IMPORTANT TOPICS
Itch
-Conditions: Dry skin, atopic dermatitis, and various systemic disorders.
-Itch and pain come from different receptors, but travel anterior/lateral spinothalmic tract
-Response: Stimulation of stimulated area
Referred pain
-Pain felt in an area distant from the injured sight.
-Ex: jaw pain in a heart attack, or back pain with pancreatic injury.
Phantom Limb
-Sensations that appear in areas of missing limbs post amputation
-Pain in the amputated limb, localized to distal part of phantom limb.
Vestibular apparatus
-The sensory apparatus in the inner ear that helps body maintain its equallibrium and postural
control.
-provides sensory info with head movements. Sends info to CNS regarding head and body
orientation.
-Peripheral VA includes Cochlea, Vestibule(Utricle/Saccule), 3 semicircular canals, connections to the
MEDULLA and PONS with cranial nerve VII
-Bony Labrynth: Cochlea/Vestibule/SCC (contains perilymph)
-Semicircular Canals: Detects ANGULAR acceleration
hearing apparatus
-Outer Ear: Auricle(pinna) Made from Helix and Lobule
-Sound waves move down auditory canal of outer ear.
-Sound waves strike tympanic membrane (Drum) causing vibration
-transmitted across the 3 tiny bones (Malleus/Incus/Stapes-Middle ear-Filled with air connected to
outside by eustachian tube. -Cochlea-Snail shell/Contains endolymph/contains cochlear duct/Organ
of corti(thousands of hair cells(vibration receptors)
Structure of Ear
 -External or outer ear, consisting of: Pinna or auricle. This is the outside part of the ear. ...

Tympanic membrane (eardrum). The tympanic membrane divides the external ear from the middle
ear.

Middle ear (tympanic cavity), consisting of: Ossicles/Malleus/Incus/Stapes/Oval/Round windows
Eustachian tube

Inner ear, consisting of: Cochlea/cochlear duct/Organ of corti
Structure of Eye
-Sclera: White of eye/dense connective tissue/adds shape and protects
-Cornea: Anterior most portion of sclera/cloudy appearance/First portion to receive light.
-Optic Nerve: Cranial Nerve II/ Carries info regarding visual stimuli to occipital lobe.
-Lens: hard and opaque/Shape of Lens determines where light will be focused on retina.
Suspensory Ligament: attaches lens to ciliary body.
Iris: gives the eye color
Pupil- Black circle in center of iris/light regulation to retina
Retina: Contains photoreceptors necessary for vision.
Aqueous Humor- Anterior cavity of eye (Glaucoma – Blockage-intraocular pressure)
Vitreous Humor – Thick/Gel-like/Posterior cavity behind lens/maintains retina
Choroid – Black/supplies outer retina nutritionally/maintains temp./space between lens and cornea/Filled
with AHumor.
Glaucoma-Damage to optic nerve due to pressure due to intraocular pressure of aqueous humor. Blind spots.
Visual Abnormalities : Myopia-Nearsightedness(cant see far) Rays focus in front retina/ Hypermetropia Far
sightedness Rays focus behind retina( Cant see close) Presbyopia-Farsightedness caused by loss of elasticity
in lens/happens with age and AstigmatismCornea not cylindrical/shaped like football/overall blurry vision
Function of circulatory system-Blood transported through the body delivering nutrients and oxygen
Consists of Heart/Lungs/Arteries/Veins/vessels
Arteries: Carries oxygenated blood away from heart(except pulmonary artery)
Veins: carries deoxygenated blood to the heart (except Pulmonary Vein)
Coronary circulation: flow of blood to heart through tissues
Systemic circulation: (largest part of circ. System- Oxygen rich blood por vided to the organs and tissues
except heart and lungs)
Capillaries- Links arteries and veins/1 cell thick to allow easy gas exchange.
