General characteristics of central nervous system by keara

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Class Preparation #1 Essential background information: • • • Homeostasis: The basis of organism survival Positive and negative feedback regulation

General Structure of the plasma membrane: Passive membrane processes: Simple diffusion Facilitated diffusion Active membrane processes: Active transport Membrane physiology and the electrochemical gradient:

• •

Nervous System: • Resting potential and the polarized nerve tissue membrane: Ionic distribution Selective membrane permeability WHY? Nerve tissue membrane response to signal or stimuli: Depolarization to threshold Voltage dependent sodium channels Diffusion of sodium and the depolarization process Voltage dependent potassium channels Diffusion of potassium and the repolarization process • • • Stimulants, depressants, local anesthetic compounds: How do they work? Membrane threshold and the all-or-none phenomenon: Why? Stimulus strength and rate/frequency coding by neurons How does neuron response differentiate between lighter, lower intensity signals and to heavier more intense signals?



Class Preparation #2 • Nerve signal conduction: continuous vs saltatory role of myelination neuron size Relate these aforementioned characteristics to function and disease: e.g. multiple sclerosis: cause, symptoms, and treatments


Neuron-neuron junctions - synapses: structure sequence of events post-synaptic membrane potentials Impact of various drugs of synaptic functioning


Types of neurotransmitters: Relate to common disorders: e.g. Parkinson’s disease: cause, symptoms and treatments


The neuromuscular junction: structure sequence of events that lead to muscle contraction disorders at the neuromuscular junction myesthenia gravis: cause, symptoms, and treatments curare – primitive hunting drug!!!!


Class Preparation #3 General characteristics of central nervous system - protective coverings–skull, meninges (application – meningitis, encephalitis) - cerebrospinal fluid – spinal tap why????? - ventricles - choroid plexus produce CSF from cerebral circulation (carotid arteries + others), drained by arachnoid villi into venous return system - link to jugular vein. Hydrocephalus Divisions and functions of the brain sections • Brainstem – primitive brain – control of basic life support functions • cardiovascular center, respiratory center, vestibular nuclei (for balance and equilibrium–link to inner ear) • Posterior tectum (corpora quadragemina – superior/inferior colliculi – initiate head and neck reflex responses to visual and auditory signals • Diencephalon • thalamus – relays all sensory phenomena except olfaction (mamillary body) • hypothalamus – regulation of homeostasis … many examples. • pineal – secretes melatonin – sleep/wake regulator • pituitary – close to hypothalamus, control of many glands • Cerebrum lobes of cerebrum frontal – relate to motor control parietal – relate to somatic sensations temporal – relate to auditory signals occipital – relate to visual signals Basal Nuclei ……… background tone of muscle…… Parkinson’s Brain dysfunctions ….. Alzheimer’s, Cerebral Palsy, Huntington’s • Cerebellum input signals from proprioceptors ensures movements are smooth and coordinated. Effect of Alcohol on cerebellar function


Class Preparation #4 Spinal Cord • General structure of spinal cord - Enlargements - White and Gray matter • General functions of spinal cord – reflexes, asc./desc. tracts • Spinal reflexes • Components of a reflex • Vertebral curvatures • Spina Bifida • Spinal cord injury Spinal Nerves - mixed nerves - plexi brachial, lumbo-sacral Cranial nerves - olfactory, optic, vestibulocochlear, vagus Autonomic system - sympathetic and parasympathetic structural differences origins of each division Norepinephrine vs acetylcholine Neurotransmitters – chemical differences

- organ/tissue responses (fight or flight vs rest and recovery)


Class Preparation #5 Hormone Action - hormone-receptor complex.......specificity Hormone-Tissue Interaction Mechanisms - first messenger – steroid hormone activator of intracellular processes - second messenger – non-steroid hormone activator of cell processes via cyclic AMP Hormone Secretion Control 1. hormone induced hormone release: Example: hypothalamus (gonadotropin releasing hormone) ---> anterior pituitary (FSH) ------> ovary -------> estrogen 2. blood molecule concentrations Example: hyperglycemia ----> beta cells of pancreas -----> release insulin 3. direct activation by nervous system Example: sympathetic nervous system -----> adrenal medulla -----> release adrenaline (epinephrine and norepinephrine) Posterior Pituitary - no production, just secretion of 2 hormones - cervical pressure ------> oxytocin release -----> uterine muscle contraction -----> cervical pressure ------> oxytocin release -----> ……… positive water retention by feedback mechanism - antidiuretic hormone: dehydration ----> ADH ----> kidneys Anterior Pituitary - six produced and secreted 1. growth hormone -------> many effects 2. prolactin ---------> production of lactate (milk) in mammary gland 3. thyrotropin (TSH) -------> thyroid gland (t3 and t4) -----> Graves’ Disease 4.&5.gonadotropins (FSH and LH) -----> females -----> FSH -----> ovary ---> oogenesis (and estrogen production) and LH ----> ovulation (and progesterone production) males ------> FSH ----> testis ----> spermatogenesis and LH (also known as ICSH) -----> testosterone production 6. andrenocorticotropin (ACTH) -------> adrenal cortex (outer shell) glucocotrticoids -----> cortisol, cortisone,….. stress response ( glucose and fat mobilization) and anti-inflammatory hormones…….. long-term stress response Other Adrenal Cortex Hormones


