NASM: Chapter 5 - The Nervous, Skeletal, and Muscular Systems Part 2

6 types.

1. Gliding (plane)

2. Condyloid (condylar or ellipsoidal)

3. Hinge

4. Saddle

5. Pivot

6. Ball-and-socket

• A nonaxial joint that has the simplest movement of all joints.

• Movement: Either back and forth or side to side.

• Examples:

1. Foot joint between the navicular bone and the second and third cuneiform bones

2. The carpals of the hand

3. The facet (spine) joints

• Named because the condyle of one bone fits into the elliptical cavity of another bone to form a joint.

• Movement: predominately occurs in one plane (flexion and extension in the sagittal plane) with minimal movement in others (rotation in the transverse plane, adduction, and abduction in the frontal plane).

Examples:

1. Wrist between the radius and the carpals

2. The joints of the fingers (metacarpophalangeal).

• A uniaxial joint allowing movement predominately in only one plane of motion, the sagittal plane.

• Examples:

1. Elbow

2. Interphalangeal (toes)

3. Ankle

• One bone looks like a saddle, the other articulating bone straddles it like a rider.

• Only found in the carpometacarpal joint in the thumb.

• Movement: predominantly in two planes of motion (flexion and extension in the sagittal plane, adduction and abduction in the frontal plane) with some rotation to produce circumduction (circular motion).

• Allow movement in one plane of motion (rotation, pronation, and supination in the transverse plane.

• Location:

1. in the atlantoaxial joint at the base of the skull (top of the spine)

2. In the proximal radioulnar joint at the elbow.

• They allow movement on all three planes.

| - Examples: shoulder and hip

Joints that do not have a joint cavity, connective tissue, or cartilage.
They exhibit little to no movement.
*Examples: sutures of the skull, the distal joint of the tibia and fibula, and the symphysis pubis (pubic bones).

Ligaments have poor vascularity (or blood supply) and thus are slower to heal.

-Flattened or indented portions of bone, which can be muscle attachment sites.

A common depression is known as a "fossa"

Example: the supraspinous or infraspinous fossa located on the scapulae (shoulder blades).

Another form of depression: "sulcus"

Example: intertubercular sulcus located between the greater and lesser tubercles of the humerus (upper arm bone).

Series of muscles that moves the skeleton.

• Multiple bundles of muscle fibers held together by connective tissue.

Three types:

1. Skeletal

2. Cardiac

3. Smooth

Function:

• Primary connective tissue that connects bones together to provide static and dynamic stability, as well as input to the nervous system (proprioception), guidance, and the limitation of improper joint movement.

Made of:

• Primarily collagen (a protein that runs parallel to the forces that are typically placed on a ligament)

• Contain varying amounts of elastin (a second protein that provides flexibility or elastic recoil to withstand bending and twisting)

• Not all ligaments will have the same amount of elastin.

Example:

• Anterior cruciate ligament (ACL) of the knee contains very little elastin and is mostly collagen and is much better suited for resisting strong forces and making a good stabilizing structure of the knee.

• The first bundle (actual muscle itself) wrapped by an outer layer of connective tissue (fascia), and an inner layer that is underneath the fascia and surrounds the muscle (epimysium).

• Fascia and epimysium are also connected to the bone and help to form the muscle's tendon.

• The outermost layer of connective tissue that surrounds the muscle.

• A grouping of muscle fibers that house the myofibrils.

• The connective tissue that surrounds the fascicles.

A portion of the muscle that contains myofilaments located in the cell components of the sarcolemma.

The contractile components of muscle tissue known as actin (thin stringlike filaments) and myosin (thick filaments) that form a number of repeating sections within the myofibril. Each section is known as a sarcomere.

• A plasma membrane that encase muscle fibers that contain cell components such as cellular plasma (sarcoplasm)

• Cell components, or cellular plasma, that contains glycogen, fats, minerals, and oxygen-binding myoglobin that are contained within the sarcolemma.

