exam 2

Chapter 10:
 

1. Nervous system general functions:

   1. Act as the body's communication network

      1. Sensory perception, motor control, cognition, emotional regulation, learning and memory, homeostasis regulation, sleep regulation, response to stimuli

2. Name 2 groups of nervous system organs

   1. Central nervous system (CNS): brain and spinal cord

   2. Peripheral nervous system (PNS): rest of the body, cranial and spinal nerves

      1. Sensory: detect changes; receptors convert info into impulses; conduct along peripheral nerves to CNS

      2. Motor: transmit impulses from CNS to effectors

         1. Somatic: transmits voluntary commands to skeletal muscles

         2. Autonomic: transmits involuntary commands to viscera

3. Name 2 cell types in neural tissue

   1. Neurons: conduct electrical impulses; respond to changes/stimuli

      1. 3 parts:

         1. Cell body: makes decisions based on info

         2. Dendrites: receive sensory info

         3. Axons: signal gets sent down axon; motor output; efferent

            1. Myelin: mixture of fats and proteins that cover parts of axon; keeps signal going down axon

            2. Myelin sheath: wrapped coating that acts as insulator

               1. Will have muscle weakness if signal can't get all the way down axon

               2. Multiple Sclerosis (MS): immune response that destroys myelin

                  • Scars are left behind, which stops the neurons from making impulses

                  • w/o motor neurons, muscles stop contracting and undergo atrophy

                  • Tx: immunosuppressants

               3. Myelinated vs. unmyelinated

                  • Myelinated: has myelin sheath, faster conduction from node to node

                  • Unmyelinated: no myelin sheath, slower conduction along length of axon

            3. Nodes of Ranvier: gaps in between myelin; electrical signal jumps over nodes from 1 myelin to the next

            4. End of axon: there are synaptic knobs and where the neurons communicate is called a synapse

               1. Synaptic cleft: separates the 2 neurons

               2. Presynaptic: before cleft; neuron sends signal

               3. Postsynaptic: after cleft; neuron receives signal

               4. Neurotransmitter is released across cleft by exocytosis to transfer message

                  • Excitatory: increase threshold

                  • Inhibitory: decrease threshold (anesthesia)

                  • Acetylcholinesterase breaks down acetylcholine to stop neurotransmitter from binding to receptor

                  • Monoamine oxidase breaks down norepinephrine and epinephrine

      2. Different types:

         1. Multipolar: many dendrites, 1 axon (looks like the one we drew in class)

         2. Bipolar: 1 dendrite, 1 axon

         3. Unipolar: 2 branches that act as 1 axon

   2. Neuroglia: support, protect, insulate and nourish neurons; do not conduct electrical impulses

      1. 6 types: (first 4 in CNS)

         1. Astrocytes: part blood brain barrier, form scar tissue

         2. Oligodendrocytes: myelinate CNS axons

         3. Microglia: phagocyte cells

         4. Ependymal cells: make CSF

         5. Schwann cells: myelinate PNS axons

         6. Satellite cells: grow, repair and regenerate skeletal muscles

4. Function of sensory, interneurons and motor neurons:

   1. Sensory (afferent): transfer sensory info to neurons in CNS

   2. Interneurons: transfer info from one part of CNS to another

   3. Motor (efferent): transfer instructions from CNS to effectors

5. Explain how polarized axon responds to stimulation:

   1. When a polarized axon is stimulated, it depolarizes, which creates an action potential

6. Action potential:

   1. Ion channel:

      1. Closed: can still pump things through, requires energy

      2. Open: pumps things through w/o energy

   2. Neuron action potential:

      1. Resting potential: uses pump

         1. neuron charge = -70, higher concentration of K+ inside cell, higher concentration of Na+ on outside of cell

         2. When axon is stimulated, release of Acetylcholine binds to receptor to turn on pump, pumps Na+ into neuron slowly, raises charge to thehold

