Biological School/ Nervous System

Nervous System- starts with an individual nerve cell called a neuron

Neuron Firing- resting potential: slightly negative charge; reach the threshold when enough neurotransmitters reach dendrites; finally goes into action potential (firing)

• All or None Response- idea that either the neuron fires or it doesn't- no part way firing

Types of Neurotransmitters

• Acetycholine (ACH)- deals with motor movement and memory, linked to alzheimer's
• Dopamine- deals with motor movement and alertness; lack of dopamine leads to Parkinson's; too much leads to schizophrenia
• Serotonin- involved in mood control
• Endorphins- involved in pain control; many addictive drugs
• Gaba- major inhibitory neurotransmitters
• Glutamine- immune system and brain function

Drugs

• Agonists- make neuron fire
• Antagonists- stop neural firing
• Reuptake Inhibitors- block neurotransmitters from entering the neuron

Types of Neurons

• Sensory Neurons-take info from senses to the brain
• Inter Neurons- take messages from sensory neurons to brain
• Motor Neurons- takes information from brain to rest of the body

Nervous Systems

• Central- brain and spinal cord; inter neuron
• Peripheral- all nerves not encased in bone; everything but brain and spinal cord
• Somatic- controls voluntary muscle movement; uses motor neurons
• Autonomic- controls the automatic functions of the body
• Sympathetic- fight or flight response; automatically accelerates heart rate, breathing, dilates pupils
• Parasympathetic- automatically slows down after stressful event; slows down heart rate and breathing

• Endocrine system- system of glands that secrete hormones

The Brain

Accidents- Phineas Gage Story- personality changed after accident

Lesions-removal or destruction of some parts of the brain; frontal lobotomy

• Electroencephologram (EEG)- detects brain waves through electrical waves
• Computerized Axial Tomography (CAT SCAN)- good for tumor locating but tells nothing of function
• Magnetic Resonance Imaging- more dedicated picture of brain using magnetic field to knock electrons off axis
• Positron Emmission Topography (PET SCAN)- measures how much of a chemical the brain is using

Hindbrain

structures on top of spinal cord; controls basic biological structures

• Medulla- control of blood pressure, heart rate, breathing
• Pons- involved in facial expressions;connects hind brain to mid brain to high brain
• Cerebellum- "little brain"; coordinates fine muscle movement, voluntary muscle

Mid Brain- coordinates simple movements with sensory information

• Reticular Formation- controls arousal and ability to focus

Forebrain- what makes us human; largest part of brain

• Thalamus- switchboard of brain; receives sensory signal from spinal cord and sends them to other parts of brain; every sense except smell
• Hypothalamus- controls and regulates body temp, sexual arousal, hunger, thirst, and endocrine system
• Hippocampus- involved in the processing and storage of memories
• Amygdala- involved in how we process memory; more involved with volatile emotion
• Cerebral Cortex- made up of densely backed neurons called "gray matter; divided into 2 hemispheres. Left deals with logic and sequential tasks; Right deals with spatial and creative tasks

Lobes

• Frontal- abstract thought and emotional control; contains motor cortex which sends to our body controlling muscle movements; contains Broca's area which controls muscles for producing speech
• Parietal- contains sensory cortex: receives incoming touch sensations from rest of the body; mostly made up of association areas
• Occipital- deals with vision
• Temporal- processes sound sensed by our ears; contains Wernicke's area which deals with language comprehension