By A. Mannig. Colorado State - Pueblo. 2018.
Thymus gland—secretes thymosin buy loratadine 10mg, which aids in develop- 2 purchase loratadine 10 mg amex. Controlled by environmental light tex of adrenal gland d purchase loratadine 10mg free shipping. Stomach and small intestine—secrete hormones that regu- e purchase 10 mg loratadine overnight delivery. Follicle-stimulating hormone (FSH)—acts on gonads late digestion f. Kidneys—secrete erythropoietin, which increases produc- 3. Brain—releasing and inhibiting hormones, ADH, oxytocin tion of water in the kidneys 1. Atria of heart—ANP causes loss of sodium by kidney b. Oxytocin—stimulates uterine contractions and lowers blood pressure 4. Pituitary tumors—may cause underactivity or overactiv- 2. Placenta—secretes hormones that maintain pregnancy ity of pituitary and prepare breasts for lactation B. Thyroid gland (1) Prostaglandins—other cells throughout body 1. Hormones produce prostaglandins, which have varied a. Thyroxine (T4) and triiodothyronine (T3) increase effects 12 metabolic rate b. Growth hormone—treatment of deficiency in children, in a. Goiter—enlarged thyroid elderly for bone strength and body mass b. Insulin—treatment of diabetes mellitus (cretinism) or myxedema C. Steroids—reduction of inflammation, suppression of c. Epinephrine—treatment of asthma, anaphylaxis, shock thyroiditis E. Parathyroid glands—secrete parathyroid hormone (PTH), G. Androgens—promote healing which increases blood calcium levels H. Estrogen and progesterone—contraception, symptoms of D. Epinephrine and norepinephrine—act as neurotrans- V. Body’s response to stress involves nervous and endocrine 2. Hormones of adrenal cortex (outer region) systems, hormones a. Glucocorticoids—released during stress to raise nu- B. Fight-or-flight response mediated by brain: hypothalamus, trients in blood; e. Hormones help body, meet stressful situations; can be balance; e.
Structure of the Plasma Membrane accounts for their presence in slightly basic seawater and shellfish discount loratadine 10mg. All mammalian cells are enclosed by a plasma membrane composed of a lipid bilayer (two layers) containing embedded proteins (Fig order 10 mg loratadine free shipping. The membranes The variable carbohydrate compo- are continuous and sealed so that the hydrophobic lipid bilayer selectively nents of the glycolipids on the cell restricts the exchange of polar compounds between the external fluid and the surface function as cell recognition intracellular compartment order loratadine 10mg with amex. The membrane is referred to as a fluid mosaic markers order 10mg loratadine visa. For example, the A, B, or O blood because it consists of a mosaic of proteins and lipid molecules that can, for the groups are determined by the carbohydrate most part, move laterally in the plane of the membrane. The proteins are classi- composition of the glycolipids. Cell surface fied as integral proteins, which span the cell membrane, or peripheral proteins, glycolipids may also serve as binding sites which are attached to the membrane surface through electrostatic bonds to lipids for viruses and bacterial toxins before pene- or integral proteins. Many of the proteins and lipids on the external leaflet con- trating the cell. For example, the cholera AB tain covalently bound carbohydrate chains and therefore are glycoproteins and toxin binds to GM1-gangliosides on the sur- glycolipids. This layer of carbohydrate on the outer surface of the cell is called face of the intestinal epithelial cells. The toxin is then endocytosed in caveolae the glycocalyx. LIPIDS IN THE PLASMA MEMBRANE Each layer of the plasma membrane lipid bilayer is formed primarily by phos- One of the bacterial toxins secreted pholipids, which are arranged with their hydrophilic head groups facing the aque- by Clostridium perefringens, the ous medium and their fatty acyl tails forming a hydrophobic membrane core (see bacteria that cause gas gangrene, Fig. The principle phospholipids in the membrane are the glycerol lipids is a lipase that hydrolyzes phosphocholine phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine and the from phosphatidylcholine and from sphin- sphingolipid sphingomyelin (Fig. The resulting lysis of the cell ferent cell types, with phosphatidylcholine being the major plasma membrane lipid membrane releases intracellular contents in most cell types and sphingolipids the most variable. These bacteria are strict anaer- The lipid composition of the bilayer is asymmetric, with a higher content of phos- obes and grow only in the absence of oxy- phatidylcholine and sphingomyelin in the outer leaflet and a higher content of phos- gen. As their toxins lyse membranes in the phatidylserine and phosphatidylethanolamine in the inner leaflet. Phosphatidylserine endothelial cells of blood vessels, the capil- contains a net negative charge that contributes to the membrane potential and might be laries are destroyed, and the bacteria are important for binding positively charged molecules within the cell. Phosphatidylinosi- protected from oxygen transported by the tol, which is found only in the inner membrane, functions