Muscle objectives Flashcards
Define the Muscular System
The Muscular system is the system that provides movement, posture, blood circulation , heat production, and support.
what do cardiac muscle do?
pump blood
what do smooth muscles do?
help move blood and fluids through vessels
What is Fascia?
A thin layer of connective tissue that surrounds muscles, organs, and other structures
Superficial fascia
located under the skin, it seperates muscles from skin
Deep Fascia
Surrounds and seperates individual muscles or groups of muscles providing support, protection and pathways for nerves
Epi-my-si-um
Per-i-my-sium
en-do-my-si-um
Layes of fascia within muscles enclosing bundles of muscle fibers
Tendon
connective tissues that attaches muscle to bone and enables movement by transmitting force from muscle contraction
Ligament
A band of connective tissue that connects bones to other bones and stabilizes the joints
Aponeurosis
a flat sheet- like tendon that connects muscles to bones or or muscles ex: abdominal region
Agonist (Prime mover)
The muscle primarily responsive for producing a specific movement (example: the muscles when they contract)
Antagonist
The Muscle that opposes the agonist controlling or balancing the movement (example: the triceps when they are relaxed during arm flexions and biceps are contracted)
Synergist
A muscle that assist the agonist by stabilizing joints or adding force to the movement (example: Brachialis during arm flex
Origin
The fixed attachment point of a muscle to bone that remains stationary during contraction (The top of the muscle)
Insertion
The movable attachment point of muscle to bone where the muscle causes movement
Belly
The thick, central part of the muscle where most of the fibers are located (example: rectus and deltoid muscle)
How are fascicles arRANGED?
They are arranged in patterns that affect a muscles strength and RANGE OF MOTION
Parallel
Fibers run in straight lines
What are Fascicles?
When a group of muscle fibers are bundles as unit within the muscle
Convergent
Fibers spread out and converge at a single tendon (ONLY ONE TENDON)
Circular
Fibers form rings controlling opening(a literal ring) example orbicularis oris around the mouth
Pennate
Fibers attach at an angle to a tendon maximizing force (shape of feather) (2 ways going opposite)
Explain how the muscles are named (ex. size, # origins etc.
Muscles are named based on specific characteristic such as their shape, size, location, action, direction of fibers, and more
location ex: temporalis (on the temporal bone
Shape ex: Deltoid (Triangle shaped
Size ex: Maximus: long
Number of origins ex: Biceps (two origins) triceps: three origins
Origin and insertion ex: sternocleidomastoid: sternum and clavicle and inserts at the mastoid process
Whenever a muscle or tissue surrounds, it what?
protects
What is Sac-cro-lem-ma?
The Cell membrane of a muscle fiber?
Where is sac-cro-lem-ma located?
Surround the muscle cell (protecting from bone and other muscle)
What is the function of sarcolemma?
The function of the sarcolemma is to help transmit signals for muscle contraction
What is Sacroplasm?
The cytoplasm of the muscle fiber (JELLY LIKEK SUBSTANCE THAT CONTAINS NEED NUTRIENT AND MATERIALS FOR CELL TO OPERATE
What does the sarcoplasm contain?
Proteins, enzymes, and energy molecules NEEDED FOR CONTRACTION
What is the The Cell membrane of a muscle fiber?
Sacrolemma
The Cyoplasm of a muscle fiber is
Sacroplasm
What are Myofibrils
Rod like structures inside the muscle fiber that is responsible for muscle contraction
What do Myofibrils contain?
they contained repeating units called sarcomeres which are responsive for contraction
What are Sarcomere made of?
Actin (Thin filaments)
Myosin (Thick filaments)
What do actin and myosin do during contraction?
Slide over each other
What is Sar-co-plas-mic Reticulum?
A network of tubes that stores and RELEASES CALCIUM IONS that are ESSENTIAL for muscle contraction
what are T-Tubules (Transverse Tubules)?
