Physics: Sound and Light

Things to note:

1. Determine whether a wave is undisturbed, reflected, refracted, diffracted, or dispersed.
2. Lenses and mirrors follow the three optics rules: the focal point rule, the object rule and the image rule. 
3. To solve for the Doppler Effect: when a wave source and observer move towards one another, frequency increases--add Δf to fs to get fo. When a wave source and observer move away from each other, frequency decreases--subtract Δf from fs to get fo. 

Equations: 

• v = fλ , where 'v' is velocity, 'f' is frequency, and 'λ' is wavelength
• T = 1/f , where 'T' is period 

*Sound requires a medium to travel, while light does not. The velocity of a wave is dictated by the medium through which it travels, so when a wave travels from one medium to another, its velocity changes according to the features of the new medium. Again, mechanical waves require a medium in which to travel through, while electromagnetic waves such as light are able to travel in the absence of a medium. 

Two characteristics of a given medium determine the velocity of waves traveling through it: 

1. The medium's elasticity, or resistance to change in shape
2. The medium's inertia, or resistance to change in motion 

*The velocity of sound waves in a gas is limited by the average speed of the molecules within that gas. Sound waves move more quickly through hot gases than through cold ones. 

Remember, a frequency of a wave that moves from one medium to another does not change, but the velocity does. 

*Heaver and denser media tend to slow waves down, while "stiffer" media tend to speed waves up, because they have greater elasticity, which is caused by increasing intermolecular forces, which consequently move the waves along. 

In general: 

'v' of sound in solid > 'v' of sound in liquid > 'v' of sound in gas

Physiology: Nervous System (General)

Divisions of the brain:

• Forebrain (Telencephalon & Diencephalon)
• Diencephalon
• Hypothalamus
• Thalmus
• Cortex
• Sub-cortical areas
• Midbrain (Mesencephalon)
• Tectum & tegmentum
• Hindbrain (Metencephalon & Myelencephalon) 
• Cerebellum & Pons
• Medulla oblongata

CNS:

• White matter = Tracts/Pathways (Columns = many tracts)
• Gray matter = Nuclei

PNS: 

• White matter = Nerves
• Gray matter = Ganglia

31 Spinal nerves: "812551"

8 cervical

12 thoracic

5 lumbar

5 sacral

1 coccygeal

*Cervical spinal nerves exit from above the respective vertebra. 

     -Spinal nerve root 1 from above C1, and spinal nerve root 2 from b/w C1 and C2

     -The rest of the spinal nerves (Thoracic, lumbar, etc.) emerge from below. 

-Spinal cord ends at L1

Dorsal roots - Sensory fibers from dorsal root ganglia (DS) 

     -Carries afferent information

Ventral roots - Motor fibers from anterior gray column of spinal cord. (VM)

     -Carries efferent information 

Plexuses:

Cervical plexus (C1-C4) 

     -Innervate the muscles and skin of the neck and shoulder. 

     -Phrenic nerve supplies motor action of diaphragm. That's why neck injuries are so dangerous. Can cause respiratory arrest.

Brachial plexus: 

Lumbar plexus: 

Innnervates anterior and medial muscles of thigh. 

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Order of meninges: 

Brain --> pia mater --> arachnoid membrane --> dura mater 

Epidural injections are steroid injections used to reduce the inflammation and pain associated with nerve root compressions. Can be caused by herniated discs, spinal stenosis and etc.

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Cranial Nerves:

I. Olfactory - Sense of smell

II. Optic - Sense of vision

III. Oculomotor - 4-6 muscles of eye (up & in), and contraction of pupil

IV. Trochlear - oblique muscle of eye (down & out)

V. Trigeminal - V1 opthalamic; V2 maxillary; V3 mandibular

VI. Abducens - Lateral rectus muscle of eye (abducts outwards) 

VII. Facial - Facial expressions; anterior 2/3 tongue; salivary and lacrimal glands

VIII. Vestibulocochlear - Equilibrium & Hearing

IX. Glossopharyngeal - poterior 1/3 tongue; muscles of swallowing; senses carotid BP

X. Vagus - Senses aortic BP, slows heart rate, 

XI. Accessory - Sternocleidomasteroid, trapezius, swallowing

XII. Hypoglossal - Innervation of tongue muscles

Locations in order, First 2 in Forebrain, second 2 in midbrain (brainstem), third 4 in pons (brainstem), last 4 in medulla (brainstem) 

Tests:
Olfactory - sniff coffee beans

Optic - Visual fields

Oculomotor - present eye with light for pupilary reflexes. Should move up & in. The eyes go down and out if there is a problem

Trochlear - Extraoecular movements. If eye can't go down & out, there is a problem 

Trigeminal - light touch, plus corneal reflex, and clench teeth and open mouth against resistance.

