments of hepatitis b, Q. What are the modes of t...

Q. What are the modes of transmission, main signs and symptoms and treatments of hepatitis B? The Hepatitis B is a disease caused by a DNA virus. The transmission is by blood (

Which are the structures that are part of the nervous system, Which are the...

Which are the structures that are part of the nervous system? The structures that form the nervous system can be separated into the central nervous system (CNS) and the periphe

What are organic compounds in the cytoplasm, High salt concentrations can b...

High salt concentrations can be toxic to plants as they have the potential to disrupt essential cell functions. Yet many halophytes sequester high amount of salt in their vacuoles,

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