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By N. Agenak. Tufts University.

Brachial Plexus Block monitor and manage the patient’s physiologic status but he or she must ensure that the patient remains calm and cooperative buy viagra sublingual 100mg cheap erectile dysfunction or cheating. The anesthesiolo- gist must be alert to the development of complica- tions and must also be prepared to convert to a general anesthetic at any point in the procedure 100 mg viagra sublingual mastercard erectile dysfunction morning wood. Understanding the anatomy of the region (Figure 10 discount viagra sublingual 100mg online erectile dysfunction kuala lumpur, Figure 11) is crucial to understanding the blocks. In epidural anesthesia, a tiny plastic catheter is placed into the epidural space, which is the anatomic space lo- cated just superficial to the dura. Epidural catheters placed for surgical anesthesia or an- algesia are most commonly used at the thoracic or lum- bar regions depending on the site of the surgery. From the epidural space, it is slowly absorbed into the subarach- noid space where it blocks the nerves of the spinal cord From “Introduction to Regional Anaesthesia” by D. The volume of anesthetic delivered Figure 12 Insertion of Tuohy needle into epidural and the site of the catheter determine the level or space “height” of the block. The presence of an indwelling catheter allows the block to be extended in height or du- ration as required. After local infiltration, a specially de- signed 17 or 18 gauge epidural needle (common trade names Tuohy® or Hustead®) is inserted into the spinous interspace. While ad- vancing the needle, the anesthesiologist maintains pres- sure on the syringe in order to sense the resistance of Reproduced with permission from Astra Pharma Inc. The epidural space is a “potential space” such that when it is entered Figure 13 Insertion of epidural catheter with the needle, a sudden loss of resistance is detected. The syringe is then removed so that a catheter can be threaded through the needle into the epidural space (Figure 13), after which the needle is removed. Inserting an epidural through tattooed skin is undesir- able as it may bring a plug of ink into the epidural space, the consequences of which are not known. In this case, the anesthesiologist is able to locate a small Reproduced with permission from Astra Pharma Inc. Bupivacaine, while second challenge is performing a technical procedure possessing a slower onset of effect, has a longer dura- in a patient who is in active labour. The dermatomal level of block is tested esthesiologist pauses while the patient is having con- by pinprick or ice cube (Figure 14). The patient is able to do an excellent job of re- 20-30 minutes for an adequate epidural block to take maining still, which is quite important during this deli- effect. The higher the surgi- carefully for the moment of the “loss of resistance”, cal site is, the higher the block must be. Table 10 de- when the gentle pressure on the hub of the syringe fi- scribes the dermatomal level of block required for some nally gives way, as the needle has entered the “poten- of the more common surgical procedures which apply tial” space that is the epidural space. Late complications are related to needle and catheter insertion, and include nerve injury, epidural abcess or hematoma, and post-dural puncture head- ache (if the dura is accidentally punctured). Because the dura is a tough membrane, a definite “pop” is often felt as the needle passes through into the intrathecal space. However, if The contraindications to spinal anesthesia are listed in the block dissipates prior to the end of the procedure Table 11. Through- procedures on the distal upper extremity (below the el- out their journey to the axilla, the nerve roots merge bow). After cannulating a vein distal to the surgi- roots travel through the intervertebral foramina and cal site, the operative arm is elevated and an elastic ban- emerge between the anterior and middle scalene mus- dage is applied to promote venous drainage. As they exit the 50 ml of dilute lidocaine (without epinephrine) is then axilla, the plexus divides one final time to form the axil- injected slowly into the cannula in the operative arm. The brachial plexus block provides anesthesia tem to the interstitium