Vagus Nerve- Cranial Nerve X/Main Functions: Digestion/HR/RR/Swallowing/Vomiting
Stomach-Stores food/ digestive proteins/delivers partially digested foods into small intestine/Hydrochloric
acid &pepsinogen(chief cells)/ Mucus protects lining/
B -B lymphocyte- Humoral immunity/ responsible for mediating the production of antigen-specific
immunoglobulin (Ig) directed against invasive pathogens
T Cells: Helper T Cells CD4: help activities of OTHER immune cells/ Cytotoxic Killer T Cells CD8 : Destroy
host cells that harbour foreign cells. Cell Mediated Immunity/ Memory T cells
Peptic Ulcers-common cause is H-Pylori/destroys chief/parietal cells/open sores inside lining of stomach
Parts of GI System: Mouth-break down carbs/Pharynx/Esophagus/stomach break down protein/small
intestine/lrg intestine/rectum/anus
Cirrhosis-Late stage scarring of liver(hepatitis/Alcoholism),
Cholecystitis-inflammation of the gall bladder/Bile gets traps in gallbladder,
Hepatitis-inflammation of the liver(medications and alcohol), Jaundice-High levels of bilirubin/yellowskin
Motility processes in GI system (
peristalsis-the involuntary constriction and relaxation of the muscles of the intestine or another canal,
creating wave-like movements that push the contents of the canal forward.
mastication-Food is crushed and mixed with saliva (salivary amylase to form the bolus for swallowing. ,
ingestion-swallowing or absorbing liquids or solids into the body, deglutition-the act or process of
swallowing.
Segmentation- alternating contractions and relaxation in non adjacent segments of the intestine that move
food back n forth, then breaking apart and miing with juices.
FSH and LH-Males: FSH stimulates the cells of the seminiferous tubules to produce sperm. LH stimulates the
interstitial cells of the testes to produce androgens. Androgens exert negative feedback on the production of
GnRH, FSH, and LH. ... In human males, these feedback loops keep androgen levels relatively stable. Females
The ratio of LH to FSH secretion rises as the frequency of pulsatile GnRH release increases during the late
follicular phase of the normal menstrual cycle. Increased LH secretion stimulates estrogen production from
the ovary which through positive feedback leads to the midcycle LH surge that causes ovulation.
Estrogen-The positive feedback effect of estrogen is the mechanism by which the GnRH cells of the brain
and the pituitary gonadotropes produce surges in the secretion of GnRH and gonadotropins,
respectively, that lead to ovulation.
Testosterone: The feedback loop that controls testosterone production begins with the hypothalamus
and the secretion of GnRH. ... The LH then causes the Leydig cells to produce testosterone. Some of the
testosterone enters the seminiferous tubules to control germ cell (sperm) development.
Cortisol(Steroid) -Adrenal Cortex/zona fasciculata/reticularis/needs cholesterol from liver/ increases
plasma glucose and other metabolites and ACTH The hypothalamus produces CRH which causes the anterior
pituitary to produce ACTH, which results in the adrenal cortex to increase cortisol (as well as aldosterone).
ACTH binds to the receptor and then stimulates a G-protein cascade which triggers the synthesis of cortisol
Acromegaly-a rare condition associated with a tumor where the body produces too much growth hormone
causing tissues and width of bones to grow more quickly. Leads to enlarged hands and face,
Gigantism-Excessive size and stature caused by hypersecretion of HGH
Myxedema-A skin and tissue disorder usually due to severe prolonged hypothyroidism/An accumulation of
hydrophilic mucopolysaccharide substance in the connective tissues throught the body,especially lower legs,
Oxytocin -promotes contraction of myometrium & myoepithelial cells surrounding mammary acinar
cells/involve(s) IP3 2nd messenger system (but not cAMP)
ADH(antidiuretic) -Vasopressant/increases permeability of MCD to urea/vasoconstriction/involve(s) both
cAMP and IP3 2nd messenger systems/plasma osmolality, Blood Volume,angiotensin 2 regulate ADH
secretion/osmoreceptors involved with secretion/an increase in plasma [angiotensin II] promotes increase
ADH secretion
ADH+OXYTOCIN not bound to plasma protein/synthesized in different neurons in the
hypothalamus/Hormone/dendrite transport/releasedin response to action potential/
Enterohepatic Circulation and Urobilinogen - refers to the process whereby a drug or a metastable
metabolite thereof in the liver is secreted into the bile, stored in the gall bladder, and subsequently
released into the small intestine, where the drug can be reabsorbed back into circulation and subsequently
returned to the liver/bilirubin-non water soluble breakdown from heme/small intestine change bilirubin to
urobilinogen by bacteria in small intestines/20% of urobilinogen not absorbed in sm. Intestine/ if not
absorbed changed to sercobilin.
