A&P 4 Flashcards
What are the two main divisions of the nervous system?
Central Nervous System
Peripheral Nervous System
What makes up the Central Nervous System?
Brain and Spinal Cord
What makes up the Peripheral Nervous System?
Cranial and spinal nerves
What are the functions of the CNS?
It is the integrative and control center
What are the functions of the PNS?
It is the communication line between the CNS and the rest of the body
What are the divisions of the PNS?
Sensory and Motor divisions
What are the divisions of the motor division?
Somatic and Autonomic nervous systems
What are the divisions of the autonomic nervous system?
Parasympathetic and sympathetic nervous systems
What makes up the sensory division of the PNS?
Somatic and visceral sensory nerve fibers
What is the function of the sensory division of the PNS?
It conducts impulses from receptors to the CNS
What makes up the motor division of the PNS?
Motor nerve fibers
What is the function of the motor division of the PNS?
It conducts impulses from the CNS to the effectors
What are the effectors of the PNS?
Muscles and glands
What is the function of the Autonomic nervous system?
It conducts impulses from the CNS to cardiac muscles, smooth muscles, and glands
What is the function of the somatic nervous system?
It conducts impulses from the CNS to skeletal muscles
What neurons make up the autonomic nervous system?
Involuntary; visceral motor neurons
What neurons make up the somatic nervous system?
Voluntary; somatic motor neurons
What is the function of the sympathetic division?
It mobilizes body systems during emergency situations; fight or flight system
What are the functions of the parasympathetic division?
It conserves energy and promotes nonemergency functions
What is the function of the nervous system in general?
It communicates and controls the various physiological functions of the body
What is the function of the sensory input?
It gathers info from both external and internal environments
What is the function of the integration and control center?
It receives input from the sensory neurons and determines the appropriate response
What is the function of the motor output neurons?
It initiates the response from the integration and/or control center
What receptors do somatic sensory neurons receive information from?
Proprioceptors
Chemoreceptors
Baroreceptors
What receptors send information through visceral sensory neurons?
Splanchinic/ gut
What receptors send information via special sensory neurons?
Ocular, auditory, etc
What receptors receive information from the somatic motor neurons?
Skeletal muscles receptors
What receptors receive information from the autonomic motor neurons?
Smooth muscle and glandular receptors
What type of receptors receive information from the parasympathetic and sympathetic nervous system?
Excitatory and inhibitory receptors
What receptors receive information from the enteric nervous system?
Gastrointestinal receptors
What are the three types of neurons that make up the afferent division of the PNS?
Somatic sensory
Visceral sensory
Special sensory
What are the two types of neurons that make up the efferent division of the PNS?
Somatic motor
Autonomic motor
What are the four neuroglia of the CNS?
Astrocytes
Microglia
Ependymal cells
Oligodendrocytes
What is the function of oligodendrocytes?
Cytoplasmic extensions become insulating myelin sheaths
What is the function of the ependymal cells in the CNS?
They cushion the brain and spinal tissue by circulating cerebrospinal fluid with their cilia
What is the function of the microglia in the CNS?
They are the ‘immune cells’ of the CNS; they sense neuronal health and degrade harmful substances
What are the functions of the astrocytes in the CNS?
~They provide anchoring supposrt for neurons and insure nutrient delivery
~They direct neuronal growth
~They take up potassium ions and used neurotransmitters (importance of glucose)
What are the two types of neuroglia of the PNS?
Satellite cells
Schwann cells
What are the functions of the satellite cells?
~They surround neuronal bodies
~They provide similar functions as the astrocyes in the CNS
What are the functions of the schwann cells in the PNS?
~They surround larger PNS fibers with myelin
~They help with peripheral nerve fiber regeneration
~They are similar in function to the oligodendrocytes in the CNS
What is the myelin sheath made of?
Fatty protein-lipids
What are the functions of the myelin sheath?
~They protect and insulate the axon
~They speed up the electrical transmissions (150 m/s vs 1 m/s for unmyelinated)
What makes up the neurolema?
The nucleus and cytoplasm of the schwann cell
What are the nodes of Ranvier?
They are the gaps in the myelin sheath
What are the two types of matter in the CNS and what do their names represent?
~White matter- named because their myelination makes it look white
~Gray matter- named because their unmyelinated axons look gray
What are three important facts we need to know about neurons?
~They can live over 100 years
~They are amiotic, meaning they cannot divide
~They have a high metabolic rate; thats why they require constant oxygen and glucose
What is the function of neurons?
They conduct nerve impulses
What are the three functional components of a neuron?
~Receptive region
~Conducting component
~Secretory component
What makes up the receptive region of the neuron?
Dendrites and cell body
What makes up the conducting component of a neuron?
The axon