      2. Depolarization: uses channel to increase charge to positive

         1. -55 is the threshold number

            1. Can raise or lower threshold

               1. Excitation: raise

               2. Inhibition: lower, ex: anesthesia

         2. The sodium channels open, Na+ rush in (diffusion), once it gets into the positives the sodium channels close, which will start repolarization

      3. Repolarization: uses channel to decrease charge back to original charge

         1. After sodium channel closes, potassium channel opens and K+ exits cell and the overall charge starts to become negative again

      4. Hyperpolarization: uses pump to bring some K+ back in

         1. too much potassium left cell and is below resting (= -70), so pump used to bring charge back to resting

         2. Potassium given to people who can’t relieve their cramps, cramp in the brain is a seizure (what happens when you cut your babies formula)

7. Refractory period:

   1. Absolute: time when you can't generate an action, (you're unable to move your finger away from the stove)(absolutely no action)

   2. Relative: can't generate action unless it's high-intensity

 
Chapter 11:
 

1. CNS: brain and spinal cord

2. How does grey and white matter arrangement differ in brain and spinal cord?

   1. Brain: grey matter is on the outside, while white matter is on the inside

   2. Spinal cord: grey matter is on the inside creating a "butterfly" shape, while white matter is on the outside surrounding the grey

3. What part of brain in connected inferiorly to spinal cord -> medulla oblongata

4. Meninges: membrane that protects the brain and spinal cord

   1. 3 layers:

      1. Dura mater: outer layer (top),

         1. dense connective tissue

         2. epidural tissue

      2. Arachnoid mater: middle layer

         1. Subarachnoid space contains CSF

            1. Fluid is for protection

            2. Contain 4 ventricles -> in #5

               1. Cerebral aqueduct between 3 and 4

               2. Arachnoid granulation absorbs CSF

                  • Hydrocephalus occurs w/o CSF absorption

               3. Choroid plexuses is where ependymal cells live, which produces CSF

      3. Pia mater: inner layer (bottom)

         1. Blood vessels and nerves

         2. Nourishes CNS

5. Ventricles (4): CSF flows through ventricles, subarachnoid spaces in brain and spinal cord

   1. Lateral ventricles: located in cerebrum, one in each cerebral hemisphere

   2. Third ventricle: located in diencephalon, between R and L thalamus

   3. Fourth ventricle: located in hindbrain, near brainstem

6. Cerebrum: largest part of the brain; has 4 lobes

   1. L side of brain: analytical; dominant side in most people; if I asked what's the first thing that pops into your head when I said "apple", they would picture the word

   2. R side of brain: artistic; sensitive to drugs; if I asked what's the first thing that pops into your head when I say "apple", they could picture the image of an apple

   3. Cerebral hemisphere: divides L and R side of brain; sensory is located in the back of head, motor is in the front

      1. Corpus Callosum: piece that connects the two hemispheres; looks like a rams head

         1. Frontal lobe: motor cortex; controls voluntary muscles

            1. Concentrating, planning, complex problem solving, emotional behavior, judging consequences of emotions and behavior

               1. Broca's area: not able to say words d/t motor loss

                  • L hemisphere in motor cortex; controls muscles needed for speech

         2. Temporal lobe: hearing, memory, smell

            1. Complex sensory experiences (understanding speech/reading), store memories of visual scenes, music and complex patterns

               1. Wernicke's area: you can say the words, but they don’t make sense

                  • L hemisphere in temporal/parietal lobe; understanding and formulating language

         3. Parietal lobe: sensations of the skin including pain, touch, pressure and temp.

            1. Understanding speech, choosing words to express thoughts/feelings

         4. Occipital lobe: vision

            1. Analyze and combine visual images w/ other sensory experiences

   4. Gyri: hills

   5. Sulcus: valleys

   6. Fissures:

      1. Longitudinal: groove down the middle that separates the two hemispheres

      2. Transverse: where the cerebrum and cerebellum separate

   7. Cerebral cortex: interprets impulses, initiates muscular movements, storing memory, reasoning, intelligence and personality

