Lecture Notes: Muscle, Sense, Cranial Nerves & CNS - Vocabulary

Vocabulary flashcards covering key terms from Muscle Fiber Anatomy, Sensory Systems, Ear & Vision, Neurotransmitters, Cranial Nerves, and CNS/Eye disorders.

Sarcomere

The fundamental contractile unit of a striated muscle, located between Z-lines.

Myofibrils

Rod-like bundles inside muscle fibers that contain repeating sarcomeres (actin and myosin).

Sarcolemma

The cell membrane of a muscle fiber.

Isometric contraction

A contraction that generates force without changing muscle length or joint angle.

Isotonic contraction

A contraction that changes muscle length as force is produced.

Concentric contraction

An isotonic contraction in which the muscle shortens while producing force.

Eccentric contraction

An isotonic contraction in which the muscle lengthens while producing force.

Golgi tendon organ (GTO)

A sensory receptor that detects muscle tension and helps prevent damage from excessive force.

Muscle spindle

A stretch receptor that detects muscle stretch and initiates the stretch reflex.

Hyaline cartilage

Smooth cartilage in joints and on the surfaces of ribs.

Elastic cartilage

Cartilage with elastic fibers found in the external ear and the epiglottis.

Fibrocartilage

Tough cartilage in intervertebral discs that resists compression.

Mechanoreceptors

Receptors that respond to mechanical stimuli such as touch and pressure.

Thermoreceptors

Receptors that detect temperature changes.

Photoreceptors

Receptors that detect light (rods and cones in the retina).

Chemoreceptors

Receptors that respond to chemical stimuli (e.g., chemical concentrations, smell, taste).

Nociceptors

Pain receptors that detect potentially harmful stimuli.

Pinna

The external part of the ear visible on the side of the head.

Auditory canal

The canal that channels sound to the eardrum.

Ossicles

Three tiny middle ear bones (malleus, incus, stapes) that transmit sound.

Cochlea

The spiral-shaped inner ear structure that converts sound into neural signals.

Semicircular canals

Inner ear structures that detect rotational movement and help with balance.

Lens

The eye structure that focuses light onto the retina by changing shape during accommodation.

Ciliary muscles

Muscles that adjust the lens shape for focusing (accommodation).

Pupil

The opening in the iris that regulates light entry.

Acetylcholine (ACh)

Neurotransmitter at the neuromuscular junction that triggers muscle activation.

Dopamine

Neurotransmitter involved in reward signaling and movement control.

Serotonin

Neurotransmitter associated with mood regulation.

Norepinephrine (NE)

Neurotransmitter involved in arousal, alertness, and stress response.

GABA

Gamma-aminobutyric acid, the main inhibitory neurotransmitter in the CNS.

Glutamate

Major excitatory neurotransmitter in the CNS.

Olfactory nerve (CN I)

Nerve responsible for the sense of smell.

Optic nerve (CN II)

Nerve responsible for vision.

Oculomotor nerve (CN III)

Controls most eye movements and pupil constriction.

Trochlear nerve (CN IV)

Controls the superior oblique muscle for eye movement.

Trigeminal nerve (CN V)

Sensation from the face and motor function for chewing.

Abducens nerve (CN VI)

Controls lateral eye movement.

Facial nerve (CN VII)

Controls facial expressions; taste on the anterior two thirds of the tongue.

Vestibulocochlear nerve (CN VIII)

Senses hearing and balance.

Glossopharyngeal nerve (CN IX)

Taste and swallowing.

Vagus nerve (CN X)

Autonomic control of the heart, lungs, and digestion.

Accessory nerve (CN XI)

Controls shoulder and neck movements.

Hypoglossal nerve (CN XII)

Controls tongue movements.

Parkinson's disease

Neurodegenerative disorder caused by dopamine deficiency in motor pathways.

Multiple sclerosis (MS)

Demyelinating disease of the CNS white matter.

Alzheimer's disease

Neurodegenerative disease with memory loss and brain plaques.

Glaucoma

Increased intraocular pressure that can damage the optic nerve.

Cataracts

Clouding of the lens causing blurred vision.

Otitis media

Infection of the middle ear.