Abducens - If eye doesn't abduct, problem. The patient will go cross-eyed. To compensate they will turn their head to avoid double vision. 

Facial - Wrinkle forehead, smile, pucker, close eyes. Taste anterior 2/3 of tongue

Vestibulocochlear - Tuning fork

Glossopharyngeal - Gag reflex, tough, taste with posterrior 1/3 of tongue

Vagus - ??? Not in notes

Accessory - Rotate head and shrug shoulders against resistance

Hypoglossal - Stick tongue out straight 

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Sensory representation:

Modality - Receptor type to specific type of stimulus. 

     -Labeled line coding = Direct assocaition b/w a receptor and a sensation.
Location - Stimulation of a specific area defines the receptor's receptive field. 

Intensity - Distinguished by frequency of AP's 

     -Number of receptors = population coding

     -Frequency of AP's = frequencv coding

Duration - Time

Free dendritic endings - pain and temperature 

Emcapsulated dendritic endings - nerve endings wrapped in connective tissue  and serve as mechanoreceptors. 

• Meissner's corpuscles - detect light touch
• Merkel discs - Also light touch like Meissner's corpuscles 
• Krause's End bulbs - detect fine touch in mucus membranes
• Pacinian Corpuscles - Deep connective tissue, respond to vibration and deep pressure 
• Ruffini's Corpuscles - Found in dermis to respond to continuous pressure

Tonic receptors - Adapt slowly or do not adapt at all. 

     -Ex: Muscle stretch receptors, joint proprioceptors 

CNS must continually get info about degree of muscle length and joint position. 

Phasic receptors - Rapidly adapting receptors 

     -Ex: Tactile receptors in the skin

Don't respond to maintained stimulus 

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Motor fiber types 

Sensory fiber types: 

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Proprioceptors: Provide information about joint angle, muscle length & tension. 

• Skeletal muscles, joints tendons, ligmaents 
• Muscle spindles
• Golgi tendon organs
• Joint kinesthetic receptors 

Ia sensory fibers = Annulospiral endings, muscle spindles (found throughout skeletal muscle)

II sensory fibers = Flower-spray endings, golgi tendon organs

Only type IV sensory fibers are unmyelinated

-Gamma efferent motor fibers let the brain preset the sensitivity of the spindle to stretch.

Muscle spindles detect changing length of muscle via contractions and stretches. 

Pain, temperature, coarse touch, tickles and itches cross the spinal level. Fine touch and pressure crosses at the medullary level. 

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Glutamate binds AMPA and NMDA resulting in AP, which transmit signals to higher centers.

Lateral spinothalamic - pain and temperature (cross at spinal cord)

Ventral (anterior) spinothalamic - coarse touch, tickle or itch (cross at spinal cord)

Medial lemniscus pathway - find touch, pressure (cross at medulla) (dorsal column) 

Conscious proprioception - Communicated by posterior column-medial lemniscus pathway. 

Unconscious proprioception - Communicated by dorsal spinocerebellar tract, to the cerebellum. 

Ascending and descending tracts in the white matter of the spinal cord in cross section: 

Major Ascending pathways for somatic senses: 

Spinocerebellar - proprioception from skeletal muscle to cerebellum of same side (don't cross) 

Dorsal Column - Discriminative touch sensation through thalamus to somatosensory cortex (cross in medulla) 

Spinothalamic - Nondiscriminate sensations (pain, temp pressure) through the thalamus to the primary somatosensory cortex (cross in spinal cord before ascending) 

Some Descending pathways: 

Pyramidal tracts: 

Lateral corticospinal - cross in pyramids of medulla; voluntary motor to limb muscles 

Central corticospinal - cross at spinal cord' voluntary to axial muscles

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E = CS^2 where S = Body weight, and C = Cephalization factor, and E = brain weight

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Reflexes: 

Rooting - reaction when infant's cheek is stroked

Moro reflex - startle response in reaction to sudden intense noise or movement

Grasping reflex - obvious

Sucking reflex - obvious

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Eyes open = Beta waves

Eyes closed = alpha waves

Sulcus - Groove and line

Gyrus - Hill and bump

Central sulcus - separates frontal and parietal loves. 