   8. Basal Nuclei (basal ganglia): relay station for motor impulses from cerebral cortex into brainstem and spinal cord; facilitate/help coordinate voluntary movements; dopamine is produced here; lesions in this area of the brain are related to Parkinson's

      1. Caudate nucleus

      2. Putamen

      3. Globus pallidus

7. Diencephalon: grey matter (all sensory); surrounds 3rd ventricle

   1. Thalamus: relay station for all sensory impulses ascending from other parts of nervous system to cerebral cortex (taste, smell, etc.)

   2. Hypothalamus: helps maintain homeostasis; links together nervous and endocrine systems

   3. Posterior pituitary: secretes 2 hormones

      1. Oxytocin: causes muscles contractions

      2. Anti-diuretic hormone (ADH): stops you from peeing

         1. Alcohol breaks the seal so you got to go every 5 min.

   4. Pineal gland: secretes melatonin; cool, dark room is best; if you constantly take melatonin, your body will eventually stop making it

1. Limbic system: controls emotional response, feelings and behaviors; reacts to potentially life-threatening upsets

2. Cerebellum: coordination, balance and posture; proprioception: knowing where your limbs are at even w/ your eyes closed

   1. Cerebral cortex -> grey matter; dentate vitae -> white matter

3. Brainstem: connects cerebrum to spinal cord and contains nerve fiber tracts and grey matter masses

   1. Midbrain: reflex center that move eyes and head and maintain posture

   2. Pons: relays impulses between medulla oblongata and cerebrum, helps regulate rate and depth of breathing; rounded bulge on brainstem

   3. Medulla oblongata: contains cardiac, vasomotor and respiratory control centers (vital centers)

      1. If someone tells you they hit their head and they vomited after, you got to intubate them incase their airway swells up

4. Reticular information: AKA reticular activating system; on the back of head and it turns on when you sleep on your back; paralyzes your muscles during sleep so you don't act out your dreams; inactivity causes sleep

