CQRG's Winter Medical Terminology Boot Camp
DAY 6 / INTRODUCTION TO THE SKELETAL & MUSCULAR SYSTEMS
Welcome to Day 6!
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The Skeletal System
The skeletal system plays a key role in many life-sustaining functions.
The skeletal system is essential for supporting various life-sustaining activities. Not only does it serve as the body's framework, consisting of bone, cartilage, and ligaments, but each bone also performs a specific function. In addition to supporting soft tissue, our bones allow us to move, protect our organs, allow us to breathe, help regulate electrolyte levels, and are sites of hematopoietic function.
Key term: hematopoietic
formation of blood cells or blood cellular components
Human adults have between 206 and 213 bones. Interestingly, babies normally have around 270 bones. Depending on intended use, bones can vary in size, form, and strength. Internal and external stimuli may cause changes in the bones and their structure. Increased mechanical stress in bones spurs activation of osteogenesis (the process of bone formation).
Key term: osteogenesis
bone formation
The skeletal system functions include:
blood cell production
facilitate movement
internal organ protection
storage of fat and minerals
supportive framework
“Skeleton,” derives from the greek, skeletos. The term referred to things that were dried up, or a mummy.
Anatomy
The skeleton's main function is to provide a rigid internal structure to support the weight of the body against external forces. It also provides a structure for movement.
Our skeleton has protective and storage functions.
It protects the internal organs, and also serves as the main storage site for essential minerals such as calcium and phosphate. Inside bones, the bone marrow stores fat and houses blood-cell producing tissues.
The skeleton is divided into two major sections:
the axial skeleton, and the
appendicular skeleton.
Key term: axial skeleton
the part of the skeleton that consists of the bones of the head and trunk
Key term: appendicular skeleton
the bones of the shoulder girdle, upper limbs, and pelvic girdle with the lower limbs
Physiology
The skeletal system's bones contain an inner spongy tissue known as bone marrow. There are two kinds of bone marrow: red and yellow.
Key term:
Red bone marrow is responsible for producing red blood cells through hematopoiesis. Yellow bone marrow contains adipose tissues that can serve as an energy source.
Additionally, bones store essential minerals. Your bones are the primary storage site of calcium in your body.
Bones in the body are typically connected to at least one other bone. The points where bones meet each other or where bones meet cartilage are known as articulations.
Key term:
Joints can be categorized based on their degree of mobility. In movable joints, the surfaces of the neighboring bones can glide against each other effortlessly. On the other hand, some joints may be linked by connective tissue or cartilage.
There are (3) types of joints:
Synarthrosis:
joints allow no movement.
For example: joints of the skull
Amphiarthrosis:
joint allow some movement.
For example: joints of the pubic symphysis
Diarthrosis:
joint allows for free movement.
For example: joints of the knee
A bone condition called osteoporosis arises when bone mass and mineral density decline, or when alterations occur to the composition and integrity of bone. This may result in a weakening of the bones, raising the possibility of fractures. Since osteoporosis rarely causes symptoms and may go undiagnosed until a bone breaks, it is referred to as a "silent" illness. For older men and women who have gone through menopause, osteoporosis is the main cause of fractures. Although fractures can occur in any bone, they most frequently occur in the wrist, hip, and vertebrae of the spine.
Healthcare professionals should consider bone health during patient interactions. Weight-bearing exercises offer significant benefits. However, any consistent physical activity is helpful, so recommending age- and condition-appropriate activities can assist in maintaining and improving bone health. Remember that the skeletal system is vital to numerous processes that function to safeguard and maintain well-being.
The Muscular System
Our muscles are one of the body’s four main tissue types.
There are three kinds of muscle tissue: cardiac, skeletal, and smooth. Cardiac muscle cells are found in the wall of the heart. Smooth muscle fibers are found in walls of the hollow visceral organs. Skeletal muscles help move our skeleton.
In all, there are over 600 muscles in the human body.
Anatomy
Muscle is composed of specialized cells known as fibers.
There are three different forms of muscle tissue in the body:
cardiac,
smooth, and
skeletal muscle.
A characteristic shared by the muscle tissues is excitability. This refers to the ability of their plasma membranes to transition from polarized to depolarized states and to transmit an electrical wave known as an action potential throughout the membrane's whole length.
Key term: excitability
ability to respond to a stimulus;
may be delivered from a motor neuron (or a hormone)
Muscles are surrounded by fibrous connective tissue, or fascia. Fascia is a layer of connective tissue that helps support tissues and organs.
A Closer Look At The Muscle Types
Cardiac Muscle
There is only cardiac muscle tissue in the heart. Well-coordinated heart muscle contractions push blood into and through the arteries. Heart muscle is striated and arranged into sarcomeres, with the same banding arrangement as skeletal muscle.
The cells that make up cardiac muscle fibers are highly branched as well, and intercalated discs join them at the ends. To enable the heart to function as a pump, an intercalated disc permits the cardiac muscle cells to contract in a wave-like way.
Smooth Muscle
The walls of hollow organs such as the bladder, uterus, stomach, and intestines contain smooth muscle. This muscle type gets its name from the lack of striations in its cells.
Smooth muscle is also found in the walls of arteries and veins of the circulatory system and the tracts that house the respiratory, urinary, and reproductive systems. In the skin, smooth muscle allows hair to stand straight in reaction to cold or fear.
Skeletal Muscles
Our skeletal muscles help facilitate movement and regulate the flow of various substances. they are found throughout the body at the entrances of internal systems. These muscles enable voluntary activities; these include defecation, swallowing, and urinating.
Skeletal muscles support the weight of internal organs and serve to shield against external assault. Our skeletal muscles protect our internal organs, especially our abdominal and pelvic organs.
By producing heat, skeletal muscles aid in the preservation of homeostasis. This heat is most noticeable when one is exercising, when prolonged muscle movement raises body temperature, or when one is extremely cold and shivering induces random spasms of the skeletal muscles, which raise body temperature.
Physiology
The primary role of the muscular system is to aid in movement. Muscles function in antagonistic pairs, where one muscle contracts while the other relaxes. The contraction of muscles pulls on the bones, facilitating movement. Muscle fibers shorten during contraction and lengthen during relaxation. The nervous system plays a crucial role in coordinating this sequence of relaxation and contraction.
Our muscles also contribute significantly to posture. Good posture involves a harmonious blend of strength and flexibility in the skeletal muscles. This allows us to move, sit, or stand with elegance. It is crucial to consciously engage the postural muscles, particularly when remaining seated or standing for extended durations.
Key term: postural muscles
the muscles most involved in maintaining upright posture; for example:
the calves, spinal muscles, and hip flexors
Recommended Reading (Optional)
Textbook
Medical Terminology for Healthcare Professions, Katherine Greene and Andrea Nelson
Read Chapters 6 & 7