Exam 1 Flashcards
Components of cytoskeleton
Microtubules, Microfilaments, Intermediate filaments
Microtubules
Largest cytoskeletal component --> Cell shape Transport of secretory vesicles Rigidity of cilia and flagella Mitotic spindle
Kinesin
Proximal –> Distal
Dynein
Distal –> Proximal
Microfilaments
Smallest cytoskeletal element
Actin and myosin (contractile)
Enhance cell structure and stability
Myofibroblasts
Contain actin, important in wound closure
Intermediate Filaments
Cytoskeletal component that provides resistance to externally applied cell stress (e.g. shear)
e.g. Neurofilaments, keratin
Cytoplasm
Everything inside cell except nucleus
Cytosol
Liquid portion filling cell (mostly H2O)
Endoplasmic Reticulum function
Protein and lipid production
Rough ER
Synthesizes proteins for secretion and internal membrane support
Synthesizes lipids for new membranes
Free ribosomes of ER (within cytosol)
Produce proteins for internal cell use only
Smooth ER
“Packaging and discharge” - forms buds that are sent to Golgi
Transports proteins
Synthesizes lipid hormones
Detoxification
Golgi
Receives and sends out vesicles
Raw materials processed into finished product
Sorts finished product to final destination
Lysosomes
Sacs of hydrolytic enzymes
Paired with phagocytosis
Peroxisomes
Contain oxidative enzymes –> H202
Also contain catalase to break down H202
Vaults
Transporters from nucleus –> cytoplasm?
Possibly sequester CA drugs, rendering them ineffective
Components of Plasma Membrane
Lipids (phospholipids and cholesterol), proteins, CHO
CHO in plasma membrane
Markers of cell ID, allows like cells to find each other
Only on outer membrane, anchored to proteins or lipids
Components of Extracellular Matrix
Collagen, elastin, fibronectin
ECM disorders
Emphysema: Elastin destruction
Ehlers-Danlos: Collagen dz
Desmosomes
Hold cells together, found in tissues subject to stress
Tight junctions
Block passage between cells
e.g. blood brain barrier
Gap Junctions
Facilitate passage between cells
e.g. cardiac cells
Osmotic pressure
Pulls H2O into cell
AKA oncotic, colloid pressure
Hydrostatic pressure
Pushes H2O out of cell
3 properties of receptors
Specificity
Competition
Saturation
Cholesterol function in membrane
Provides stability of membrane while allowing pliability
Extracellular Matrix function
Structural connection from cell to cell
Immediate energy sources
ATP–>ADP + Pi
ADP +Creatine phosphate
Adenylate kinase system
^Small quantities readily available in cytoplasm
Intermediate energy source
Glycolysis
glucose –> 2 ATP + 2 pyruvate
Long term energy source
Oxidative Metabolism
Uses byproducts from glycolysis
What drives source of ATP?
