BIOL 319 Lee Exam 4 Old questions plus review 2.0

Some of our "neuro" material we have been talking about from day one, so please do not overlook subjects such as

Neuron vs nerve, Nervous tissue as an excitable tissue, etc.

neuron

single nervous system cell

nerve

bundle of axons (neurons)

nervous tissue is excitable

-generate AP from RMP

-excitable=allow signals to transmit fast, immediate response to stimuli

3 major sections of the brain

hindbrain, midbrain, forebrain

forebrain

prosencephalon

-Diencephalon: thalamus, hypothalamus, epithalamus

pineal gland=melatonin

Midbrain

Mesencephalon-Reticular Activating Centers (RAC)= Wakefulness (caffeine hits receptors here

hindbrain

rhombencephalon (brain stem - medulla and pons)

Medulla oblongata: Heart rate, breathing rate, blood pressure, blood flow, vomiting, swallowing

Pons: balance & posture

Cerebellum: coordination, intricate movements, spatial equilibrium

Reticular Activating Centers function

a network of neurons that regulate sleep-wake transition and arousal

Reticular Activating Centers location

-brainstem (above the spinal cord)

-midbrain

Reticular Activating Centers neurotransmitters

acetylcholine, serotonin, dopamine, histamine

Medulla Oblongata

controls HR,BP,RR,blood flow swallowing,and vomiting

Sulcus

depression=increase in surface area=greater number of neurons that can be packed into the cerebral cortex

fissure

deeper and more prominent than a sulcus

location of central sulcus

between frontal and parietal lobes

Location of longitudinal fissure

The space between the right and left hemisphere. It is located in the cerebral cortex. It divides the cerebral cortex.

Brainstem

medulla oblongata, pons, midbrain

the brainstem connects

brain and spinal cord

Cerebellum

coordination, muscle tone, & spatial equilibrium

Female brain vs male brain

-female brain is better at multitasking

-increase in corpus callosum

-increase in synapse connections

substantia nigra

a modulator for the pyramidal tracts which is the main pathway for voluntary movement being sent to the spinal cord

substantia nigra produces

dopamine which helps fine-tune movement signals sent by pyramidal tracts

Parkinson's disease

dopamine-producing neurons are lost in the substantia nigra, which means pyramidal tracts can't send out signals properly, resulting in impaired motor control (tremors)

pyramidal tracts

-of the midbrain

-looks like pyramids

Limbic System: Amygdala

-also known as paleomammalian cortex (old)

-made of the amygdala (plays a role in memory, decision making, and emotional responses), mammillary bodies, stria medullaris, ventral nuclei of gudden

-interacts with basal ganglia (see something scary)

Why is it important that we have an emotional response and brain re-wiring when experiencing something scary?

it gets you ready to either face the threat or escape from it (fight or flight; sympathetic NS)

Lobes of the brain

frontal lobe, parietal lobe, occipital lobe, temporal lobe

frontal lobe

voluntary movements, voluntary thought, cognition, thinking, engaging in reason/cause-effect, long-term memory

parietal lobe

taste, temperature, touch, pressure, vibration detection

occipital lobe

vision

temporal lobe

short-term memory, emotions, speech, smell (olfaction), auditory stimuli

cerebellum

balance and posture, muscle tone, coordination→spatial equilibrium

midbrain function

alert, awake, conscious

pons

balance and posture

spinal cord

reflexes, walking, urination, sex organ function

Primary motor cortex

-anterior

-controls voluntary muscle movements

somatic sensory cortex

-posterior

-receives and provides sensory information from the body

the central sulcus divides

the primary motor complex and the somatic sensory complex

Hypothalamus

satiety = full

6 functions of the medulla oblongata

BP,HR,RR,Blood flow, vomiting, swallowing

cerebrospinal fluid function

"cushion" the brain and provide nutrients

cerebrospinal fluid location

-in/around the brain and spinal cord

-within the ventricles of the brain

-subarachnoid space between the arachnoid matter and the pia matter

Meninges

-the dura matter, arachnoid matter, and the pia matter

-protect CNS

Meningitis.....bones......pressure......If they find WBCs in the CSF.....

