Nervous and Sensory System Flashcards
The nervous system is made up of ______ and ____.
Neurons and glia
Specialized cells that can receive and transmit chemical or electrical signals.
Neurons
Cells that provide support functions for the neurons by playing an information processing role that is complementary to neurons.
Glia
Are bundles of nervous tissue, often containing hundreds to thousands of axons wrapped in connective tissue.
Nerves
Nerves are bundles of nervous tissue, often containing hundreds to thousands of _____ wrapped in connective tissue.
Axons
______ in the peripheral nervous system (PNS) carry information to and from neurons in the central nervous system (CNS), where information is integrated and processed.
Nerves
The Central Nervous System consists of the _____ and the ______ ____.
Brain and Spinal Cord
A structure that processes information, composed of inter-connected neurons and glial cells.
Nerves
A structure that transmits information, consisting of a thick bundle of nerve tissue that carries information about the body to the brain and from the brain to the body.
Spinal Cord
Collects information and sends commands, containing nerves that extend to and from the spinal cord.
Peripheral Nervous System
PNS is divided into ________ ______ and ________ ______.
Afferent Nerves and Efferent Nerves
Collect sensory information from the body and transmit it to the CNS.
Afferent Nerves
Are also sometimes called sensory nerves.
Afferent Nerves
Carry commands from the CNS to the body.
Efferent Nerves
Are also sometimes called motor nerves.
Efferent Nerves
What are the 3 different classes of neurons that make up the nervous system?
Afferent Neurons, Efferent Neurons, and Interneurons
Get information about what’s going on inside and outside of the body and bring that information into the CNS so it can be processed.
Afferent Neurons
Get information from other neurons and convey commands to your muscles, organs and glands.
Efferent Neurons
Only found in the CNS. Connects one neuron to another. They receive information from other neurons and transmit information to other neurons.
Interneurons
It controls and coordinates all essential functions of the body including all other body systems allowing the body to maintain homeostasis or its delicate balance.
Nervous System
Processes the information in the brain and spine, communication and coordination.
Integration Function
Sends information to the muscles, glands, and organs so they can respond appropriately.
Motor Function
Basic functional cell of nervous system. Transmits impulses (up to 250 mph).
Neuron
Receive stimulus and carries impulses toward the cell body.
Dendrites
Nucleus & most of cytoplasm.
Cell Body
Fiber which carries impulses away from cell body.
Axon
Cells which produce myelin or fat layer in the PNS.
Schwann Cells
Dense lipid layer which insulates the axon (makes the axon look gray).
Myelin Sheath
Gaps or nodes in the myelin sheath.
Node of Ranvier
Bring messages to CNS, to brain and spinal cord.
Sensory/Afferent Neurons
Carry messages from CNS, from brain and spinal cord to body.
Motor/Efferent Neurons
Between sensory & motor neurons in the CNS (both).
Interneurons
Protected by vertebrae at the dorsal (back of heart and gut).
Spinal Cord
Transmits sensory and motor signals between the CNS and the rest of the body.
Peripheral Nervous System
Vertebrae begun as (3 parts).
-Prosencephalon (forebrain)
-Mesencephalon (midbrain)
-Rhombencephalon (hindbrain)
Their nervous systems have different degrees of centralization, cephalization, and specialization.
Invertebrates
They have a simple nerve net.
Cnidarians
They have an epidermal nerve net.
Echinodermata
They are composed of longitudinal nerve cords.
Platyhelminthes
They have the most developed nervous system among all invertebrates.
Cephalopod Mollusks
They have segmental ganglia.
Arthropods
They have nerve ring.
Nematoda
They do not have true nervous system but there is oscula.
Porifera