1. Mineralocorticoids (aldosterone) -----> regulates mineral levels – especially sodium and potassium – via renal excretion and retention ----> also affects hydration. 2. Gonadocorticoids -------> minor amounts of sex hormones (testosterone mainly) – insufficient to have major androgenic or anabolic properties but the major source of libido for females. Adrenal Medulla Hormones Epinephrine (Adrenaline) and Norepinephrine (noradrenaline) -----> fight or flight, stress (physical/physiological and psychological) response hormone -----> affects function of many body tissues Calcium Control 1. Hypocalcemia ------> parathyroid hormone ------> from gut, retention in kidneys 2. Hypercalcemia ------> calcitonin hormone ------> skeletal tissue (osteoblasts). Glucose Control - Pancreas 1. Hypoglycemia ------> glucagon hormone ------> liver storage and 2. Hyperglycemia ------> insulin hormone ------> and skeletal muscle for energy storage, glucose release from glucose uptake into liver mobilization of fat from adipocytes lipogenesis from excess glucose calcium storage in calcium absorption calcium calcium release from skeletal tissue (osteoclasts),

and proteins and facilitates storage of fat in adipocytes Diabetes Mellitus - Type 1 Diabetes Mellitus -----> Beta cell destruction -----> requires exogenous insulin (injections) – about 5-8% of all diabetics Type 2 Diabetes Mellitus -----> body cells – especially skeletal muscle – become insulin resistant (unresponsive) – typically accompanied by poor lifestyle behaviors symptomized by overweight and obesity. Increases in physical activity often accompanied by reductions in body weight (fat) reverse this condition - >90% of all diabetics

EXAM #1 (Thur Jan. 25)


Class preparation #6 Cardiovascular System – The Blood Characteristics - Volume - Temperature - pH Viscosity

Functions - Transportation Regulation

Composition formed elements plasma hematocrit

White Blood Cells - Leukocytes - function - disorders- leukemia Red Blood Cells - Erythrocytes - structure - hemoglobin – carbon monoxide poisoning - Erythropoiesis - polycythemia - Anemia Hemostasis - blood coagulation Blood Typing - ABO and Rh factors - relationship to antibody and immune system function - erythroblastosis fetalis


Class preparation #7 Respiratory System Air conduction pathway Oral and nasal cavities ----> cleft palate/lip Pharynx Larynx Trachea ----> bronchial tree ----> alveolar ducts ---> alveoli Transformation from cartilage --------> smooth muscle Filtration, humidify, warming ------> role of mucous (cystic fibrosis), cilia

Bronchial constriction (asthma,……)

Lung Structure -------> lobes, shape Pleura -----> parietal, visceral, pleural cavity, pleurisy, atelectasis --> pneumothorax (internal - external) • Physics and breathing mechanics: Boyle’s Law ----> pressure gradients (quiet versus forced-heavy breathing), Charles’ Law Dalton’s Law -----> problems with altitude

• Pulmonary Measures -----> Static: Volumes – tidal volume, inspiratory and expiratory reserve volumes, residual volume. Capacities – vital capacity, total lung capacity ---> restrictive disorders (cancer) • Pulmonary Measures -----> Dynamic: FEV1.0 --------> Chronic Obstructive Pulmonary Disorders EXAM #2 (February 15)


Class preparation #8 Digestive System GI Tract – specialized “tube within a tube” concept Oral cavity ----> pharynx ------> esophagus Stomach -----> specialized secretions (HCl and pepsinogen) Small Intestine ----> duodenum ---> jejunum ---> ileum Large Intestine (colon) ----> cecum and appendix ----> ascending, transverse, descending, sigmoid colon ---> rectum -----> anus Functions: Move food from A -----> B Secrete specific degradation compounds (like HCl) Physically break down food particles – stomach churning Accessory Organs Oral Cavity <--------- salivary glands - Mucous and ptyalin (salivary amylase) Duodenum <--------- Pancreatic amylase, lipase, peptidase Gall Bladder <------ Bile storage (lipid emulsification) Liver <------- production of bile Movement of GI tract components: Peristalsis ……… sphincter valves (gastroesophageal, pyloric, ileocecal, internal and external anal) …… (intrinsic reflexes and chemical signals eg cholecystokinin stimulation of pancreas) Diarrhea and constipation