• Location: on the actin filament

• Function: block myosin binding sites located on the actin filament, keeping myosin from attaching to actin when the muscle is in a relaxed state.

• Location: on actin filament

• Function: plays a role in muscle contraction by providing binding sites for both calcium and tropomyosin when a muscle needs to contract.

• Connective tissues that attach muscle to bone and provide an anchor for muscles to produce/exert force and control the bone and joint.

• Similar to ligaments: poor vascularity (blood supply)

-A specialized synapse (junction/point) at which the (motor) neuron meets and communicates the muscle (fibers) to allow the action potential to continue its impulse.

• The contraction of a muscle generated by neural stimulation.

• The deepest layer of connective tissue that surrounds individual muscle fibers.

• The functional unit of the muscle (much like the neuron is for the nervous system) that produces muscular contraction and consists of repeating sections of actin and myosin.

• A motor neuron and all of the muscle fibers it innervates(connects).

1. Once released, they link with receptor sites on the muscle fiber specifically designed for their attachment.

2. Once attached, ACh (acetylcholine -neurotransmitter used by neuromuscular system) stimulates the muscle fibers to go through a series of steps that initiates muscle contractions.

• Chemical messengers that cross the neuromuscular joint junction (synapse) to transmit electrical impulses from the nerve to the muscle.

• The proposed process by which the contraction of the filaments within the sarcomere take place.

• Describes how thick and thin filaments within the sarcomere slide past one another, shortening the entire length of the Sacromere and thus shortening the muscle and producing force.

1. A sarcomere shortens as a result of the Z lines moving closer together.

2. The Z lines converge as a result of myosin heads attaching to the actin filament and asynchronously pulling (power strokes) the actin filament across the myosin, resulting in shortening of the muscle fiber.

Z lines denote the dividing line between each sarcomere.

During muscle contraction, the Z lines move towards one another due to the overall shrinking of each sarcomere.

• The process of neural stimulation creating a muscle contraction.

• It involves a series of steps that start with the initiation of a neural message (neural activation) and end up with a muscle contraction (sliding filament theory).

• Bottom line: Motor units cannot vary the amount of force they generate; they either contract maximally or not at all.

• Examples:

1. If the stimulus is strong enough to trigger an action potential, then it will spread through the whole length of the muscle fiber. It will spread through all muscle fibers supplied by a single nerve.

2. If the stimulus is not strong enough, then there will be no action potential and no muscle contraction.

• Action potentials.

• Slow twitch

• Large number of capillaries, mitochondria (which transforms energy from food into ATP, or cellular energy), and myoglobin, which allows for improved delivery of oxygen.

• Smaller in size

• Slow to fatigue

• Long-term contractions (stabilization)
  Example:

• Sitting upright while maintaining ideal posture against gravity, for an extended period of time.
  -Referred to as "red fibers" as it is similar to hemoglobin (red pigment found in red blood cells)

• Fast-twitch

• Separated into 2 subdivisions based off vehemently and mechanical properties (Type IIa and Type IIx)

• Fewer capillaries, mitochondria, and myoglobin

• Known as "white fibers"

1. Type IIa - higher oxidative capacity and fatigued more slowly than Type IIx - known as intermediate fast-twitch fibers because can use both aerobic and anaerobic metabolism almost equally to create energy making them a combo of Type I and Type II.

2. Type IIx- low oxidative capacity (ability to use oxygen) and fatigue quickly.

Example: movements requiring force and power such as a sprint.

1. Agonist: 'prime mover' - muscles most responsible for a particular movement. Ex. gluteus maximus is an agonist for hip extension.

2. Synergist: assist prime mover - Ex. the hamstring complex and the erector spinae are synergist with the gluteus maximus during hip extension.

3. Stabilizer: Stabilize body while prime mover and Synergist Work - Ex. tansversus abdominis, internal oblique, and multifidus (deep muscles in lower back) stabilize low back, pelvis, and hips (lumbo-pelvic-hip complex) during hip extension.

