Muscle Groups and Functions

This article explains the different muscle groups in the human body and their functions. It covers the chest, back, arms and shoulders, abdominal, and legs and buttocks muscles. Each muscle group is described in detail, including their main functions and how they contribute to movement and stability. Desklib offers study material and solved assignments on this topic.

Human Anatomy and Physiology
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1. Please explain about the various muscles groups and what they do
The muscle groups in the human body are divided into five major categories; Chest,
Abdominal, Back, (Arms and Shoulders), (Buttocks and Legs).
(a) Chest
The major type of muscle of the chest is the pectorals whose main function is to provide
support when someone is holding objects in front of the body and are activated when a
person reaches across his/her body (Zatsiorsky & Prilutsky, 2018).
(b) Back
These muscles include;
(i) Latissimus Dorsi
This is a large, flat muscle on the back which stretches to sides behind the arm which are
involved in facilitating the pulling movements in the body and compliments the arms in
performing activities like swimming (Buenzli & Sims, 2015).
(ii) Rhomboid
They are located on the upper back, and they play an important role in supporting the
scapulae and the back movements.
(iii) Trapezius
It is located between the neck and the shoulders. It is also known as the traps which controls
the scapulae blades and very important in neck movements and shrugging.
(iv) Teres Muscle

Located under the latissimus and works with the latissimus and as a rotator cuffs. Its
involved in single exercises like pullovers and pulldowns and compound exercises like
shoulder presses, rows and deadlifts.
(v) Erector Spinae
It’s a group of muscle that rotates and straightens the back. They are important when bending
sideways and forward (Buenzli & Sims, 2015).
(c) Arms and Shoulders
These includes;
(i) Biceps
The muscle is found in front of the upper arm. It controls the motion of the elbow joints and
the shoulders
(ii) Triceps
It is found on the back of the upper arm and it helps in stabilizing the shoulder joint and also
it straightens the elbow joints (Mok et al, 2015).
(iii) Deltoids
These muscles are also called shoulder muscles used in body lifting movements. The muscles
provide support when carrying things.
(d) Abdominal
The abdominal muscles assist in protecting the inner organs and in breathing processes.
These muscles are crucial in bending over motions, maintenance of good posture and in

twisting motions. The major type of muscles on the abdominals are the obliques which assist
in supporting the spine from the front (Mok et al, 2015).
(e) Legs and Buttocks
These muscles incudes;
(i) Hamstrings
The hamstrings muscle is located on the upper part of the thigh and it is involved in bending
the knees and helps in propelling the body forward.
(ii) Gluteals
The gluteals are the muscles of the buttocks and are the largest muscles that are involved
in the movements of legs both sideways and backward and also assist in maintaining the
balance while running or walking (Charlier, Mertens, Lefevre & Thomis, 2015).
4. Please explain the Skeletal System
The skeletal system is body framework which consists of the bones and other connective
tissues whose functions is to support and protects the internal organs and the body tissues.
The four main fibrous and mineralized components of the skeletal system are bones,
tendons, joints and ligaments (Katzenberg & Grauer, 2018). The human skeletal system is
made up of 206 bones. 15% of the total body weight is made up of bones and this includes
even the teeth which are not bones but attached to the jaw bones and they are included in the
overall skeletal system. Out of the 206 bones, six are tiny bones of the middle ear which
performs in the hearing process. The skeletal muscles are connected to each other by the
network of tendons, cartilage and ligaments. The general functions of the skeletal muscles

are protection, support, blood cell production, movement, endocrine regulation and in
calcium storage which enables us to survive (Muscolino, 2016).
The human bones are classified into four categories; flat bones, short bones, long bones
and irregular bones. The bones provide the framework to anchor the tendons and the muscles
and give the body its shape. The bone marrow is located inside the bones with several
functions; transportation of the oxygen, production of red blood cells and white blood cells
which fights diseases in the body. The three types of skeleton designs based on the functions
of the skeletal muscle includes exoskeleton, endoskeleton and hydroskeleton. The body
skeleton protects the soft inner organs of the body such as the heart, brain and the lungs. The
skeletons of females and males have variations (Csapo, & Alegre, 2015). The female pelvis
is flatter, proportionally larger and more rounded than that of the male.
5. Please explain the Digestive System
The human digestive system is composed of the gastrointestinal tract (GI), the pancreas,
gallbladder and the liver. The gastrointestinal tract is the series of hollow organs connected in
a twisting, long tube from the mouth to the anus. Within the hollow GI tract, there are organs
such as the esophagus, stomach, mouth, large intestine, small intestine, and the anus. The
gallbladder, liver and pancreas are the soft organs in the human digestive system. The small
intestine consists of three parts which are the duodenum, the jejunum and the ileum. The
large intestine is made up of the cecum, rectum, colon and the appendix. The cecum is the
first part of the large intestine followed by the appendix. The appendix is attached to the
cecum and its finger-shaped. The last part of the large intestine is the rectum (Bornhorst,
Gouseti, Wickham & Bakalis, 2016).

The GI tract contains the bacteria called the gut flora which help in the digestion. Food
digestion also involves parts of the circulatory and the nervous system which works together
with the bacteria, hormones and other organs of the digestive system to digest liquids and
foods one eats. The digestion is very important for the body needs nutrients from the dinks
and the food substances so that to stay healthy and function properly. Some of the nutrients
of the food that are vital in the human body include water, minerals, fats, vitamins,
carbohydrates and proteins. The digestive system breaks down these nutrients into smaller
absorbable in the body so that to produce energy this is useful in the body for growth and
repairing of the cells. The carbohydrates are broken down into simple absorbable sugars
while the protein is broken down into absorbable amino acids. The fats are broken down into
glycerol and fatty acids (Solovyev et al, 2016).
6. Please explain the Skin
The skin consists of the soft outer tissue that supports in covering the vertebrates. The
skin in humans consists of a total area of about 20 square feet making it to be the largest
organ of the body. It helps in supporting the internal organs from the outside environment
using a cellular barrier, a cushioning that is multilayered and protective oils. The skin also
plays a vital role of maintaining our body health including helping in regulating our body
temperate through flushing and sweating when the body is hot and when we are cold it also
helps in raising goosebumps. Skin also produces vitamin D which is vital for the health of
our bones from sunlight. It varies between individuals and species (Abaci et al, 2015).
The mammal’s skin is mostly composed of two primary layers, the epidermis, and the
dermis. The epidermis comprises of the outermost layers of the skin which acts as a barrier to
protect against the infection, responsible for prevention of entry of pathogens and also helps

in keeping water in the body. 95% of epidermis comprises of keratinocytes cells and the rest
percentage composes of Melanocytes cells, Merkel cells and Langerhans cells. The basement
membrane supports in controlling the traffic of the molecules and cells between the
epidermis and dermis and also it acts as a reservoir for their controlled release during repair
processes and physiological remodeling. The connective tissues of the dermis help in
cushioning the body from strain and stress. The dermis provides elasticity and tensile
strength to the skin using an extracellular matrix that is composed of elastic fibers,
microfibrils and collagen fibrils embedded in proteoglycans and hyaluronan. There exist four
types of skin the oily skin, combination skin, normal skin and dry skin (Simoni et al, 2017).

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