1. The nervous system
Chapters 48 & 49

2. You must know The anatomy of a neuron
The role of active transport in establishing the membrane potential of a neuron
How long-distance and short-distance signaling is done in neurons
The mechanisms of impulse transmission in a neuron
The process that leads to the release of neurotransmitter and what happens in the synapse
The brain serves as a master neurological center for processing information and directing responses
Different regions of the brain have different functions
Structures and associated functions for animal brains are products of evolution and increasing complexity follows evolutionary lines
How the vertebrate brain integrates information, which leads to an appropriate response

3. I. Neuron structure A. Functional unit of the nervous system
Draw with them, add Nodes of ranvier

5. Neuron vocab
Sensory receptors – collect information

6. 2. Sensory neurons – carry info from receptors to CNS 3
2. Sensory neurons – carry info from receptors to CNS 3. Interneurons – within CNS, connect sensory neurons to motor neurons 4. Motor neurons – carry info from CNS to effectors (muscles and glands) that respond

7. Nerve Impulses
A. The steps

8. II. Nerve impulses
1. Resting potential
Annotate with them

9. Depolarization & Action Potential
a. Must surpass threshold
b. All or none response to stimulus

10. Repolarization & Hyperpolarization
- Refractory period

11. 4. Return to resting potential

12. B. Propagation of nerve impulses
1. A nerve impulse is an action potential that starts at one end of a neuron and is then propagated along the axon to the other end of the neuron. 2. The propagation happens because the ion movements that depolarize one part of the neuron trigger depolarization in the neighboring part of the neuron. 3. Nerve impulses always move in one direction along neurons, because an impulse can only be initiated at one terminal of a neuron and can only be passed on to other neurons/different cell types at the other terminal.
Don’t panic! Different in the notes book

13. C. Saltatory conduction 1
C. Saltatory conduction 1. In myelinated areas, ion movement is not necessary for signal transmission 2. Impulses have to “jump” from one node of Ranvier to the next (this does require ion movement 3. Increases speed of impulse and reduces energy expenditure

14. Communication at the synapse

15. Neurotransmitters
1. Chemical messengers
2. Can be excitatory (cause depolarization of postsynaptic cell or inhibitory (cause hyperpolarization)

16. Signal Termination
1. Enzymes break neurotransmitter into pieces, causing it to fall away from the receptor (ex. Acetylcholinesterase for Ach)
2. Pieces are reabsorbed by the presynaptic cell, reassembled, and repackaged in vesicles

17. Ach and toxins Sarin nerve gas – inhibits acetylcholinesterase
Botulism toxin – prevents release of Ach from presynaptic axon

18. Iv. Nervous system anatomy
Central Nervous System (CNS) – brain and spinal cord
1. Cerebrospinal fluid (CSF) – circulates through central canal of spinal cord and ventricles of brain provide nutrients and take away waste and also cushion the brain

19. 2. White and Gray matter a. Gray composed mostly of neuron cell bodies b. White composed mostly of myelinated axons c. Glia cells – support cells

20. Peripheral Nervous System (PNS)
1. Consists of spinal and cranial nerves
2. Motor/Somatic Nervous System carries signals to skeletal muscles
3. Autonomic Nervous System – carries signals to glands, smooth muscle, and cardiac muscle, further divided into Sympathetic and Parasympathetic divisions

21. Sympathetic = Snake a. Sympathetic division – “Fight or Flight”
Response to unusual circumstances – increases activity
“E” division – exercise, excitement, emergency, embarrassment
Sympathetic = Snake

22. Parasympathetic = Panda
Parasympathetic division –
“Rest and digest”
Conserves energy and handles the usual circumstances
“D” division – digestion, defecation, diuresis
Parasympathetic = Panda

23. V. The Brain Brainstem – medulla oblongata, pons, and midbrain
1. Controls homeostatic functions like breathing, swallowing, digestion, and connects brain to spinal cord

24. Cerebellum – coordination and balance,

25. Thalamus – transmits info to and from proper area of cerebrum
Hypothalamus – regulates homeostasis – body temperature, hunger, thirst, circadian rhythms

26. Cerebrum – divided into two hemispheres, information processing and memory

27. 1. Cerebral cortex – outer layer of cerebrum, controls voluntary movement and cognitive function

28. 2. Corpus callosum – communication between hemispheres