$\huge \sf Skeletal\ System \ and \ their \ Functions$

Question

jagr2713 · Answer

$$ \hspace{70pt}\huge \sf \text{Introduction}       $$     
$\bigstar$ The $\bf Skeletal \ System$ in an adult body is made up of 206 individual bones. These bones are arranged into two major divisions: the axial skeleton and the appendicular skeleton. The axial skeleton runs along the body’s midline axis and is made up of 80 bones in the following regions:
$$\bullet\color{blue}{\bf Skull}$$$$\bullet\color{blue}{\bf Hyoid}$$$$\bullet\color{blue}{\bf Auditory \ ossicles}$$$$\bullet\color{blue}{\bf Ribs}$$$$\bullet\color{blue}{\bf Sternum}$$$$\bullet\color{blue}{\bf Vertebral \ column}$$
$\bigstar$The $\bf appendicular \ skeleton$  is made up of 126 bones in the folowing regions:
$$\bullet\color{blue}{\bf Upper \ limbs}$$$$\bullet\color{blue}{\bf Lower \ limbs}$$$$\bullet\color{blue}{\bf Pelvic \ girdle}$$$$\bullet\color{blue}{\bf Pectoral \ (shoulder) \ girdle}$$
These and many more will be explained today and i hope you guys enjoy.

jagr2713 · Answer

$$ \hspace{70pt}\huge \sf \text{Bones of the Head and Neck} $$ $\bigstar$ The bones of the head and neck play the vital role of supporting the brain, sensory organs, nerves, and blood vessels of the head and protecting these structures from mechanical damage. Movements of these bones by the attached muscles of the head provide for facial expressions, eating, speech, and head movement. The $\bf Skeletal \ Skull$ is composed of 22 bones that are fused together except for the mandible. These 21 fused bones are separate in children to allow the skull and brain to grow, but fuse to give added strength and protection as an adult. The mandible remains as a movable jaw bone and forms the only movable joint in the skull with the temporal bone. The bones of the superior portion of the skull are known as the cranium and protect the brain from damage. The bones of the inferior and anterior portion of the skull are known as facial bones and support the eyes, nose, and mouth. For more about the skull like frontal lobes etc go to my tutorial about it here: http://openstudy.com/users/jagr2713#/updates/54f65df0e4b09f47f4e50b17 $\bigstar$ The $\bf Neck$ is the part of the body that separates the head from the torso. he neck supports the weight of the head and is highly flexible, allowing the head to turn and flex in different directions.The midline in front of the neck has a prominence of the thyroid cartilage termed the laryngeal prominence, or the so-called "Adam's apple." The Neck is the start of the spinal column and spinal cord. The spinal column contains about two dozen interconnected, oddly shaped bony segments called vertebrae. The neck contains seven of these, known as the cervical vertebrae. They are the smallest vertebrae in the body

jagr2713 · Answer

$$ \hspace{70pt}\huge \sf \text{Chest and Upperback}       $$
$\bigstar$ The bones of the chest and upper back combine to form the strong, protective rib cage around the vital thoracic organs such as the heart and lungs. The rib cage also anchors the bones of the head, neck, shoulders, and arms to the trunk of the body. Powerful muscles that move the head and arms attach to these bones as well. The bones of the chest and their joints also support the upper body’s weight.

$\bigstar$ The $\bf Chest$ like its female counterpart, the male breast has a nipple and an areola (the darker pigmented circle around the nipple), but men lack the mammary glands and ducts necessary to produce milk.A man’s chest—like the rest of his body—is covered with skin that hast two layers.

    $\bullet\color{blue}{\bf Epidermis}$ is the outermost layer that provides a protective, waterproof seal over the body.
    $\bullet\color{blue}{\bf Dermis}$ is the under layer that contains sweat glands, hair follicles, blood vessels, and more.

