The adrenal medulla secretes mostly adrenaline, containing 80% adrena- line-secreting cells and 20% noradrenaline- secreting cells. Adrenal medulla 15% The adrenal medulla is the most prominent part of the chromaffin system, which consists of aggregates of chromaffin cells, which stain brown with chrome salts. Co-ordination of movement is achieved by the integration of afferent somatic sensory information with motor output from the cerebrum and brain stem. Full erection: impedance of outflow of blood, with intracavernosal pressure equalling mean systolic arterial blood pressure. Concentrating on the core knowledge of physiology, the guide is a useful reference for doctors striving to achieve postgraduate certification, as well as anyone needing to refresh their knowledge in the key elements of clinical physiology.
The Starling forces define water movement between the intra- vascular and extravascular spaces as the difference between hydrostatic forces forcing water out of the capillaries and osmotic forces drawing water into the intravascular space. The author's own experience as an examiner at all levels has been distilled here for the benefit of postgraduate trainees and medical and nursing students. These signals mediate nerve transmission, hormone release, muscle contraction and the stimulation of growth. Normally the nitrogen concentration is almost flat in this phase. Circulating C peptide levels reflect beta cell activity.
Acid-base reactions are proton transfer reactions. Increased gluconeogenesis in the liver, along with inhibition of peripheral glucose utilisation, produces hyperglycaemia. Vitamin D2 ergo calciferol is produced by the ultraviolet irradiation of the plant sterol, ergosterol. It acts in paracrine function to inhibit gastric, intestinal and pancreato-biliary secretion and cell growth. For a 24-hour monitoring period, the exposure of oesophageal mucosa to a pH less than 4 for more than 5% of the duration of the test indicates pathological acid reflux. Glucagon Glucagon is a single chain 29 amino acid polypeptide with a molecular weight of 3485. Frontal lobe lesions These may be associated with: Personality changes, such as disinhibition, impaired judgement, lack of initiative, irritability and jocularity.
Henderson-Hasselbach equation The pK of an acid is numerically equal to the pH of the solution when the molar concentrations of the acid and its conjugate base are equal. The presence of ketoacids creates a large anion gap. These vessels are largely respon- sible for vascular resistance and the maintenance of blood pressure. The presence of acid, fat digestion products and hypertonicity in the duodenum and proximal jeju- num inhibit gastric acid secretion and gastric emptying. Concentrating on the core knowledge of physiology, the guide is a useful reference for doctors striving to achieve postgraduate certification, as w Written in a user-friendly format, this concise guide to fundamental concepts in physiology--relevant to clinical practice--covers all body systems. The canal is surrounded by concentric lamellae of cell permeated layers of the bone matrix.
It is a heterodimer consisting of a larger catalytic alpha subunit and a smaller glycosylated beta subunit. Cortical bone is a complex structure of adjacent osteons and their interstitial and circumferential lamellae. Thirst is mediated by osmoreceptors. Temporal lobes Functions Integration of sensations, emotions, memory, learning and behaviour. It is secreted by the parafollicular or C cells of the thyroid gland, which comprise 0. Dietary phos- phate is absorbed in the duodenum and jejunum.
Synovial membrane This lines the joint cavity and consists of two cell types: type A cells with a prominent Golgi apparatus, numerous vesicles and vacuoles, and many mito- chondria; and type B cells, with a large endoplasmic reticulum and a few vacuoles that secrete hyaluronan. The circadian diurnal rhythm is abolished in Cushing's syndrome. Capillaries form branching networks and have a high density in metabolically active tissues such as glands, and cardiac and skeletal muscle. Continued accumulation of blood is facilitated by relaxation of the trabecular smooth muscle. Coronary circulation The coronary circulation consists of: Arteries: The two coronary arteries arise from the coronary ostia just above the respective cusps of the aortic valve. Saliva is characterised by low osmolality and a high potassium concentration.
This amounts to 50-100 mmol of hydrogen ions per day in the adult, and includes volatile acids such as carbonic acid and fixed acids such as phosphoric and sulphuric acids. Glucagon is secreted in response to hypoglycaemia and low free fatty acid levels. Tests of gastric acid secretion Pentagastrin test Augmented histamine test Insulin Hollander test Gastrin Gastrin represents a family of peptides, secreted by antral G cells. The rate-limiting step in the hepatocellular trans- port of bile salts from the portal blood to the bile is at the canalicular membrane. By counter- transport, influences concentration of other cations, e.
Peak expiratory flow records the greatest flow that can be sustained for 10 milliseconds on forced expira- tion, starting from full inflation of the lungs. Bone resorption osteoclast products Propeptides of type I collagen - serum: C-propeptide N-propeptide Tartrate- resistant acid phosphatase - serum; Hydroxyproline - urine; Hydroxylysine glycerides - urine; Collagen cross-links - urine and serum Total pyridinolines Free pyridinolines Cross-linked N- and C-telopeptides of collagen Articular cartilage Articular cartilage consists of hyaline cartilage. The colon is divided into segments called haustra by segmental contractions. Osteoporosis This is defined as a disease characterised by low bone mass and microarchitec- tural deterioration of bone tissue leading to enhanced bone fragility and a consequent increase in fracture risk. Ninety per cent of the daily load is excreted by the kidneys; the remainder by the gastrointestinal tract. Potassium balance Potassium homeostasis is maintained by a balance between intake, excretion, and cellular uptake and efflux. Rapid metabolism of malabsorbed sugars and of dietary fibre polysaccharide to short- chain fatty acids by bacteria and absorption by passive diffusion.
Apart from providing an aide-memoire for a range of presentations, it is hoped that the book will allow for better quality and informed referrals, especially between health care providers. Each gland weighs about 35 mg. Bilirubin Bilirubin is a linear tetrapyrrole. Similar displacements may be caused by changes in vascular resistance. Hypervolaemic hypernatraemia, which is due to an increase in total body sodium that is disproportionately greater than the increase in total body water. Oxford: Oxford University Press, 2004. Hypervolaemic hyponatraemia, which is associated with a disproportion- ately greater reduction in total body water than in total body sodium, and is accompanied by features of expanded extracellular fluid volume.
Ninety per cent of the total body potassium is available for exchange, allowing for major translocations or shifts between body compartments. Proinsulin is converted to insulin, immediately before secretion, in clathrin- coated prosecretory vesicles, with the excision of C peptide. Smooth muscle contraction: noradrenaline; endothelins; prostanoids; angio- tensin; vasopressin. Gastric acid secretion control mechanisms These may be: Long reflex or cephalo-vagal arcs; Local intra-gastric reflex arcs; Mediated by humoral substances, by endocrine and paracrine pathways. Primary peristaltic waves propel the bolus distally. Jj Discontinuous capillaries liver, bone marrow, spleen , with wide intercellu- I lar gaps. The remaining 1% is excreted in the urine.