Biology 1110 Exam 2 (I Can Statements)

Neuron

A nerve cell that is the basic building block of the nervous system.

Neurotransmitters

Chemical messengers that transmit signals across a synapse from one neuron to another.

Dendrites

Branch-like structures of a neuron that receive signals from other neurons.

Nerve cell bodies

The part of a neuron that contains the nucleus and organelles.

Axons

Long, slender projections of a neuron that transmit electrical impulses away from the cell body.

Axon hillock

The cone-shaped region of an axon where it joins the cell body, crucial for action potential initiation.

Synaptic terminal

The end of an axon where neurotransmitters are released to communicate with other neurons.

Synapse

The junction between two neurons where communication occurs.

Synaptic gap

The small space between the synaptic terminal of one neuron and the dendrites of another.

Interneurons

Neurons that connect other neurons within the central nervous system.

Sensory neurons

Neurons that carry incoming information from the sensory receptors to the central nervous system.

Motor neurons

Neurons that carry outgoing information from the central nervous system to muscles and glands.

Membrane potential

The voltage difference across a cell's plasma membrane.

Resting potential

The membrane potential of a neuron when it is not actively transmitting a signal, typically around -70 mV.

Sodium-potassium pump

A protein that pumps sodium out of and potassium into the cell, maintaining the resting potential.

Polarized

A state of a neuron when the inside is more negative than the outside.

Graded potential

A change in membrane potential that varies in size, unlike action potentials.

Action potential

A rapid rise and fall in membrane potential that propagates along the axon.

Depolarizes

The process of reducing the membrane potential difference, making the inside of the cell less negative.

Repolarizes

The process of restoring the membrane potential to its resting state after depolarization.

Threshold potential

The critical level to which a membrane potential must be depolarized to initiate an action potential.

Refractory period

The time following an action potential during which a neuron is unable to fire another action potential.

Electrical Synapses

Connections between neurons that allow direct electrical communication.

Chemical Synapses

Connections between neurons that involve the release of neurotransmitters.

Postsynaptic potentials

Changes in the membrane potential of the postsynaptic neuron in response to neurotransmitter binding.

Ligand gated channels

Ion channels that open in response to the binding of a chemical messenger.

Excitatory

Neurotransmitters that increase the likelihood of a neuron firing an action potential.

Inhibitory

Neurotransmitters that decrease the likelihood of a neuron firing an action potential.

Summation of Potentials

The process by which multiple postsynaptic potentials combine to influence the firing of a neuron.

Heterotrophic consumers

Organisms that cannot produce their own food and rely on consuming other organisms.

Essential nutrients

Nutrients that the body cannot synthesize and must be obtained from the diet.

Essential amino acids

Amino acids that cannot be synthesized by the body and must be obtained from food.

Minerals

Inorganic nutrients required by the body for various functions.

Essential fatty acids

Fatty acids that are necessary for health but cannot be synthesized by the body.

Vitamins

Organic compounds that are essential in small amounts for various metabolic processes.

Ingestion

The process of taking in food and liquids into the body.

Digestion

The breakdown of food into smaller components that can be absorbed.

Absorption

The process by which nutrients from digested food are taken up into the bloodstream.

Elimination

The removal of indigestible substances from the body.

Gastrovascular cavity (GVC)

A digestive cavity with a single opening found in some animals.

Alimentary canal

A complete digestive tract with two openings, mouth and anus.

Mechanical digestion

The physical breakdown of food into smaller pieces.

Chemical digestion

The enzymatic breakdown of food into smaller molecules.

Accessory organs

Organs that assist in digestion but are not part of the digestive tract.

Amylase

An enzyme that begins the digestion of carbohydrates in the mouth.

Epiglottis

A flap that covers the trachea during swallowing to prevent food from entering the airway.

Esophagus

The tube that connects the throat to the stomach.

Peristalsis

The wave-like muscle contractions that move food through the digestive tract.

Stomach

The organ where food is mixed with gastric juices for digestion.

HCl

Hydrochloric acid, a component of gastric juice that aids in digestion.

Pepsin

An enzyme that breaks down proteins in the stomach.

Pepsinogen

The inactive form of pepsin that is activated in the stomach.

Parietal cells

Cells in the stomach lining that secrete hydrochloric acid.

Gastric juice

The digestive fluid produced in the stomach, containing HCl and enzymes.

Small Intestine

The part of the digestive system where most digestion and absorption occurs.

Duodenum

The first section of the small intestine where most chemical digestion occurs.

Pancreas

An organ that produces digestive enzymes and hormones.

Gall bladder

An organ that stores bile produced by the liver.

Emulsifies

The process of breaking down fats into smaller droplets to aid digestion.

Bile

A digestive fluid produced by the liver that helps in the digestion of fats.

Villi

Small, finger-like projections in the small intestine that increase surface area for absorption.

Microvilli

Tiny projections on the surface of epithelial cells that further increase absorption surface area.

Lacteals

Lymphatic vessels in the small intestine that absorb fats.

Large Intestine

The part of the digestive system that absorbs water and forms feces.

Rectum

The final section of the large intestine, leading to the anus.

Anus

The opening at the end of the digestive tract through which feces are expelled.

Open Circulatory Systems

A type of circulatory system where blood is not always contained within vessels.

Hemolymph

The fluid that circulates in an open circulatory system, equivalent to blood.

Closed Circulatory Systems

A type of circulatory system where blood is contained within vessels.

Arteries

Blood vessels that carry blood away from the heart.

Arterioles

Small branches of arteries that lead to capillaries.

Capillaries

Tiny blood vessels where gas and nutrient exchange occurs.

Venules

Small vessels that collect blood from capillaries and transport it to veins.

Veins

Blood vessels that carry blood back to the heart.

Atria

The upper chambers of the heart that receive blood.

Valves

Structures in the heart and veins that prevent backflow of blood.

Ventricles

The lower chambers of the heart that pump blood out of the heart.

Single Circulation

A circulatory system where blood passes through the heart once during each complete circuit.

Double Circulation

A circulatory system where blood passes through the heart twice during each complete circuit.

Pulmonary circuit

The part of the circulatory system that carries blood to the lungs for gas exchange.

Systemic circuit

The part of the circulatory system that carries oxygenated blood to the body.

Blood Velocity

The speed at which blood flows through the circulatory system.

Blood Pressure

The force exerted by circulating blood on the walls of blood vessels.

Systolic pressure

The pressure in the arteries during the contraction of the heart.

Diastolic pressure

The pressure in the arteries when the heart is at rest between beats.

Vasoconstriction

The narrowing of blood vessels, which increases blood pressure.

Vasodilation

The widening of blood vessels, which decreases blood pressure.

Capillary Flow

The movement of blood through the capillaries.

Precapillary sphincters

Muscle fibers that regulate blood flow into capillaries.

Plasma

The liquid component of blood that holds cells in suspension.

Erythrocytes

Red blood cells responsible for transporting oxygen.

Platelets

Cell fragments involved in blood clotting.

Leukocytes

White blood cells that are part of the immune system.

Ventilation

The process of moving air in and out of the lungs.

Respiratory media

The medium (air or water) through which gas exchange occurs.

Respiratory surface

The area where gas exchange takes place, such as alveoli or gills.

Partial pressure

The pressure exerted by a single type of gas in a mixture of gases.

Body Surfaces

The external areas of an organism that can facilitate gas exchange.

Gills

Respiratory structures in aquatic organisms that extract oxygen from water.

Countercurrent exchange

A mechanism that maximizes gas exchange efficiency by having fluids flow in opposite directions.