By L. Luca. Keuka College.
For example generic 75 mg triamterene, an aldohexose is a monosaccharide that con- tains a total of six carbon atoms including that of the aldehyde in its structure cheap 75 mg triamterene with mastercard. Similarly, a ketopentose has five carbons in its structure including the one in the keto group. Oligosaccharides are carbohydrates that yield from two to about nine monosaccharide molecules when one molecule of the oligosaccharide is hydrolysed. Small oligosaccharides are often classified according to the number of monosaccharide residues contained in their structures. For example, disac- charides and trisaccharides contain two and three monosaccharide residues respectively whilst polysaccharides yield larger numbers of monosaccharide molecules per polysaccharide molecule on hydrolysis. They exhibit a wide variety of biological functions but in particular act as major energy sources for the body. Those with five or more carbon atoms usually assume either a five (furanose) or six (pyranose) membered ring structure. These cyclic structures are formed by an internal nucleophilic addition between a suitably positioned hydroxy group in the molecule and the carbonyl group (Figure 1. This internal nucleophilic addition introduces a new chiral centre into the molecule. The carbon of the new centre is known as the anomeric carbon and the two new stereoisomers formed are referred to as anomers. In this convention solid lines represent bonds above the plane of the ring whilst dotted lines are used to indicate bonds below the plane of the ring. Reproduced from G Thomas, Chemistry for Pharmacy and the Life Sciences including Pharmacology and Biomedical Science, 1996, by permis- sion of Prentice Hall, a Pearson Education Company In many cases pure a- and b-anomers may be obtained by using appropriate isolation techniques. For example, crystallization of D-glucose from ethanol yields a-D-glucose [a] þ112. However, in aqueous solution these cyclic structures can form equilibrium mixtures with the corresponding straight chain form (Figure 1. The change in optical rotation due to the conversion of either the pure a- or pure b-anomer of a monosaccharide into an equilibrium mixture of both forms in aqueous solution is known as mutarotation (Figure 1. The specific rotation of the aqueous equilib- rium mixture is þ52 All monosaccharides have a number of stereogenic centres. The configurations of these centres may be indicated by the use of the R/S nomenclature system. However, the historic system where the configurations of all the chiral centres are indicated by the stem name of the monosaccharide (Figure 1. In the D form this hydroxy group projects on the right of the carbon chain towards the observer whilst in the L form it projects on the left of the carbon chain towards the observer when the molecule is viewed with the unsaturated group at the top. These configurations are usually represented, on paper, by modified Fischer projections (Figure 1. The D and L forms of a monosaccharide have mirror image structures, that is, are enantiomers (Figure 1. The system is based on the relative positions of adjacent hydroxy groups with the carbonyl group being used as a reference point for the hydroxy groups. Epimers are compounds that have identical configurations except for one carbon atom. For example, both a-D-glucose and a-D-fructose react with phenylhydrazine to form the same osazone. This means that after a short time a basic aqueous solution of a monosaccharide will also contain a mixture of monosaccharides that will exhibit their character- istic chemical properties. For example, a solution of fructose will produce a silver mirror when treated with an ammoniacal solution of silver nitrate (Tol- len’s reagent). This is because under basic conditions fructose undergoes tauto- merism to glucose, whose structure contains an aldehyde group, which reduces Tollen’s reagent to metallic silver. The approximate concen- trations of the isomers present at equilibrium are given in the brackets 1. Commonly used trivial names are given in the brackets monosaccharides are based on a stem name indicating the number of carbon atoms, a prefix indicating the configuration of the hydroxy group and either the suffix -ose (aldoses) or -ulose (ketoses). Five membered ring monosacchar- ides have the stem name furanose whilst six membered ring compounds have the stem name pyranose together with the appropriate configurational prefixes indicating the stereochemistry of the anomers (Figure 1. Monosacchar- ides in which one of the hydroxy groups has been replaced by a hydrogen atom have the prefix deoxy- with the appropriate locant, except if it is at position 2, when no locant is given. These are compounds which consist of a carbohydrate residue, known generally as a glycone, bonded to a non-sugar residue, known generally as an aglycone, by a so called glycosidic link to the anomeric carbon of the glycone. Since the glycosidic link is formed to the anomeric carbon both a- and b-isomers of a glycoside are known. Each type of glycosidic link will exhibit the characteristics of the structure forming the link. For example, oxygen glycosidic links are effectively acetals and so undergo hydrolysis in aqueous solution.
