The Nervous System

Can spina bifida be prevented?

YES; preventable when folic acid (B9) is taken during pregnancy

What is the prevalence of Huntington's disease?

affects 10 out of every 10,000 people (VERY small)

What is the prevalence of Alzheimer's disease?

affects 15% of people over the age of 65

What is the prevalence of Parkinson's disease?

affects about 1% of the population over 60 years old and 4% over 80 years old

Does multiple sclerosis (MS) affect more than or women?

affects more women and men

What is multiple sclerosis (MS)?

an autoimmune disease that destroys myelin sheaths leading to weak or ineffective nerve impulses

Why is the "mind and body" all in one?

because they can't work without each other

What is the purpose of SSRI drugs?

blocks re-uptake by binding to the protein (feeling lasts longer)

What is the function of the parasympathetic subdivision of the motor division?

body relaxes and then becomes tired (constriction of the pupils, decreases heart rate, decreases blood pressure)

What is the central nervous system (CNS)?

brain and spinal cord

What is Huntington's disease?

cell death due to too much Huntington protein build-up (too much dopamine is released from brain cells)

What is Parkinson's disease?

cell death due to unknown origin, resulting in too little dopamine

Which part of the nervous system is the "processor"?

central nervous system (CNS)

What are the two divisions of the nervous system?

central nervous system (CNS) and peripheral nervous system (PNS)

Which part of the brain is also called a "little brain"?

cerebellum

What are ganglia?

clusters of cell bodies in the PNS

What is Wernicke's area responsible for?

comprehension of speech (listening)

What is the axon hillock?

cone-shaped area from which the axon arises

What is the somatic (voluntary) nervous system?

conscious control of skeletal muscles

What is the cerebellum responsible for?

coordinates fine motor movement, precision, timing, accuracy, and posture

What do nerves primarily run on?

glucose (it is a fast form of fuel)

What is the temporal lobe responsible for?

important in hearing and smell, as well as an abstract thought processes

What is the purpose of the patellar (knee) stretch reflex?

it is a way to test your muscle spindles and proprioceptors (check the nerve relay through L2-L4)

Why should you get more than 6 hours of sleep every night?

keeps beta-amyloid levels low

What is proprioception?

knowing/sensing where are your body is in space without having any visual feedback

What is the parietal lobe responsible for?

major center for sensory information (feeling)

What does "multiple sclerosis" mean?

many scars

What is a concussion the same thing as?

mild traumatic brain injury (mild TBI)

Longer axons tend to be _______________ and shorter axons tend to be _______________

myelinated; unmyelinated

What is the peripheral nervous system (PNS)?

nerves that extend from the brain and spinal cord (outside of the CNS)

What do nerves need a continuous supply of?

oxygen

What is an example of a reflex arc?

patellar tendon reflex (knee jerk)

Which part of the nervous system is the "messenger"?

peripheral nervous system (PNS)

What are some treatments of Huntington's disease?

pharmaceuticals are employed and embryonic cell tissue in certain show promise

What is the function of the sympathetic subdivision of the motor division?

prepares the body's "fight or flight" response (dilates pupils, increases heart rate, increases blood pressure)

What are neurofibrils (neurofilaments) and what is their function?

provides structure and shape to the nerve cell

What is the primary somatosensory cortex responsible for?

receives information from sensory receptors

What is the occipital lobe responsible for?

reception and integration of visual stimulus (seeing)

The ___________ division of the PNS moves toward the CNS, the ___________ division of the PNS moves away from the CNS

sensory; motor

What is Broca's area responsible for?

speech and language production

What is saltatory conduction?

the "jumping" of an action potential between the unmyelinated nodes of ranvier (the jumping is a faster way of transmitting a deep polarization wave)

What do muscle spindles tell us?

the LENGTH of the muscle

What do golgi tendons tell us?

the TENSION in the muscle and tendons

What is a reflex arc?

the coordinated attempt to move away from something that is causing you pain/damage (communication between the PNS, CNS, then back to the PNS)

What is spina bifida?

the incomplete formation of the vertebral arches and/or a spinous processes of at least one lumbar vertebrae

What is the most important factor in increasing conduction velocity?

the myelin sheath

What does it mean if there is no response from the patellar (knee) reflex test?

there is damage to the L2-L4 vertebrae

What happens if a person does NOT have proprioception?

they would fall to the floor like a ton of bricks

What is the motor division of the PNS?

transmits impulses from the CNS to effector organs

Who is affected by spina bifida?

unborn fetuses (the bone doesn't form well and the spinal cord can protrude outside of the bony covering)

What is the frontal lobe responsible for?

voluntary motor skills ("thinking"), motivation, aggression, sense of smell

What is the primary motor cortex responsible for?

voluntary movement and motor function

Can nerves improve their function with use and practice?

yes, then the nerves will be able to send a faster and stronger impulse

What are the big three CNS diseases?

1. alzheimer's disease 2. parkinson's disease 3. huntington's disease

What are the two factors that may be a result of brain cell death with Alzheimer's disease?

1. beta-amyloid peptide plaque build-up between two neurons 2. tau proteins causing neurofibrillary tangles (keeps the cell from working)

What are two conclusions of the nun study?

