Functional Organization of Nervous Tissue (09) Flashcards
What are the Functions of the Nervous System?
Sensory, Motor, Integrative
What does the Sensory Function do?
Senses changes in our external environment (eg, touch, vision, hearing). Specialized receptors inside the body detect internal changes (eg, Blood pressure, oxygen levels, pH changes)
What does the Motor Function do?
Takes info that has come from sensory receptors, decide if we need to use or have a response and then create a response. Effects muscles and glands
What does the Integrative Function do?
Analyzes incoming sensory info, stores some aspects, and makes decisions regarding appropriate behaviours.
What are the Nervous System components?
Brain, Spinal cord, sensory receptors
What is a nerve?
a bundle of axons and their sheaths that connects CNS to sensory receptors, muscles, and glands, Going either towards the CNS or away from the CNS
What are Cranial Nerves and how many pairs do they have?
they originate from the brain; 12 pairs
What are Spinal Nerves and how many pairs do they have?
originate from the spinal cord: 31 pairs
What is a ganglion?
collections of neuron cell bodies bundled together outside the CNS.
What is a Plexus?
extensive network of axons, and sometimes neuron cell bodies, located outside the CNS
Explain an action potential
we carry nervous system info via electrical signals called action potentials. They get created by sensory info or stimuli from the environment which triggers receptors
Divisions of the PNS
Sensory (afferent); transmits action potentials from receptors to CNS
Motor (efferent); transmits action potentials from CNS to effectors (muscles and glands)
What does a single neuron system mean?
It means that the neuron cell body is located inside the spinal cord. The axon exits the spinal cord and will go all the way to the target tissue
What is a synapse?
a connection between one neuron and another neuron, or a connection between a neuron and a target tissue. Places where we are making decisions about our nervous system signals.
Where can you fine the Autonomic Nervous System
from CNS to smooth muscle tissue, cardiac muscle and certain glands
Functions of the Autonomic Nervous System
involuntary control, two neuron system: first from CNS to ganglion; second from ganglion to effector
Divisions of the ANS
Sympathetic: prepares body for physical activity (fight-or-flight), Parasympathetic: Regulates resting or vegetative functions such as digesting food (rest-and-digest)
Where is the Enteric Nervous System?
plexuses within the wall of the digestive tract independently of the CNS, but still communicate with CNS via the ANS (parasympathetic and sympathetic neurons contribute to the plexus)
Why do we have the ENS?
because our brain doesn’t always know what’s happening in our digestive system for it to work, so there is a series of neuron plexuses or networks associated with the digestive tract organs that allow for digestion
What is the role of sensory neurons within the digestive system?
monitor chemical environment and stretching of walls
What is the roles of motor neurons within the digestive system?
contracts smooth muscle and control secretions of GL organs and endocrine cells
What is the order of the systems?
Receptor, Sensory NS, CNS, Motor NS, Effector