• Metabolism: Catabolic (degradation): Energy release and anabolic (synthesis) processes (energy storage, tissue building,…) Adenosine Tri-phosphate (ATP) ………. Energy “currency” Derived from the degradation of food derivatives (primarily glucose and fatty acids) ATP --------> Cellular work + ADP


Carbohydrate Catabolism Step One: Glycolysis Glucose (6 carbons) ---> 2 pyruvic acid (3 carbons) + 2 ATP Step Two: Krebs Cycle Pyruvic Acid ---> Lots of hydrogen + 2 ATP + CO2 Step Three: Electron Transport Chain Hydrogen + Oxygen (O2) --> Water (H2O) + 32 ATP Glycogenolysis: Degradation of hepatic glycogen (pancreatic hormone – glucagon) to increase circulating glucose under hypoglycemic conditions. Carbohydrate Anabolism Glycogenesis: Storage form of glucose (~100gm in liver – helps regulate blood glucose) (~250-300gm in skeletal muscle – used to produce energy for physical work). Gluconeogenesis: Liver produces glucose from fat or protein derivatives Lipid Catabolism Step One: Beta oxidation Fatty acid (16C) ---> acetic acids (8x2 carbons) + hydrogens Step Two: Krebs Cycle Acetic Acid ---> Lots of hydrogen + 2 ATP + CO2 Step Three: Electron Transport Chain Hydrogen + Oxygen (O2) --> Water (H2O) + 129 ATP Lipid Anabolism Lipogenesis: • Predominant form of energy storage – At 9kcals/gram 70kg person (20% body fat) = 14kg fat ---> 14,000gm x 9kcal/gm = 126,000kcals energy • Primary energy storage signal ----> insulin ---> formation of triglycerides (storage form of fat) from dietary lipids, extra glucose, and extra protein. • Dominant adipose locations – subcutaneous and visceral Protein Catabolism Only under starvation or high protein intake states … otherwise < 5% of energy from protein


Step One: Deammination Amino acid (nitrogen amine + carbon/hydrogen/oxygen skeleton) --> removal of the amine portion (ammonia + CO2 -----> urea) and use of the C-H-O portion for energy through Kreb Cycle and ETC reactions Protein Anabolism Essential (n=8) and nonessential (n=12) amino acids: • Predominant structural component of cells • Cells very possessive of a-a’s. • Excess levels ---> gluconeogenesis ---> lipids ---> storage Metabolic Rate: Basal metabolic rate ------> true resting state Resting metabolic rate ------> close to basal Exercise metabolic rate ---> related to duration & intensity of exercise Obesity: Environmental (behavioral) versus genetic cause Treatments: Diuretics……………… Diet pills (stimulants caffeine, ephedrine,…) Drugs: Sibutramine (modification of “phen fen”) CNS appetite suppression (seratonin re-uptake inhibition) Orlistat (pancreatic lipase inhibitor) Surgery: Stomach stapling, intestinal bypass, liposuction, and bilopancreatic diversion.


Class preparation #9 Renal System Kidneys – the primary filtration and reconditioning system for body fluids and the regulation of fluid balance • Kidneys: Location, protection (adipose, skeletal, muscle) Internal division (cortex, medulla <-------- pyramids, and pelvis • Collecting ducts -----> calyces ------> pelvis ------> ureter ------> to the bladder • Nephron: The functional unit of the kidney Structures: Bowman’s capsule (extensive filtration) Re absorption and active secretion sites Proximal convoluted tubule Loop of Henle Distal convoluted tubule Remaining filtrate ------> urine to bladder • What is filtered out of the blood in Bowman’s capsule? • What is reabsorbed back into the blood from the tubule and loop of Henle sections? • Characteristics of urine – what do they indicate ph specific gravity color • Abnormal components – what do they indicate protein glucose blood bilirubin