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Cerebral cortex:

Supplementary motor area - Complex patterns of movement (opening or closing hand) 

Premotor cortex - Important in orienting the body and arms toward a specific target

Posterior parietal cortex - Lies posterior to primary somatosensory cortex

     -If damaged, cannot process complex sensory information to accomplish purposeful movement.

Broca's area - in frontal lobe

Wernicke's area - in temporal-parietal lobes

Circumventricular organs - Parts of the brain that lack a BBB 

Pericytes - contractile cells that wrap around the endothelial cells of capillaries throughout the body. Allow the cells to regulate capillary blood flow. 

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Membrane equilibrium for potassium = -90mV

Membrane equilibrium for sodium = +60mV

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Conduction speed of electricity through neurons is proportional to square root of the diameter. 

Increasing diameter = Increase conduction velocity 

Decrease capacitance (through myelination) = Decrease amount of energy it takes to depolarize a membrane. 

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Tests to diagnose Multiple Sclerosis include lumbar puncture, including CSF oligoclonal banding. Also an MRI scan of the spine. 

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Kinesin + Dynein = Fast axonal transport

Astrocytes take up and degrade glutamate and GABA. They also take up excess K+ from brain ECF.

Microglia release nerve growth factor which helps neurons and glial cells survive.

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NT's made from tyrosine = Dopamine, Noradrenaline, Adrenaline

NT's made from tryptophan = Serotonin, Histamine

Parkinson's disease - deficiency of dopamine

Schizophrenia - dopamine receptor abnormalities 

Norepinephrine though to be involved in etiology of bipolar affective disorders

1. Glutamate - Excitatory

• Ionotropic
• NMDA receptors (high permeability to Ca+)
• Important in learning in memory
• Neurotoxic if present in high doses for a long period of time. 
• Neurons literally stimulated to death. 
• AMPA is a non-NMDA-type ionotropic transmembrane receptor for glutamate

2. GABA - Inhibitory 

• Selectively permeable to Cl- 
• Benzodiazepines, barbiturates and alcohol augment effect. 
• Decrease GABA inhibition = epilepsy 

Neuropeptides: 

Substance P - Transmits pain. 

Neuropeptide Y - Stimulates appetite and food intake 

NO and CO activates guanyl cyclase and cGMP 

H2S is a neuroprotectant against oxidative stress. It shows cardioprotective effects.

*Nicotinic receptor = Excitatory at neuromuscular junctions with skeletal muscle

*Muscarinic receptor = Inhibitory in cardiac muscle

Ionotropic receptors: 

• Ion channels
• Nicotinic receptors
• Minimal amplification
• Rapid
• Glutamate and GABA act through these 

Metabotropic receptors: 

• G protein-coupled receptors (GPCRs)
• Muscarinic receptors
• Large amplification
• Not rapid 
• Neuropeptides and biogenic amines act through these

Nicotine is an ACh agonist (ionotropic)

Curare is an ACh antagonist, and causes paralysis (ionotropic)

Muscarine mimics ACh (muscarinic) 

Atropine blocks ACh (muscarinic) 

Two types of muscarinic receptors:

M2: heart; opens K channels to hyperpolarize 

M1: intestine; closes K channels to depolarize 

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Adrenergic receptors 

alpha-receptor response = vasoconstriction

beta-receptor response = vasodilation

Opioid receptors belong to a family of 7 transmembrane GPCRs

To get rid of ACh = acetylcholinesterase

To get rid of Norepinephrine = MAO (monoamine oxidase)

Ion channels = fast EPSP

GPCRs = slow EPSP

Presynaptic inhibition = inhibits some response

Postsynaptic inhibition = inhibits all response

Long-Term potentiation (LTP) = Activity at a synapse induces sustained changes in quality or quantity of connections . Glutamate is key element in potentiation since it's the main excitatory NT. 

Myasthenia gravis (PNS) - Severe weakness of the muscle. Functional disorder at the synapse b/w the motor neuron and skeletal muscle. 