provides surgical anesthesia for virtually any type of upper extremity surgery. If the surgical procedure lasts less than 20 rect needle placement is ensured through the use of ei- minutes then one must wait until 20 minutes has ther ultrasound or nerve stimulator. The supraclavicu- lar and interscalene blocks pose the additional risks of There are many potential complications of a brachial pneumothorax, phrenic nerve block and recurrent la- plexus block. Intrathecal injection Figure 17 Brachial plexus: roots, trunks, divisions, cords is a rare complication of interscalene block. Drugs Used in the drugs, there is an ever-increasing variety of tech- agents (both intravenous and inhaled) at our dis- Maintenance of Anesthesia niques used to provide general anesthesia. Emergence techniques strive to achieve the following goals, specific effects such as analgesia or muscle relaxa- known as the “Four A’s of Anesthesia”: tion and therefore can be used to achieve the de- • Lack of Awareness: unconsciousness. The practice of using combinations of agents, each for a specific purpose, is what is termed • Analgesia: the abolition of the subconscious re- “balanced anesthesia”. An example of a balanced actions to pain, including somatic reflexes technique would be the use of propofol for induc- (movement or withdrawal) and autonomic re- tion of anesthesia; the administration of des- flexes (hypertension, tachycardia, sweating flurane and nitrous oxide for maintenance of un- and tearing). Be- • improved hemodynamic stability cause the above-described goals were achieved by a progressive depression of the central nerv- • more effective muscle relaxation ous system rather than by any direct or specific 56 • more rapid return of respiratory function, conscious- Induction ness and airway control following the completion of The goal of the induction phase of anesthesia is to in- the procedure duce unconsciousness in a fashion which is pleasant, • provision of post-operative analgesia with appropri- rapid and maintains hemodynamic stability. If the anes- ate timing and dosing of opioids administered intra- thetic plan includes control of the airway and ventila- operatively tion then the induction phase also aims to achieve mus- cle relaxation to facilitate endotracheal intubation. A balanced technique is still the most common tech- nique used for the provision of general anesthesia. Anesthesia can be induced by having the patient However, with the development of short-acting intrave- breathe increasing concentrations of inhaled gases by nous agents such as propofol and remifentanil, the mask. While there are settings where this is the desired above-described goals of general anesthesia can be at- technique, it tends to be slow and can be unpleasant. Understanding the dynamics of induction mined, one can proceed with administering the anes- requires a grasp of the essential pharmacology of these thetic. A general anesthetic consists of four phases: in- agents; the reader can do so by touching the hyperlink duction, maintenance, emergence and recovery. Rapid Sequence Induction Although regurgitation and aspiration are potential complications of any anesthetic, there are factors which place some patients at higher risk (Table 7). However, even a prolonged period of fasting does not guarantee an “empty stomach” if gastric emptying is delayed. Ex- 57 amples of conditions which impair gastric emptying in- The purpose of pre-oxygenation is to lessen the risk of clude diabetes, trauma, recent opioid administration hypoxemia occurring during the apneic period after in- and bowel obstruction. Traditionally teaching is that for aspiration, the time between inducing anesthesia the Sellick maneuver provides occlusion of the esopha- and securing the airway with a cuffed endotracheal gus between the cricoid cartilage (a complete circumfer- tube must be minimized. Such a technique is termed a ential cartilage) and the cervical vertebrae thus mini- “rapid sequence induction”. A rapid sequence induction is performed as follows: Succinylcholine Succinylcholine (Sch), a depolarizing muscle relaxant, 1. Suction apparatus is checked and kept readily avail- is a very useful and very powerful drug; the anesthesi- able. Pre-oxygenation of patient with 100% oxygen for 3-5 tions of Sch in order to avoid causing harm or death.