Class preparation #10
Renal System – Part II Endocrine-Renal interaction and the regulation of fluid balance • Hypothalamic osmoreceptors Hyper hydration ------> inhibit ADH release (post. pituitary) -----> increased renal filtration pressures --------> increased urine production ------> decreased body fluid levels Dehydration ------> increased ADH release ----> increased water reabsorption from post-capsule tubular system and collecting ducts production ----> enhanced water retention. Endocrine-Renal interaction and the regulation of blood pressure • Baroreceptors …………… Carotid and Aortic Bodies Hypertension -------> increased renal filtration pressures -------> increased urine production ------> decreased blood plasma levels ----> decreased blood volume -----> decreased blood pressure Hypotension ------> increased renal hormone (rennin) release ----> release of aldosterone from adrenal cortex ----> increase sodium chloride reabsorption from post-capsule tubular system ------> increased water reabsorption by osmosis from post-capsule tubular system and collecting ducts ----> decreased urine production ---> enhanced water retention -----> increased plasma/blood volume ------> increased blood pressure. Hypotension ------> increased renal hormone (rennin) release ----> activation of vasoactive plasma protein angiotensin ----> increase tonus of vascular smooth muscle (especially the arterioles and large veins) ----> vasoconstriction ----> increased blood pressure. Endocrine-Renal interaction and erythropoeisis • Oxygen pressure receptors ……… specialized renal (juxtaglomerular) cells Hypoxia (reduced oxygenation of blood) -----> erythropoeitin release ------> bone marrow ---> increased red blood cell production ---> increased oxygen carrying capacity of the blood -----> return to normal blood oxygenation levels Hyperoxia ------> elevated oxygenation of blood) -----> inhibition of erythropoeitin release ------> bone marrow ---> decreased red blood cell production ---> decreased oxygen carrying capacity of the blood -----> return to normal blood oxygenation levels ------> decreased urine


Learning Guide #11 Reproductive System: Functions: • To produce gametes (spermatogenesis, oogenesis) • To deliver gametes to appropriate location for fertilization (tubular systems) • To house gamete-gamete combination during development (uterus) • To produce and secrete hormones that result in maturation and development of secondary sex characteristics (testosterone, estrogen, progesterone) Male Anatomy: Scrotum --------> house testes ------> very important for temperature regulation (3oC lower than core temperature ~34oC …. surface area (tonus of skin) and proximity to pelvis (cremaster muscle derived from abdominal wall muscle) -----> essential for generation of viable sperm. Testes – sperm production, the duct system and accessory glands for delivery of sperm • Produce and secrete spermatids (spermatogenesis – millions per day – 23 chromosomes/sperm) <-------- FSH from anterior pituitary. • Seminiferous tubules produce immature sperm -----> spend about 20 days moving through epididymis where they mature and gain motility)----> vas (ductus) deferens (part of spermatic cord) -----> through inguinal rings into pelvic cavity. • Fluid input from seminal vesicles (nutrient laden – fructose, vit. C, alkaline pH ….) ---------> ejaculatory duct --------> prostatic urethra -----> (additional fluid input from prostate gland) -------> alkaline input from bulbourethral gland to neutralize slightly acidic urethral environment -----> through spongy urethra -----> ejected. • Interstitial cells of Leydig produce and secrete testosterone (into blood) <-------------LH from anterior pituitary. Penis: • Erectile tissue (corpora cavernosa and corpus spongiosum) – highly vascular… entrapment of blood … glans (head) and prepuce (foreskin) – circumcision practice. • Viagra, Maxium, Cialis – facilitates vasodilation and engorgement of erectile tissue with blood by interfering with enzymatic function of smooth muscle.


Learning Guide #12 Reproductive System – Part II: Functions: • To produce gametes (spermatogenesis, oogenesis) • To deliver gametes to appropriate location for fertilization (tubular system: vagina, cervix, uterus, and uterine (fallopian) tubes) • To house gamete-gamete combination during development (uterus) • To produce and secrete hormones that result in maturation and development of secondary sex characteristics (testosterone, estrogen, progesterone) Female Anatomy: Ovary: • Produce gamete (mature ovum – 23 chromosomes) (oogenesis is the process). • Three distinct phases (See fig. 16-12): follicular (follicle maturation) ----> relate to FSH from anterior pituitary, ovulatory (ovulation process – release of ovum from ovary) -------> relate to LH release from anterior pituitary), and luteal (related to corpus luteum – scar body remaining on ovary after ovarian rupture). The duct system for fertilization • Uterine (fallopian) tube -----> site for fertilization --------> no direct communication with ovary ------> fimbriae generate wave-like motions attract ovum to tube opening -------> moves slowly down tube by peristalsis. • Vagina: entry for penis and seminal fluid ………… birth canal for developed fetus ……………… pathway for endometrial lining. • Pelvic Inflammatory Disease (PID) – continuous pathway from vaginal opening through uterus ------> fallopian tube (may cause narrowing-scarring-blockage of tubes) ------> into pelvic cavity Implantation and sustaining of fertilized ovum • Uterus: peri, myo, and endometrium. Myometrium – responsive to posterior pituitary hormone oxytocin. Endometrium: highly vascular and mucous laden ………. Necessary environment for survival of fetus …… removes after ~28 days if implantation does not occur. • Cervical portion ……. Pap smear …………cervical dilation indication of imminent birth. External genitalia • Labia majora and minora ……… vestibular glands • Clitoris ……… body ……… glans …….prepuce (hood) Exam #3 (As per final exam schedule)

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