     -Antibodies block or reduce number of nicotinic ACh receptors

Parkinson's (CNS) - Decreased stimulation of motor cortex by the basal ganglia. Insufficient formation of dopamine 

Schizophrenia (CNS) - Increased dopamine activity in mesolimbic pathway

-Benzodiazepines facilitate GABA binding 

-Agonistic action of GABA may account for the sedative-hypnotic and anesthetic properties. 

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Sympathetic Nervous System = T1-L2

Parasympathetic Nervous System  = Cranial nerves III, VII, IX, X and emerge from sacral at S2-S4

Parasympathetic = ACh

Sympathetic = Norepinephrine 

Sympathetic = Long post-ganglionic neurons, postganglions release into adrenergic receptors, however, preganglions secrete ACh

Parasympathetic = Long pre-ganglionic neurons, postganglions release ACh, preganglions secrete ACh also

ACh is made from acetyl-CoA and choline

Catecholamines are made from phenylalening and tyrosine, in that order

Reserpine is a drug that blocks the transport of dopamine into vesicles. 

Nicotinic receptors = found on postganglionic cell bodies of all autonomic ganglia. 

Muscarinic receptors = found on effector cell membranes.

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Adrenergic receptor systems

Beta 1 = heart, adipose tissue, Renin release from JG cells

Beta 2 = vascular smooth muscle, airway smooth muscle 

Muscarinic receptors - cardiac conduction system and exocrine glands and smooth muscles in PNS

     -In CNS, sweat glands

Termination of NT activity - through COMT and MAO.

Kaplan: Psychology/Sociology

Chapter 1:

• When the Lateral Hypothalamus is destroyed, one Lacks Hunger. 
• When the VentroMedial Hypothalamus is destroyed, one is Very Much Hungry.
• When the Anterior hypothalamus is destroyed, one is Asexual. 

Destruction of basal ganglia = Parkinson's Disease

Psychology/Sociology: The Biopsychosocial Model, Society and Culture

• Social Constructionism - Adds to the idea of scientific models as representations of reality.
• Symbolic Interactionism - Is related to social constructionism in that it allows for social determination of shared realities. (Small scale interactionism) 
• Functionalism - Factions of society work together to maintain stability. These are different components working together. 
• Conflict theory - Takes a different approach from functionalism by viewing society in terms of competing groups that act according to their own self-interests, rather than according to the need for societal equilibrium. 
• Culture shock - Shocking experience when faced with new cultures. 

Societies are two or more people that inhabit a place that share culture. All societies have cultures but not all cultures are societies. 

• Environmental Justice - The equal treatment of all people regardless of race, gender or other social grouping with regard to prevention and relief from environmental and health hazards--is another example of how spatial inequality acts as a system of geographical hierarchy. 

Chemistry: Organic Chemistry

Physics: Electricity

Three things to note:

1. The Electric field (E) is a general expression of force - force per unit charge - and voltage (V) is a general expression of unit energy - energy per unit charge. 
2. R ∝ L/A, C ∝ A.D. Think of resistors and capacitors in parallel as having increased width (more capacitance, less resistance) and resistors or capacitors in series as having increased length or distance (more resistance, less capacitance) 
3. Static electricity describes point charge and is like gravity. Current describes moving charge and is like fluid flow. 

Physics: Fluids

Things to note:

1. Fluids are described by density 'ρ'. The mass of a fluid is m = ρV
2. When an object is floating, masses are equal - the mass of the object equals the mass of fluid displaced. When an object is submerged, volumes are equal - the volume of the object equals the volume of fluid displaced. 
3. It's good to think of still fluids as forces in equilibrium, and moving fluids in terms of energy.
4. A fluid is a liquid or a gas.

Physics: Energy and Equilibrium

Equations: (E = Energy)

• τ = Fr(sinθ)
• KE = 1/2mv^2
• PE = mgh
• EPE = 1/2kΔx^2 (EPE = Elastic Potential Energy)
• W + q = ΔEtotal
• P = W/t
• P = ΔE/t (more generally)

Physics: Motion and Force

Equations:

• F = ma
• W = Fd, or F = W/d (Where d = displacement)
• W = Fd = ΔPE = mgΔh
• x = vt (where v = average velocity)
• v = x/t (average) (where x = displacement)
• speed = distance/time (average)
• acceleration = Δv/t (instantaneous) 
• F = G (m1 x m2)/r^2 
• fs ≤ μsFn
• fk = μkFn
• F = -kΔx

Biology: Lab Techniques

Basic laboratory techniques can be divided into three categories:

1. Separations divide mixtures into their components based on intermolecular forces and can be used for purification, identification, or collection. 
2. Spectroscopy and spectrometry provide structural information that can be used to identify compounds. 
3. Genetic techniques have many applications, including the isolation/identification of genes and the manipulation of DNA on the molecular level. 