4. Antagonist: oppose prime mover - Ex. the psoas (a deep hip flexor) is antagonistic to the gluteus maximus during hip extension.

• Literal meaning: "hormone secreting"

• The system of glands that secrete hormones into the bloodstream to regulate the control of mood, growth and development, tissue function, and metabolism.

Consists of:

• Host organs (glands)

• Chemical messengers (hormones)

• Target (receptor) cells.

Special proteins will bind to some hormones, acting as carriers that control the amount of hormone that is available to interact with and affect the target cells.

Anterior lobe secretes:

1. Growth hormone, prolactin to stimulate milk production after giving birth

2. Adrenocorticorophic hormone (ACTH) to stimulate adrenal glands

3. Thyroid-stimulating hormone (TSH) to stimulate thyroid gland

4. Follicle-stimulating hormone (FSH) to stimulate ovaries and testes

5. Luteinizing hormone (LH) to stimulate the ovaries or testes.

1. Hypothalamus

2. Pituitary ("master" gland because it controls the functions of the other endocrine glands)

3. Thyroid

4. Adrenal glands.

Secretes melanocyte-stimulating hormone to control skin pigmentation

Posterior lobe secretes:

1. Antidiuretic hormone (ADH) to increase absorption of water into the blood by the kidneys

2. Oxytocin to contract the uterus during childbirth and stimulate milk production

Thyroid gland produces hormones that regulate the rate of metabolism and affect the growth and rate of function of many other systems in the body.

Adrenal glands secrete hormones such as corticosteroids and catecholamines, including cortisol and adrenaline (epinephrine) in response to stress.

Carbohydrate, specifically glucose (also principal fuel for the brain) regulated by the pancreas which produces two specific hormones: insulin and glucagon.

• Triggering muscle contraction

• Stimulating protein and fat synthesis

• Activating enzyme systems

• Regulating growth and metabolism

• Determine how the body will physically and emotionally respond to stress.

1. Epinephrine (adrenaline)

2. Norepinephrine

• Increases heart rate and stroke volume

• Elevates blood glucose levels

• Redistributes blood to working tissues

• Opens up the airways

The complex carbohydrate molecule used to store carbohydrates in the liver and muscle cells. When carbohydrate energy is needed, glycogen is converted into glucose for use by the muscle cells.

• Fundamental role in growth and tissue repair.

| - Raised levels of testosterone are indicative of an anabolic (tissue building) training status.

Under times of stress, such as exercise, cortisol is secreted by the adrenal glands and serves to maintain energy supply through the breakdown of carbohydrates, fats, and proteins.

A protein hormone released by the pancreas that helps glucose move out of the blood and into the cells in the body, where the glucose can be used as energy and nourishment.

• Located at the top of the femur and are the attachment sites for the hip musculature.

• The greater trochanter is commonly called the hipbone.

• Responsible for human metabolism (carbohydrate, protein, and fat metabolism), basal metabolic rate, protein synthesis, sensitivity to epinephrine, heart rate, breathing rate, and body temperature.

• Regulated by pituitary gland

• Low thyroid leads to: low metabolism, fatigue, depression, sensitivity to cold, and weight gain.

• Located at the top of the humerus at the glenohumeral (shoulder) joint.

• Shoulder musculature.

• Located on the inner and outer portions of the humerus to help form the elbow joint.

• Located on the inner and out portions at the bottom of the femur (thigh bone) and top of the tibia (shin bone) to form the knee joint.

• Spinous process found on the vertebrae and the acromion

| - Coracoid processes found on the scapulae.

• Responsible for most of the growth and development during childhood up to puberty, when primary sex hormones take over that control.

• Increase development of bone, muscle tissue, and protein synthesis; increases fat burning; and strengthens the immune system.

• Primarily an anabolic hormone

• Stimulate by several factors (estrogen, testosterone, deep sleep, and vigorous exercise).