Module 4 : Neural and Hormonal Systems Flashcards
Biological Perspective
Perspective concerned with the links between biology and behavior.
Neuron
A nerve cell, the basic building block of the nervous system.
Dendrites
A neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body.
Axon
The neuron extension that passes messages through its branches to other neurons or to muscular glands.
Myelin Sheath
A fatty tissue layer segmentally encasing the axons of some neurons. Enables vastly greater transmission speed as neural impulses hop from one node to the next.
Action Potential
A neural impulse, a brief electrical charge that travels down an axon.
Threshold
The level of stimulation required to trigger a neural impulse.
Synapse
The junction between the axon tip of the sending neuron and the dendrite of cell body of the receiving neuron. Gap at this junction is called the synaptic gap or synaptic cleft.
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neutral impulse.
Reuptake
A neurotransmitter’s reabsorption by the sending neuron.
Nervous System
The body’s speedy electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
Central Nervous System
The brain and spinal chord.
Peripheral Nervous System
The sensory and motor neurons that connect the central nervous system to the rest of the body.
Parasympathetic Nervous System
The division of the autonomic nervous system that claims the body, conserving its energy.
Nerves
Bundled axons that form neural cables connecting the central nervous system with muscles, glands and sense organs.
Sensory Neurons
Neurons that carry incoming information from the sensory receptors to the brain and spinal chord.
Motor Neurons
Neurons that carry outgoing information from the brain and spinal chord to the muscles and glands.
Interneurons
Neurons within the brain and spinal chord that communicate internally and intervene between the sensory inputs and motor outputs.
Somatic Nervous System
The division of the peripheral nervous system that controls the body’s skeletal muscles.
Autonomic Nervous System
The part of the peripheral nervous system that controls the glands and the muscles of the internal organs. Sympathetic and parasympathetic division.
Sympathetic Nervous System
The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.
Parasympathetic Nervous System
The division of the autonomic nervous system that calms the body, conserving its energy.
Reflex
A simple automatic response to a sensory stimulus, such as the knee jerk response.
Endocrine System
The body’s slow chemical communication system. A set of glands that secrete hormones into the bloodstream.
Hormones
Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream and affect other tissues.
Adrenal Glands
A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.
Pituitary Glands
The endocrine system’s most influential gland. Under the influence of hypothalamus, the pituitary regulates growth and controls other endocrine glads.
