THE WORLD OF MUSCULAR SYSTEM

8 things that you need to know about the Muscular System

MUSCULAR SYSTEM Main Function: The muscular

system provides for movement of 1. The Skeleton and its joints the body and its parts, maintains support, protect, and provide flexibility for the posture, generates heat, and body, but the Skeleton stabilizes joints. cannot move itself. 2. That job is performed by the Muscle Tissue that makes up the muscular system. 3. A muscle tissue is a tissue that can contract in a coordinated fashion and includes muscle tissues, blood vessels, nerves, and connected tissue. 4. Approximately 40 to 50 percent of the MASS of the Human Body is composed of Muscle Tissue. 5. The muscular system is composed of muscle tissue (muscle fiber) that is highly specialized to contract, or shorten, to produce movement when stimulated. 6. The Word Muscle is derived from the Latin word "MUS", meaning mouse. 7. Muscle tissue is found everywhere within the body, not only beneath the skin but deep within the body, surrounding many internal organs and blood vessels. 8. The size and location of muscle tissue helps determine the shape of our bodies and the way we move.

Skeletal Muscle • Skeletal Muscle is responsible for moving parts of the body, such as the limbs, trunk, and face. • Skeletal Muscle are generally attached to bones and are at work every time we make a move. • A Skeletal Muscle is made of Elongated Cells called MUSCLE FIBERS. Varying movements require Contraction of variable numbers of Muscles Fibers in a Muscle. • Skeleton Muscle Cells are large and have more than one nucleus. They vary in length from 1mm to 30 to 60 cm. • When viewed under a microscope, Skeletal Muscles appear to have STRIATIONS (BANDS OR STRIPES).This gives Skeleton Muscle the name of VOLUNTARY OR STRIATED MUSCLE.

Smooth Muscles Smooth Muscles are not usually not under voluntary control. Smooth Muscles cells are spindle shaped and have a single nucleus, are not striated and interlace to form sheets of smooth muscles tissue. Smooth muscle fibers are surrounded by connective tissue, but the connective tissue Does Not unite to form TENDONS as it does in Skeletal Muscles. The contractions in Smooth Muscles move food through our digestive tract, control the way blood flows through the circulatory system, and increases the size of the pupils of our eyes in bright light. Most Smooth Muscle Cells can CONTRACT WITHOUT Nervous Stimulation. Because most of its movements Cannot be consciously controlled, Smooth Muscle is referred to as Involuntary Muscle.

Cardiac Muscles The only place in the body where cardiac muscle is found is in the heart. Cardiac Cells are striated, but they are NOT under Voluntary Control. Cardiac Muscle Contract without Direct stimulation by the Nervous System. A bundle of specialized muscle cells in the upper part of the heart sends electrical signals through cardiac muscle tissue, causing the heart to rhythmically contract and pump blood through the body. The Cardiac Muscle Cell contains ONE Nucleus located near the center; adjacent cells form branching fibers that allow Nerve Impulses to pass from cell to cell.

Mechanism of Muscle Contractions 1. The Sarcomere is the functional unit of Muscle contractions. 2. When Muscle Cells Contract, the light and dark bands contained in Muscle Cells get closer together. 3. This happens because when a Muscle Contracts, Myosin Filaments and Actin filaments interact to shorten the length of a Sarcoma.

4. When Myosin Filaments and Actin Filaments come near each other, many knob (heads) like projections in each Myosin Filament form CROSS-BRIDGES with an Actin Filament. 5. When the Muscle is Stimulated to Contract, the Cross-bridges MOVE, PULLING the Two Filaments past each other.

6. After each Cross-bridge has moved as far as it can, it releases the Actin Filament and returns to its original position. The Cross-bridge then attaches to the Actin Filament at another place and the cycle is repeated. This action Shortens the Length of the Sarcomere. 7. The synchronized shortening of Sarcomeres along the full length of a Muscle Fiber causes the Whole Fiber, and hence the Muscle, to Contract.

How does muscular system help maintaining homeostasis? Skeletal muscles contribute to maintaining temperature homeostasis in the body by generating heat. Muscle contraction requires energy and produces heat as a byproduct of metabolism.

Short Quiz 1. Which of the following types of muscle tissues is found in the walls of the stomach, intestines, and blood vessels? a. cardiac muscle b. smooth muscle c. skeletal muscle d. voluntary muscle

2. Which of the following types of muscle tissues is responsible for moving most parts of the body? a. cardiac muscle b. smooth muscle c. skeletal muscle d. involuntary muscle

3. Your hair and nails are part of your? a. skeleton system b. integumentary system c. nervous system d. muscular system

4. Muscle tone of skeleton muscle results from their? a. total relaxation b. partial relaxation c. total contraction d. partial contraction

5. The dermis contains all of the following Except a. striated muscle b. nerves c. glands d. blood vessels

MUSCLES STRUCTURE . •

•

•

Muscle Fibers consist of Bundles of thread like structures called MYOFIBRILS.

•

Each Myofibril is made up of TWO Types of Protein FilamentsThick ones and thin ones.

•

The THICK FILAMENTS are made up of a PROTEIN called MYOSIN.

•

The THIN FILAMENTS are made of a PROTEIN.

A Muscle made is made up of hundreds or even thousands of Muscle Fibers, depending on the Muscles Size. Although Muscle Fiber makes up most of the Muscle Tissue, a large amount of Connective Tissue, Blood Vessels, and Nerves are also present.

•

A Muscle Fiber is a single, Multinucleated Muscle Cell.

•

The health of Muscle depends on a sufficient Nerve and Blood Supply. Each Skeletal Muscle has a Nerve Ending that controls its activity.

•

Active Muscles use a lot of Energy and require a continuous supply of Oxygen and Nutrients, which are supplied by Arteries. Muscles produce large amounts of Metabolic Waste that must be removed by Veins.

Can you label this muscle?

References: https://motioncow.com/index.php/product/muscles-skeleton-rigged/ https://quizlet.com/34679150/ch-6-the-muscular-system-flash-cards/ https://www.elephango.com/index.cfm/pg/k12learning/lcid/12636/Basics_of_the_ Muscular_System https://training.seer.cancer.gov/anatomy/muscular/structure.html https://studylib.net/doc/8545448/section-46-3--muscular-system https://www.registerednursern.com/smooth-muscle-tissue/ https://opentextbc.ca/anatomyandphysiologyopenstax/chapter/cardiac-muscletissue/ https://www.healthpages.org/health-a-z/anatomy-major-anterior-muscles/ https://www.registerednursern.com/muscle-song/ https://courses.lumenlearning.com/suny-ap1/chapter/muscle-fiber-contraction-andrelaxation/ https://www.pinterest.ph/pin/382876405795517301/ The Creators: 12 – STEM 2 (Group 11) Ronell Nathaniel U. Jordan – Script Writer and Designer Jan Lorrienne Martinez – Layout Designer and References Judhea De Guzman – Layout Designer and References