Intensity of activity
Glycolysis
Breakdown of 6C chain to 2, 3C chains
Directly –> 2 ATP
Produces byproducts (NADH and pyruvate) used in oxidative metabolism
Pyruvate –> lactate in anaerobic condition
NADH
“energy escort” - escorts H to MT for oxidative metabolism
Anaerobic: NADH degraded
Oxidative Metabolism
Permits metabolism of CHO, proteins, and fats
Oxidation of pyruvate through Krebs/TCA cycle
–> 15 ATP per pyruvate (30 total)
–> 12/ 2 C unit of lipid
Steps of Oxidative Metabolism
3C pyruvate –> 2C acetic acid
Acetic acid + CoA –> Acetyl CoA
Acetyl CoA–> MT –> 15 ATP
Lipid (Fat) Metabolism
Must be oxidative
Begins at site of fat
Costs 2 ATP to raise energy level of fatty acid to enter MT
—> Large quantities of ATP
Review Steps of Lipid Metabolism
There are 7
“Mobilization” Step of Lipid metabolism
Breakdown of lipid to FFA
Inhibited by increased insulin, blood glucose levels
Stimulated by degreased blood glucose, increased sympathetic stimulation
Carnitine
Transports energized fatty acid into MT
Beta oxidation
Breaking off 2C units from fatty acid to enter Krebs cycle
Each cleavage of 2C unit –> 5 ATP
CHO vs. lipid metabolism
CHO produces ATP more quickly and can produce ATP anaerobically. Lipids produce more ATP
Lipid vs. CHO metabolism at low intensity
60% lipid, 40% CHO
Lipid vs. CHO metabolism at moderate intensity
50/50%
Lipid vs. CHO metabolism at around 65%
CHO becomes primary source of energy
“Off Label” Prescriptions
Prescriptions for drug for use other than it’s approved purpose
Threshold dose
Smallest dose that will elicit a response
Plateau/ Ceiling effect/ Maximal efficacy
Further increase in dose will not increase response
Potency
A more potent drug requires a lower dose to produce the same effect
Median effective dose (ED50)
Dose at which 50% of population responds to drug in specified manner
Median toxic dose (TD50)
Dose at which 50% of population exhibits adverse effects
Therapeutic Index
Assesses relative safety of drug
TI = TD50/ED50
Larger TI = Safer drug
Pharmacokinetics
What the body does to the drug
Pharmacodynamics
What the drug does to the body
Enteral Administration
Oral, Sublingual, Buccal, Rectal
Oral: First pass effect
Rectal: Poor absorption
Parenteral
Inhalation, Injection, Topical, Transdermal
Topical: Poor absorption - local treatment
Transdermal: High absorption
Bioavailability
% of administered amount of drug that reaches blood stream
Storage of drugs
Fat (primary source b/c many drugs are lipid soluble)
Muscle
Bone
Organs (liver, kidney)
Biotransformation
Drug changed to inactive or less active metabolite while still in body
Excretion of drugs
Primarily lungs, also GI tract
1 factor affecting response and metabolism of drug
Genetics
3 Types of extracellular receptors for drugs
Channels, enzyme linked, G-protein linked
Agonist vs. Antagonist
Agonist binds and –> Change (Has affinity and efficacy)
Antagonist binds and –> NO change (Has affinity and no efficacy)
Competitive Antagonist
Has equal affinity to receptor as agonist, binding is reversible
–> Whichever compound is in higher concentration will rule
Noncompetitive antagonist
Forms a strong permanent bond to receptor (for life of receptor protein)
Increasing levels of agonist does not displace antagonist
Receptor desensitization
Temporary period of decreased receptor responsiveness
Temporary decrease in functional receptors
Receptor downregulation
Prolonged, permanent decrease in number of receptors, decrease in responsiveness
Only reversed when receptor is replaced
Receptor Supersensitivity
Increased receptor sensitivity following decreased stimulation
Lipophilic hormones
Bind directly to target cell nucleus to influence production of new proteins
Circulate in blood bound to proteins
Lipophobic hormones
Bind to surface membrane to activate 2nd messenger systems and affect activity of existing proteins
Circulate freely in plasma
Tropic glands
Glands that regulate other endocrine glands
Anterior Pituitary
Glandular tissue
Linked to hypothalamus via vascular pathway
Produces and secretes 6 hormones
Posterior Pituitary
Neural tissue