Physiology: Respiratory System

Two Types of Respiration:

• External respiration
• Internal respiration

Anatomical order of air passage:
Nasal passages/mouth --> Pharynx --> Larynx --> Trachea --> Primary Bronchus --> Seocndary Bronchus --> Bronchiole --> Alveolus --> Alveolar Sac

Physiology: Cardiology

Systemic circulation = Circulation to and from the body

Pulmonary circulation = Circulation to and from the lungs

Atrioventricular valves:

• Tricuspid (Right side)
• Mitral (Left side) 

Semilunar Valves:

• Pulmonary Valve
• Aortic Valve

Biology: Metabolism (Biochemistry)

Carbohydrates are stored primarily in the muscle and liver as glycogen. This process is called glycogenesis. Taking carbohydrates out of storage to be broken down for energy is called glycogenolysis.

Lipids, on the other hand, go through much of the same process. Triglycerides are mainly stored in adipocytes. The chemical breakdown of a FA is called beta-oxidation.

Biology: Basic Genetics

Genetics focuses on the physical genome, or genomic nucleotide sequences of species.

Epigenetics however, is a term used to describe changes that are made around the genome that do not alter the actual nucleotide sequence. These epigenetic chemical markers and histone modifications can be passed down from one generation to the next.

Biology: Biological Molecules and Enzymes

Lipids:

The major groups of lipids include: 

1. Fatty acids (FA's) - Component of phospholipids, glycolipids, and sphingolipids of cell membranes. Composed of long chains of carbons (usually even # of carbons) with a carboxylic acid at the end, and separated into saturated and unsaturated FA's. Used for long-term energy storage. 
2. Triacylglycerols (Triglycerides) - Are also known as "fats" and "oils", which are constructed from a three carbon (hence tri) backbone called glycerol, which is attached to three FA chains. Their function is to store energy.
3. Phospholipids - Lipids with a phosphate group attached. More specifically, phosphoglycerides are exactly like triglycerides except that one of the FA's is replaced with a phosphate group. The phosphate group is polar, and the FA isn't, so this makes this molecule amphipathic. This is an integral molecule in cell membranes.
4. Glycolipids - Just like phosphoglycerides, except that one or more carbohydrates are attached to glycerol instead of the phosphate group. (Remember: Glyco = Carbohydrate) Also amphipathic. Largely found in the human nervous system. 
5. Steroids - Four-ringed structures. (Includes some hormones, vitamin D, and cholesterol)
6. Terpenes - Often part of pigments in the body. Include vitamin A, which is important for vision. 
7. Waxes - Formed by an ester linkage between a long-chain alcohol and a long-chain FA. 

Endocrinology: The Endocrine Control of Salt and Water Balance

ECFV (Extracellular Fluid Volume) = interstitial water + plasma (1/3 of the body)

Control includes the absorptive and excretory processes in the GI (waste), kidneys (urine), skin (sweat) and lungs (water vapor)

*Remember that glucose and Na+ share concentration characteristics via a symport channel.
-Water comes in through aquaporins (water channels)

Endocrinology: The Adrenal Medulla

Medullary hormones are tyrosine based, and have a DOPA precursor that turns into dopamine, and then eventually noradrenaline and adrenaline.

Endocrinology: The Adrenal Cortex

From the Medulla to the Definitive Cortex is from the innermost to the outermost.

During fetal growth throughout the first year of life, the adrenals cortices develop into two zones, which contain the larger inner fetal zone and an outer definitive zone:
     -The larger zone produces the steroid hormones - weak androgens DHEA (Dehydroepiandrosterone) and androstenedione (and ultimately the fetal Estrogen)

After birth, fetal zone goes away, and the definitive zone (called definitive because it will definitively differentiate after birth) proliferates into an outer glomerulosa and an inner fasciculata zone.
     -Also, at around one year, the innermost reticularis zone has developed.