The most striking hematologic finding is a leukocytosis of 40—50 X 109/L with 60—97% small order discount viagra sublingual on line erectile dysfunction quran, normal-appearing lymphocytes generic viagra sublingual 100mg zocor impotence. Serologic tests to detect the presence of heterophil antibodies are helpful in differentiating this disease from more serious diseases order genuine viagra sublingual erectile dysfunction emotional. Internal quality control Program designed to verify the validity of program laboratory test results that is followed as part of the daily laboratory operations. Intrinsic factor A glycoprotein secreted by the parietal cells of the stomach that is necessary for binding and absorption of dietary vitamin B12. Ischemia Deficiency of blood supply to a tissue, caused by constriction of the vessel or blockage of the blood flow through the vessel. Jaundice Yellowing of the skin, mucous membranes, and the whites of the eye caused by accumulation of bilirubin. Karyorrhexis Disintegration of the nucleus resulting in the irregular distribution of chromatin fragments within the cytoplasm. Involved in several activities such as resistance to viral infections, regulation of hematopoiesis, and activities against tumor cells. Knizocytes An abnormally shaped erythrocyte that appears on stained smears as a cell with a dark stick- shaped portion of hemoglobin in the center and a pale area on either end. Large granular Null cells with a low nuclear-to-cytoplasmic ratio, lymphocyte pale blue cytoplasm, and azurophilic granules. Leukemia A progressive, malignant disease of the hematopoietic system characterized by unregulated, clonal proliferation of the hematopoietic stem cells. Leukemic hiatus A gap in the normal maturation pyramid of cells, with many blasts and some mature forms but very few intermediate maturational stages. Eventually, the immature neoplastic cells fill the bone marrow and spill over into the peripheral blood, producing leukocytosis (e. Leukemoid reaction A transient, reactive condition resulting from certain types of infections or tumors characterized by an increase in the total leukocyte count to greater than 25 X 109/L and a shift to the left in leukocytes (usually granulocytes). Leukoerythroblastic A condition characterized by the presence of reaction nucleated erythrocytes and a shift-to-the-left in neutrophils in the peripheral blood. Lupus-like anticoagulant A circulating anticoagulant that arises spontaneously in patients with a variety of conditions (originally found in patients with lupus erythematosus) and directed against phospholipid components of the reagents used in laboratory tests for clotting factors. The nucleus is usually round with condensed chromatin and stains deep, dark purple with romanowsky stains. These cells interact in a series of events that allow the body to attack and eliminate foreign antigen. Lymphocytic leukemoid Characterized by an increased lymphocyte reaction count with the presence of reactive or immature- appearing lymphocytes. Reactions are associated with whooping cough, chickenpox, infectious mononucleosis, infectious lymphocytosis, and tuberculosis. Lymphocytosis An increase in peripheral blood lymphocyte concentration (>4 X 109/L in adults or >9 X 109/ L in children). Lymphoma classification Division (grading) of lymphomas into groups, each with a similar clinical course and response to treatment. Marginating pool The population of neutrophils that are attached to or marginated along the vessel walls and not actively circulating. This parameter will correlate with the extent of chromasia exhibited by the stained cells and is calculated from the hemoglobin and hematocrit. Megakaryocyte A large cell found within the bone marrow characterized by the presence of large or multiple nuclei and abundant cytoplasm. Megaloblastic Asynchronous maturation of any nucleated cell type characterized by delayed nuclear development in comparison to the cytoplasmic development. The abnormal cells are large and are characteristically found in pernicious anemia or other megaloblastic anemia. Microenvironment A unique environment in the bone marrow where orderly proliferation and differentiation of precursor cells take place. Mixed lineage acute An acute leukemia that has both myeloid and leukemia lymphoid populations present or blasts that possess myeloid and lymphoid markers on the same cell. Monoclonal An alteration in immunoglobulin production that gammopathies is characterized by an increase in one specific class of immunoglobulin. Monocyte-macrophage A collection of monocytes and macrophages, system found both intravascularly and extravascularly. Morulae Basophilic, irregularly