1. if they were studious in young adulthood, they seemed to be protected from Alzheimer's (wrote essays with complicated sentence structure and good vocabulary) 2. if they dedicated their life to being a student, studying, reading, and being curious, they seemed to be protected from Alzheimer's

What are the six steps of nerve synapse (nerve signal conduction)?

1. impulse comes down to the axon terminal 2. calcium floods into the axon terminal 3. vesicles containing neurotransmitters move to the wall to be released by exocytosis 4. the neurotransmitters move across the synaptic cleft and binds to protein receptors 5. the binding causes ion channels to open which causes a depolarization wave 6. the neurotransmitter will either defuse away, get dissolved by an enzyme and get broken down, or get pulled back in through an ion channel into the presynaptic neuron to be re-used (re-uptake)

What are the steps of the patellar (knee) stretch reflex?

1. patellar ligament is struck 2. the muscle spindle detects the muscle lengthening 3. a sensory neuron sends a signal to the spinal cord 4. the impulse is split into two impulses in the grey matter of the spinal cord 5. the two impulses simultaneously leave the CNS via PNS motor nerves 6. the agonist contracts while the antagonist relaxes 7. as a result, the lower leg kicks forward

What are the five steps of the reflex arc?

1. receptor - site of stimulus action 2. sensory neuron - transmits afferent impulses to the CNS 3. integration center - transmits the signal within the CNS 4. motor neurons - transmits impulses to an effector organ 5. effector - muscle fiber or gland responding to an impulse

What are the two functional divisions of the PNS?

1. sensory (afferent) division 2. motor (efferent) division

What are the two divisions of the motor division of the PNS?

1. somatic (voluntary) nervous system 2. autonomic (involuntary) nervous system (ANS)

What are the two functional subdivisions of the motor division of the PNS?

1. sympathetic 2. parasympathetic

What is proprioceptive neuromuscular facilitation (PNF)?

- an advanced muscle stretching technique - involves maximal muscle contractions prior to lengthening the same muscle

What are axon terminals and what is their function?

- branches at the end of the axon - secretory region - release the neurotransmitters of the presynaptic cell (synaptic cleft)

What is an axon?

- conducting region of a neuron - generates and transmits nerve impulses (action potentials) away from the cell body

What are a few examples of good nutrition for the brain?

- fish oil and multivitamins - whole grains - antioxidants - low calories - lean proteins - unsaturated fats

What is a Node of Ranvier and what is its function?

- gap in the myelin sheath of a nerve, between adjacent Schwann cells - areas which depolarize along the axon - the unmyelinated area of a myelinated nerve

What are some treatments of Parkinson's disease?

- implanted electrodes causing stimulation of cells - gene and embryonic cell insertion - vigorous exercise

What is the benefit of physical activity for the brain?

- increases blood flow to the brain which increases the oxygen supply - increases brain derived neurotropic factor (BNDF) which aids neurogenesis in the prefrontal cortex and temporal lobes

What does it mean if an axon is unmyelinated?

- lack a myelin sheath - conduction is SLOW (~1-4 mph)

What are some treatments of multiple sclerosis (MS)?

- medication to lessen the audio immune response - rehabilitation, physical activity, good nutrition, stress reduction

What is the cell body and what is its function?

- organelle center and receptive region - network of neurofibrils (neurofilaments)

What is Alzheimer's disease?

- progressive mental deterioration - linked with brain cell death and the decrease in ACH formation (associated with forming new memories and retrieving old ones -- HIPPOCAMPUS)

What are Nissl bodies and what is their function?

- rough ER - where neurotransmitters are created

What are dendrites and what is their function?

- short, tapering, and diffusely branched ("tree-like") - receptive (input) region of a neuron (sensory) - convey impulse waves toward the cell body

What is the sensory division of the PNS?

- somatic afferent fibers convey impulses from skin, skeletal muscles, and joints - visceral afferent fibers convey impulses from the visceral organs (i.e., gut)

What does it mean if an axon is myelinated?

- surrounded by a myelin sheath - comprised of Schwann cells - conduction is FAST (~10-60 mph)

What is the purpose of the golgi tendon reflex?

- tells us when to force the muscle to relax when it is under too much tension - helps to prevent damage due to excessive stretch - produces muscle relaxation (lengthening) in response to tension

What is the autonomic (involuntary) nervous system?

- unconscious control (you don't have to think about it) - visceral motor nerve fibers - regulates smooth muscle, cardiac muscle, digestion, sweating, blood pressure, glands, etc.

What is a Schwann cell and what is its function?

- wrap the axon with myelin sheath - improves the speed of conduction

What are the steps of the golgi tendon reflex?

1. you extend your knee and tilt your pelvis forward to cause a hamstring stretch 2. you contract your hamstrings for 20 seconds 3. golgi tendon organs are activated in the hamstring tendon 4. sensory fibers send an impulse to the gray matter of the spinal cord 5. impulse is carried over two interneurons to two motor neurons 6. impulse travels away from the spinal cord toward the upper leg muscles 7. a dampening impulse is received at the hamstring muscles causing them to relax 8. an impulse is sent to the quadriceps muscles causing them to contract (then the hamstring muscle can be stretched further)

What are muscle spindles composed of?

3-10 short intrafusal muscle fibers in a connective tissue capsule