Biology Chapter on Digestion and Circulation

The process of breaking down food into small molecules that the body can absorb.

The physical breakdown of food by chewing and grinding.

The chemical breakdown of food using enzymes.

The breakdown of food molecules within a cell.

The breakdown of food molecules outside of a cell.

The organ that stores food and mixes it with gastric juice.

A highly acidic fluid containing enzymes that digest proteins.

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

The process of maintaining a stable internal environment within a cell or organism.

The hormone released by the pancreas to lower blood glucose levels. It allows cells to take in glucose from the blood, lowering its concentration.

The hormone released by the pancreas to elevate blood glucose levels. It causes the liver to release stored glucose, increasing its concentration.

The movement of molecules from a region of high concentration to a region of low concentration.

The type of circulatory system where blood is confined to vessels and is separate from the interstitial fluid. Efficient for larger and more active organisms.

The pressure exerted by a particular gas in a mixture of gases. This difference drives gas exchange in the body.

The movement of gas from an area of higher partial pressure to an area of lower partial pressure.

The tiny air sacs in the lungs where gas exchange with the blood occurs.

The system that circulates blood throughout the body, transporting oxygen, nutrients, and waste products.

A type of circulatory system where blood surrounds organs directly, common in insects and arthropods.

The movement of blood through the heart and lungs, where oxygen-poor blood is oxygenated.

Blood vessels that carry blood away from the heart.

Blood vessels that carry blood towards the heart.

The process of air moving into the lungs.

The process of air moving out of the lungs.

The functional unit of the kidney responsible for filtering blood and producing urine.

The process of filtering blood in the Bowman's capsule, where waste products and nutrients are separated from the blood.

The selective reabsorption of water, glucose, and amino acids back into the bloodstream from the filtrate.

The process of actively transporting certain waste products and excess substances from the bloodstream into the filtrate.

The final step in the excretory process where urine is expelled from the body.

The initial part of the nephron where filtration occurs, separating blood from the filtrate.

The part of the nephron responsible for reabsorbing most of the water and nutrients back into the bloodstream.

The portion of the nephron that primarily reabsorbs water, concentrating the filtrate.

The exchange of oxygen and carbon dioxide between an organism and its environment. This occurs at the cellular level using mitochondria.

The regulation of the blood pH by adjusting the rate and depth of breathing. This is controlled by the brain stem (medulla oblongata), which senses changes in blood pH.

Pigments that bind to oxygen and increase its carrying capacity in the blood.

A protein found in red blood cells that binds to oxygen. It has a higher affinity for oxygen at high partial pressure, and releases oxygen readily at low partial pressure.

A graph showing the relationship between the partial pressure of oxygen and the saturation of hemoglobin with oxygen. The curve demonstrates that a slight change in partial pressure can dramatically affect the delivery of oxygen to tissues.

The shifting of the hemoglobin dissociation curve to the right or left, reflecting changes in the affinity of hemoglobin for oxygen. A right shift indicates lower affinity, and a left shift indicates higher affinity.

A type of immune response that involves the production of antibodies by B cells.

A type of immune response that involves the activation of T cells to destroy infected cells.

White blood cells that mature in the bone marrow and are responsible for producing antibodies in the humoral immune response.

The specific part of an antigen that is recognized and bound by an antibody or B cell receptor.

White blood cells that mature in the thymus and play a key role in the cell-mediated immune response.

A type of T cell that directly kills infected cells by inducing apoptosis.

A type of T cell that helps activate both the humoral and cell-mediated immune responses by providing signals.

A type of immune cell that kills cells that are tagged with antibodies. They also secrete IFN-gamma to stimulate macrophages.