shaped granular, cytoplasmic inclusions found in leukocytes in an infectious disease called ehrlichiosis. Mosaic Occurs in the embryo shortly after fertilization, resulting in congenital aberrations in some cells and some normal cells. The cell is associated with chronic plasmocyte hyperplasia, parasitic infection, and malignant tumors. In instances where large sequences of nucleotides are missing, the alteration is referred to as a deletion. Myelofibrosis with A myeloproliferative disorder characterized by myeloid metaplasia excessive proliferation of all cell lines as well as progressive bone marrow fibrosis and blood cell production at sites other than the bone marrow, such as the liver and spleen. Myeloid-to-erythroid ratioThe ratio of granulocytes and their precursors to (M:E ratio) nucleated erythroid precursors derived from performing a differential count on bone marrow nucleated hematopoietic cells. Myeloperoxidase An enzyme present in the primary granules of myeloid cells including neutrophils, eosinophils, and monocytes. Myelophthisis Replacement of normal hematopoietic tissue in bone marrow by fibrosis, leukemia, or metastatic cancer cells. Seen in bacterial infections, inflammation, metabolic intoxication, drug intoxication, and tissue necrosis. Normal pooled plasma Platelet-poor plasma collected from at least 20 individuals for coagulation testing. The plasma is pooled and used in mixing studies to differentiate a circulating inhibitor from a factor deficiency. Nuclear-cytoplasmic A condition in which the cellular nucleus matures asynchrony slower than the cytoplasm, suggesting a disturbance in coordination. As a result, the nucleus takes on the appearance of a nucleus associated with a younger cell than its cytoplasmic development indicates. Nuclear-to-cytoplasmic The ratio of the volume of the cell nucleus to the ratio (N:C ratio) volume of the cell’s cytoplasm. This is usually estimated as the ratio of the diameter of the nucleus to the diameter of the cytoplasm. Nucleus (pl: nuclei) The characteristic structure in the eukaryocytic cell that contains chromosomes and nucleoli. Most oncogenes are altered forms of normal genes that function to regulate cell growth and differentiation. Optimal counting area Area of the blood smear where erythrocytes are just touching but not overlapping; used for morphologic evaluation and identification of cells. Orthochromatic A nucleated precursor of the erythrocyte that normoblast develops from the polychromatophilic normoblast. Osmotic fragility A laboratory procedure employed to evaluate the ability of erythrocytes to withstand different salt concentrations; this is dependent upon the erythrocyte’s membrane, volume, surface area, and functional state. Pelger-Huët anomaly An inherited benign condition characterized by the presence of functionally normal neutrophils with a bilobed or round nucleus.

These patients are unable to appreciate the weight of pressure and change their position 2) Paralysed patients (Paraplegic and quadriplegic patients) purchase 100 mg viagra sublingual with visa erectile dysfunction at the age of 19. Diabetes Prevention of decubitus ulcers: A) Prevent Pressure: 1) Establish a turning schedule for bedridden patients; turn hourly cheap viagra sublingual online amex impotence at 18. B ) Prevent Friction: 1) When changing position of your patient lift him and do not drag him on to bed purchase viagra sublingual 100mg without prescription erectile dysfunction and diabetes a study in primary care. D ) Prevent Predisposing causes: 1) Improve patient’s health by means of good food, ventilation, sunlight and exercises. E ) Observe early signs and symptoms of decubitus ulcers: 1) Redness 2) Dark discoloration 3) Bruising 4) Tenderness of the area 5) Burning sensation 9 F ) Give good care to pressure points: Careful cleaning and massage should be carried out 3 or 4 times a day for all bed­ridden patients. Equipment 1) A bowl of warm water 2) Sponge cloth 3) Soap 4) Towel 5) Dusting powder 6) Spirit Procedure: 1) Explain procedure to patient­ Arrange articles at the bedside. Treatment of decubitus ulcer: 1) Clean ulcers with aseptic precautions­Use antiseptics such as eusole (or) hydrogen peroxide. Give long firm strokes from back of neck to the buttocks 14) Watch for any redness over the pressure areas. Type of Therapeutic Baths 1) Hot water tub bath: Immersion in hot water helps relieve muscle soreness and spasm. Problems may result from poor care of the feet and nails such as biting nails or trimming them improperly, exposure to chemicals and wearing poorly fitted shoes. Purposes of care of the nails 1) To keep nails harmless 2) To prevent accumulation of