If WBC's are in CSF then that could signify meningitis

meningitis

inflammation of the meninges of the brain and spinal cord

effects of meningitis

-purulent labrynthitis

-deteriorates the organ of Corti

-can cause ossification of the cochlea

-severe-to-profound sensorineural hearing loss

signs of meningitis

high fever, stiff neck, drowsiness, and intense headache; may progress to coma then death within hours of onset

Epidural block...where

between L3 and L4

Epidural block...where.....pharmacology

caines and opioids

caines

mepivacaine, ropivacaine, levobupivacaine, chloroprocaine

opioids

fentanyl, morphine, hydromorphone, oxycodone, sufentanil

*** Neuro-pharmacology in general!! ***

local pain blockers and systematic pain blockers

local pain blockers

-anaesthetics

-"caine" blocks VG Na+ so that there is no depolarization and no signal at the source of pain (signal never sent to brain)

systematic pain blockers

-opiates/narcotics

-lead to pleasure/reward pathways

-FLATPEG

-E= endorphins,endrogenous

**** "-caines"; narcotics/opiates; SSRIs vs SRIs

Caines, Opiods/narcotics, SSRI,SRI

SSRI

-take a long time to be effective (2-4 weeks)

-selective serotonin reuptake inhibitor

-selective=only in brain

-elevates serotonin levels in brain

drug examples of SSRI

Zoloft (generic: sertraline), Prozac (fluoxetine), Lexapro (escitalopram)

SRI

-works very fast and short-term

-serotonin reuptake inhibitor

-illegal

-blocks all over body

-leads to feedback inhibition

-body stops production

-elevates dopamine levels in brain (plays into addiction centers in brain) because fast dopamine hit = brain happy -> brain wants easy happy feeling more)

examples of SRI

methamphetamine

both SSRi and SRi elevate

mood (dopamine and serotonin)

Proprioception...inner ear fluid....CN VIII....

-Vestibulocochlear Nerve (CN VIII)

- the semicircular canals of the ear have fluid that plays a role in balance in detection of acceleration/ deceleration

Cranial nerves

olfactory nerve I, optic nerve II,Oculomotor nerve III, Trochlear IV, Trigeminal Nerve 5,Abducens nerve VI, Facial Nerve VII, Vestibulocochlear nerve VIII,Glossopharyngeal nerve IX, Vagus nerve X, Accessory nerve XI, Hypoglossal nerve XII

Olfactory nerve I

-Larger in vertebrates with a better sense of smell

-Proprioception is a sensory function

-Smell and taste are linked and are both chemoreceptors

-Smell is linked to memory

Optic Nerve II

-Vision

-Optic chiasm: part of the brain where optic nerves cross

-Vision centers are in the occipital lobe

Oculomotor nerve III

-Double vision and blurred vision and drooping eyelids (ptosis)

-Superior, inferior, medial rectus and inferior oblique = proprioceptive

-Parasympathetic to the sphincter of the pupil(constriction) and ciliary muscles (accomodation)

Trochlear IV

-Superior oblique, motor and proprioceptive

-Some of the smallest motor units are found within the muscle of the eye

-Lens mineralize= cataract

-Double vision

Trigeminal Nerve V

-Mastication = chewing (mainly V3)

-V3= mandibular branch = masseter, temporalis, medial and lateral pterygoids

Abducens Nerve VI

-Double vision

-Lateral rectus

Facial Nerve VII

-Facial expressions

-Facial palsy

Vestibulocochlear Nerve VII

-Semicircular canals of the ear have fluid that plays a role in balance and detection of acceleration/deceleration

-Cochlea play a role in hearing

Glossopharyngeal Nerve IX

-Parasympathetic increases salivary gland secretion

-Motor to pharyngeal muscle

-Proprioceptive to pharyngeal

Vagus Nerve X

-"To wander"

-Vagus nerve goes all over the body; Only nerve to extend beyond head and neck to visceral organs in thorax and abdomen

