PSYC62H3 Chapter Notes - Chapter 2: Central Nervous System, Hindbrain, Frontal Lobe
PSYC62
CHAPTER 2
Chapter 2: The Nervous System
Cells in the Nervous System
• Neurons: specialized cells that control behaviour, senses, and movement
o Communicate by receiving and sending info to other neurons in NS and other
cells in and body
• Glial cells: support function of neurons
Neural Communication
• 4 main components:
o Soma
o Dendrites
o Axon
o Axon terminal
• Soma: body of neuron
o Contains nucleus (holds all the DNA)
• Dendrites: receive info from other neurons
o Branch off of soma
o Dendritic spines: grow along length of dendritic branches
o Membranes of of dendritic/spines have receptors that NTs can activate
o The more dendrites a neuron has, more input it can receive from other neurons
• Axons: send NT to other neurons
o Begins at axon hillock and ends with multiple branches containing axon terminals
• Axon terminal (aka presynaptic terminals)
o Contains and releases NTs near part of a dendrite (postsynaptic terminal)
▪ This is the part of the dendrite that contains receptors for the NT
o Small space b/w axon terminal and postsynaptic terminal = synaptic cleft
• Synapse = axon terminal + postsynaptic terminal + synaptic cleft
• Interneuron: neuron with soma and axon found within the same structure
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PSYC62
CHAPTER 2
• Sensory neurons: convey sensory info via axons to CNS
o Afferent neurons
• Motor neurons : convey motor information via axons from CNS
o Efferent neurons
Glial Cells: Facilitating Nervous System Functions
• 3 different types
o Oligodendrocytes
o Astrocytes
o Microglial cells
• Oligodendrocytes
o Extend themselves around axons to form myelin
▪ Facilitates movement of electrical impulses down axon by serving as an
insulator
o Schwann cells are like oligodendrocytes but are found in PNS
o Symptoms of multiple sclerosis result from degeneration of myelin sheaths
surrounding axons in NS
• Astrocytes
o Form blood-brain barrier
▪ Force endothelial cells to fit tightly together
o Facilitate neuronal function
▪ Act at synapse during transmission
o Responding to injury
▪ Through process called gliosis
▪ Surround damaged tissue and segregate it from undamaged tissue
• Microglial cells
o Remove normal cellular waste and serve as immune cells in CNS
o Two types: M1 and M2
▪ M1→ release chemicals that promote inflammation and damage BBB
▪ M2 → release chemicals that reduce inflammation and promote growth
and development cells
THE NERVOUS SYSTEM: CONTROL OF BEHAVIOUR AND PHYSIOLOGICAL FUNCTIONS
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Document Summary
Cells in the nervous system: neurons: specialized cells that control behaviour, senses, and movement, communicate by receiving and sending info to other neurons in ns and other cells in and body, glial cells: support function of neurons. Interneuron: neuron with soma and axon found within the same structure. Chapter 2: sensory neurons: convey sensory info via axons to cns, afferent neurons, motor neurons : convey motor information via axons from cns, efferent neurons. The nervous system: control of behaviour and physiological functions. The peripheral nervous system: controlling and responding to physiological processes in the. Body: two subsections, somatic ns, autonomic ns. Somatic nervous system: delivering motor signals to muscles and sensory signals to the. The autonomic nervous system: controlling vital functions: controls involuntary movement for functions such as, heartbeat, breathing, swallowing, sweating, consists of 2 systems, sympathetic ns, parasympathetic ns, sympathetic ns, prepares body for rigorous activity.