dirt under the nails and reduce occurrence of infection. Characteristics of a healthy nails:A normal healthy nail is transparent, smooth and convex with pink nail beds and translucent white tips. Common foot and nail problems 1) Callus: Is a thickened portion of epidermis caused by local friction or pressure. A person’s appearance and a feeling of well­being depend on the way the hair looks and feels hair growth, distribution and pattern can be indicators of general health status. Proper hair care: 1) Frequent brushing helps keep hair clean and distributes oil evenly along hair shafts. Hold it with your left hand tightly at the root of the hair to prevent pulling of hair and comb it from top to downwards. B) Pediculosis corporis or vestimenti (Body louse) –Refer Antiseptic Bath in procedure “Applying Hot Applications”. C) Pediculosis pubis (Crab louse) · A tray containing a) Protective sheet and towel b) Bowl of warm water c) Razor and blade d) Soap and brush e) Antiseptic lotion in a kidney tray and paper bag. Guidelines 1) Combing: Hair are combed and arranged in the style the patient prefers at least twice a day. B) Rash a) Neck and behind ears in head louse b) All over the body in body louse c) On and around the part affected in crab louse. C ) Sores a) Scalp in head louse b) Body in body louse c) On the part affected in crab louse The common parasiticides used are: a) Mediker. Wait for atleast 15 minutes § Before placing the thermometer in the mouth rinse the thermometer in cold water to remove all disinfectants § Do not use hot water for washing thermometer § Before placing thermometer in position wipe it from the bulb to stem to keep the bulb clean § After taking the thermometer wipe it from stem to bulb to avoid contaminating the fingers of the care giver with saliva and faeces. In auxiliary method leave the thermometer in position for 5 minutes 6) Count the pulse and respirations while the thermometer is still in place 7) Place the patients hand over his chest with the wrist extended and the palm downwards. Place the finger tips over the pulse point 8) Holding the watch in the left hand, start to count the pulse rate with zero then 1,2 etc. If the pulse is not regular, count the rate for one full minute 10) Continue palpation of the pulse to assess the rhythm, volume, tension and irregularity 11) With the right hand still on the pulse count respiration by watching the rise of the chest, with out the knowledge of the patient 12) If the respirations are normal count the number of respirations in the 30 seconds and multiply by 2. If the respirations are abnormal, count the rate for full one minute and note the pattern of breathing 13) Remove the thermometers after 2 minutes (after 5 minutes in case of auxillary method). Keep clients upper body and lower extremities covered with sheet or blanket 3) Apply disposable gloves 4) Hold end of glass thermometer with finger tips 5) Read mercury level while gently rotating thermometer at eye level. If mercury is above desired level, grasp tip of thermometer securely, stand away from soiled objects and sharply flick wrist downward. Ask the client to deep breath slowly and relax 9) Gently insert thermometer into anus in the direction of umbilicus 3. Don’t force the thermometer 10) If resistance is felt during inserting, withdraw the thermometer immediately. Never force the thermometer 11) Hold thermometer in place for 2 seconds or according to agency policy 12) Carefully remove thermometer, discard plastic sleeve cover in appropriate container, and wipe off any remaining secretions with clean tissue. Gently rotate until scale appears 14) Wipe client’s anal area with soft tissue to remove lubricant or feces and discard tissue. It is believed that when the patient is flat in bed, respiration often is more free and turning is easier, advantages that are important in the prevention of respiratory complications. Prone Position: In the prone position, the client lies on the abdomen with the head turned to one side. Both children and adults often sleep in this position, sometimes with one or both arms flexed over their heads (Figure 34­16). When used periodically, the prone position helps to prevent flexion contractures of the hips and knees, thereby counteract­ing a problem caused by all other bed positions. The prone position also promotes drainage from the mouth and is especially useful for unconscious clients or those clients recovering from surgery of the mouth or throat. Fowler’s Position: Off all the positions prescribed for a patient, perhaps the most common, as well as the most difficult to maintain is the Fowler’s position. The patient’s with abdominal drainage usually are put in