5. Spinal cord: stops at L2; you want to go past L2 if doing a lumbar puncture; C=7, T=12, L=5

   1. Positions:

      1. Cervical enlargement: supplies nerves to upper limbs

      2. Lumbar enlargement: supplies nerves to lower limbs

      3. Conus medullaris: cone looking end of the spinal cord

      4. Filum terminale: where the meninges stop; this cord connects tissue that anchors spinal cord to coccyx

      5. Cauda equina: horse hair like fibers that come down after spinal cord ends

   2. Structures: SAME DAVE (Sensory, Afferent, Motor, Efferent, Dorsal, Afferent, Ventral, Efferent)

      1. White matter: surrounds core of grey matter; arranged in tracts; myelinated

      2. Grey matter: butterfly shape; arranged in horns; unmyelinated

      3. Posterior roots: sensory neurons

      4. Anterior roots: motor neurons

6. Reflex arc: neural pathway

   1. Receptor: sensitive to specific type of internal/external change

   2. Sensory nerve: conducts impulse from receptor into brain/spinal cord

   3. Interneuron: processing center

   4. Motor neurons: conducts impulses from brain/spinal cord out to synapse w/ effector

   5. Effector: respond to stimulation

7. Ascending vs. descending tracts:

   1. Ascending: conducts sensory impulses to brain

   2. Descending: conducts motor impulses from brain to muscles and glands

8. PNS: cranial and spinal nerves

9. Autonomic vs. somatic nerve fibers:

   1. Somatic: voluntary and conscious activities; spinal nerves connect CNS to skin

   2. Autonomic: involuntary and subconscious activities; spinal nerves connect CNS to viscera

      1. Sympathetic: fight or flight; speeds body up (think of a bear chasing you)

         1. Pupils and bronchi dilate, HR and breathing increases

         2. Neurotransmitter: norepinephrine/epinephrine (monoamine oxidase (MAO) inactivates norepinephrine)

      2. Parasympathetic: rest and digest; slows body down (think about after thanksgiving); Vagus (X) nerve

         1. Pupils and bronchi constrict, HR and breathing decreases

         2. Neurotransmitter: acetylcholine (Acetylcholinesterase (AChE) decomposes acetylcholine)

 
Nerve fibers: send nerve signals to organ through network of neurons

1. Preganglionic: signal still at the nerves; always acetylcholine

2. Postganglionic: once signal gets to muscles/glands; transmitter depends on para/sympathetic

Vagal maneuver: stimulates vagus nerve; slows down HR
Cholinergic fibers: release acetylcholine
Muscarinic: slow, excitatory
Nicotine: rapid, excitatory; activated by tobacco/nicotine
Adrenergic fibers: release norepinephrine; adrenaline
Bind to alpha and beta receptors: there are 2 types in each alpha and beta
Beta-agonist: straight to lungs w/o affecting HR

1. Structure of peripheral nerve:

   1. Epineurium: covers the whole nerve

   2. Perineurium: covers fascicles (bundles of axons)

   3. Endoneurium: covers each axon

2. Name cranial nerves, list major functions

   1. Olfactory: sense of smell; sensory

   2. Optic: sight/vision; sensory

   3. Oculomotor: movement of eye; motor

   4. Trochlear: looks down; motor

   5. Trigeminal: sensation to face; both; motor part=chewing

   6. Abducens: looks out; motor

   7. Facial: facial movement; both; sensory part=taste, tip of tongue

   8. Vestibulocochlear: hearing/balance; sensory

   9. Glossopharyngeal: swallowing; both; sensory part=taste, back of tongue

   10. Vagus: parasympathetic; both; motor part=vocal cords

   11. Accessory: shrugging shoulders/moving neck; motor

   12. Hypoglossal: moving tongue around; motor

Sensory: 1,2,8      Motor: 3,4,6,11,12        Both: 5,7,9,10

1. Spinal nerves: 31 pairs; all pairs are mixed (sensory and motor); nerves lay below corresponding spinal cord except for nerve C1; C=8, T=12, L=5, S=5, 1 coccygeal

   1. Dermatomes: territory of skin that nerve supplies; all nerves below C1

2. Nerve plexuses:

   1. Cervical: C1-C5

      1. Phrenic nerve: innervates diaphragm; neurotransmitter released -> acetylcholine (bc we can move it)

         1. Hiccups is a spasm of diaphragm, squeeze nerve by carotid for 5 sec.

   2. Brachial: C5-T1

      1. Musculocutaneous nerve: innervates muscles of anterior arms and skin of lateral forearms

      2. Radial nerve: innervates posterior muscles of arms, forearms and hands; sensation to posterior side of thumb, index and middle fingers

      3. Median nerve: supplies flexor muscles to forearm; sensation to anterior side of thumb, index and middle fingers

      4. Ulnar nerve: open and close finger, move wrist; sensation to ring and pinky fingers anterior/posterior

      5. Axillary nerve: innervates shoulder

   3. Lumbosacral: L1-S4

      1. Obturator nerve: medial part of leg; adduction of legs (bringing together)

      2. Femoral nerve: sensation to anterior and medial thigh; extends leg

      3. Sciatic nerve: runs down back of each leg; helps bend (flexion) leg

 
Chapter 12:
 

1. General senses vs. special senses:

   1. General: receptors widely distributed throughout the body; touch, pressure, pain

   2. Special: receptors confined to structures in the head; (Synesthesia: senses are mixed/swapped out; one sense coming from another)

      1. Smell: olfactory, cranial nerve 1; chemoreceptor; receptors located in olfactory epithelium of nose

      2. Taste: gustation, cranial nerves 7,9 and 10; chemoreceptor; 5 taste sensations

         1. Taste buds: organ that allows you to taste and perceive flavors

         2. Saliva: necessary to taste because it acts as a solvent to dissolve chemicals to allow them to activate the taste receptors on tongue

