Musculoskeletal system Flashcards
What is myogenic activity and what muscle types possess it?
Myogenic activity refers to muscles that can contract without stimulation from the nervous system
Cardiac and smooth muscle
What is the difference between endochondrial ossification and intramembraneous ossification?
Endochondrial ossification refers to the formation of bone from cartilage while intramembraneous ossification refers to the formation of bone from undifferentiated connective tissue (occurring mostly in the head)
This type of muscle is:
-voluntary
-innervated by the somatic nervous system
-striated
-multinucleated
-contains red and white twitch fibers
Skeletal muscle
This type of twitch fiber is high in mitochondria and myoglobin. It contracts slowly, but is able to maintain activity for a longer period of time
Red twitch fibers (slow twitch)
This type of twitch fiber is low in mitochondria and myoglobin. it contracts rapidly, so it tires out quickly
White twitch fibers (fast twitch)
This type of muscle is:
-involuntary
-innervated by the autonomic nervous system
-myogenic
-uninucleated
-Has tonus (can sustain contractions)
Smooth
This type of muscle is:
-involuntary
-innervated by the autonomic nervous system
-striated
-myogenic
-normally uninucleated but can have 2 nuclei
-connected via intercalated discs connected by gap junctions
Cardiac
Thick filaments are made up of _____ while thin filaments are made of ____, ____ and ____
Myosin
Actin, troponin, tropomyosin
Troponin and tropomyosin regulate interactions between ____ and ____
Actin and myosin
This band is made entirely of thick filament and is the only band that doesn’t decrease in size during contraction
A-band
This band is made entirely of thin filament
I-band
This zone contains only thick filaments
H-zone
This line defines the boundaries of the sarcomere/is found at the end of the sarcomere
Z-line
This zone goes through the center of the sarcomere, right through the myosin filaments
M-line
____ anchors myosin and actin filaments to prevent them from stretching
Titin
____ is the cytoplasm outside the sarcoplasmic reticulum
Sarcoplasm
____ is the cell membrane of the myocyte and has the ability to propagate action potentials to all sarcomeres in a muscle system
Sarcolemma
Sarcomeres attach end to end to form ____
Myofibrils
Many myofibrils arranged in parallel is called a _____
Myocyte (also can be called muscle fiber, since many myocytes make up muscle)
Many myocytes in parallel is called a ____
Muscle
The ____ is the long cylindrical part of long bones
Diaphysis
The ____ is the bulbous end of the bone with cartilaginous growth plates at both ends (epiphyseal plates)
Epiphysis
The ____ is the slightly curved part of long bone in between the diaphysis and epiphysis
Metaphysis
What is the difference between the axial and appendicular skeletal systems?
The axial component is the framework for the body and includes the skill, vertebral column, ribcage and hyoid bone
The appendicular component is made up of the limbs, pelvis and pectoral girdle (so mostly the peripheral things)
This type of bone is dense and provides strength
Compact
This type of bone is made of a lattice with points called trabecule. Bone marrow fills in the gaps of the lattice
Spongy/cancellous bone
This type of bone marrow is made of fat and is relatively inactive
Yellow
The diaphysis and metaphysis are filled with ____
Bone marrow
Tendons connect ____ to ____ while ligaments connect ____ to ____
Tendons- muscle to bone
Ligaments- bone to bone
This occurs when acetylcholine is degraded by acetylcholinesterase, which terminates the action potential and allows the sarcolemma to repolarize
Relaxation
This type of bone marrow is made of hemopoietic stem cells (used in production of all blood cells)
Red
This occurs when muscles are unable to relax
Tetanus
____ occurs when frequent, prolonged stimulation gives insufficient time for relaxation, so the contractions become stronger and more prolonged
Frequent summation
The ____ surrounds/protects the long bones and serves as a place for muscle attachment
Periosteum
What is the difference between osteoblasts and osteoclasts?
Osteoblasts form bone while osteoclasts are macrophages used in bone resorption
____ decrease the angle across joints while ___ increase or straighten the angle
Flexors
Extensors
____ is away from the midline while ___ is towards the midline
Abduction
Adduction
____ means the axis moves towards the midline while ___ means the axis moves away from the midline
Medial
Lateral
This type of tissue is made of chondrin, which is secreted by chondrocytes. It is avascular and not innervated
Cartilage
This hormone releases more calcium into the blood by promoting the resorption of bone
Parathyroid hormone
This hormone takes calcium out of the blood and promotes bone formation
Calcitonin
Explain the steps of the sliding filament model
Myosin carrying ADP and Phosphate binds to the open binding site on actin. This binding releases the ADP and Pi, which causes the actin and myosin to slide over each other in the powerstroke. Then, ATP binds to the free receptor in myosin which causes myosin to release actin, and the process can begin again once ATP is hydrolyzed to be ADP and Pi
Explain the steps of muscle contraction from initiation to the opening of the myosin binding site
The contraction starts in the neuromuscular junction, where the nervous system communicates via efferent neurons, and releases acetylcholine into the synapse. Acetylcholine binds to the sarcolemma and causes a depolarization, which then begins an action potential that reaches the sarcoplasmic reticulum and releases Ca2+. The Ca2+ binds to troponin, which induces a change in tropomyosin, which then exposes the myosin binding site of actin. From here, myosin is able to bind and form the contraction
If action potentials are all or nothing, how can the force behind a contraction be changed?
Although the strength of the action potential cannot be changed, the number of motor units responding to that action potential can change the strength of the contraction. The more motor units involved, the stronger the contraction, with the strongest contractions occurring when all the motor units are activated
This matrix makes up the strength of compact bone via organic and inorganic material. It has two canals: Haversian which run parallel to bone and Volkmann’s which run perpendicular to the bone and contain the blood and lymph vessels, and nerves
Bone matrix
This fluid is secreted by the synovium in order to provide smooth movement in moveable joints
Synovial fluid