Extensions of the sarcolemma that go deep into the muscle fiber to carry the rapid
transmission electrical signals throughout the muscle cell in order to ensure the entire muscle fiber CONTRACTS coordinately
Mitochondria
Provide ATP (energy for contraction. Skeletal muscles need a lot of energy
Nuclei
Nuclei produce proteins needed to maintain and repair the muscle fiber (protein=repairs)
Describe the Neuromuscular junction
The neuro muscular junction isi the communication site where a motor neuron meets a muscle fiber. The neuron relases a-ce-tyl-cho-line a chemical messanger that triggers the muscle fiber to contract
Describe the synthesis and inactivation of acetylcholine?
synthesis: Acetylcholine is produced in the neuron and STORED IN VESICLES
release When a signal arrives, ACH is released into the synaptic cleft
ioknactivation: Acetylcholinesterase ( an enzyme ) breaks down ACH to stop the signal
Explain the sliding filament mechanism of contraction
Muscles contract by the process of thin actin filaments sliding past thick myosin filaments within a muscle fiber, effectively shortening the sarcomere and generating force, without the filaments themselves actually changing length
Atp provides eergy for this process
The role of calcium in muscle contraction
When a nerve impulse reaches the muscle, calcium ions are released from the sarcoplasmic reticulum, binding to tro-po-nin (a protien found in skeletal msucles to repair) on the actin filament. this allows the sliding filament mechanism to occur.
List the energy sources for muscle contraction
ATP, Creatiine Phosphate (ATP), Glucose(more ATp), and Fatty Acids
Twitch
a single, brief contraction in response to a stiimulus
SUMmation
multiple twitches combine for a stronger contraction
Tetanus
tetanus contraction without relaxation
Tone:
a low-level, constant muscle contraction for POSTURE
Fatigue:
When muscles can no longer contract effectively
Oxygen Debt
the amount of oxygen required after exercise to restore energy reserves
Aerobic metabolism:
Uses oxygen to produce energy efficiently; ideal for endurance activates
Anaerobic metabolism
DOESNT REQUIRE OXYGEN, producing LESS ENERGY but QUICKYLY USED for Shortburst of intense activity
Fast twitch fibers
contract quickly but fatigue easily; used in sprinting or weightlifting
Slow twitch fibers
contract slower but resist fatigue; used in endurance activities like long distance running
How are smooth graded contractions produced?
By gradually recruiting more motor units and increasing the frequency of nerve signals to the muscle
The role of motor units in smooth graded contractions
Motor units play a crucial role in producing smooth, graded contractions by allowing muscles to vary their force of contraction by selectively activating different numbers of motor units, essentially “recruiting” more or fewer muscle fibers as needed to generate the desired level of force; this process is called motor unit recruitment.
Isotonic contractions:
when the muscle changes length (ex: lifting weights)
isometric contraction
When the muscle stays the same length (ex holding a plank
Describe the effect of exercise on muscle structure
exercises makes muscles grow stronger by: adding more fibers (hypertrophy) and increasing energy storage
Atrophy:
when muscles shrink from not being used
hypertrophy:
when muscles grow bigger from exercise
What chemical helps to regenerate ATP?
creatine phoshate
What’s is flexion and extension?
movements that occur in the sagittal plane. They refer to increasing and decreasing the angle between two body parts:
Flexion
refers to a movement that decreases the angle between two body parts.
Extension
refers to a movement that increases the angle between two body parts.
Medial rotation
a rotational movement towards the midline.
Lateral rotation
a rotating movement away from the midline.
Elevation
to movement in a superior direction
depression
refers to movement in an inferior direction.
supination
With your hand resting on a table in front of you, and keeping your shoulder and elbow still, turn your hand onto its back, palm up.
pronation
Again, keeping the elbow and shoulder still, flip your hand onto its front, palm down. This is the prone position
Circumduction
Circular movement of a limb extending from the joint at which the movement is controlled.
