Nervous System I

A stimulus with a higher rate of action potentials per unit time.

Chemicals that decrease the likelihood of a nerve impulse creating a negative change in the membrane potential.

The mammalian eye's ability to increase the response to light through a signal transduction cascade.

Two primary inhibitory neurotransmitters in the brain which hyperpolarize the postsynaptic membrane.

A temporary hyperpolarization in the postsynaptic membrane. It makes the postsynaptic neuron less likely to fire an action potential.

Light-sensitive photoreceptor cells in the retina specialized for low-light vision (black and white).

Sedatives increase the effects of inhibitory neurotransmitters.

Photoreceptor cells in the retina that detect color.

Ion channels in the postsynaptic membrane that open or close in response to a specific neurotransmitter.

A light-sensitive membrane protein in rod cells, composed of opsin and retinal.

The light-absorbing part of rhodopsin, a prosthetic group for a photon, which converts the receptor protein from inactive state to active state.

A graded potential in sensory neurons that are triggered by a stimulus.

Neurons in the brain process information encoded through the rate at which action potentials occur.

A series of intracellular events triggered by light absorption, amplifying the initial light signal.

A decrease in membrane potential in a cell, caused by light, resulting in receptor activation, in photoreceptors.

A chemical that stimulates pain receptors (thermo and pain related receptors).

Hormones that can pass through cell membranes and directly affect the nucleus.

The process of a hormone's message being carried into the cell and ultimately changing cell behavior.

Hormones that bind to membrane receptors and trigger a cascade of intracellular events.

Proteins on the cell membrane that bind to water-soluble hormones to initiate a response.

Molecules activated within the cell by a hormone-receptor interaction, creating internal signaling.

A protein that acts as an intermediary between the hormone-receptor complex and an enzyme that produces a second messenger.

An enzyme that phosphorylates other proteins, changing their activity.

The process where a gene's instruction are used to create a protein.

Change in electrical charge across a muscle cell membrane, causing muscle contraction initiation.

Where nerve and muscle meet; initiates muscle contraction.

Muscle cell's electrical signal spreading along the fiber.

Muscle structure that stores calcium, crucial for contraction.

Tunnel-like structures in muscle cells allowing action potentials to reach myofibrils.

Neuromuscular disease affecting acetylcholine receptors, causing weak muscle contractions.

Motor neuron degeneration causing muscle weakness and loss of function.

Neuromuscular disorder affecting presynaptic calcium channels, reducing neurotransmitter release.

Calcium influx triggers calcium release from sarcoplasmic reticulum.

Neurotoxin that inhibits acetylcholine release, causing muscle paralysis.

Engulfs and degrades bacteria and dead cells, including antibody-coated and non-antibody-coated cells.

A specific immune response that is adapted to target a particular invader; it is slower initially but becomes faster with subsequent exposures due to memory.

The antibody response where B cells produce antibodies that target and neutralize free bacteria and viruses.

T cell response. Specialized T cells destroy cells infected with intracellular pathogens, such as viruses.

A foreign molecule, such as a protein or polysaccharide, that triggers an antibody response.

A protein that targets and binds to an antigen, marking it for destruction and complement activation.

There are millions of B-cells producing unique. antibodies, ready to recognize diverse antigens. Activated B-cells differentiate into plasma cells that release antibodies and memory B-cells for faster future response

Cytotoxic T-cells identify and destroy cells that are infected with intracellular pathogens, such as viruses.

The anterior pituitary stores growth hormone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), endorphins, enkephalins (natural opiates), and adrenocorticotropic hormone (ACTH).

The thyroid gland produces thyroxine (T4) and triiodothyronine (T3) from tyrosine, crucial for basal metabolic rate.

Increased T3 and T4 lead to higher blood pressure, body temperature, and weight loss by boosting metabolism.

Calcitonin, a thyroid hormone, lowers blood calcium levels by inhibiting calcium absorption and reabsorption.

Parathyroid hormone raises blood calcium levels by stimulating calcium release from bones and absorption by intestines and kidneys.

TRH, released by the hypothalamus, stimulates the anterior pituitary to release thyroid-stimulating hormone (TSH).

TSH, released by the anterior pituitary, prompts the thyroid gland to produce T3 and T4.

High levels of T3 and T4 signal the hypothalamus to reduce TSH release, maintaining homeostasis.