            1. Sweet: carbs

            2. Sour: acids (H+)

            3. Salty: salts (Na+/K+)

            4. Bitter: coffee, poison, organic compounds (Mg and Ca salts)

            5. Umami: amino acids (MSG)

      3. Hearing:

         1. Outer/external:

            1. Auricle (Pinna): funnel-shaped outside you can touch and tragus; collects sound waves

            2. External acoustic meatus: S-shaped tube you stick the Q-tip into

            3. Tympanic membrane (eardrum): responds to sound waves w/ vibrations; hair cells move and bend to send signal

         2. Middle:

            1. Tympanic cavity: air-filled space in temporal bone

            2. Auditory ossicles: malleus, incus and stapes (stapes is the smallest bone in the body)

            3. Oval window: stapes vibrates against it to move fluids in the inner ear

Tympanic reflex: muscles contract during loud noises; muscle: tensor tympani and stapedius

1. Inner/internal:

   1. Auditory (eustachian) tube: connects middle ear to throat; maintains pressure on both sides of eardrum

   2. Osseous (bony) labyrinth: perilymph fluid; semicircular canals -> dynamic equilibrium

   3. Membranous labyrinth: endolymph fluid; includes semicircular canals, utricle and saccule -> located in vestibule -> static equilibrium

      1. Cochlea: hearing; 3 compartments w/ membranes that separate the compartments

         1. Scala vestibuli: upper

            1. Vestibular membrane: separates scala vestibuli and cochlear duct

         2. Cochlear duct: middle

            1. Basilar membrane: separates cochlear duct and scala tympani; spiral organ lies here

         3. Scala tympani: lower

            1. Tectorial membrane: sits above hearing receptor organ -> spiral organ: sense of hearing; contain hair cells

2. Auditory pathway: cochlear CN 8 -> medulla oblongata -> midbrain -> thalamus -> auditory cortex in temporal lobe

3. Sensory impulse steps:

   1. Sound waves enter external acoustic meatus

   2. Sound waves cause tympanic membrane to reproduce vibrations coming from sound-wave source

   3. Auditory ossicles amplify and transfer vibrations to end of stapes

   4. Vibrations pass through vestibular membrane and enter endolymph of cochlear duct

   5. Neurotransmitter stimulates sensory neurons

   6. Sensory impulses conduct along fibers of cochlear branch of cranial nerve 8

   7. Auditory cortex of temporal lobe interprets sensory impulse

4. 2 types of hearing loss:

   1. Conductive: interference w/ conduction of sound vibrations to inner ear; from accumulation of ear wax, hardening/injury of tympanic membrane, injury to auditory ossicles, otosclerosis

   2. Sensorineural: damage to cochlea, auditory nerve and/or nerve pathways; from long-term exposure to loud noises

5. Equilibrium:

   1. Static (not moving): lets you know where your head is when it isn't moving

      1. Utricle and saccule; each chamber contain macula (has hair cells); otoliths (calcium carbonate crystals)

   2. Dynamic (moving): lets you know where head is when you're moving/bending;  impulse sent to vestibular branch of cranial nerve 8

      1. Semicircular canals; Crista ampullaris (has hair cells); cupula (jelly-like substance that moves and stimulates the hair cells when you move your neck)