Fowler’s position as soon as they have recovered conciousness, but great caution must be observed in raising the bed. Hand washing is a vigorous, brief rubbing together of all surfaces of hands lathered in soap, followed by rinsing under a stream of water. The purpose is to remove soil and transient organisms from the hands to reduce to microbial counts over time. Situation for hand washing: Garnerand Favero recommend that nurses wash hands in the following situations. Medical Hand Washing Equipments: 1) Easy to reach sink with warm running water 2) Antimicrobial soap / Regular soap. Use circular movements to wash palms, back of hands, wrists, forearms and interdigital spaces for 20­25 Seconds. Ask the assisting nurse to bring the gown over shoulders 3) The assisting nurse fastens the ties at the neck. Assess the patients for following: § Muscle strength § Joint mobility and contracture formation(arthritis) § Paralysis or paresis § Orthostatic hypotension(risk of fainting) § Activity tolerance § Level of comfort(pain) § Vital signs 2. Assess the patients sensory status § Adequacy of central and peripheral vision § Adequacy of hearing § Loss of peripheral sensation § Cognitive status 3. Assess for any contra indications to lift or transfer § Check for the doctors order § Assess patients level of motivation § Patients eagerness § Whether patient avoids activity § Assess previous mode of transfer § Assess patients specific risk for falling when transferred § Assess special equipments needed to transfer § Assess for safety hazards § Perform hand hygiene § Explain procedure to patient § Transfer the patient After care: § Following each transfer assess the patients body alignment, tolerance, fatigue, comfort § If the patient is transferred to bed after transfer, side rails are raised 41 § If the patient is transferred to wheel chair the brakes are released before moving the patient § Record the procedure accurately. The patients performance is also recorded § Any difficulty of disruption occurred during the transfer is also recorded with date and time § The patients comfort, vital signs are all recorded Procedure: § Transferring a patient from a bed to stretcher § An immobilized patient who must be transferred from a bed to a stretcher requires a three person carry or two person carry § Another method is using a sheet to lift Transferring a patient from a bed to stretcher: § Three of you should stand side by side facing of patients bed § Each person assumes responsibility for one of three areas a) Head and Shoulders b) Hips and thighs c) Ankles § Perform three­person carry from bed to stretcher(Bed at Stretcher level) § Three persons stand side by side facing side of patients bed 1.

The system functions in protection cheap viagra sublingual impotence at 70, in the regulation of body temperature trusted viagra sublingual 100 mg impotence in the bible, in the excretion of waste materials buy 100 mg viagra sublingual free shipping health erectile dysfunction causes, in the synthesis of vitamin D3 with the help of sunrays, and in the reception of various stimuli perceived as pain, pressure and temperature. These are stratum cornium, lucidium, granulosum, spinosum and basale, Stratum cornium is the outer, dead, flat, Keratinized and thicker layer. Stratum basale rests on the basement membrane, and it is the last layer of epidermis next to stratum spinosum. Dermis / true skin/ a strong, flexible, connective tissue mesh work of collagen, reticular and elastic fibers. In some areas papillary layer have special nerve endings that serve as touch receptors (meissner’s corpuscles). It is made of dense connective tissue with course of collagenous fiber bundles that crisscross to form a storma of elastic network. In the reticular layer many blood and lymphatic vessels, nerves, fat cell, sebaceous (oil) glands and hair roots are embedded. Hypodermis is composed of loose, fibrous connective tissue, which is richly supplied with lymphatic and blood vessels and nerves. Protection: against harmful microorganisms, foreign material and it prevents excessive loss of body fluid. The color of blood reflected through the epidermis * The main function of melanin is to screen out excessive ultraviolet rays. The person 47 Human Anatomy and Physiology who is genetically unable to produce any melanin is an albino. Sudoriferous /sweat/ glands Types: Eccrine and Apocrine glands Eccrine glands are small, simple coiled tubular glands distributed over nearly the entire body, and they are absent over nail beds, margins of lips of vulva, tips of penis. The sweat they secret is colorless, aqueous fluid containing neutral fats, albumin, urea, lactic acid and sodium chloride. Apocrine