1. Endocrine System

2. Nervous SystemEndocrine System Both Fast Action Short-term Effects Only target cells get signal & respond Neurons Slow Action Long-term Effects All cells get signal- only target cells respond Glands & Hormones Monitor Stimuli Process Info Respond to Stimuli Maintain Homeostasis

3.  Functions include:  Sensation  Integration center  Reaction (Response) A network of billions of nerve cells linked together in a highly organized manner to act as the control center of the body.

4. Sensation: Monitors stimuli (inside and outside the body) Integration: Processes and Interprets sensory information Response/Reaction: Activates muscles or glands

5.  Central nervous system (CNS)  Brain & Spinal Cord  Peripheral nervous system (PNS)  Cranial nerves-  neck & head  Spinal nerves-  spinal cord to lower extremities

7.  Somatic nervous system  VOLUNTARY (generally)  Conduct impulses from the CNS to skeletal muscles  Autonomic nervous system  INVOLUNTARY  Conducts impulses from the CNS to smooth muscle, cardiac muscle, and glands.

8.  Sympathetic NS  “Fight or Flight”  Parasympathetic NS  “Rest and Digest” These two systems are antagonistic. Typically, we balance them to keep ourselves in a state of dynamic equilibrium.

9. Two cell types: 1. Neuroglia (“glial cells”) Supporting cells 90% of CNS 2. Neurons Functional, signal-conducting cells OVERVIEW Glial cells Neuron

10. Example: Schwann cells Form myelin sheaths around the larger nerve fibers in the PNS. Vital to neuronal regeneration Neuroglia

11. 2003-2004 dendrites cell body axon synapse  Neuron = a nerve cell signal direction signal direction

12.  The most specialized cells in animals  The longest cells:  Blue Whale neuron = 10-30 meters  Giraffe neuron = 5 meters  Human neuron = 1-2 meters Nervous system allows for 1 millisecond response time Neurons are:

13. Dendrite Axon terminals Cell body Axon Myelin sheath Node of Ranvier (Myelin Sheath Gap)

14. Myelination in the CNS Myelination in the PNS A Schwann cell is glial

15. 2003-2004 signal direction myelin coating Multiple Sclerosis  immune system (T cells) attacks myelin coating  loss of signal Multiple Sclerosis  immune system (T cells) attacks myelin coating  loss of signal  Axon coated with insulation made of myelin cells  = speeds signal  signal hops from node to node  330 mph vs. 11 mph

16. Resting potential Neuron at rest: - inside of the neuron is negative relative to the outside. - concentrations of ions attempt to balance out on both sides of the membrane - ions cannot balance because the cell membrane allows only some ions to pass through ion channels. There is a charge imbalance. (The resting membrane potential of a neuron is about -70 mV). At rest, there are more sodium ions outside the neuron and more potassium ions inside the neuron.

17.  Stimulus causes potential difference to move toward 0 mV.  When potential difference reaches -55 mV (threshold level), neuron will fire an action potential.  When threshold level is reached, an action potential of a fixed sized will always fire. "ALL OR NONE".

18. 1 2 Na+ transport proteins They have 2 gates

19. 3 45

20. Between the opening of the Na + channel activation gate and the opening of the inactivation gate, a Na + channel CANNOT be stimulated.  This is the REFRACTORY PERIOD.  Action potential is unidirectional.

22. All or none response Threshold stimulus Refractory period Clogs

23. - Toilet handle triggers flushing. Voltage-gated channels trigger an action potential if the membrane is stimulated with enough voltage. - If pressed hard enough, a complete flush will occur. Pushing harder on the handle will not make a bigger flush. This is true for the action potential: all-or-none. - Flush involves movement of "materials" through plumbing. The action potential involves movement of Na+ and K+ ions through voltage-gated channels. - The force for fluid movement in the toilet is water pressure. The ‘pressure’ for ion movement is an electrochemical gradient. - Toilets can clog so materials cannot move. Drugs and toxins can prevent ion movement and “clog” the action potential.

24.  Unmyelinated neurons undergo continuous chemical conduction  Myelinated neurons undergo saltatory conduction - alternating electrical conduction and chemical conduction.

25.  In this situation, the wave of depolarization travels along the axon  Analogous to dominos falling In unmyelinated axons:

26.  Saltare is a Latin word meaning “to leap.”  The Myelin Sheath is segmented. There are ‘myelin-free’ regions along the axon, called the nodes of Ranvier, or Myelin Sheath Gaps. Myelinated axons: Saltatory Conduction

28. 1. Which do you think has a faster rate of AP conduction – myelinated or unmyelinated axons? 2. Which do you think would conduct an AP faster – an axon with a large diameter or an axon with a small diameter? The answer to #1 is a myelinated axon. Could you move 100m faster if you walked heel to toe or if you bounded in a way that there were 3m in between your feet with each step? What about throwing an object? The answer to #2 is an axon with a large diameter. Could you move faster if you walked through a hallway that was 4 m wide or if you walked through a hallway that was 1m wide?

