Unit 8 - Hormones, Nervous system & Cell Signaling Flashcards
acetylcholine
It has functions in both the peripheral nervous system and in the central nervous system as a neuromodulator. In the peripheral nervous system, acetylcholine activates muscles, and is a major neurotransmitter in the autonomic nervous system.
action potential
A momentary change in electrical potential on the surface of a cell, especially of a nerve or muscle cell, that occurs when it is stimulated, resulting in the transmission of an electrical impulse.
Biological Transducer
it is a device that receives energy from one system and transmits it, often n a different form, to another. Glycogen phosphorylase receives information from the cell of organism in the form of metabolic signals.
Brain
it is one of the two components of the central nervous system, the brain is the center of thought and emotion. It is responsible for the coordination and control of bodily activities and the interpretation of information from the senses.
Cardiovascular (CV) System
it consists of the heart, blood vessels, and blood. It’s main functions are; transport of nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes, protection of the body by white blood cells, antibodies, and complement proteins that circulate in the blood and defend the body against foreign microbes and toxins, and regulations of body temperature, fluid pH, and water content of cells.
Cholinergic synapse
Synapses are junctions between cells that allow for the transmission of chemical messages. The chemicals used to send messages are known as neurotransmitters, and one important type of neurotransmitter is acetylcholine. A cholinergic synapse is a gap where a neuron that produces acetylcholine sends messages to other neurons, or to skeletal muscle cells.
diabetes
a metabolic disease in which the body’s inability to produce any or enough insulin causes elevated levels of glucose in the blood.
dopamine
it is a neurotransmitter of the catecholamine and phenethylamine families that plays a number of important roles in the human brain and body. In the brain, dopamine functions as a neurotransmitter—a chemical released by nerve cells to send signals to other nerve cells. The brain includes several distinct dopamine systems, one of which plays a major role in reward-motivated behavior. Most types of reward increase the level of dopamine in the brain, and a variety of addictive drugs increase dopamine neuronal activity. Other brain dopamine systems are involved in motor control and in controlling the release of several other important hormones. Several important diseases of the nervous system are associated with dysfunctions of the dopamine system. Parkinson’s disease, a degenerative condition causing tremor and motor impairment, has been related to the loss of dopamine-secreting neurons in the midbrain area called the substantia nigra.
Electrochemical Gradient
it is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts, the electrical potential and a difference in the chemical concentration across a membrane.
homeostasis
it is the tendency of an organism or a cell to regulate its internal conditions, usually by a system of feedback controls, so as to stabilize health and functioning, regardless of the outside changing conditions or the ability of the body or a cell to seek and maintain a condition of equilibrium or stability within its internal environment when dealing with external changes. In humans, homeostasis happens when the body regulates body temperature in an effort to maintain an internal temperature around 98.6 degrees Fahrenheit. For example, we sweat to cool off during the hot summer days, and we shiver to produce heat during the cold winter season.
inhibition
To limit, prevent or block the action or function of; as in to inhibit an enzyme, or to inhibit a chemical reaction.
insulin
a hormone produced in the pancreas by the islets of Langerhans that regulates the amount of glucose in the blood. The lack of insulin causes a form of diabetes.
inegration
incorporation of the genetic material of a virus in to the host genome. A term used to confirm the successful binding of foreign DNA into an organisms own genome.
Motor Neuron
a nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland. The function of a motor neuron is to carry an electrical signal to a muscle, triggering it to either contract or relax. In vertebrate animals, including humans, movement of the articulated internal skeletal structure is enabled by coordinating the contractions of the many muscles attached to it.
myelin
a mixture of proteins and phospholipids forming a whitish insulating sheath around many nerve fibers, increasing the speed at which impulses are conducted.
myelinated neuron
Neurons with a fatty covering of myelin over the axon. Over time the myelin around the axon depletes
negative feedback
The counteraction of an effect by its own influence. In terms of hormones, high levels of a hormone in blood may inhibit further production of the hormone
neuromuscular joint
Connects nervous system to muscular system via nerve fibers and muscle fibers
neuron
The cells of the nervous system, passing signals from the source of stimulus to the brain
neurotransmitter
Chemical messengers passed through synaptic gaps between neurons
nodes of ranvier
Gap between the myelin sheath. Capable of generating electrical activity
postsynaptic
changes in the membrane potential of the postsynaptic terminal of a chemical synapse.
reflex
Involuntary and immediate response to stimulus
refractory period
the short time immediately after an action potential in which the neuron cannot respond to another stimulus, owing to the inactivation of voltage-gated sodium channels
resting potential
the membrane potential characteristic of a nonconducting excitable cell, with the inside of the cell more negative than the outside
salutatory conduction
rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of ranvier to another, skipping the myelin sheath regions of membrane
schwann cells
a type of glial cell that forms insulating myelin sheaths around the axons of neurons in the peripheral nervous system
sense organs
five senses: sight, hearing, taste, smell and touch
sensory receptor
dendrites of sensory neurons specialized for receiving specific kinds of stimuli. Sensory receptors are classified by three methods: 1) receptor complexity 2) location 3) type of stimulus detected
serotonin
chemical created by the human body that works as a neurotransmitter. It is regarded by some researchers as a chemical that is responsible for maintaining mood balance, and that a deficit of serotonin leads to depression
stimulus
variable that triggers a response
synapse
a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter
g coupled receptors
a signal receptor protein in the plasma membrane that responds to the binding of a signaling molecule by activating a g protein
transducer
a device that transforms one type of energy to another
