Nervous System (cont)
Dopamine Deals with motor movement and alertness. Lack of dopamine has been linked to Parkinson s disease. Too much has been linked to schizophrenia.
Endorphins Involved in pain control. Many of our most addictive drugs deal with endorphins.
Select Neurotransmitters Acetylcholine (Ach) Involved in muscle movement and memory (undersupply - ALZ) Serotonin Involved in mood and sleep (Undersupply - Depression) Dopamine Involved in movement and reward systems (Excess -Schizophrenia, undersupply - Parkinson s ) GABA (gamma-aminobutyric acid) Inhibitory NT (undersupply seizures, tremors, insomnia) Norepinephrine Involved in arousal, mood, and sympathetic nervous system activation (Bipolar) Endorphins elevate pleasure/mood and reduce pain, act by either increasing or decreasing specific NT activity, mimic effects of opium based drugs like morphine
Neural Communication Serotonin Pathways Dopamine Pathways
Drugs can be.. Agonists- make neuron fire Antagonists- stop neural firing Reuptake Inhibitors- block reuptake
Some Drugs work on receptors Some drugs are shaped like neurotransmitters Antagonists : fit the receptor but poorly and block the NT e.g. beta blockers(beta blockers block the action of epinephrine (adrenaline) and norepinephrine(noradrenaline) part of the sympathetic nervous systemwhich mediates the "fight or flight" response.) Agonists : fit receptor well and act like the NT e.g. nicotine
Neural Communication Neurotransmitter molecule Receiving cell membrane Receptor site on receiving neuron Agonist mimics neurotransmitter Antagonist blocks neurotransmitter
Neural Communication: The Neural Chain
Neurons and Synapses Types of Neurons Sensory Motor Interneurons
Motor Neurons Nerves that carry outgoing information from the central nervous system Carries messages from the brain and spinal cord to other parts of your body Sensory Neuron Brain Spinal Cord Motor Neuron
Sensory Neurons Nerves that carry incoming information to the central nervous system Connect the sense organs to the brain Sensory Neuron Brain Spinal Cord and spinal cord
Interneurons Connect the other 2 neurons. Only found in the brain and spinal cord. Sensory Neuron Brain Spinal Cord Motor Neuron
A Neural Chain
The Structure of the Nervous System
A Simplified Neural Network Neurons that learn to work together as a team.
The Nervous System Nervous System the body s speedy, electrochemical communication system consists of all the nerve cells of the peripheral and central nervous systems Nerves neural cables containing many axons part of the peripheral nervous system connect the central nervous system with muscles, glands, and sense organs
The Nervous System Central Nervous System (CNS) the brain and spinal cord Peripheral Nervous System (PNS) All nerves that are not encased in bone Everything but the brain and spinal cord the sensory and motor neurons that connect the central nervous system (CNS) to muscles and organs (Peripheral = outer region) Divided into two parts Somatic Autonomic
The Nervous System
Subparts of the nervous system
Somatic Nervous System Controls voluntary muscle movement Uses motor neurons
Autonomic Nervous System Controls the glands and muscles of the internal organs Monitors the autonomic functions Controls breathing, blood pressure, and digestive processes Divided into the sympathetic and parasympathetic nervous systems
Sympathetic Nervous System The part of the autonomic nervous system that arouses the body to deal with perceived threats Automatically accelerates heart rate, breathing, dilates pupils, slows down digestion Fight or flight response
Parasympathetic Nervous System Automatically slows the body down after a stressful event Calms the body Heart rate and breathing slow down, pupils constrict and digestion speeds up
Normally, sensory (afferent) neurons take info up through spine to the brain. Some reactions occur when sensory neurons reach just the spinal cord. Survival adaptation. Reflexes
The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System
The Endocrine System
Endocrine System A second type of communication system in the body made up of a network of glands that produce hormones--chemical messengers that circulate in the blood Examples of hormones: Estrogen/testosterone Thyroid growth hormone follicle-stimulating hormone
Hormone Chemical messengers produced by the endocrine glands and circulated in the blood Similar to neurotransmitters in that they are also messengers Slower communication system, but with longer lasting effects Hormones Neurotransmitters
Endocrine System/ Endocrine Glands
The Brain
Lower-Level Brain Structures: The Brainstem The Thalamus The Cerebellum The Limbic System
The Brain Pons
Brainstem Is responsible for automatic survival functions Located where the spinal cord swells and the brain just begins Includes the medulla and reticular formation
Medulla The base of the brainstem Breathing Heart rate Digestion Other vital reflexes swallowing coughing vomiting sneezing
Reticular Formation A nerve network extending up and down the spinal cord into the brain (through the spinal cord and thalamus) Controls an organism s level of alertness, sleep, and arousal.
Pons Helps coordinates movements on right and left side of body Sleep and wakefulness Maintain balance while standing or moving
Thalamus Sits atop the brainstem The brain s sensory switchboard -- directs messages to the sensory receiving areas in the cortex