Muscles & Systems Unit Test Flashcards
Compare and Contrast: Agonist vs. Antagonist
The agonist is the muscle primarily responsible for movement. The antagonist is the muscle that counteracts the agonist, lengthening when the agonist muscle contracts. They are both stabilizers and cause movement. Eg. bicep curl - the biceps contract while the triceps relax.
Compare and Contrast: Insertion vs. Origin
The insertion is the attachment site that moves when the muscle contracts. The origin is the attachment site that doesn’t move when the muscle contracts. They both aid in contraction and are connected by tendons (attached to bone). Eg. When the biceps contract, you pull your forearm toward your shoulder, pulling towards the origin. The insertion is at the end of the radius, called the radial tuberosity, that moves during contraction.
Compare and Contrast: Fast Twitch vs. Slow Twitch
Slow twitch muscle fibres are red or dark in colour and generate and relax tension slowly. They are able to maintain a lower level of tension for long durations. Eg. long-distance running, cycling, swimming. Fast twitch muscle fibres are more pale in colour and generate and relax tension quickly. They are able to generate tension with low endurance levels and can activate 2-3 times faster than slow twitch making them ideal for fast, powerful muscle contractions. Eg. short sprints, powerlifting. Both fuel muscle contractions.
Compare and Contrast: Anaerobic vs. Aerobic
The anaerobic energy system occurs without the requirement of oxygen. It can occur in 2 metabolic pathways, 1 not involving the breakdown of glucose and the other involving the partial breakdown of glucose. The aerobic energy system occurs with the requirement of oxygen. it involves many enzymes and several complex sub-pathways, leading to the complete breakdown of glucose. Both produce ATP.
Compare and Contrast:
Lactic vs. Alactic
Lactic - lactic acid is a byproduct.
Alactic - lactic acid is not a byproduct.
Compare and Contrast: Acetyl CoA vs. Lactic Acid
Acetyl CoA is produced from pyruvic acid when oxygen is present. Lactic acid is produced from pyruvic acid when oxygen is not present.
Compare and Contrast: ADP vs. ATP
ATP - has 3 phosphate groups.
ADP - has 2 phosphate groups.
Compare and Contrast: CNS vs. PNS
The CNS includes only the brain and spinal cord. Responsibilities include receiving, processing and responding to sensory information. The PNS consists of cranial and spinal nerves responsible for sending information from different body areas back to the brain and carrying out commands from the brain to various parts of the body.
Compare and Contrast: Afferent vs. Efferent
Afferent neurons carry information from sensory receptors found throughout the body towards the CNS. Efferent neurons carry motor information away from the CNS to the muscles and glands of the body to initiate an action. Both are connected to the CNS and carry the nerve impulses.
What is Cardiac Muscle?
Cardiac muscle is found only in the heart. It is responsible for creating the action that pumps blood from the heart to the rest of the body. They are involuntary muscles (controlled by the autonomic nervous system).
What is Smooth Muscle?
Smooth muscle surrounds the body’s internal organs, including the blood vessels, hair follicles, and the urinary, genital, and digestive tracts. They contract more slowly than the skeletal muscles but can remain contracted for longer periods. They are involuntary.
What is Skeletal Muscle?
Skeletal muscles are attached to bones by tendons and other connective tissues. They are the most prevalent muscle type in the human body (30-40% of human weight) and are voluntary. The muscle tissue is referred to as striated, or stripped, because of alternating light and dark stripes.
What is The Musculoskeletal System?
Supports the body, keeps it upright, allows movement, and protects vital organs. Serves as a storage system for calcium, phosphorus, and components of blood. Made of bones, skeletal muscles, and connective tissue that binds them together.
What is LADSNOR?
L - location of muscle
A - action of muscle
D - direction of fibres
S - shape of muscle
N - number of divisions/heads
O - origin and insertion
R - relative size
Anatomy of the Muscle: Sarcolemma
A plasma membrane that lies beneath the endomysium.
Anatomy of the Muscle: Sarcoplasm
The muscle cell’s cytoplasm which is contained within the sarcolemma.
Anatomy of the Muscle: Sarcomeres
The units of skeletal muscle that contain the cellular proteins myosin and actin.
Anatomy of the Muscle: Sarcoplasmic Reticulum
A network of channels in each muscle fibre that transports the electrochemical substances involved in muscle activation.
Anatomy of the Muscle: Perimysium
A sheath of connective tissue (within the epimysium) that binds groups of muscle fibre (fascicles) together.
Anatomy of the Muscle: Epimysium
A larger and stronger sheath that envelops the entire muscle.
Anatomy of the Muscle: Endomysium
A sheath of connective tissue that surrounds each muscle fibre.
Anatomy of the Muscle: Muscle Fibre
A cylindrical multinucleate cell composed of many myofibrils that contract when stimulated.
Anatomy of the Muscle: Myofibril
Thread-like structures that run along the length of the muscle fibre. Contains actin and myosin filaments.
Anatomy of the Muscle: Myosin
A cellular protein that consists of a “head” and “tail”. The myosin head will have an attachment site for actin, and actin will have a binding site for the myosin head.
Anatomy of the Muscle: Actin
A cellular protein that consists of 2 other proteins - troponin which has a binding site for calcium, and tropomyosin, which is the stringy-looking cord-like structure that covers the binding site on actin. Together these 2 proteins behave like a swivel-locking mechanism - they will not allow the myosin head to attach until calcium is released from the sarcoplasmic reticulum.
What is Concentric Contraction?
Shortening
What is Eccentric Contraction?