Unlike a woman’s chest, a male chest typically develops some type of thick, dark hair in late puberty that usually doesn’t reach full growth until the early 30s. Like a woman’s breasts, men’s chest hair is a secondary sex characteristic, or a feature that distinguishes the differences between the two sexes.
$\bullet\color{blue}{\bf Cervical}$ (neck) - 7 vertebrae
$\bullet\color{blue}{\bf Thoracic}$ (chest) - 12 vertebrae
$\bullet\color{blue}{\bf Lumbar}$ (lower back) - 5 vertebrae
$\bullet\color{blue}{\bf Sacrum}$ 1 vertebrae
$\bullet\color{blue}{\bf Coccyx}$ (tailbone) - 1 vertebrae

jagr2713 · Answer

$$ \hspace{70pt}\huge \sf \text{Bones of the Arm and Hand}       $$
$\bigstar$The bones of the arm and hand have the important jobs of supporting the upper limb and providing attachment points for the muscles that move the upper limb. These bones form joints that provide a wide range of motion and flexibility needed to manipulate objects deftly with the arm and hand. They also provide strength to resist the extreme forces and stresses acting upon the arms and hands during sports, exercise, and heavy labor consisting of the clavicle (collar bone) and scapula (shoulder blade), the pectoral girdle forms the attachment point between the arm and the chest.

Despite being such a small region of the body, the hand contains twenty-seven tiny bones and many flexible joints.

    The $\bf carpals$ are a group of eight roughly cube-shaped bones in the proximal end of the hand. They form the wrist joint with the ulna and radius of the forearm and also form joints with the metacarpals of the palm of the hand. The carpals form many small gliding joints with each other to give extra flexibility to the wrist and hand.
    The five long, $\bf cylindrical \ metacarpals$ form the supporting bones of the palm of the hand. Each metacarpal forms a joint with the carpals and another joint with the proximal phalanx of a finger. Metacarpals are able to abduct to spread the fingers and palm apart and can adduct to draw the fingers and palm together. The metacarpals also give flexibility to the hand when gripping an object or when touching the thumb and pinky finger together.
    The $\bf phalanges$ (singular: phalanx) are a group of fourteen bones that support and move the digits. Each digit contains three phalanges – proximal, middle, and distal – except for the thumb, which contains just a proximal phalanx and a distal phalanx. The phalanges are long bones that form hinge joints between themselves and also condyloid (oval) joints with the metacarpals. These joints permit the flexion, extension, adduction, and abduction of the digits.

Our arms and hands require a balance of strength and dexterity to perform diverse tasks such as lifting heavy boxes, swimming, playing a musical instrument, and writing. The joints of the arm and hand permit a wide range of motion while maintaining the strength of the upper limb. Many skeletal muscles attach to and pull on these bones to move them with strength, speed, and accuracy. Like all bones of the body, upper limb bones help the body to maintain homeostasis by storing minerals and fats and by producing blood cells in the red bone marrow.

jagr2713 · Answer

$$ \hspace{70pt}\huge \sf \text{Pelvis and Lower back }       $$ $\bigstar$The bones of the pelvis and \lower back work together \to support the body’s weight, anchor the abdominal and hip muscles, and protect the delicate vital organs of the vertebral and abdominopelvic cavities. The vertebral column of the \lower back includes the five lumbar vertebrae, the sacrum, and the coccyx. These bones work together \to provide flexibility \to the trunk, support the muscles of the trunk, and protect the spinal cord and spinal nerves of the back.  There are many structural differences \between the male and the female pelvis, most of which reflect the role of childbirth \in the female. The male pelvis is smaller and narrower with a thinner pubic symphysis. The female, on the other hand, has a much wider and more prominent pelvis that provides extra interior \space with a wider, more flexible pubic symphysis.  

Lumbar vertebrae support much more body weight than the other vertebrae \in the body and are \therefore the largest and most robust vertebrae \in the body. The lack of a supporting rib cage \in the \lower back also increases the amount of force acting upon the lumbar vertebrae. The sacrum and coccyx form the inferior \end of the vertebral column where \it meets the hip bones \to form the pelvis. The triangular sacrum forms joints \between the lumbar vertebrae and the hip bones. It also contains many passages for the spinal nerves that exit the spinal cord and spread through the pelvis and legs. The coccyx, or tailbone, is inferior \to the sacrum and made of several \tiny, fused vertebrae. Several pelvic muscles attach \to the coccyx\]

jagr2713 · Answer

$$ \hspace{70pt}\huge \sf \text{Bones of the leg and foot }       $$  
$\bigstar$ The bones of the leg and foot form part of the appendicular skeleton that supports the many muscles of the lower limbs. These muscles work together to produce movements such as standing, walking, running, and jumping. At the same time, the bones and joints of the leg and foot must be strong enough to support the body’s weight while remaining flexible enough for movement and balance.

