Muskulo Skeletal System Flashcards
What does the musculoskeletal system do?
provides protection for the organs
essential in the survival response
stores important salts like calcium and phosphorus
involved in the production of red cells (haematopoisis)
keeps important organs such as the heart, blood vessels or the digestive system working: most key organs of the body are formed by muscles
What is the cortical bone?
It is the hard outer layer of the bone. This is also called the compact bone. It accounts for 80% of the total bone mass in the human skeleton. Each column bone is formed by multiple osteons.
What is an osteon?
This is the primary anatomical and functional unit of the cortical bone. Each column is formed by multiple layers of osteocytes that form a honeycomb like matrix that helps to give the bone rigidity. In the middle of each osteon the harversian canal contains blood vessels that feed the bone and allows for the exchange of calcium and phosphates for bone remodelation.
What is the trabecular bone?
Also known as cancellous or spongy bone. This is the internal part of the bone, formed by a porous network, which makes it more flexible than the cortical bone. It is typically found at the end of long bones, near joints and in the interior of vertebrae. It is highly vascular and contains bone marrow.
What is bone marrow?
It is a semisolid tissue composed by stem blood cells, that is in charge of new blood production (haematopoiesis)
What is an osteocyte?
These are mature bone cells that have become trapped in the bone remodelation process. their function is to monitor and maintain bone tissue.
What is periosteum?
It is the most outer layer of the bone, covering the surface of the bone and with the ability to transform into osteoblast to create more bone.
What is bone?
Bone is a dynamic, living tissue, constantly being remodelled and renewed. Just like skin, it is being replaced throughout life through the action of cells.
What are the 2 types of cells that help to renew and remodel bones?
Osteoblast and osteoclast
Describe an osteoblast.
These cells are the immature bone cells that, as the bone develops, become trapped within the newly formed bone, transforming into osteocytes (mature bone cells)
Describe an osteoclast.
these cells break down the bone, releasing calcium and phosphate into the blood stream
What 2 hormones mediate the process remodelling bone?
Calcitonin
Parathyroid
What does calcitonin do?
it facilitates the absorption of calcium from the blood to osteoblast to form new bone
What does the parathyroid hormone do?
it facilitates the release of calcium from the bone back to the blood stream with the action of the osteoclasts
What is ossification?
The formation of bone
At the fetal stage what are bones formed of?
cartilage
How is the cartilage transformed into bone?
Through the action of osteoblasts. This process will take approx 25 years
What are the 2 types of bones?
axial
sesamoid
what is an axial bone?
The bones forming the main, central axis of the body, while appendicular are the bones in the extremities
What is a sesamoid bone?
These are bones that are not in contact with any other bone, but instead they are embedded in a tendon or muscle to protect tendons from stress and wear: there are often in the hands and feel, or the kneecap
What is the structure of a long bone?
Contains both epiphysis and diaphysis
what is the epiphysis?
the rounded end of the bone, usually forming a joint with another bone. This part is mainly formed by trabecular or spongy bone. The head is in contact with the joint is covered by articular cartilage.
what is the diaphysis?
this is the shaft of the bone. Formed mainly be compact bone, with the medulla cavity that contains bone marrow
what is the transition from the epiphysis and diaphysis called?
metaphysis
the part of the bone that grows during childhood, as it formed mainly by cartilage tissue. Once bones have reached the adult size this part will ossify
What do muscles do?
provide strength, balance, posture, movement and heat for the body to keep warm
what are the 3 types of muscles?
Skeletal muscles, smooth muscles and cardiac muscles
Describe skeletal muscles.
these are muscles attached to the bones by ligaments. they are also known as voluntary muscles: when they contract they are responsible for movement. the cells of this type of muscles are long, single cylindrical and with multiple nuclei like strips
Describe smooth muscles.
These type of muscle tissue form the internal hollow organs, such as the digestive system, the lungs, the uterus or blood vessels. these are also known as involuntary muscles: they are controlled by the nervous system, but you cannot choose to control or relax this tissue. the smooth muscle cells are small, have one single nucleus and are spindle shaped
Describe cardiac muscle.
This is the only type of muscle that can contract without external nerve stimulus, just by the action of the cardiac pacemaker. This is a highly coordinated tissue
How are skeletal muscles formed?
By bundles of muscular cells called fibres. These are rope like structures, all contained inside a bag called fascia, that terminates in a cord like structure called tendon. Tendons attach muscles to bones.
What initiates the skeletal muscle contraction?
electrical signal from the somatic nervous system, that arrives to the muscle at the neuromuscular junction
What does the skeletal muscular contraction need to happen?
calcium and energy
How is a smooth muscle contraction controlled?
Through a combination of the autonomous nervous system and the endocrine nervous system
What does smooth muscle respond to?
electrical impulses and hormones that are released to by specialised organs or even physical factors such as stretching , changes in ph and temp
What is an example of hormone stimulation?
oxytocin triggers uterine contractions
what is an example of a physical factor?
when the pupil reacts to light
What is peristalsis?
the wave like motion that smooth muscle can move in
What is essential for maintaining steady pressures in blood vessels?
the contraction of of the smooth muscle starts slower and lasts much longer than skeletal muscle. It is almost like smooth muscle is always in a continued partial contraction
Smooth muscle is generally found in 2 layers;
Longitudinal; causes organ dilation and shortening and it is often the outer layer of the organ
Circular; causes organ constriction and elongation, and it is often the inner layer
What explains the fact that the uterus can enlarge and the vagina can dilate?
the longitudinal and circular layers give the smooth muscle layer have greater flexibility, elasticity and resistance than the skeletal muscles
what is the deltoid muscle?
Located at the top of the arm, this is a muscle you may use to administer intramuscular injections
What is the gluteus muscle?
These are a groups of three muscles which make up the buttocks, inserted from the ilium and sacrum to the femur.
What are the abdominal rectus?
these are the abdominal muscles that connect the ribs with the pubis and will separate in pregnancy with the growth of the uterus
flexion vs extension
refers to a movement that decreases/ increases the angle between two body parts
abduction vs adduction
refers to a movement towards or away from the midline of the body
circumduction
it is a circular motion, where the limb forms a cone of movement around the joint
rotation
refers to the movement of the limbs around their long axis
supination vs pronation
refers to the movement where the part of the body is turned to the anterior part (supine) or the posterior part (prone) of the body
inversion vs eversion
refers to movements which occur at the ankle joint referring to the rotation of the foot around its long axis
How are most of the changes in pregnancy related?
They are related to the physical changes in body weight distribution that happens in a short period of time
How are the adaptations to pregnancy mediated?
through hormones such as relaxin and progesterone
relaxin relaxes the ligaments in the body which progesterone reduces the contraction of the smooth muscles
What is symphysis pubic diastasis (SPD)?
the pubic bones can separate causes severe discomfort
What cause leg cramps in the second half of pregnancy?
They are common and can be related to mineral metabolism and increases neuromuscular irritability
What can cause swelling in the lower limbs?
water retention leads to soft tissue oedema (swelling) in the lower limbs. This along with the musculoskeletal changes may cause nerve entrapment, often in the form if sciatica or tunnel carpal syndrome.
Why are pregnant women at risk of falling?
The changes in the posture control and body balance
they have the same risk as someone over 65
