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Somewhere . . . Over the brainbow . . . . The Central Nervous System, Peripheral Nervous System, the Neuron, and other stuff!. Fun Facts about Le Brain. Neurons: Milky Way 100 Billion- 300 Billion- 15ft- 10 minutes- No pain 4 times around the earth!. Convolutions are Key!!!
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Somewhere . . . Over the brainbow . . . The Central Nervous System, Peripheral Nervous System, the Neuron, and other stuff!
Fun Facts about Le Brain. • Neurons: Milky Way • 100 Billion- • 300 Billion- • 15ft- • 10 minutes- • No pain • 4 times around the earth! Convolutions are Key!!! Gyri and Sulci
Outline: Here’s what we’re going to learn! • THE NERVOUS SYSTEM: • The Purpose of the Nervous System • The different parts of the CNS/PNS • Anatomy of a neuron • Synapse • Transmission of a signal • Major Parts/Function of the brain
What is the Purpose of the Nervous System? • 1. It acts as a network with all the nerve cells throughout your whole body. • 2. It controls all the systems in your body by sending messages in between your brain and your body. • 3. It stores memories, and allows you to think.
Organization of the Nervous System • CNS: The Brain and spinal cord • PNS: Sensory and motor neurons • Subdivided into Autonomic + Somatic Nervous system • Autonomic is subdivided into Sympathetic + Parasympathetic
Somatic Nervous System:Voluntary Nervous System • Smiling • Walking • Arm Wrestling • Sensing stimuli • Responding to stimuli
The Autonomic Nervous System : Involuntary nervous system consists of sensory neurons and motor neurons that run between the central nervous system and various internal organs such as the: heart lungs glands (both exocrine and endocrine) Monitors different aspects of homeostasis, adjusts as necessary. Metabolism Temperature Regulation Heart beat, etc. Controls contraction of smooth and cardiac muscle
Sympathetic vs. Parasympathetic • Sympathetic • stimulates heartbeat • raises blood pressure • dilates the pupils • dilates the trachea and bronchi • shunts blood away from the skin and viscera to the skeletal muscles, brain, and heart • inhibits peristalsis in the gastrointestinal (GI) tract • inhibits contraction of the bladder and rectum • Parasympathetic • •slowing down of the heartbeat (as Loewi demonstrated) • •lowering of blood pressure • •constriction of the pupils • •increased blood flow to the skin and viscera • •peristalsis of the GI tract
Neuron Anatomy • Sensory neurons carry signals from the outer parts of your body (periphery) into the central nervous system. • Motor neurons (motoneurons) carry signals from the central nervous system to the outer parts (muscles, skin, glands) of your body. • Interneurons connect various neurons within the brain and spinal cord.
Cell Body Break it down. I have many entry points to receive signals, and one point to send a signal! • Cell Body (Soma)- Control center / Recycling center • Dendrites- Receive signals from other neurons • Axon- Conducts signals away from the cell body to terminals • Myelin Sheath- Speeds neural signaling Dendrites Axon Myelin Sheath Terminal
Neuron Photoshoot! Neurons and astrocytes isolated from rat hippocampus stained for DNA (blue), neuronal-specific βIII-tubulin (green) and astrocyte-specific GFAP (red)
Largest Neurons: I “Cepha-love” giant axons! UP TO 1 MM THICK!!!!!! Unbelievable.
Synapse: Signaling junction • Neurotransmitters: • Acetylcholine • Inhibitory • Endorphin • Dopamine • Seratonin • Excitatory • Norepinephrine • Epinephrine
Lights, Camera, ACTION POTENTIAL! • STEPS FOR AP! • 1. Action Potential arrives at axon terminal • 2. Ca channels open, Ca enters axon terminal • 3. Ach is released into cleft, Ca is pumped out of axon terminal • 4. Ach binds to receptors • 5. Action Pot. is generated and propogated • 6. Causes release of Ca ions • 7. Ca ions trigger muscle contraction http://www.youtube.com/watch?v=yQ-wQsEK21E
THE BRAIN!!!!! A nice, sweet meat! • Separated into two hemispheres • Right= Creative • Left= Analytical • Connected by Corpus Collosum • Consists of 4 lobes • Frontal Lobe • Parietal Lobe • Temporal Lobe • Occipital Lobe
Frontal Lobe: • Functions of the frontal lobe! • Emotions • Reasoning • Planning • Movement • Parts of speech • Creativity • Judgement • Problem-solving • Planning
Temporal Lobe: • Functions of the Temporal Lobe: • Hearing • Memory • Meaning • Language • Emotion • Learning • Interpreting and processing auditory stimuli
Parietal Lobe: • Functions of the Parietal Lobes: • Processing of nerve impulses related to senses • Touch • Pain • Taste • Pressure • Temperature • Language
Occipital Lobe: • Functions of the Occipital Lobe: • Object Recognition • Vision
Order of the Brain: Take Two! • Medulla Oblongata • Unconscious, essential functions • Circulation, muscle control, breathing, digestion etc. • Cerebellum • Motor coordination, balance • Enlarged in birds • Pons • Connects forebrain and hindbrain • Sleep and arousal
ForeBrain, MidBrain, HindBrain • The Brain uses more oxygen and energy than any other organ • Midbrain and Hindbrain - Brainstem • Connects CNS and PNS • Homeostasis and coordination • Forebrain • Cerebrum • Greatly enlarged in mammals • Information processing