Exam 2 Study Topics on Neurotransmitters, Muscle Physiology, and Cardiovascular System

These flashcards cover key vocabulary and concepts related to neurotransmitters, skeletal muscle physiology, and cardiovascular health relevant to the upcoming exam.

Neurotransmitters

Chemical messengers that transmit signals across a synapse between neurons.

Cholinergic neuron

A neuron that releases acetylcholine (ACh).

Cholinergic receptor

A receptor that binds acetylcholine.

Adrenergic neuron

A neuron that releases norepinephrine (norepi) or epinephrine (epi).

Nicotinic acetylcholine receptors (nAChRs)

Receptors located on the motor end plate that bind acetylcholine (ACh) and are involved in muscle contraction.

Motor end plate

The specialized region of the muscle fiber membrane (sarcolemma) that interacts with the motor neuron at the neuromuscular junction.

Sympathetic nervous system (SNS)

Part of the autonomic nervous system that prepares the body for 'fight or flight' responses.

Parasympathetic nervous system (PNS)

Part of the autonomic nervous system responsible for 'rest and digest' functions.

Tonic activity

Continual, low-level activity in a system.

Sympathetic tone

A continual partial state of vasoconstriction in blood vessels due to tonic firing of sympathetic neurons.

Parasympathetic tone

A continual partial state of contraction in smooth muscles of the GI tract due to tonic firing of parasympathetic neurons.

Myofibrils

Cylindrical structures within muscle fibers composed of sarcomeres, the contractile units of muscle.

Sarcomeres

The functional contractile units of muscle, containing actin and myosin filaments.

Cross-bridge cycle

The process of myosin heads interacting with actin filaments during muscle contraction.

Rigor mortis

Muscle stiffness that occurs after death due to the lack of ATP needed for myosin detachment from actin.

Myoglobin

A protein in skeletal muscle that binds and stores oxygen.

T-tubules

Transverse tubules that are invaginations of the sarcolemma that help conduct electrical impulses into the muscle fibers.

Motor unit

A motor neuron and the muscle fibers it innervates.

Twitch summation

The process of adding together multiple twitches to increase total force of contraction.

Tetanic contraction

A sustained muscle contraction resulting from rapid stimulation that prevents relaxation between twitches.

Muscle tone

The natural, slight, and continuous contraction of a muscle at rest, providing firmness and readiness for action.

Cardiac output

The volume of blood the heart pumps per minute, influenced by heart rate and stroke volume.

Baroreceptors

Sensory receptors that detect changes in blood pressure by sensing stretch in the arteries.

Atherosclerosis

Buildup of fats, cholesterol, and other substances in and on artery walls.

Myocardial infarction

A heart attack caused by a decrease in blood flow to the myocardium leading to cell death.

Ischemia

Restriction of blood supply to tissues, leading to oxygen deprivation.

Hypoxia

Deficiency in the amount of oxygen reaching the tissues.