3 - The Remarkable Body Flashcards
any of a great number of working proteins
that speed up a specific chemical reaction,
such as breaking the bonds of a nutrient, without
undergoing change themselves.
enzyme
an inborn error of metabolism that interferes with the body’s
handling of the amino acid phenylalanine, with
potentially serious consequences to the brain
and nervous system in infancy and childhood.
phenylketonuria (PKU)
a genetic variation present from birth that may result in
disease.
inborn error of metabolism
cells that specialize in the storage of fat and form the fat tissue.________ also produce fat-metabolizing enzymes; they also produce hormones involved in appetite and
energy balance
Fat cells
systems of cells working together
to perform specialized tasks. Examples are
muscles, nerves, blood, and bone.
tissues
discrete structural units made of tissues
that perform specific jobs. Examples are the
heart, liver, and brain.
organs
a group of related organs that work together to perform a function. Examples are the circulatory system, respiratory system, and nervous system.
body system
the fluid of the cardiovascular system;
composed of water, red and white blood cells,
other formed particles, nutrients, oxygen, and
other constituents. lymph (LIMF) the fluid that moves from the bloodstream into tissue spaces and then travels
in its own vessels, which eventually drain back
into the bloodstream (see Figure 3–6).
blood
blood vessels that carry blood containing
fresh oxygen supplies from the heart to the
tissues
arteries
blood vessels that carry blood, with the
carbon dioxide it has collected, from the tissues
back to the heart
veins
minute, weblike blood vessels that
connect arteries to veins and permit transfer
of materials between blood and tissues
plasma the cell-free fluid part of blood and
lymph.
capillaries
a pair of organs that filter wastes from
the blood, make urine, and release it to the
bladder for excretion from the body.
kidneys
the body’s long, tubular organ of
digestion and the site of nutrient absorption.
liver a large, lobed organ that lies just under
the ribs. It filters the blood, removes and
processes nutrients, manufactures materials for
export to other parts of the body, and destroys
toxins or stores them to keep them out of the
circulatory system.
intestine
the body’s organs of gas exchange. Blood
circulating through the lungs releases its carbon
dioxide and picks up fresh oxygen to carry to
the tissues.
lungs
fluid residing inside the
cells that provides the medium for cellular
reactions.
intracellular fluid
fluid residing outside the cells that transports materials to and from the cells.
extracellular fluid
chemicals that are secreted by
glands into the blood in response to conditions
in the body that require regulation. These
chemicals serve as messengers, acting on other
organs to maintain constant conditions.
pancreas an organ with two main functions.
One is an endocrine function—the making of
hormones such as insulin, which it releases
directly into the blood (endo means “into” the
blood). The other is an exocrine function—the
making of digestive enzymes, which it releases
through a duct into the small intestine to assist
in digestion (exo means “out” into a body cavity
or onto the skin surface).
hormones
a hormone from the pancreas that
helps glucose enter cells from the blood
insulin
a hormone from the pancreas that
stimulates the liver to release glucose into the
bloodstream.
glucagon
the outermost layer of something. The
brain’s cortex is the part of the brain where
conscious thought takes place.
cortex
a part of the brain that senses a variety of conditions
in the blood, such as temperature, glucose
content, salt content, and others. It signals other
parts of the brain or body to adjust those conditions
when necessary.
hypothalamus (high-poh-THAL-uh-mus)
reaction the body’s instinctive hormone- and nerve-mediated reaction to danger. Also known as the stress response.
fight-or-flight
the major hormone that elicits the stress response.
epinephrine (EP-ih-NEFF-rin)
a compound related to epinephrine that helps to
elicit the stress response.
norepinephrine (NOR-EP-ih-NEFF-rin)
the sum of all physical and chemical
changes taking place in living cells; includes
all reactions by which the body obtains and
spends the energy from food.
metabolism
chemicals that are released at the end of a nerve cell when a nerve impulse arrives there. They diffuse across the gap to the next cell and alter the membrane of that second cell to either inhibit or excite it.
neurotransmitters
bacteria, viruses, or other organisms
invisible to the naked eye, some of which cause
diseases. Also called microorganisms.
microbes
a system of tissues and organs that defend the body against antigens, foreign materials that have penetrated the skin or body linings.
immune system
white blood cells that participate in the immune response;
B-cells and T-cells.
lymphocytes (LIM-foh-sites)
white blood cells that can ingest and destroy antigens. The process by which phagocytes engulf materials
is called phagocytosis. The Greek word phagein
means “to eat.”
phagocytes (FAG-oh-sites)