-Parasympathetic to SA node of the heart= HR down

-Remember, the SA node will fire twice per second without "vagal tone"

Accessory Nerve XI

-Most posterior

-Sternocleidomastoid

-Trapezius

hypoglossal nerve XII

-"Under tongue"

-Intrinsic tongue muscles are entirely within the tongue

-Extrinsic tongue muscle attach the tongue to other structures

**Cranial nerves associated with vision ***

optic nerve II

**Cranial nerves associated with double vision ***

Oculomotor Nerve lll, Trochlear nerve lV, Abducens nerve Vl

Motor units are BACK on CN IV! Why the need for such small motor units associated with the eye??

-Smaller motor units create finer motion

-Smallest motor units are used in eye muscles (small movements and help with focusing sight)

sympathetic

-Regulates arousal and energy generation

-Fight or flight

-Stronger: hormone from adrenal medulla

-Thoraco-lumbar nervous system

parsympathetic

-antagonistic effects on target organs and promotes calming and a return to "rest and digest" functions

-default system

-Cranio-sacral nervous system

CN V - branches

-Ophthalmic (V1)

-Maxillary branch (V2)

-Mandibular branch (V3)

.....teeth.....dentist......"-caines"....This question is writing itself!!!

-Canines=local anesthesia

-Blocks voltage-gated sodium channels

-No depolarization

Both parasympathetic and sympathetic

-have pre and post-ganglionic

-PNS

-Acetylcholine=pre and post NT

CNS

-Acetylcholine= ONLY post ganglionic

CN X.....parasympathetic.....heart rate.....NT (?)......NOT a nicotinic ACH

receptor....which means the same binding molecule can have different effects of different tissue...? And one's answer must be more than "a different receptor"!

-all over the body

-parasympathetic to SA (sinoatrial) node of the heart = HR down

-remember the SA node will fire twice per second without "vagal tone"

CN XI....muscles....medical condition

-sternocleidomastoid and trapezius

-difficulty elevating the scapula or rotating the neck

Graded Potential

-barrage of EPSPs

-determine if an AP is generated

-Na+, Cl-, K+

-summation

Action Potential

-transmit signals over long distances

-Na+, K+

-no summation

Leak Channel

-ion channel that is always open, allowing ions and substances to pass through

-aka passive channels or non-gated channels

Carrier

-membrane protein that moves molecules across a cell membrane

Pump

-generate a membrane potential by creating an electrochemical gradient across the membrane (against the concentration gradient)

LIGAND GATED RECEPTOR/CHANNEL

-protein embedded in a cell membrane that acts as a gate, allowing specific ions to pass through only when a signaling molecule (called a ligand) binds to it

-opening the channel by triggering a conformational change in the receptor protein

VG CHANNEL

-transmembrane protein that opens and closes in response to changes in a cell's electrical potential

sympathetic fibers

pre-ganglionic: short

post-ganglionic: long

sympathetic NTs

Acetylcholine is pre

sympathetic location of origination within spinal cord

thoracic and lumbar

why is sympathetic stronger?

due to release of Ach on adrenal medulla, which releases norepinephrine

Parasympathetic fibers

pre-ganglionic: long

post-ganglionic: short

Parasympathetic NTs

Acetylcholine is pre and post

Parasympathetic location of origination within spinal cord

sacrum and coccyx

Myelination....APCV

-Myelinated sheaths are faster sheaths

-Length doesn't matter (hence the myelination=saltatory conduction)

-BUT diameter does matter

release of NT

Step 1: An AP arrives at the axon terminal

Step 2: voltage gated Ca2+ channels open and Ca2+ diffuses into axon terminal

Step 3: the calcium ions stimulate vesicles to release their NT via exocytosis

Step 4: The NT crosses the cleft via diffusion

Step 5: The NT binds to its receptors on the postsynaptic cell and causes chemical gated channels to open, iniating graded potential

Step 6: NT activities cease when:

a. neurotransmitter reuptake back into axon occurs

b. the NT diffuses away from its receptor

c. enzymes degrade or break up NT