The Skeletal System: Functions and Components

Study Notes

Skeletal System

The skeletal system plays many roles in the human body, including giving the body its shape, aiding movement, protecting organs, storing minerals, and creating new blood cells.
It is made up of 3 sections: Cervical Spine (neck, cranium, mandible), Thoracic Spine (rib cage, sternum, ulna, radius, humerus, carpals, metacarpals, phalanges), and Lumbar Spine (pelvis, sacrum, tailbone/coccyx, femur, patella, fibula, tibia, calcaneus, tarsals, metatarsals, phalanges).
The skeletal system protects many of the main organs, such as the brain, lungs, and heart.
There are around 206-213 bones in a full-grown adult, with the longest being the femur and the shortest being the bones in the ear.
Ligaments connect bones to each other, while tendons connect muscles to bones.
Cartilage covers bones, preventing them from rubbing against each other.

Nervous System

The nervous system is made up of neurons, which transfer messages from the brain to the rest of the body.
Neurons have dendrites, where they receive messages, and axons, where they pass messages on to the next neuron.
The average resting potential of a neuron is -70 mv, and the action potential is -55 mv.
The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS).
The PNS is divided into the autonomic nervous system (ANS) and the somatic nervous system (SNS).
The ANS has subdivisions, including the sympathetic and parasympathetic areas of the nervous system.

The Eyes

Light enters the eye through the cornea, where it gets focused onto the pupil.
The light then reaches the lens, where it gets focused onto the retina, where vision is formed.
The retina contains 120 million rods and 7 million cones, which help us see in black and white and color.
The image is then transported to the brain using the optic nerve, and the brain classifies the object.

Muscular System

The muscular system aids in support, movement, blood circulation, and protection in the body.
There are 3 types of muscles: skeletal muscles, smooth/visceral muscles, and cardiac muscles.
Skeletal muscles work with the skeletal system through tendons with bones or by cushioning bones.
Smooth/visceral muscles line the insides of organs, like the lungs.
Cardiac muscles make up the inside of the heart, helping pump blood through the heart.
Most muscles are made of a protein called myofibril.

Description

Learn about the vital functions of the skeletal system, including its role in providing body shape, protecting organs, and storing minerals. Discover the different sections of the skeletal system, including the Cervical Spine, Thoracic Spine, and Lumbar Spine, and their various components.