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