Organization of the Nervous System Flashcards
What is a nervous system?
-A network of:
neurons [cells with electrical activity]
support (glial) cells [no electrical activity]
-Signals pass from sensory receptors/neurons and integrated. New signals are generated and conducted through neurons to the effector cells.
Sensory neuron gets info from? Sends info to?
Gets info from the internal/external environment and sends it to the CNS
Where are interneurons?
Within the CNS
The CNS is made up of?
Spinal cord and Brain
Motor neuron gets info from? Sends info to?
Gets info from the interneurons and sends it to the body of effector cells (part of the body that needs to be activated)
Efferent
Away from
“Motor”
Afferent
To
“Sensory”
The Nervous System is broken into two sections:
Central Nervous System (CNS)
Peripheral Nervous System (CPNS)
The CPNS has two subsections:
Autonomic
Somatic
Autonomic Nervous System
Automatic, involves visceral organs such as reproductive and the digestive tract
Somatic Nervous System
Nonvisceral organs, voluntary
Ex: muscles, skin
The Autonomic Nervous System is divided into three sections:
Parasympathetic
Sympathetic
Enteric
Parasympathetic
Excitory/Stimulatory
“Rest and Digest”
Sympathetic
Inhibitory
“Fight or Flight”
What are the 4 functions of the nervous system?
-Regulate muscle contraction
-Regulate secretions from glands
-Gather info about external/internal environment
>maintain homeostasis
>detect pain, pressure, chemical [ ] s
-Stimulate thirst, hunger and other survival mechanisms
Two Key Characteristics of the CNS
-Centralization: integrating area (incoming messages go to CNS, outcoming messages originate from CNS
“CONTROL CENTER”
-Cephalization: structures concentrated towards head
Allows animal to be more responsive to their environment (Most animals walk on all fours, head is first to react to new environment)
“SURVIVAL ADVANTAGE”
Cerebral Cortex (2)
- Incoming/Outgoing Messages
- Higher sensory, motor and integrative functions
Hippocampus
Learning and memory
Basal Ganglia
Motor control
Limbic System
Emotions
Thalamus (3)
- Major sensory relay
- Where info gets initially organized
- Directs messages to/from cerebral cortex
Hypothalamus (3)
- Regulates body temperature
- Communicates with the endocrine system
- Homeostatic and endocrine regulation / circadian clock
Cerebellum
Motor Coordination
Medulla
Autonomic and respiratory control
Brainstem
Regulates RR and HR
What does the nervous system help animals do? (4)
- Regulate muscle contraction
- Regulate secretions from glands
- Gather information about the external/internal environment
- Stimulate thirst, hunger, and other survival mechanisms
2 Types of Neural Circuits in the Spinal Cord
- Local
- Ascending/Descending
Describe the LOCAL neural circuit
- Sensory neurons, interneurons and motor neurons all in the same segment
- Control the output of that segment
- Primitive reflexes
Describe the ASCENDING/DESCENDING neural circuit
-Communication to/from the brain for higher integration
What is grey matter?
Cell bodies, synapses, unmyelinated axons
What is white matter?
Tracts of myelinated axons
-Ascending and decending
What is a tract?
Bundle of myelinated axons in the CNS
What are nuclei?
Groups of nerve cell bodies in the CNS
What is a nerve?
A bundle of neuron axons in the peripheral nervous system
- Cranial nerves - Spinal nerves
What is a ganglion?
A grouping of nerve cell bodies in the peripheral nervous system
Peripheral Nervous System
Any nervous tissue located outside of the brain and spinal cord
- Sensing the environment - Activating tissue/organ responses
Which neurons carry information from the peripheral nervous system towards to central
nervous system?
Sensory Neuron
This part of the brain communicates closely with the endocrine system:
Hypothalamus
This part of the brain is the area where the majority of integration and processing occurs
in the brain (ie. taking in all the incoming messages, organizing them and generating a
response):
Cerebral Cortex
The two types of neural circuits involving the spinal cord are the _________________
which carry information to/from the brain and the __________________ which carry
information to/from the periphery.
To/From brain - Ascending/Descending Circuits
To/From Periphery - Local Circuits
Which neurons carry information from the peripheral nervous system away from the central
nervous system?
Motor Neurons