Linked to hypothalamus via neural pathway
Stores and releases 2 hormones (vasopressin and oxytocin) - these are produced in hypothalamus
Vasopressin
AKA ADH
Increases H2O retention; BP regulation
Oxytocin
Uterine contractions, milk ejections
Hypothalamus
Endocrine and ANS control center
Follicular cells form follicle enclosing:
Colloid - mostly thyroglobulin (Tg)
Parafollicular cells produce
Calcitonin
T4 vs. T3
T4 is the most commonly secreted
T3 is the most biologically active
Thyroid hormone functions
Regulation of Metabolism
Sympathomimetic (increases responses to catecholamines)
Adrenal cortex produces
Steroids (Mineralocorticoids, glucocorticoids, sex hormones)
Main mineralocorticoid
Aldosterone - Na retention
Main Glucocoricoid
Cortisol - Increases blood glucose; anti inflammatory and immunosuppresive
Adrenal medulla produces
Catecholamines
*Primarily epinephrine
Catecholamine receptors
alpha and beta ONE: excitation
alpha and beta TWO: inhibition
Hypercalcemia –>
Decreased excitability
Hypocalcemia –>
Increased excitability
Parathyroid hormone
Increases plasma Ca (from bone)
Calcitonin
Movement of Ca from bone into blood
Vitamin D
Facilitates absorption of Ca in intestine
Insulin
Beta cells of pancreas
Promotes uptake and storage of glucose by cells
Stimulated by increased BG
Glucagon
Alpha cells of pancreas
Promotes release of stored glucose and gluconeogenesis
Stimulated by decreased BG
Catecholamines
Promote glycolysis and lypolysis
Shunt blood away from non-working tissue
Cortisol function re: glucoregulation
Stimulates breakdown of protein and works with catecholamines to shunt blood
GH is a cortisol antagonist
Goal vs. diabetes Fasting Plasma glucose values
Goal: 110
Diabetes: 126+
Normal vs. Diabetes HbA1c values
Normal: 3-6%
Diabetes: >6%
DM Type I treatment
Exogenous insulin, diet
DM Type II treatment
Exercise, diet, medications (not necessarily insulin)
Greatest risk for exercise induced hypoglycemia (time):
6-14 hrs p exercise.
Large risk for Type I, some risk for Type II
Hyperpituitarism
Gigantism, Acromegaly
Hypopituitarism
Dwarfism
Hyperthyroidism conditions
Graves disease (most common hyper condition - increased T4), thyrotoxicosis (increased TH), thyroid storm (Acute episode)
Hyperthyroidism symptoms
Increased basal metabolism, increased sympathetic action, lipid depletion, nutritional deficiency, goiter, exopthalmus
Thyroid storm: fever, dehydration, delusion
How is hyperthyroidism diagnosed?
Decreased TSH levels
Hyperthyroidism treatment
Antithyroid meds
Radioactive iodine to induce hypothyroidism
Thyroidectomy
Hypothyroidism
*most common thyroid disorder
Decreased basal metabolism –> fatigue, myxedema, bradycardia, decreased mental function
Hypothyroidism causes
Autoimmune, iatrogenic
Hypothyroidism diagnosis
T4 levels gradually decrease
TSH levels increased
Hypothyroidism treatment
Exogenous thyroid hormone replacement
Hyperparathyroidism
Hypercalcemia, bone demineralization, kidney stones
Increased fracture risk
Hyperparathyroidism diagnosis
Increased PTH levels and Ca serum levels.
Skeletal damage per X-ray
Hyperparathyroidism treatment
Parathyroidectomy
Meds to inhibit Ca release from bone
Hypoparathyroidism
Decreased serum calcium levels
Increased neuromuscular irritability (can –> tetany)
Increased serum phosphate levels
Calcifications
Hypoparathyroidism treatment
Acute tetany: Ca IV
Chronic: Medications
Calcifications irreversible
Adrenal Insufficiency AKA:
Addison’s Disease
Gender tendencies for diseases:
Addisons: = men and women
Thyroid, parathyroid: more common in women
Non-iatrogenic Cushings: more common in women
Addison’s symptoms
Decreased cortisol –> weakness, hypotension, fatigue, weight loss, N/V, tan appearance, hypoglycemia b/c of decreased gluconeogenesis
Decreased aldosterone –> Dehydration, hypotension, decreased cardiac output
Addison’s diagnosis
Decreased ACTH, positive response to ACTH treatment
Adrenal Hyperfunction AKA:
Cushing’s disease
Cushing’s
Excess cortisol–> weakening of protein structures, hyperglycemia, abnormal fat distribution, proximal muscle weakness (steroid induced myopathy),