Mucles topic 1

Diego, Damián, Darío And Enrique

By Group 3

Topic 8

Muscular system 1

5. Muscle contraction

4. Mimic muscles

3. Type of muscle acording to their shape

2. Type of muscle acording to the type of fiber that constitute them

1. What is a muscle

Index

What is a mucle?

Muscles are structures or tissues existing in humans that have the ability to generate movement by contracting and relaxing.​ The tissue that forms muscle is called muscle tissue and is made up of specialized cells called myocytes.

What is a muscle?

Type of muscle acording to the type of fiber

The term striated refers to the fact that, when viewed under a microscope, we can observe regular alternation.

Skeletal or striated muscleThis type forms the muscles that are attached to bones, such as those involved in locomotion. These muscles have voluntary contraction, which can be very fast, and they suffer from muscle fatigue.

There are three types of muscles fibers:

Cardiac muscleThese forms costitute the main tissues of the wall of the heart muscle or myocardium and these tissues are responsible for bombarding blood through the circulatory system through contraction.it has a striated structure, contracts involuntarily and does not suffer muscle fatigue.

Smooth muscle Consists of thick and thin filaments. This makes up the muscles of the internal organs, or in other words, in the walls of the gastrointestinal tract, airways, the walls of arteries and veins, ureters, urinary bladder, oviducts, uterus, etc.

Type of muscle acording to their shape

One example is the pectoralis major muscle.

TRIANGULAR SHAPE Triangle-shaped. They cover a wide area and converge into a central tendon.

Different shapes of muscles

2. Flat muscles

1. Elongated muscles

2. Fusiform muscles

PARALLELIn this type of muscles, the fascicles are located in a parallel arrangement, along the longitudinal axis of the muscle. There are three types of parallel muscles:

FlatThey are fan-shaped, that is, their fibers emerge from a narrow base, ending with one end much wider than the other. One example is the pectoralis-major muscle.

FusiformThey are ovoid in shape with a wider central portion and thinner ends, like the biceps brachii muscle.

ElongatedThey are located on the extremities and allow a great range of movement. For example, the sartorius muscle.

ORBICULARThey are muscles that form a ring-like structure around an opening or surround an orifice. For example, the orbicular muscles in the eyelids.

3. MultipeniformIn this type of muscle, all the tips of the muscle are inserted into a big tendon. An example is the deltoid muscle.

2. BipeniformThe fascicles insert into the tendon on opposite sides. An example is the rectus femoris muscle in the thigh.

1. UnipeniformThe fascicle inserts on only one side of the tendon, like the extensor digitorum longus muscle.

PENIFORM MUSCLESIn this type of muscle, the fascicles are short and insert obliquely to a central tendon that runs along the muscle. There are 3 types:

Mimic muscles

BuccinatorsThey puff out their cheeks

NasalsThey wrinkle the nose

FrontalThey raises the eyebrows and wrinkles the forehead

Frontal

RisoriesThey stretch the lips

Orbicular of the lipsThey open and close the mouth

Orbicular of the eyelidThey open and close the eyes

muscle contraction

MUSCLE CONTRACTION MUSCLE RELAXATION

THE MUSCLE PERFORMS TWO MOVEMENTS

Antagonist muscle: BicepsAgonist muscle: Triceps

Antagonist muscle: TricepsAgonist muscle: Biceps

IN CONTRACTION IN RELAXATION

MOVEMENTS AROUND A JOINT ARE ARCHIEVED BY THE JOINT ACTION OF TWO MUSCLES:

¡THANK YOU FOR PAYING YOUR ATTENTION!