Lecture Exam 3

Excitability

The ability of a muscle to respond to a stimulus, such as a nerve signal or hormone. Ex. nerve signal from the brain can cause your leg muscles to move when you decide to walk

Contractibility

All types contract differently. When you lift a weight, the muscle fibers in your bicep contract to pull your forearm up.

Extensibility

Muscle lengthening. When you stretch your leg, the muscles in your quadriceps and hamstrings are able to lengthen

Elasticity

Muscles ability to go back after lengthening. After you stop running, your muscles will naturally return to their resting size and shape, not remain stretched out.

Muscle tissue layers from innermost to outermost

Endomysium —> perimysium —> epimysium

Sarcoplasm

the cytoplasm of a muscle cell

Thin filaments

actin, troponin, tropomyosin

Neuromuscular junction

region where motor neuron meets skeletal muscle

Sodium-potassium pump

restores plasma membrane to resting state after an action potential

Muscle tension

Force exerted by contracting muscle

Graded muscle response

Twitch —> wave summation —> unfused tetanus

Twitch

one motor unit contracting

Wave summation

A second stimulus is applied before the muscle has fully relaxed from the first causing the twitches to add together, resulting in a stronger contraction

Unfused tetannus

Higher frequency of stimulation causes the twitches to become more frequent and fused, but the waves are still distinguishable

Aerobic respiration

Energy used by cells that’s anything over 1 minute. Requires oxygen to convert energy

Smooth muscle contraction

Starts with calcium binding to calmodulin to contract like an accordian

Pectoralis major muscle arrangement

Convergent fascicle

Masseter

Muscle of mastication; not a muscle of facial expression

Genioglossus

Muscle that protrudes tongue

Sternocleidomastoid

Muscle that attaches to neck

Diaphragm

Prime mover of inspiration

4 abdominal muscles

rectus abdominus, external oblique, internal oblique, transversus abdominus

4 rotator cuff muscles

Supraspinatus, infraspinatus, subscapularis, teres minor

Biceps brachii function

flexes and supinates forearm

Latissimus dorsi function

prime mover of arm extension

Tibial tuberosity

the insertion of all quadricep muscles

Ischial tuberosity

the origin of all hamstring muscles

Gastrocnemius function

plantarflexes ankle

Schwann cells

myelin sheath in PNS

Axons

contain myelin sheath

Motor neurons

sends information to skeletal muscles

Large diameter of myelinated axons

What causes a faster nerve conduction velocity?

Longitudinal fissure

separates left and right hemispheres of cerebral cortex

Temporal lobe

Contains olfactory cortex

Occipital lobe

Contains visual cortex

Visceral association areas

Brain areas that interpret an upset stomach

4 major brain areas

Cerebral cortex, diencephalon, brain stem, cerebellum

Brain meninges

Dura mater, arachnoid mater, pia mater

Ventricles funciton

makes and houses CSF

Anterior cerebrum

motor part of cerebrum

Spinal dural sheath

The meninges of the spinal column

Amyotrophic lateral sclerosis (ALS)

progressive neurodegenerative disease that involves the destruction of the lateral horn motor neurons

Proprioreceptors

Relay movement of muscle and bones

Tactile corpuscles

Responds to light touch

Cranial nerves for eye

Optic, oculomotor, trochlear, abducens

Trigeminal nerve

Innervates muscle of mastication

Brachial plexus

Includes axillary nerve, musculocutaneous, radial, ulnar, and median nerves

Autonomic nervous system

Nervous system that’s part of the PNS

Sympathetic nervous system

Part of nervous system that increases heart rate

Taste

Is most associated with smell

Inferior rectus muscle

Depresses the eye (moves eye down)

Sensorineural deafness

Permanent condition caused by damage to vestibulocochlear nerve

Sartorius

Longest muscle of the body

Diencephalon

Includes the epithalamus

Facial nerve

controls facial expression muscles

Taste sensation nerves

Facial and glossopharyngeal