The femur, or thigh bone, is the largest, heaviest, and strongest bone in the human body. Many strong thigh muscles attach to the femur and pull on the femur during movements of the hip and knee joints.

At the proximal end of the femur is a rounded prominence known as the head of the femur. The head of the femur forms the ball and socket hip joint with the acetabulum of the hip bone. The hip joint gives the leg an incredible range of motion while still providing support to the body’s weight.

At the distal end of the femur, two rounded condyles meet the tibia and fibula bones of the lower leg to form the knee joint. The knee is a strong but flexible hinge joint that uses muscles and ligaments to withstand the torques and strains of powerful leg movements. Between the femur and tibia is the meniscus, a layer of tough fibrocartilage that acts as a shock absorber.

In the lower leg, the tibia bears most of the body’s weight while the fibula supports the muscles of balance in the lower leg and ankle. The tibia forms the flexible ankle joint with the tarsal bones of the foot. Body weight is distributed among the seven tarsals, which can shift slightly to provide minute adjustments to the position of the ankle and foot. The calcaneus, or heel bone, is the largest tarsal bone and rests on the ground when the body is standing.

The tarsal bones and the five long metatarsal bones together form the arches of the foot. Body weight supported by the foot is spread across the arches from the tarsal and metatarsal bones, which make contact with the ground while standing. Like the tarsal bones, the position of the metatarsals can be adjusted to change the shape of the foot and affect balance and posture of the body.

jagr2713 · Answer

Hope you guys have a better understanding of the skeletal system and its functions. I would stay vigilant for my next tutorial because it will be a great one :D

~Have a great day everyone :D

domebotnos · Answer

@sammixboo

praetorian.10 · Answer

Well played

eclipsedstar · Answer

Nicely done @jagr2713 ! ^_^

jagr2713 · Answer

Thanks :D

jagr2713 · Answer

Stay tuned for my next tutorial which is going to be the great


$$\huge \color {Blue}{Muscular \ System }$$

joel_the_boss · Answer

Wow it looks nice :D @shrutipande9 @Abhisar

jagr2713 · Answer

Thanks :D took me like 6HOURS lol

joel_the_boss · Answer

LOL It was well worth it :) 
 
You did excellent. 

*Still reading*

jagr2713 · Answer

it was worth it

aaronq · Answer

Looks great! good job

jagr2713 · Answer

Thanks :D

kainui · Answer

@Somy is the human anatomy expert haha. Looks good!

jagr2713 · Answer

Not for long :D

thesmartone · Answer

Good job! Haha :)

jagr2713 · Answer

Thanks :D

somy · Answer

∙Sacrum 1 vertebrae
∙Coccyx (tailbone) - 1 vertebrae

Sacrum is made of 5 fused sacral vertebrae
Coccyx is made of 4 or 5 coccygeal vertebrae 

$\sf \huge \color {pink}{Great~ Job!!!~}$ 
Though you did mention about 'fused vertebrae' regarding the two of them later on, but you gotta always include how many of them make up sacrum or coccyx T_T coz there are medical cases where 5th lumbar is fused with 1st sacral vertebrae and stuff like that 
brings back painful memories~  
But you've done a great job here! :D

jagr2713 · Answer

yea i had alot more but its to much and i didnt want to make like a whole lecture about it. I just put the simple stuff

jagr2713 · Answer

i have like another like 7more pages of this going in depth and the stuff u just said but its to much. Ill keep it simple :D

somy · Answer

T_T painfulllll  
u r med student too though?

jagr2713 · Answer

not yet but graduating in may :D

somy · Answer

oh yeah? goood luuuuck!!! lol im finishing first year in med school yet i feel like you know more than me lol shaaaaame on me XD

jagr2713 · Answer

no you know more than me lol

jagr2713 · Answer

i struggle in some parts

somy · Answer

yeah well its tough 
for this year i only did all the bones

jagr2713 · Answer

yea its tough learning all the medical terms and i forget some lol

shrutipande9 · Answer

@somy gave u the expert advice!! Great job

jagr2713 · Answer

ikr i greatly appreciate that

dtan5457 · Answer

nice tutorial !

jagr2713 · Answer

Thanks @AlexandervonHumboldt2

unavailabilityy · Answer

I loved this!

jagr2713 · Answer

Thank you :D

unavailabilityy · Answer

You are welcome :D

jamierox4ev3r · Answer

Quite impressive ^.^