Nervous System (Bio101)
Steps of Action Potential
1. A grade depolarization brings an area of an excitable membrane to threshold. 2. Sodium channel activation occurs 3. Sodium ions enter the cell and depolarization occurs 4. Sodium channels are inactivated 5. Potassium channels open and potassium moves out of the cell, initiating repolarization 6. Sodium channels regain their normal properties 7. A temporary hyperpolarization occurs
Functions of Nervous System
1. Receive Sensory Information 2. Integrative processing of sensory to motor information 3. Sending motor information to effectors
Cranial Nerves
12 pairs
Cerebellum
Area of the brain concerned with balance
Cerebrum
Area of the brain with the highest levels of information processing
Neurotransmitter
Chemical messages released from synaptic ternimals.knobs
Left Hemisphere
Controls functions associated with reading, writing, math etc. If a person had a stroke on the left frontal lobe for example, they would potentially lose use of their right arm.
Autonomic Nervous System
Controls involuntary structures such as the visceral organs. Helps maintain homeostasis
Facial Nerve
Controls muscles of facial expression
Peripheral Nervous System (PNS)
Cranial and spinal nerves
Parasympathetic effects
Decrease heart rate, blood vessels to the skin constrict, increase level of digestive system activity, pupils constrict
Sympathetic Division
Division of the autonomic nervous system that prepares the body for activity and stress. "Fight or Flight"
Parasympathetic Division
Division of the autonomic nervous system that slows the body down. "Rest and Digest" functions
Astrocytes
Glial cells responsible for maintaining the blood brain barrier
Microglia
Glial cells responsible for phagocytosis in the CNS
Oligodenrocytes
Glial cells responsible for producing myelin in the CNS
Schwann Cells
Glial cells responsible for producing myelin in the PNS
Vagus Nerve
Important nerve associate with the diaphragm, and viceral organs. Damage to this nerve can result in death
Sympathetic effects
Increased blood flow to skeletal muscles, reduced circulation to the skin, dilation of pupils, and increase sweating
Frontal Lobe
Location of motor cortext and somatic motor association
Occipital Lobe
Location of the visual cortex of the brain
Amnesia
Loss of memory from disease or trauma
Calcium
The ion needed to initiate the release of acetylcholine into the synaptic cleft
Face
Most sensitive area in the body
Broca's Area
Motor speech area. If damaged, cannot form words, only sounds
Neuron
Nerve cells responsible for processing information
Interneuron
Only found in the CNS, that integrade sensory and motor information
Medulla oblongota
Part of the brain that contains the major centers for autonomic control of breathing, blood pressure, heart rate, and digestion
Withdrawl Reflex
Pulling away from a painful stimulus example: touching a hot stove
Reflex Arc
Receptor --> sensory neuron --> interneuron --> motor neuron --> effector
Motor Division (Efferent Division)
Responsible for sending signals from the CNS to effectors such as muscles to tell them what to do
Sensory Division (Afferent Division)
Responsible to detecting stimuli and bringing that information to the CNS.
Peripheral Nerves
31 pairs
Central Nervous System (CNS)
Brain and spinal cord
Somatic Nervouse System
Under concious control. Controling the skeletal muscles