29.  Synapses

30. Junction between nerve cells  1st cell releases chemical to trigger next cell  Where drugs may affect N.S. 2003-2004 animation

31. 1. Electrical current travels down the axon 2. Vesicles with chemicals move toward the membrane and merges with the membrane of synaptic bulb 3. Chemicals are released and diffuse toward the next cell’s plasma membrane 4. The chemicals open up the transport proteins and allow the signal to pass to the next cell http://learn.genetics.utah.edu/content/addiction/reward/neurontalk.h tml

33. Cerebrum Corpus callosum Cerebellum Thalamus Hypothalamus Midbrain Pons Medulla oblongata Spinal cord

34.  Functions  Basic body functions:  breathing, heart, digestion, swallowing, vomiting  Homeostasis  Coordination of movement  The “lower brain”  medulla oblongata  pons  cerebellum

35.  Cerebrum  2 hemispheres  left controls right side of body; right controls left  Corpus callosum  The connection between the 2 hemispheres

36.  Left hemisphere  “Logic side”  Language, math, logic, vision & hearing  Fine motor control  Right hemisphere  “Creative side”  Pattern recognition, spatial relationships, non-verbal ideas, emotions, multi-tasking

37.  Regions specialized for different functions  Lobes  Frontal: speech, control of emotions  Temporal: smell, hearing  Occipital: vision  Parietal: speech, taste, reading frontaltemporaloccipitalparietal

38. Controls basic emotions (fear, anger), involved in emotional bonding, establishes emotional memory

39. Occipital lobe- visual processing Temporal lobe-memory, sound processing, auditory stimuli Frontal lobe- higher thought functions, judgment, personality, emotion, problem-solving, planning, movement Parietal lobe- sensation, language (left side) Pons- breathing, relay

41. Organs of the Peripheral Nervous System (PNS) 1.Nerves =a true organ (made of different tissue) and performs one function Function: transport nerve impulses from one part of the body to another 2. Ganglia = clusters of neuron cell bodies located outside the CNS

42.  Reflex, or automatic response  Rapid response: automated  Signal only goes to spinal cord  No higher level processing= Does not involve brain  Advantage  Don’t need to think or make decisions about: Ex’s: Blinking, balance, pupil dilation, flinching

43.  Accidents  Drugs  Alcohol  Disease  Contagious  Hereditary http://learn.genetics.utah.edu/content/addicti on/drugs/mouse.html

44. What if neurons die or get damaged here? or here

45. Function: Chemical regulation of bodily processes -Uses hormones -Called ductless glands (secrete directly into bloodstream)

46.  Chemical messengers  Secreted from glands/cells- in small amounts  Travel through bloodstream  Act on Target cells (receptors) ▪ Effect rates of reactions/processes ▪ Enzymes rates ▪ Protein synthesis ▪ Transport of materials across a membrane

47. Negative Feedback: -Response in opposite direction of stimulus -Like a thermostat -Ex. Parathyroid hormone- Regulates Calcium levels Ca 2+ rise= stops secretion of hormone Positive Feedback: -Response in same direction as stimulus -When positive response, signals release of more Ex. Oxytocin= Uterine contractions during childbirth -Increase strength of contraction until birth video

48. GLAND  Pituitary (GH, PRL, TSH, ACTH, MSH, FSH, LH)  Thyroid (T4, T3, Calcitonin)  Parathyroid (PTH)  Pineal (Melatonin)  Thymus (Thymosin) FUNCTION  Growth, Skin, Breast milk, Metabolism, Ova, Sperm, Gonads, Fluid balance  Metabolism, Growth, Ca 2+ levels  Ca 2+ / Phosphate levels  Inhibit secretion of FSH and LH, animal sleep-wake cycles, other cycles  Stimulates maturation of T lymphocytes

49. Adrenal (Epinephrine, Norepinephrine) Pancreas (Glucagon, Insulin) Gonads Ovaries (Estrogen) Testes (Testosterone) “Flight or Fight” Response- metabolism, HR, BP Conversion of glycogen to glucose (Glucagon) and conversion of glucose to glycogen (Insulin) Sexual development Estrogen: female sex characteristics, ovarian cycle, and menstrual cycle Testosterone: male sex characteristics and sperm cell production