Pheochromocytoma- is a rare tumor of adrenal gland tissue. It results in the release of too much
epinephrine and norepinephrine, hormones that control heart rate, metabolism, and blood
pressure/headache/profuse sweating(diaphoresis/Tachycardia/altered
Functions of Exogenous Glucocorticoids- are essential to life. They control electrolyte and fluid
homeostasis, systemic fuel metabolism, the immune system and the stress responses. These actions are
mediated through activation of glucocorticoid receptor (GR) within target tissues. Related to Cushings
syndrome.
Hyperthyroidism - AKA thyrotoxicosis. Clinical syndrome where the tissues are exposed to high levels of
thyroid hormone. More common in women (3 in 1,000 women occurrence)/Grave’s Disease/Thyroid stormA life-threatening sudden exacerbation of hyperthyroidism. Sx: fever, tachycardia, delirium, and
coma/amiodarone + iodine can cause HT/ elevated T3-T4 can diagnose
Hypothyroidism - A condition in which the thyroid gland doesn't produce enough thyroid hormone ---->
slow metabolic rate -Primary: Destruction of thyroid tissue or decreased hormone synthesis (increased TSH)
-Secondary: Pituitary/Hypothalamic dysfunction (decreased TSH or TRH)/More common in woman over
60/caused by Atrophy of the thyroid gland, which is usually the end results of Hashimotos thyroiditis or
Graves disease/signs:fatigue/weakness/bradycardia/weightgain/hair loss/cold intolerance
Thyroid hormone-Made by tyrosine/Regulated by TRH&TSH/ TRH is secreted by neurons in hypothalamus
which is inhibited by T3/ TRH binds to cell surface receptors, which causes increased Ca2+ levels which
leads to exocytosis of TSH and increased synthesis of TSH/stimulates TSH release in anterior pituitary. -- Colloid found on apical surface/calcitonin secreted/
Circadian Rhythm- biological rhythm and lasts about 24 hours. It is mostly referring to the sleep/wake cycle
and the body-temperature cycle. The master clock is directly influenced by environmental cues, especially
light, which is why circadian rhythms are tied to the cycle of day and night.
Phagocytic cells macrophages, neutrophils are most common, monocytes, tissue dendritic cells, and
mast cells.
acrosome – membranous enzyme cap that helps sperm penetrate the egg/flagellate spermatazoa
Respiratory Distress Syndrome – ARDS -Fluid builds up in the tiny elastic air sacs. RDS-Immature
development respiratory tract Inadequate amount surfactant often in babies.
Obstructive-COPD/Bronchitis/Asthma and Restrictive Lung -pulmonary fibrosis/chest wall
constriction. Disease tests- Obstructive Spirometry is a common office test used to evaluate how well
your lungs function by measuring how much air you inhale and how much/how quickly you exhale. It can be
very helpful in differentiating obstructive and restrictive lung diseases, as well as determining the severity of
these diseases. Restrictive: Doctors will order a pulmonary function test.
Micturition- process by which a urine-filled, distended bladder is sensed followed by the relaxation of
sphincters and the contraction of the bladder resulting in the expulsion of urine/controlled by sacral spinal
cord/pelvic & pudendal nerves/parasympathetic, sympathetic, and somatic pathways/lower tract=bladder &
urethra/muscles: detrusor, internal (smooth muscle) & external urethral sphincter(skeletal muscle), stretch
receptors-> pelvic>spinal cord/
Insulin -secreted by pancreatic langerhanscells/ regulates carb/lipid/protein metabolism/allows glucose to
enter the cell and be used as energy/maintains glucose in blood stream within normal levels/through the
tyrosine-kinase receptor pathway.