Lengthening
What is Isometric Contraction?
No movement
The Reflex Arc: Receptor
Receives the initial stimulus (eg. loud noise, prick to the skin).
The Reflex Arc: Sensory (afferent) Nerve
Carries the impulse to the spinal column or brain
The Reflex Arc: Intermediate Nerve Fibre (Interneuron)
Interprets the signal and issues response.
The Reflex Arc: Motor (efferent) Nerve
Carries the response message from the spinal cord to the muscle or organ.
The Reflex Arc: Effector Organ
Carries out the response (eg. moving away from danger)
What is the function of several different muscles?
- Provides support for the skeleton and organs.
- Allows movement of joints and body.
- Involved in breathing, eating, and beating of the heart.
- Production of heat.
What is the Sliding Filament Theory?
The sliding filament theory describes the process used by muscles to contract. According to this theory, muscle contraction occurs through the relative sliding or overlapping of actin and myosin filaments which causes the sarcomere (thus the whole muscle fibre) to contract (shorten). At very high levels of magnification, it is possible to detect small bridges on thick filaments that extend to thin filaments called myosin cross-bridges that attach, rotate, detach, and reattach in rapid succession. This causes the filaments to overlap each other. The “trigger mechanism” is the release of calcium ions when the nerve impulse is transmitted through the muscle fibre. The release of calcium in the presence of the proteins troponin and tropomyosin facilitates the interaction of actin and myosin molecules. Muscle relaxation caused by the re-uptake of calcium ions requires ATP which is used to detach the myosin from the actin molecule.
Muscle Fibres: Type I or Slow -Oxidative
- Generate energy slowly
- Fatigue Resistant
- Primarily depend on aerobic processes
Muscle Fibres: Type IIA or Fast-Oxidative Glycolytic
- Intermediate-type muscle fibres
- Allows for high-speed energy release
- Allow for glycolytic capacity
Muscle Fibres: Type IIB or Fast-Glycolytic
- Store glycogen and high levels of enzymes
- Allows for quick contraction without the need for oxygen
What are The 3 Key Energy Nutrients?
Carbohydrates, Proteins, and Fats.
Three Energy Pathways: ATP-PC (anaerobic alactic)
- Location: Cytoplasm
- Energy source: Creatine
Phosphate - Uses oxygen: No
- ATP produced: 1
- Duration: 10-15 seconds
- # of chemical reactions: 1-2
- By-products: None
- Formula: PC + ADP = ATP +
creatine - Types of activities: Power
surges, speed events - Types of exercise that rely
on this system: Sprints,
jumping, weightlifting - Advantages: Very quick
surge of power - Limitation: Short duration;
muscles store small
amounts of ATP and
creatine phosphate
Three Energy Pathways: Glycolysis (anaerobic lactic)
- Location: Cytoplasm
- Energy Source: Glucose
(glycogen) - Uses Oxygen: No
- ATP Produced: 2
- Duration: 15 secs to 3 mins
- # of chemical reactions: 11
- By-Products: Lactic acid and
pyruvate ‘1 - Formula: C6H12O6 + 2ADP
+2Pi → 2C3H6O3 + 2ATP +
2H2O - Types of Activities:
Intermediate
activities/sprint finish - Types of Exercise: 200-700
meter sprints; a shift in
hockey - Advantages: Quick surge of
power - Limitation: Buildup of lactic
acid causes pain and
fatigue
Three Energy Systems: Cellular Respiration (aerobic)
- Location: Mitochondria
- Energy Source: Glycogen,
protein, fats - Uses Oxygen: Yes
- ATP produced: 36
- Duration: 120 seconds and
beyond - # of chemical reactions:Glycolysis, Krebs cycle, and
the Electron Transport
Chain - By-products: Water and
Carbon Dioxide - Formula: C6H12O 6 + 6O2
= 6CO2 + 6H2O + ATP - Types of Activities:
Prolonged activities - Types of exercise:
Marathons - Advantages: Long duration;
complete breakdown of
glucose - Limitation: Slow; requires
large amount of oxygen
Why are East African runners so dominant in long-distance running?
- Genetics: they have a
higher capacity to take in
and use oxygen. - Cultural Factors: Their
childhood may have
involved
more running and walking.
Eg. going to school, and
collecting food and water. - Role Models: Due to early
success in the 1960s for
both Ethiopian and Kenyan
runners, young people
started to look up to these
athletes. - Diet: Eating much healthier
(not as much
“fattening/greasy” food). - Low Resting Heart Rate:
Allows them to run much
faster and more efficiently
then others.
How can we train each of the different energy systems, and what happens when we train them?
- DURATION (ATP-PC - do
sprints, glycolysis - lift
weights, cellular respiration,
run a marathon) - Training for Strength:
The goal is to increase the
explosive capacity of
muscles. The training aims
to increase the power the
athlete will require for
competition. Short
powerful training exercises
(a few seconds) will
increase creatine
phosphate stores in
muscle. Intense exercise
(up to 90 sec) will increase
glycogen stores and the
ability to convert glucose
quickly, delaying the onset
of lactic acid production
and impeding performance. - Training for Endurance
Aimed at developing
muscles that do not fatigue
quickly. Training to increase
oxygen processing capacity
of lungs and blood.
Aerobic training leads to: - Increased number of
mitochondria in muscle
cells - Increased amounts of
oxygen store myoglobin
molecules - Enhanced ability of muscle
enzymes to utilize oxygen
in the complete breakdown
of glucose
Achieved through exercise
that raised heart rate well
above normal for long
period.