in the transfer of informa- red blood cells. They are also protected from tion from hormones and neurotransmitters across the cell membrane into the cell antibiotics and components of the immune (Fig. CH3 CH CH N+ CH 3 O 3 3 P + + o CH3 N CH3 NH3 C O— CH2 l + CCH2 CH2 H3N C H CH2 a r CH2 CH2 CH2 O O O O O — h e O P O— O P O— O P O— O a d O O O CH2 H2C CH CH2 HC NH Ethanolamine Serine C O C O HOCH C O CH2 CH2 HC CH2 CH2 CH2 CH CH2 H CH2 CH2 CH2 CH2 y CH CH CH CH d 2 2 2 2 r CH2 CH2 CH2 CH2 o p CH2 CH2 CH2 CH2 h CH CH CH CH o 2 2 2 2 b CH2 CH2 i c CH2 CH2 t CH2 CH2 a CH2 CH2 i l CH2 CH2 s CH CH 2 2 CH2 CH2 CH2 CH3 CH2 CH3 Phosphatidyl- Sphingomyelin choline Fig. Common phospholipids in the mammalian cell membrane. The polar head groups shown for ethanolamine and serine replace the choline in phosphatidylcholine to form phos- phatidylethanolamine and phosphatidylserine, respectively. Phosphatidylcholine, phos- phatidylethanolamine, and phosphatidylserine are phosphoacylglycerols. In contrast, sphin- gomyelin does not contain the glycerol backbone but has a sphingosine backbone and is a sphingolipid. CHAPTER 10 / RELATIONSHIP BETWEEN CELL BIOLOGY AND BIOCHEMISTRY 161 O O H2C R1 R2 O H2C O – O O – O O H – Inositol O 1 triphosphate HO HO (IP3) 2 5 H OH H 3 4 H O O O– O– Phosphatidylinositol 4,5–bisphosphate (PIP2) Fig. The portion of PIP2 that becomes inositol triphosphate, the polar head group extending into the cytosol, is shown in blue. Cholesterol, which is interspersed between the phospholipids, maintains Al Martini is suffering from both membrane fluidity. In the phosphoacylglycerols, unsaturated fatty acid chains bent short-term and long-term effects of ethanol on his central nervous sys- into the cis conformation form a pocket for cholesterol, which binds with its tem.
Rota- tion is completed by an attraction between the negatively charged glutamyl residue ADP + Pi and a positively charged arginyl group on the a subunit cheap loratadine 10mg otc. According to the binding change mechanism purchase loratadine 10 mg visa, as the asymmetric shaft rotates to a new position generic loratadine 10 mg without a prescription, it forms different binding associations with the subunits (Fig effective loratadine 10 mg. The new position of the shaft alters the conformation of one subunit so that it releases a molecule of ATP and another subunit spontaneously catalyzes synthesis of ATP from inorganic phosphate, one proton, and ADP. Thus, energy from the electrochemical gra- ATP dient is used to change the conformation of the ATP synthase subunits so that the newly synthesized ATP is released. Twelve c subunits are hypothesized, and it takes 12 pro- 2 ADP + Pi tons to complete one turn of the rotor and synthesize three ATP. Oxidation–Reduction Components of the Electron Transport Chain Electron transport to O2 occurs via a series of oxidation–reduction steps in which each successive component of the chain is reduced as it accepts electrons and oxidized as it passes electrons to the next component of the chain. The ATP oxidation–reduction components of the chain include flavin mononucleotide (FMN), Fe-S centers, CoQ, and Fe in the cytochromes b, c1, c, a, and a3. Binding change mechanism for a component of cytochromes a and a (Fig. The three subunit pairs of these electron acceptors are tightly bound to the protein subunits of the carriers. This energy is used to move protons against their concentration gradient, unit. Step 1: When ADP Pi bind to an open site and the proton influx rotates the spindle so that they become concentrated on the cytosolic side of the inner membrane. Bound ADP and Pi combine to form ATP at another site. Step 2: site for NADH, several FMN and iron-sulfur (Fe-S) center binding proteins, and As the ADP Pi bind to the new open site, binding sites for CoQ (see Fig 21. An FMN accepts two electrons from NADH and the shaft rotates, the conformations of and is able to pass single electrons to the Fe-S centers (Fig. Fe-S centers, the sites change again, and ATP is released. Fe-S centers are also present in other enzyme systems, such as other proteins, which transfer electrons to CoQ, in the cytochrome b–c1 complex, and in aconitase in the TCA cycle. SUCCINATE DEHYDROGENASE AND OTHER FLAVOPROTEINS the vitamin riboflavin. It contains In addition to NADH dehydrogenase, succinic dehydrogenase and other flavopro- the electron-accepting flavin ring teins in the inner mitochondrial membrane also pass electrons to CoQ (see structure, but not the adenosine monophos- phate (AMP) portion of FAD (see Fig. ETF-CoQ oxidore- Severe riboflavin deficiency decreases the ductase accepts electrons from ETF (electron transferring flavoprotein), which ability of mitochondria to generate ATP from acquires them from fatty acid oxidation and other pathways. Both of these flavo- oxidative phosphorylation due to the lack of proteins have Fe-S centers. CHAPTER 21 / OXIDATIVE PHOSPHORYLATION AND MITOCHONDRIAL FUNCTION 385 Intermembrane Glycerol 4H+ 2H+ space + 3-phosphate 4H dehydrogenase Cyt c CoQH CoQH Fe-s Cyt c CuA 2 FAD 2 1 Fe-S Cyt a I Cyt b CoQ II CoQ Cyt a3 FMN Fe-S Fe-S CuB FAD (FAD) IV NADH