Term 3 Flashcards
Homeostasis
Maintainance of a relatively stable internal environment, Keeps internal factor in optimal range.
Stimulus-response model
The stimulus-response model is a characterization of a statistical unit (such as a neuron) as a black box model, predicting a quantitative response to a quantitative stimulus, for example, one administered by a researcher.
`Negative feedback
the diminution or counteraction of an effect by its own influence on the process giving rise to it, as when a high level of a particular hormone in the blood may inhibit further secretion of that hormone, or where the result of a certain action may inhibit further performance of that action.
Glucose
a simple sugar which is an important energy source in living organisms and is a component of many carbohydrates.
pancreas
a large gland behind the stomach which secretes digestive enzymes into the duodenum. Embedded in the pancreas are the islets of Langerhans, which secrete into the blood the hormones insulin and glucagon.
Insulin
a hormone produced in the pancreas by the islets of Langerhans, which regulates the amount of glucose in the blood. The lack of insulin causes a form of diabetes.
glycogen
a substance deposited in bodily tissues as a store of carbohydrates. It is a polysaccharide which forms glucose on hydrolysis.
Multicellular Organism
Multicellular organisms are organisms that consist of more than one cell, in contrast to unicellular organisms.
Central Nervous System
the complex of nerve tissues that controls the activities of the body. In vertebrates it comprises the brain and spinal cord.
Peripheral Nervous System
the nervous system outside the brain and spinal cord.
Sensory Neurons
a nerve cell that conducts impulses from a sense organ to the central nervous system.
Motor Neurons
a nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland.
Nuerotransmitters
a chemical substance which is released at the end of a nerve fibre by the arrival of a nerve impulse and, by diffusing across the synapse or junction, effects the transfer of the impulse to another nerve fibre, a muscle fibre, or some other structure.
Endocine Glands
Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands.
Hormones
a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.