External to the tunica albuginea is a layer of cuboidal cells known as the germinal epithelium 75mg triamterene visa. During growth of the ovary in a female fetus prior to birth purchase triamterene 75mg on-line, the germinal epithelium dips into the body of the ovary in various places. Over time, a mass of epithelial cells called primordial follicles, or primary follicles, becomes separated from the main body of the ovary. The ovaries of a young girl contain from 100,000 to 400,000 of these follicles, most of them present at birth. Usually, only one follicle matures to become a Graafian follicle (twins, triplets, or even more fetuses result if more than one follicle matures to the point of releas- ing an ovum). One cell of this mass, the oocyte (produced by oogenesis, or meiosis), becomes the ovum while the remaining cells surround the ovum as part of the cumulus oophorus and others line the fluid-filled follicular cavity as the membrana granulosa. As the ovum matures, its follicle moves toward the ovary’s surface and begins secreting the hormone estrogen, which signals the endometrium (uterine lining) to build up in preparation for pregnancy. Ringed by follicular cells in what’s called the corona radiata, the ovum enters the coelom (body cavity) and is swept into the Fallopian tube by a fringe of tissue called fimbriae. It takes approximately three days for the ovum to travel from the Fallopian tube to the uterus. Meanwhile, back at the ovary, a clot has formed inside the ruptured follicle and the membrana granulosa cells are being replaced by yellow luteal cells, forming a corpus luteum (literally “yellow body”) on the surface of the ovary. This new endocrine gland secretes progesterone, a hormone that signals the uterine lining to prepare for possible implantation of a fertilized egg, inhibits the maturing of Graafian follicles, ovulation, and the production of estrogen to prevent menstruation; and stimulates further growth in the mammary glands (which is why some women get sore breasts a few days before their periods begin). If pregnancy occurs, the placenta also will release proges- terone to prevent menstruation throughout the pregnancy. If the ovum isn’t fertilized, the corpus luteum dissolves after 10 to 14 days to be replaced by scar tissue called the corpus albicans. If pregnancy does occur, the corpus luteum remains and grows for about six months before disintegrating. Only about 400 of a woman’s primordial follicles ever get a chance to make the trip to the uterus. The rest ripen to various stages before degenerating into what are known as atretic follicles (or corpora atretica) over the course of her lifetime. Fallopian tubes, oviducts, uterine tubes — call them what you will, but they’re where the real business of fertilization takes place. Because an egg must be fertilized within 24 hours of its release from the ovary to remain viable. These small, muscular tubes lined with cilia are nearly 5 inches long and, somewhat surprisingly, aren’t directly connected to the ovaries. Instead, the funnel-shaped end, the infundibulum, of a tube is fragmented into finger-like projections called fimbriae that help to move Chapter 14: Carrying Life Forward: The Female Reproductive System 221 the ovum from the body cavity into the tube. When it’s in the tube, where fertilization takes place, the combined motions of both cilia and peristalsis (the same muscle contractions that move food through the digestive system) propel the ovum toward the uterus for implantation. If a fertilized egg implants anywhere else — say in the hollow of the Fallopian tube itself — the pregnancy is referred to as ectopic and the woman must have immediate surgery to remove the developing embryo before it can damage any vital organs. While not attached to the ovaries, the Fallopian tubes are attached to the pear-shaped uterus, which is located between the urinary bladder and the rectum. Its upper, wide end is called the fundus; the lower, narrow end that opens into the vagina is the cervix; and the central region is the body. Endometrium lines the uterus in varying amounts depending on the stage of a woman’s menstrual cycle or pregnancy. This lining is sup- ported by a thick muscular layer called the myometrium, which is under the control of the autonomic nervous system and comes into play when the uterus contracts, such as during labor. Sperm enter and menstrual fluid leaves through the vagina, a muscular tube that connects the uterus with the outside of the body. Lined with a fold of highly elastic mucous membrane, the vagina can enlarge greatly during childbirth. A folded mem- brane of connective tissue called the hymen lies at the opening of the vaginal canal until it is ruptured or torn, often by sexual intercourse but sometimes by other physical activities. At either side of the vaginal opening are two Bartholin glands that secrete a lubricating mucous. On the outside, the female genitalia extends toward the posterior from a mound of soft, fatty tissue called the mons pubis that covers the bone structure called the pubic symphysis. Behind this, the vulva consists of two flaps of fatty tissue: the outer lips, or labia majora; and the smaller, hairless inner lips, the labia minora. Just above where the inner lips join is a small flap of tissue called the clitoral hood, under which is the clitoris, erectile tissue that swells during sexual arousal.
Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care buy triamterene 75mg online, 7th Edition discount 75mg triamterene with amex. A stimulus, an agent, act, or other inﬂuence capa- meals could be prepared to stimulate taste; ﬂowers, ble of initiating a response by the nervous system cards, and pictures could be displayed to stimulate b. Know the danger signals that indicate serious translate the impulse into a sensation. Visual: Read different types of books to the is at high risk for sensory deprivation. Olfactory: Have child identify different odors; patient who is confused cannot process prepare enticing meals and savor the aromas. Perceptual responses: Inaccurate perception of with different foods with varying colors, tastes, sights, sounds, tastes, smells, and body shapes, and textures; introduce ﬁnger foods position; poor coordination and equilibrium; into diet. Tactile: Use games and sports to increase body from daydreams to hallucinations contact with child; demonstrate affection by b. Cognitive responses: Inability to control the hugging, holding child in lap, and so on. Developmental considerations: The adult may memory, problem solving, and task performance experience the need to compensate for the loss c. Emotional responses: Inappropriate emotional of one type of stimulation by increasing other responses: apathy, anxiety, fear, anger, belliger- sources of sensory stimuli. Cultural care deprivation is a lack of culturally reception of sensory stimuli; medications that assistive, supportive, or facilitative acts (e. Infant: Soothing sounds, rocking, holding and sensory stimulation if the type of stimulation changing position, changing patterns of light present is developmentally appropriate. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. Objective data are underlined; subjective data are in patients include confused patients and patients boldface. Assess the George Gibson, an 81-year-old, married, African patient’s abilities to transmit, perceive, and American man, reluctantly reports, after much prod- react to stimuli during everyday interactions. More and more, people just seem to be by name, and speak in a normal tone of voice. Hearing-impaired patients: Avoid excessive seated on the edge of his chair and bends toward noise, avoid excessive cleaning of ears, and you when you speak to him. Unconscious patients: Be careful of what is said room whenever people come to visit because he is in the patient’s presence, assume the person embarrassed by his inability to hear. Nursing Process Worksheet Health Problem: Sensory/perceptual alteration: Sample Answers auditory 1. What nursing interventions might be appropriate Etiology: Reluctance to accept that he has an for Mr. Therefore, attempts to deny hearing loss and attributes the nursing plan of care should include sensory problem to others who are “mumbling”; has greatly stimulation for Mr. The nurse reduced opportunities for conversation; has not should also investigate if hearing aids would help sought help until now Mr. The nurse should Expected Outcome: After medical evaluation of hear- assess both Mr. Pirolla and his wife to see how they ing loss and treatment, patient demonstrates better are coping with the changes in their social environ- coping skills by increasing amount of time he ment. The nurse should Nursing Interventions: incorporate knowledge of the guidelines for a. Explain that hearing loss often accompanies communicating both with persons with reduced aging and that a medical evaluation is important vision and hearing when developing a teaching to provide proper treatment. What would be a successful outcome for this tion skills and preventing social isolation. Pirolla states that he is adapting to hearing aid has enabled patient to comprehend his condition and receiving new sensory most one-to-one conversations, but ability to hear stimulation from his environment. What intellectual, technical, interpersonal, and/or gate possibility of learning to lip-read. No longer ethical/legal competencies are most likely to bring avoids company, especially if it is only one or two about the desired outcome? Patient strengths: Healthy until now; wife is support- and how the body responds, including sensoristasis ive; previous history of strong interactional skills and adaptation; ability to integrate knowledge of Personal strengths: Recognize signiﬁcance of sensory alterations, including factors contributing sensory/perceptual alterations; able to distinguish to disturbed sensory perceptions changes in perceptual abilities normally related to Interpersonal: demonstration of the ability to aging from those indicating treatable medical prob- empathize and communicate with patients with lems; able to establish trusting relationship with sensory deﬁcits and interact effectively with older patients patients and their caregivers. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. Diabetes: Some men may be candidates for a revealed a partial sensorineural loss that was distort- penile prosthesis; pharmacologic management of ing his perception of certain frequencies; partially erectile dysfunction may be indicated. Cardiovascular disease: Teach gradual close to speaker, but in a one-to-one conversation, resumption of sexual activity, comfortable posi- his responses demonstrate his ability to correctly tion for affected partner. Loss of body part: Teach acceptance of body reports that he still has great difﬁculty listening in image.
