Unit 4 Flashcards
What are cells?
The smallest units in which independent life can exist. All living things are single cells or organisms made of cells
Enzyme
A number of working proteins that speed up a specific chemical reaction, such as breaking the bonds of a nutrient, without undergoing change themselves.
Fat cells
cells that specialize in the storage of fat and form the fat tissue. Fat cells also product enzymes that metabolize fat and hormones involved in appetite and energy balance.
Nutritional genomics
The science of how nutrients affect the activities of genes and how genes affect the activities of nutrients. (also called molecular nutrition or nutrigenomics)
Tissues
Systems of cells working together to perform specialized tasks. (ex: Muscles, nerves, blood, bone)
Organs
Structural units made of tissues that perform specific jobs.
Body system
a group of related organs that work together to perform a function. (ex: Circulatory system, respiratory system)
Blood
the fluid of the cariovascular system; composed of water, red and white blood cells, other formed particles, nutrients, oxygen, and other constituents.
Lymph
the fluid that moves from the bloodstream into tissue spaces and then travels in its own vessels, which eventualy drain back into the bloodstream.
Arteries:
Blood vessels that carry blood containing fresh oxygen supplies from the heart to the tissues
Veins
blood vessels that carry blood, with carbon dioxide it has collected, from the tissues back to the heart
capillaries
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
extracellular fluid
fluid residing outside the cells that transports materials to and from the cells.
intracellular fluid
Fluid residing inside the cells that provides the medium for celluar reactions
Lungs
The bodys organs of gas exchange. blood circulating through the lungs releases its CO2 and picks up fresh O2 to carry to the tissues.
Where does blood carry nutrients from?
From the intestine to the liver, which releases them to the heart, which pumps them to the waiting body tissues.
Intestine
The body’s tubular organ of digestion and the site of nutrient absorption
Liver
a Large lobed organ that lies just under the ribs.
It filters blood
-removes and processes nutrients
-manufactures materials for export to other parts of the body -destroys toxins or stores them to keep them out of circulation
- excretes fat-soluble waste products into the small intestine.
Kidneys
A pair of organs that filters waste from the blood, make urine, and release it to the bladder for excretion from the body.
Importance of blood and lymph
- delivers nutrients to all the body’s cells and carry waste materials away from them
- Blood delivers oxygen to cells
Importance of the cardiovascular system
ensures that fluids circulate properly among all organs
Hormones
Chemicals that are secreted and released by glands into the blood stream 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:
- Endocrine function: Makes hormones such as insulin which releases directly into the blood.
- exocrine function: Making of digestive enzymes, which it releases through a duct into the small intestine to assist in digestion.
Insulin
A Hormone from the pancreas that helps glucose enter cells from the blood
glucagon
a hormone from the pancreas that stimulates the liver to release glucose into the bloodstream with blood glucose concentration dips
What do glands secrete
Hormones that act as messengers to help regulate body processes
Cortex
the outer most layer of something. The brains cortex is the part of the brain where conscious thought takes place.H
Hypothalamus
The 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 of body to adjust those conditions when necessary
Fight or flight reaction
The body’s instinctive hormone and nerve mediated reaction to danger.
neurotransmitters
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.
epinephrine
The major hormone that elicits the stress response
norepinephrine
a compound related to epinephrine that helps elicit the stress response
metabolism
the sum of all physical and chemicals changes taking place in living cells. Includes all reactions by which the body obtains and spends the energy from food.
What do the nervous system and hormonal system join to do?
Regulate body processes through communication among all the organs. They collectively respond to the need for food, the act of eating, regulate digestion, and call for the stress response.
Mircobes
Bacteria, viruses, and other organisms invisible to the naked eye, some of which cause diseases
Antigen
a microbe or substance that is foreign to the body