      2. Issue w/ this causes motion sickness

6. Vision:

   1. Accessory organs: upper/lower eyelids and eyelashes provide protection

   2. Lacrimal apparatus:

      1. Lacrimal gland: secretes tears; tears collect in the inner corner of eye

      2. Canaliculi: 2 ducts that collect tears

      3. Lysozyme: antibacterial for tears

      4. Lacrimal sac: collects tears

      5. Nasolacrimal duct: collects tears from lacrimal sac and empties into nasal cavity

   3. Muscles:

      1. Lateral rectus: moves eye outward; cranial nerve 6

      2. Superior oblique: moves eye down; cranial nerve 4

      3. Superior rectus: moves eye up and in

      4. Inferior rectus: moves eye down and in

      5. Medial rectus: moves eye inward

      6. Inferior oblique: moves eye up and laterally

   4. Wall of the eye: 3 layer

      1. Outer (fibrous) tunic:

         1. Cornea: anterior; light transmission and refraction

         2. Sclera: posterior; attach to muscles; protection

      2. Middle (vascular) tunic:

         1. Choroid coat: posterior; provides blood supply; pigment prevents reflection

         2. Ciliary body: anterior; ciliary muscles move lens and holds it in place

         3. Iris: anterior; pigment of eye; accommodation; control light intensity

            1. Muscles of iris regulate size of pupil

      3. Inner (nervous) tunic:

         1. Retina: posterior; photoreception; impulse conduction

   5. Optic nerve: long nerve that connects the eyes to the occipital lobe

   6. Optic chiasma: where the optic nerve cross over to collect vision info from the other eye; also where pituitary gland is located

      1. Pituitary tumor: person would have tunnel vision; wouldn't be able to see peripherally

   7. Optic disc: blind spot d/t no rods or cones

   8. Rods: night vision; sensitive to light;

   9. Cons: color vision; sensitive to dim light

   10. Refraction: bending of light

       1. Concave: lens caved in, causes light waves to diverge; lens for near-sided people

          1. Near-sided (myopic): ciliary muscles contract, decreasing tension on ligaments; lens becomes thicker and more rounded; eye too long

       2. Convex: lens makes eyes look big and causes light waves to converge; lens for far-sided people

          1. Far-sided (hyperopic): ciliary muscles relax, increasing tension on ligaments; lens becomes thinner; eye too short; point of focus behind retina

       3. Aqueous humor: anterior; fluid that is before the lens

       4. Vitreous humor: posterior; fluid that is after the lens

7. 5 general types of sensory receptors:

   1. Chemoreceptors: respond to chemicals; smell, taste, oxygen concentration

   2. Pain (nociceptors) receptors: free nerve endings; respond to mechanical (pressure, pinch), thermal (extreme heat/cold) and chemical (substance released by damaged tissue) stimuli

      1. Visceral (referred) pain: sensation of pain in a different area of the body than the source of injury

         1. Example: if your heart hurts, it's most likely heart burn; heart attack pain would be felt in the shoulder (mostly w/ men; women experience more indigestion)

      2. Fast pain fibers (A-delta): myelinated

      3. Slow pain fibers ( C ): unmyelinated

      4. Pain pathways:

         1. Thalamus: begins sensation of pain; all sensory info comes to thalamus

         2. Cerebral cortex: judges intensity and locates source

         3. Grey matter in brainstem: regulates impulses from spinal cord

   3. Thermoreceptors: respond to changes in temp.; 2 types: warm and cold

   4. Mechanoreceptors: respond to mechanical forces that distort reception; touch, tension, pressure, BP, stretch (example: yoga)

      1. Proprioceptive: associated w/ changes in muscles, tendons, joints and body position; stimulated when changing position/exercising

   5. Photoreceptors: respond to light; eyes

8. What do all types of receptors have in common -> sensory receptors

9. Sensation vs. perception:

   1. Sensation: action potentials that make the brain aware of sensory

   2. Perception: brain interprets sensory impulse; example: sound of biting into an apple

10. Sensory adaptation:

    1. Fast: smell and taste

    2. Slow: proprioception (knowing where your body parts are even w/ your eyes closed)

    3. pain receptors do NOT adapt; you want to be able to feel pain; diabetics w/ foot ulcers are not able to feel that they have one d/t neuropathy

11. Touch and pressure receptors: 3 types; mechanoreceptors

    1. Free nerve endings: itching

    2. Tactile (Meissner's) corpuscles: fine touch; 2 points

    3. Lamellated (Pacinian) corpuscles: heavy pressure and vibration