Nervous system Overview Flashcards
What are the two divisions of the Nervous system?
Central nervous system Peripheral nervous system
What are the three functions of the Nervous system?
Three basic functions of the nervous system are: 1.detecting stimuli (sensory function); 2.analyzing, integrating, and storing sensory information (integrative function); 3.and responding to integrative decisions (motor function).
What makes up CNS?
Brain and Spinal Cord
What makes up PNS ? Give examples.
All nervous tissue outside CNS. Cranial nerves Spinal nerves Ganglia Sensory receptors on skin
Name three divisions of PNS?
Somatic nervous system Autonomic nervous system Enteric nervous system
What is the SNS ?
The SNS consists of sensory neurons that conduct impulses from somatic and special sense receptors to the CNS and motor neurons from the CNS to skeletal muscles.
What is the ANS?
The ANS contains sensory neurons from visceral organs and motor neurons that convey impulses from the CNS to smooth muscle tissue, cardiac muscle tissue, and glands.
What are the five sensory receptors ,give their function.
1.Mechanoreceptors—respond to touch, pressure, vibration, stretch, and itch 2.Thermo receptors—sensitive to changes in temperature 3.Photoreceptors—respond to light energy (e.g., retina) 4.Chemoreceptors—respond to chemicals (e.g., smell, taste, changes in blood chemistry) 5.Nociceptors— sensitive to pain-causing stimuli (e.g. extreme heat or cold, excessive pressure, inflammatory chemicals
What are the three parts of a neuron? Give function.
Neurons have three parts. 1.The dendrites are the main receiving or input region. 2.Integration occurs in the cell body. 3.The output part typically is a single axon, which conducts nerve impulses toward another neuron, an effector: muscle fiber, or a gland cell.
Classification of neurons based on structure.
Unipolar Bipolar Multipolar
Classification of neurons based on function.
Sensory neurons -afferent Motor neurons -efferent Interneurons-association neurons
Somatic reflex arcs
receptor sensory neuron association neuron motor neuron effector
Autonomic and Enteric reflex arcs
receptor sensory neuron association neuron motor neuron effector
What do the Autonomic and Enteric reflex arcs stimulate?
smooth muscle cardiac muscle endocrine and exocrine glands adipose tissue
give examples of neuroglia cells in CNS and PNS and their function.
Neuroglia support, nurture, and protect neurons and maintain the interstitial fluid that bathes them. -Neuroglia in the CNS include astrocytes, oligodendrocytes, microglia, and ependymal cells. -Neuroglia in the PNS include Schwann cells and satellite cells
Name two types of neuroglia cells that produce myelin sheaths.
Two types of neuroglia produce myelin sheaths: Oligodendrocytes myelinate axons in the CNS, and Schwann cells myelinate axons in the PNS.
What is the difference between white matter and gray matter?
White matter consists of aggregates of myelinated axons. Gray matter contains cell bodies, dendrites, and axon terminals of neurons, unmyelinated axons, and neuroglia
What is a nerve impulse?
Neurons communicate with one another using nerve action potentials, also called nerve impulses
What is the resting membrane potential?
-70mV
What causes the resting membrane potential?
The resting membrane potential arises due to an unequal distribution of ions on either side of the plasma membrane and a higher membrane permeability to K+ than to Na+. The level of K+ is higher inside and the level of Na+ is higher outside, a situation that is maintained by sodium–potassium pumps
what is a polarized cell?
A cell that exhibits a membrane potential is polarized.
What is a synaptic transmission?
Neurons communicate with other neurons and with effectors at synapses in a series of events known as synaptic transmission
What happens at the synapse?
At a synapse, a neurotransmitter is released from a presynaptic neuron into the synaptic cleft and then binds to receptors on the plasma membrane of the postsynaptic neuron
how is a neurotransmitter removed?
Neurotransmitter is removed in three ways: 1 diffusion, 2 enzymatic destruction, 3 re-uptake by neurons or neuroglia
give examples of neurotransmitters
acetylcholine, glutamate, aspartate, gamma aminobutyric acid (GABA), glycine, nor-epinephrine, dopamine, serotonin, neuropeptides, and nitric oxide.
