Human Musculoskeletal System: Bones, Joints, and Muscles Overview

What is the musculoskeletal system composed of?

It is composed of the skeletal and muscular systems.

How many bones and joints are there in the human body?

There are 206 bones and 360 joints.

What is the structure of a bone?

it is made up of a harder outer surface of compact bone.

- certain larger bones have a central cavity containing spongy bone and bone marrow.

What are the parts of the human skeleton?

Axial skeleton - head, vertebrae and rib cage (protecting vital organs)

Appendicular skeleton - shoulder, pelvic girdle and limbs (designed for movement)

What is the function of bone?

It provides support, protection, movement, storage of energy and minerals, blood cell production, and hormone regulation

What are some of the major bones of the body?

What is a long bone?

It is a shaft with bulbous head on each end

- mostly compact bone encasing spongy bone

- It supports eight and facilitates movement

e.g. femur, tibia, phalanges, radius, etc.

What is a short bone?

- It is cube-shaped

- it is a spongy bone with a thin layer of compact bone on surface

- complex structures of wrist and ankles

e.g. carpals and tarsals

What are flat bones?

- Two thin plates of compact bone encasing spongy bone

- Often used to protect internal organs

E.g. Cranial bones, sternum, ribs and scapula

What are irregular bones?

Bones with complex shapes made for specific functions, such as muscle attachment and organ protection.

What are sesamoid bones?

Bones embedded within tendons to increase strength of joints,

E.g. the patella.

Name the three types of joints in the body.

Fibrous, cartilaginous, and synovial joints.

What are synovial joints?

Highly movable joints that have a joint capsule, synovial fluid, and supporting ligaments.

What are the types of synovial joints?

Ball and socket joints, hinge joints, gliding joints, condyloid joints, saddle joints, and pivot joints.

How many muscles are in the human body?

Over 700 muscles.

What are the three types of muscles?

Cardiac muscle, smooth muscle, and skeletal muscle.

What is the role of skeletal muscles?

They connect to bones and cross joints to produce movement.

What is the function of cardiac muscle?

It contracts to circulate blood around the body and is involuntary.

What is the function of smooth muscle?

It lines the digestive system and moves fluid to aid digestion, also involuntary.

What are the four properties of muscle?

Excitability, contractility, extensibility, and elasticity.

What is the difference between isotonic concentric and isotonic eccentric contractions?

Isotonic concentric contractions shorten the muscle, while isotonic eccentric contractions lengthen the muscle.

What is an isometric contraction?

A contraction where the muscle does not change length but remains under tension.