glands are odiferous, found at the armpits, in the dark region around nipples, the outer lips of the vulva, and the anal and genital regions. The female breasts are apocrine glands that have 48 Human Anatomy and Physiology become adapted to secret and release milk instead of sweat. It functions as a permeability barrier, an emollient (skin softening) and a protective a gent against bacteria and fungi. Acne vulgaris is a condition when there is over secretion of sebum, which may enlarge the gland and plug the pore. It covers the entire body except the palms, soles, lips, tip of penis, inner lips of vulva and nipples. Hair consist epithelial cell arranged in three layers from the inside out medulla, cortex and cuticle. Part of the hair follicle is attached with the bundle of smooth muscle about halfway down the follicle. The fastest growth rate occurs over 51 Human Anatomy and Physiology the scalp of women aged 16 to 24 years. Nails are composed of flat, cornified plates on the dorsal surface of the distal segment of the fingers and toe. The proximal part of nail is lunula, which is white in its color because of the capillaries underneath are covered by thick epithelium. Skin gets its color from a) Carotene b) Underlying blood vessels c) Melanin d) a and b only e) a, b and c 54 Human Anatomy and Physiology 4. Sudoriferous glands secret their secretion in response to: a) Physiological process b) Heat c) Stress d) Sexual experience e) In all of the above condition 5. But from structural point of view, the human skeletal system consists of two main types of supportive connective tissue, bone and cartilage. Movement: skeletal muscles attached to the skeletal system use the bone to levers to move the body and its part. Short bones are about equal in length, width and thickness, which are shaped with regular orientation. Typical sesamoid bones are patella and pisiform carpal bone, which are in the tendon of quadriceps femuris and flexor carp ulnaris muscle respectively. Gross anatomy of a typical long bone You can take Tibia (in the leg) one of the longest bones in the body. The red marrow also known as myeloid tissue Endosteum is the lining the medullary cavity of compact bone tissue and covering the trabeculae of spongy bone tissue. It is more rigid than other tissues because it contains inorganic salts mainly calcium phosphate & calcium carbonate. Osteons are made up of concentric layers called lamellae, which are arranged seemingly in wider and wider drinking straws. In the center of the osteons are central canals (haversion canal) , which are longitudinal canals that contains blood vessels, nerves and lymphatic vessels. Central canals, usually have branches called perforating canals /valkmann’s canal that run at right angle to central canal extending the system of nerves and vessels out ward to periosteum and to endosteum. Radiating from each lacuna are tiny canaliculi containing the slender extensions of the osteocytes where nutrients and wastes can pass to and from central canal. Spongy (cancellous) Bone tissue Is in the form of an open interlaced pattern that withstands maximum stress and supports in shifting stress. They are able to synthesize and 63 Human Anatomy and Physiology secrete un-mineralized ground substance, act as pump cell to move calcium and phosphate in and out of bone tissue. Bone in embryo develops in two ways: Intra-membranous ossification, If bone develops directly from mesenchymal tissue. The 64 Human Anatomy and Physiology cartilage it self do not converted into bone but the cartilage is replaced by bone through the process. Endochondrial ossification produces long bones and all other bones not formed by intra-membranous ossification. These are surface markings where muscles, tendons and ligaments attached, blood & lymph vessels and nerves pass. Example: External auditory meatus Groves and sulcus: are deep furrow on the surface of a bone or other structure. Example Medial condyle of femur Head, expanded, rounded surface at proximal end of a bone often joined to shaft by a narrowed neck. The upper part of the lower extremity, between the pelvis and knee, is the thigh; the leg is between the knees an ankle. Made up of horizontal, cribriform plate, median perpendicular plate, paired lateral masses; contains ethmoidal sinuses, crista galli, superior and middle conchae. Forms roof of nasal cavity and septum, part of cranium floor; site of attachment for membranes covering brain. Shaped like large scoop; frontal squama forms forehead; orbital plate forms roof of orbit; supraorbital ridge forms brow ridge; contains frontal sinuses, supraorbital foramen.

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