NAD+ III Succinate + 1/2 O2 + 2H H2O NADH Succinate ETF: Q Cytochrome b-c1 Cytochrome c dehydrogenase dehydrogenase oxidoreductase complex oxidase Matrix Fig. NADH dehydrogenase (complex I) spans the membrane and has a proton pumping mech- anism involving CoQ. The electrons go from CoQ to cytochrome b–c1 complex (complex III), and electron transfer does NOT involve complex II. Succinate dehydrogenase (complex II), glycerol 3-phosphate dehydrogenase, and ETF:Q oxidoreductase (shown in blue) all transfer electrons to CoQ, but do not span the membrane and do not have a proton pumping mechanism. As CoQ accepts protons from the matrix side, it is con- verted to QH2. Electrons are transferred from complex III to complex IV (cytochrome c oxidase) by cytochrome c, a small cytochrome in the intermembrane space that has reversible binding sites on the b–c1 complex and cytochrome c oxidase. The free energy drop between NADH and CoQ of approximately 13 to 14 PrPr kcal is able to support movement of four protons. However, the FAD in succinate Cys dehydrogenase (as well as ETF-CoQ oxidoreductase and -glycerophosphate dehy- SS S Fe drogenase) is at roughly the same energy level as CoQ, and there is no energy Pr Cys S Fe S released as they transfer electrons to CoQ.
Many different types of toileting seats are available quality loratadine 10mg. Other home positioning devices may include floor sitters (A) or side liers (B) 10 mg loratadine with amex. The indication for these different positioning proximately 4 years of age discount loratadine 10 mg mastercard, an appropriate toilet seat should be obtained for devices requires consideration of the benefit families based on a trial-and-error evaluation of the individual child’s com- to an individual child and the available home fort on the toilet seat order loratadine 10 mg with visa. These toilet seats can be tried either in school environ- space to use the device. As children reach adolescent size, most can use a standard toilet with some assistance. The availability of handrails in a bathroom is very helpful for many individuals. Bath Chairs Children who are not able to sit independently by 3 years of age should be measured for a bath chair. The simplest bath chair that works well for young children is an open-mesh sling seat that can be set into the bathtub (Figure 6. When children get too large to lift out of the bathtub, a shower chair can be used. Bath chairs, which are powered by the pressure of tap water, are available. These bath chairs allow children to sit in a sling seat in the water in the bathtub, but then can be raised to chair height to assist care- takers in lifting the children out of the tub. Another option for heavier chil- dren is to use a mesh-covered stretcher that sets above the bathtub and the caretakers can use a shower nozzle for bathing. This option works well for larger adolescents who are unable to assist with sitting. For individuals who are able to sit independently but are not able to stand independently, the use of a shower stall with a bench seat is the best alternative. Desks The use of adaptive desks in school is often a difficult issue. For children with good seating ability, which means most ambulatory children, sitting at a reg- ular desk at school is expected. Sometimes the height of the desk may need to be adjusted. Children who require full trunk support should be seated in their wheelchair and not placed in a desk, which universally provides poor trunk support. Children who fall in between need individual evaluations. Children who are able to sit at regular desks often feel more included with their peers in the classroom. However, for children who are unable to sup- port themselves and do not have good trunk stability, there is often decreased functional ability for fine motor skills, such as writing. For children who are between definitely needing the trunk support and definitely being able to sit 232 Cerebral Palsy Management A Figure 6. There are many variation of adaptive toilets seats available; however, toilet training is difficult if the child does not at a desk, there is some advantage of them doing both. In this situation, chil- have a comfortable seating chair. Some de- dren will spend some time sitting at the desk to stimulate balance and trunk vices are stand-alone potty chair designs with control mechanisms, and then will spend time sitting in the wheelchair work- armrests and foot supports (A), while others ing on fine motor skills. Good trunk stability im- parted by armrests is important and, for some Floor Positioning Devices children, is all that is required (C). Individuals with severe quadriplegic pattern involvement with no head or trunk control need some position changes throughout the day. These position changes should include getting children out of the wheelchair into different lying positions, such as side lying and prone positioning (see Figure 6. These individuals often need pillows or supports for side lying and prone lying. Wedges are often helpful to position these children into the prone po- sition, which allows them to still have interaction with others in the room.