Anatomy final

Agonist

Primary mover for a movement: Biceps brachii during elbow flexion

Antagonist

Muscle that opposes the action of the agonist (control and stabilization): triceps brachii during elbow flexion

Stabilizer

Muscles that stabilize a joint or body segment allowing other muscles to perform their action effectively: Rotator cuff muscles during shoulder press

Neutralizer

Muscle that prevents unwanted movements caused by agonist: pronator teres prevent supination during elbow flexion

Reverse actions of muscles

When origin and insertion of a muscle switch roles usually due to the stabilization of the distal end: during a pull-p the lats perform reverse action by pulling the torso towards fized arms

Concentric

Muscles shorten when generating a force: biceps during a bicep curl

Eccentric

Muscles lengthen while under tension to control movement: Downward phase of bicep curl

Isometric

Muscle generates tension without changing length:plank

Stretch-Shortening Cycle (SSC)

Rapid lengthening (eccentric phase) followed by immediate shortening (concentric) enhancing force production enhancing force production due to stored elastic energy and reflex activation

Example of SSC

The preparatory dip before doing a vertical jump

Passive insufficiency

When a muscle cannot stetch enough to allow full range of motion across multiple joints

Example of passive insufficiency

Hamstrings limiting hip flexion when the knee is fully extended

Active Insufficiency (stretched)

When a muscle cannot produce sufficient tension because it is shortened excessively

What’s an example of active insufficiency (shortened)

Biceps brachii struggling to flex the elbow fully when the shoulder is also flexed

Cranial nerve 1

smell (olfactory)

Cranial nerve 2

Vision (optic)

Cranial nerve 3

Eye movement, pupil constriction (oculomotor)

Cranial nerve 4

Eye movement (Trochlear)

Cranial nerve 5

Facial sensation, mastication (trigeminal)

Cranial nerve 6

Eye movement (abducens)

Cranial nerve 7

Facial expression taste (facial)

Cranial nerve 8

Hearing and balance (Vestibulocochlear)

Cranial nerve 9

(Glossopharyngeal): Taste (posterior 1/3 tongue), swallowing

Cranial nerve 10

Parasympathetic control, swallowing, speech (vagus)

Cranial nerve 11

Shoulder shrug, head-turning (accessory)

Cranial nerve 12

Tongue movement (hypoglossal)

Dermatomes

Areas of skin supplied by sensory fibers from a single spinal nerve.

Example: The C6 dermatome covers the thumb.

Myotomes

Muscle groups innervated by motor fibers from a single spinal nerve.

Example: C5 controls shoulder abduction (deltoid).

Upper motor neuron/lesion symptoms

Spasticity. Hyperreflexia. Weakness without significant muscle atrophy. Positive Babinski sign.

Lower motor neuron/lesion symptoms

Flaccid paralysis. Hyporeflexia or areflexia. Muscle atrophy. Fasciculations.

Frontal lobe

Responsible for motor control, decision-making, personality, and speech (Broca's area).

Parietal lobe

Processes sensory input and spatial awareness

Temporal lobe

Hearing, language comprehension (Wernicke’s area) and memory

Occipital lobe

Vision

Cerebellum

Coordination and balance

Motor units

A motor neuron and all the muscle fibers it innervates. Smaller motor units are involved in fine motor control, while larger ones generate more force.

Proprioception

The body's ability to sense its position, movement, and orientation in space.

Stretch reflex

A reflexive contraction of a muscle in response to its rapid stretch, mediated by muscle spindles.

Example: The knee-jerk reflex.

Reciprocal inhibition

​​The process where activation of an agonist muscle inhibits the antagonist muscle to facilitate movement.

Muscle spindles

 Sensory receptors in muscles that detect changes in length and trigger the stretch reflex.

Golgi tenson units

Sensory receptors in tendons that monitor tension and inhibit muscle contraction to prevent damage.

What axis of rotation does hip flexion occur on?

Frontal (coronal)

Which of these structures is most medial

Brachioradialis insertion

biceps brachii insertion

extensor digitorum origin

pronator teres origin

Pronator teres origin

Which of the following muscles is acting as a neutralizer: The rhomboids while you are being pulled water skiing, the hamstrings during a quad leg extension, the tibialis anterior during straight plane ankle inversion using the tibialis posterior, or the biceps brachii during a biceps curl?

1. The tibialis anterior during straight plane ankle inversion using the tibialis posterior