Question

Wich of the following statements is incorrect? 4 Seoth muscles are found in urinary bladder, alimentary canal and genital tract. B) Asriated muscle is a syncytium i.e., a multinucleate stivuture. d. The ctoplasm of striated muscle is called endoplasm. 4 The plasma membrane and \(\mathrm{ER}\) of striated muscles are cled sarcolemma and sarcoplasmic reticulum respectively.

Short answer

The incorrect statement is C: The cytoplasm of striated muscle is called sarcoplasm, not endoplasm.

Step-by-step solution

Analyze Statement A

Review the locations where smooth muscles are typically found – the urinary bladder, the alimentary canal, and the genital tract. Verify if the smooth muscle is indeed located in these areas.

Analyze Statement B

Assess whether striated muscle can be characterized as a syncytium, which would mean that it is a multinucleate structure where the cells fuse to form a single structure with multiple nuclei.

Analyze Statement C

Examine if the term 'endoplasm' is the correct term for the cytoplasm of striated muscle cells. Typically, the cytoplasm of striated muscle is known as 'sarcoplasm'.

Analyze Statement D

Check the terminology for the plasma membrane and endoplasmic reticulum of striated muscles to confirm if they are correctly called 'sarcolemma' and 'sarcoplasmic reticulum' respectively.

Identify the Incorrect Statement

Compare the previous statements with the established biological nomenclature and anatomical facts to find which statement is incorrect.

Key concepts

Smooth Muscles

Smooth muscles are a unique type of muscle tissue found within the body and possess several distinct characteristics. Unlike striated muscles, smooth muscles have a non-striated appearance under the microscope due to the absence of visible banding patterns.

They are classified as involuntary muscles because they are not under conscious control. They can be found in various parts of the body, including the urinary bladder, where they perform the essential function of controlling evacuation. Similarly, within the alimentary canal, they facilitate the propelling movements known as peristalsis, essential for moving food through the digestive system. In the context of the genital tract, smooth muscles play a role in processes such as childbirth and the ejection of reproductive fluids.

Location and Function

Smooth muscle cells are spindle-shaped with a single central nucleus. Their slow and prolonged contractions are crucial in maintaining functions such as regulation of blood vessel diameter and airway size without the need for conscious thought. Understanding the role of smooth muscles in such autonomic processes is vital for comprehending the overall physiology of the human body.

Striated Muscle

Striated muscle tissue, also known as skeletal muscle, is characterized by a distinctive striped appearance, which is visible under a light microscope. This banding pattern is due to the organized arrangement of myofilaments within the muscle fibers.

Striated muscles are typically attached to bones through tendons and account for the voluntary movements of the skeletal system. They are composed of long cylindrical muscle fibers that contain multiple nuclei, peripherally situated, giving rise to a structure known as a syncytium.

Cellular Structure of Striated Muscles

Within these muscle cells, the cytoplasm is referred to 'sarcoplasm', while the specialized plasma membrane is called 'sarcolemma'. Contained within the sarcoplasm is the sarcoplasmic reticulum, an equivalent of the endoplasmic reticulum, which plays a critical role in the regulation of calcium ions during muscle contraction and relaxation cycles. Enhancing students' knowledge about striated muscle tissue, including its anatomy and physiology, enables a deeper appreciation of how our bodies produce movement.

Muscle Cell Structure

Muscle cell structure is complex and highly specialized to accommodate contraction and relaxation, which are essential for movement and stability in animals. The structure of muscle cells, commonly known as muscle fibers, varies between smooth and striated muscles.

These cells are elongated and filled with contractile proteins called actin and myosin. In striated muscles, these proteins are organized into repeating units called sarcomeres, which give rise to the striated pattern. In contrast, smooth muscle cells do not have sarcomeres but still contain the actin and myosin necessary for contraction.

Specialized Components

Both types of muscles contain unique organelles adapted to their function. For instance, the sarcoplasmic reticulum stores and releases calcium ions to trigger contractions, while mitochondria provide the energy required for these processes. Understanding the detailed structure of muscle cells is fundamental for uncovering the biomechanics behind muscle function and is a pivotal topic in biology education.