Glucagon- protein secreted by the alpha cells of the pancreas. When released, glucagon results in blood
glucose elevation by increasing the breakdown of glycogen to glucose (glycogenolysis) and stimulating
glucose synthesis (gluconeogenesis)
GI motility
Peristalsis(mechanical digestion)- the involuntary wave-like constriction and relaxation of the muscles of
the intestine or another canal, creating wave-like movements that push the contents of the canal
forward/happens in esophagus/stomach/Sm. & LRG intestines/ Musclularis externa
Segmentation- alternating contractions and relaxation in non adjacent segments of the intestine that move
food back n forth, then breaking apart and mixing with juices making homogenous mixture.
GI Sphincters: Circular/limit movement of food from one to other/tonic contractions keep closed/UES
skeletal muscle/LES=stomach and esophagus/swallowing is voluntary(buccal) and involuntary(pharynxUES
and esophageal LES)/
GERD- retrograde movement of gastric contents from the stomach into the esophagus
FUNDUS-food storage
Starling Forces -fluid movement due to filtration across the wall of a capillary is dependent on the balance
between the hydrostatic pressure gradient and the oncotic pressure gradient across the capillary.
***Glomerular capillaries are are more permeable to water
hydrostatic pressure in the capillary
hydrostatic pressure in the interstitium
Hydrostatic pressure refers to physical force of fluids behind their barrier
oncotic pressure in the capillary
oncotic pressure in the interstitium
osmotic pressure generated by the presence of proteinaceous solutes. Because plasma proteins cannot cross
the capillary barrier, these osmotically-active solutes are at higher concentration in the plasma than in the
interstitial fluid.
Fluid absorption
PCTIn the lumen of the PCT, HCO3– combines with hydrogen ions to form carbonic acid (H2CO3). This
is enzymatically catalyzed into CO2 and water, which diffuse across the apical membrane into the cell.
Water can move osmotically across the lipid bilayer membrane due to the presence of aquaporin water
channels.
In PCT, reabsorption involves absorbing ions, molecules, and water into the peritubular capillary that are
required for homeostasis to be preserved by the body. Henley's ascending loop consumes the remaining
necessary electrolytes, allowing the urine concentration to be hypotonic.
DCT- The hormone aldosterone increases the amount of Na+/K+ ATPase in the basal membrane of the distal
convoluted tubule and collecting duct. ... In addition, as Na+ is pumped out of the cell, the resulting
electrochemical gradient attracts Ca2+ into the cell.
90% of sodium has been absorbed/100% K absorbed/ Principal cells/Aldosterone
Role of ADH- ADH regulates the permeability of water in the distal tubule and collecting duct. it acts to
increase Aquaporin 2 insert on the apical membrane of distal tubule and collecting duct, allow water to be
reabsorbed from the renal tubule.
1.acts on the kidney:
-increases the water reabsorption from the DCT and collecting ducts
-increases plasma volume
2.acts to constrict blood vessels:
-increases peripheral vascular resistance
-increases arterial blood pressure
Reabsorption of Glucose in kidneys
Glucose is a polar molecule and dissolves in water and blood plasma. It easily passes through the glomerular
basement membrane. It is almost completely reabsorbed from the tubules by active transport molecules
found in the proximal convoluted tubule (PCT) called sodium-coupled glucose cotransporters
RAAS system
The renin (An enzyme that is synthesized, stored, and secreted by juxtaglomerular (JG) cells in the kidney)
angiotensin aldosterone system is a series of reactions designed to help regulate blood pressure.
1)When blood pressure falls (for systolic, to 100 mm Hg or lower), the kidneys release the enzyme renin into
the bloodstream.
2)Renin splits angiotensinogen, a large protein secreted from the liver that circulates in the bloodstream into
pieces. One piece is angiotensin I.
3) Angiotensin I, which is relatively inactive, is split into pieces by angiotensin converting enzyme (ACE),
found in high levels in the lung. One piece is angiotensin II, which is very active.
4) Angiotensin II, a hormone, causes the muscular walls of small arteries (arterioles) to constrict, increasing
BP.
5) Angiotensin II also triggers the release of the hormone aldosterone from the adrenal glands.
6) Aldosterone causes the kidneys to retain salt (sodium) and excrete potassium. The sodium causes water
to be retained, thus increasing blood volume and blood pressure