Sound waves travel through the auditory canal buy triamterene 75mg low price, striking the eardrum and making it vibrate and setting the three ossicle bones into motion discount triamterene 75 mg otc. The stapes at the end of the chain strikes against the oval window of the vestibular canal, translating the motion into the perilymph fluid in the vestibu- lar and tympanic canals of the cochlea. The vibrating fluid begins moving the basilar membrane that separates the two canals, stimulating the endolymph fluid in the membranous area of the cochlea. The stimulated endolymph fluid in turn stimulates the hair cells of the organ of Corti, which transmit the impulses to the brain over the auditory nerve. Three semicircular canals, each with an ampulla (or small, dilated por- tion) at each end, lie at right angles to each other. The ampullae connect to a fluid-filled sac called a utricle, which in turn connects to another fluid-filled sac called a saccule. Both sacs contain regions called maculae that are lined with sensitive hairs and contain concretions (solid masses) of calcium carbonate called otoliths (or otoconia). When linear acceleration pulls at them, the otoliths press on the hair cells and initiate an impulse to the brain through basal sensory nerve fibers. When the head changes posi- tion, it causes a change in the direction of force on the hairs. Movement of the hairs stimulates dendrites of the vestibulocochlear nerve (the eighth cranial nerve) to carry impulses to the brain. Use the terms that follow to identify the internal structures of the eye shown in Figure 15-7. The structure in the eye that responds to the ciliary muscles during focusing is the a. The structure that contains the receptor cells for the perception of sound is the a. The small bone in the ear that strikes against the oval window of the vestibular canal, setting into motion the perilymph fluid in the vestibular and tympanic canals of the cochlea, is the a. Use the terms that follow to identify the structures of the ear shown in Figure 15-8. Stapes Chapter 15: Feeling Jumpy: The Nervous System 261 Answers to Questions on the Nervous System The following are answer to the practice questions presented in this chapter. Sense organs’ capacity to generate nerve impulse to stimulation d Coordination: b. Ability to receive impulses and direct them to channels for favorable response e Conceptual thought: e. Capacity to record, store, and relate information to be used to deter- mine future action f The brain and spinal cord are called the a. Some of the other answer options are parts of a neuron, but the neuron is the central unit. The nodes of Ranvier are gaps along the myelin sheath, so one of them can’t be found at the end of the line. When present, this fiber actually wraps around the myelin sheath, so it’s always on the outside. Cells that contribute to the repair process of the central nervous system l Microgliacytes: d. Cytoplasmic projections carrying impulses to the cell body p The neuroglia cells are important as b. With all that acetylcholine and cholinesterase floating around, it must be a chemical transmission. Outer thin membrane around an axon fiber Part V: Mission Control: All Systems Go 262 u Schwann cell: c. Negatively charged ion on the inner surface of the cell membrane B Polarization: a. Reshuffling of cell membrane ions; permeability of cell membrane D Cholinesterase: b. To remember, use the word “occipital” to bring to mind the word “optic,” which of course is related to visual activity. Controls motor coordination and refinement of muscular movement Chapter 15: Feeling Jumpy: The Nervous System 263 U Medulla oblongata: b. Contains the centers that control cardiac, respiratory, and vasomotor functions V Cerebrum: e. Contains the corpora quadrigemina and nuclei for the oculomotor and trochlear nerves X The largest quantity of cerebrospinal fluid originates from the c. Y The part of the brain that contains the thalamus, pituitary gland, and the optic chiasm is the a. Count them: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral — plus 1 tailbone (coccygeal).
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