While every effort has been made to provide a complete and accurate account of the subject, we realize that in any undertaking of this size, omissions and errors occur. Modern textbooks of histology discuss not only the microscopic morphology of the body, but also its function.
Light Microscopy
By treating successive sections with the enzyme amylase, to digest glycogen, the absence of the purple-. When viewed with a fluorescent microscope, the fluorescence represents the location of the antibody reacting with the antigen.
6 confocal Microscopy
Electron Microscopy
The amino acid cystine is removed from the lumen of the renal proximal tubule by a carrier protein. When the signaling molecule binds to the extracytoplasmic portion of the receptor, the cytoplasmic aspect of the receptor undergoes a conformational change that activates the g protein (Fig. 2.5).
Protein Synthetic Machinery of the cell
Receptors linked to G-proteins (guanine nucleotide-binding proteins) are transmembrane proteins whose extracytoplasmic aspects have binding sites for specific signaling molecules (ligands), and their cytoplasmic aspect is bound to the G-protein on the inner leaflet of the plasmalemma. When the gs protein is activated, it exchanges its gDP for guanosine triphosphate (gtP); the α subunit dissociates from the other two components and contacts adenylate cyclase, which it activates to catalyze the transformation of cytoplasmic AtP to cAMP.
14 Protein Synthesis
As a new aminoacyl-tRNA carrying an amino acid occupies the A site, the spent tRNA at the E site falls off the ribosome. The initiator transfer RNA (tRNA) binds to its cognate amino acid, methionine, at the P site.
Protein Trafficking
18 Membrane Trafficking
The disease is due to the inability of peroxisomes to incorporate peroxisomal enzymes because the required peroxisomal targeting signaling receptors are missing from the membrane of the peroxisomes. This results in the inability of peroxisomes to carry out β-oxidation of long-chain fatty acids to synthesize plasmalogens.
20 Mitochondria
Mitochondrial myopathies are conditions that are inherited from the mother, because all of an individual's mitochondria come from the egg cell. Myopathy may manifest itself as muscle weakness and fatigue after exertion, but in severe cases it can be fatal.
22 Inclusions and the cytoskeleton
Gel-like networks are associated with the protein filamin to form high-viscosity matrices such as those of the cell cortex. Intermediate filament binding proteins attach to and bind intermediate filaments to aid in the formation of the three-dimensional cytoskeleton.
Nuclear Envelope
Although the nucleus can vary in shape, location and number, in most cells it is centrally located and spherical in shape.
An additional difference is that one of the pyrimidine bases is uracil rather than thymine. Nucleolar matrix, the arrangement of fibers responsible for maintaining the organization of the nucleolus.
34 cell cycle
Cancer chemotherapy has been improved by a more complete understanding of the cell cycle and mitoses. At telophase, the chromosomes have reached the opposite poles of the cell and the nuclear envelope is transformed due to.
Reductional Division)
Equatorial Division)
Apoptosis
During meiosis I, when the homologous pairs of chromosomes normally separate and migrate to opposite poles (anaphase I), non-disjunction can occur - one daughter cell contains both homologous chromosomes resulting in 24 chromosomes, while the other daughter cell is completely devoid of that chromosome, which resulting in 22 chromosomes. The newly separated chromosomes of the two daughter cells move to opposite poles of their spindle.
Ground Substance
Fibronectin, a large V-shaped dimer of approximately 440,000 Da, produced by connective tissue cells such as fibroblasts, has binding sites for multiple ecM components and integrin molecules, facilitating cell adhesion to the ecM. Entactin (nidogen), binds to laminin and type IV collagen, facilitating adhesion between laminin and basal lamina.
Plasma fibronectin, a soluble form of fibronectin, is present in the blood, where it aids in coagulation, phagocytosis, and wound healing. Tenascin is a large glycoprotein (1700 kDa) composed of six polypeptides that resembles a spider with only six legs that project outward from a central mass and have binding sites for fibronectin and syndecan, a transmembrane proteoglycan.
Ground Substance (cont.)
In addition, type iii and V collagens are mixed into the substance of type i collagen fibers. Scurvy is a condition resulting from a deficiency of vitamin C, a substance required for the hydroxylation of proline moieties.
46 basement Membrane
Integrins and Dystroglycans
In both cases the autoimmune reaction is against the type IV collagen of the basal lamina. The onset of Goodpasture syndrome usually occurs after a respiratory infection and the lung disease is related to smoking.
Epithelial Tissue
Additional types of cell junctions are located in regions of the cell other than at terminal rods and do not belong to the junctional complex. Basal lamina, cell membrane appliques and hemidesmosomes are the three main specializations of the basal surfaces of epithelial cells (see Fig. 5.7).
Glands
Blood, lymph, and connective tissue act as a medium of exchange by delivering nutrients, waste products, and signaling molecules to and from the body's cells. Cardiovascular problems are life-threatening and include valve problems and dilation of the ascending aorta.
64 connective Tissue cells
Neutrophils respond to neutrophil chemotactic factor released by mast cells and act in acute inflammation, phagocytizing and digesting bacteria. Eosinophils are recruited to the site by eosinophil chemotactic factor released by mast cells and acting in acute inflammation.
Dense connective tissue is much richer in fiber and much poorer in cells than loose connective tissue. Regular dense elastic connective tissue is arranged in perforated sheets, as in the fenestrated membrane of the aorta, or as thick, short bundles, as in the ligamentum nuchae of the spinal column.
CSF, secreted by osteoblasts, bind to CSF receptors on osteoclast precursor cells,
Additional ossification centers are needed in the larger flat bones, such as those of the skull. Plasma calcium ion levels are monitored by parafollicular cells (c-cells) of the thyroid gland.
Skeletal Muscle
ADP is also released and the thin filament is dragged towards the center of the sarcomere. New ATP binds to the myosin head which releases the bond between the S1 part of myosin II and the G-actin of the thin filament.
104 cardiac Muscle
Myocardial infarction refers to damage to the heart muscle caused by a lack of blood flow to the affected area. The damage is reversible if blood flow resumes within 20 minutes; after that time the damage is irreversible and the heart muscle cells that are not perfused die.
106 Smooth Muscle
In most cases, the tumor spreads; metastasis may occur 10 to 15 years after excision of the primary tumor, and the long-term survival prognosis for leiomyosarcoma patients is unfavorable. Somatic nervous system that exclusively serves motor impulses to the skeletal muscles of the body via a single neuron.
Development of Nervous Tissue
Spina bifida is a malformation resulting from an incomplete fusion of the neural tube in which the spinal cord and spinal meninges can extend through the defect. Hirschsprung's disease, or congenital megacolon, results from the failure of neural crest cells to migrate into the wall of the forming distal colon.
110 Nervous System cells
Unipolar neurons (pseudounipolar neurons) are located in the dorsal root ganglion and some cranial nerve ganglia. Bipolar neurons are found in the olfactory epithelium and in the ganglia of the vestibulocochlear nerve.
116 Generation and conduction of Nerve Impulses
Propagation of the impulse (depolarization wave) cannot continue in the direction of the soma (retrograde propagation); but it can and does. Presence of Ca++ ions in the cytoplasm allowing transmembrane proteins in the synaptic vesicle and presynaptic membrane rab3A, synaptotagmin, synaptobrevin, syntaxin, SNAP-25 (soluble N-ethylmaleimide sensitive fusion protein binding protein-25) and synapto to physin. each other to complete the fusion process and allow the release of the neurotransmitter substances into the synaptic cleft.
Generation and conduction of Nerve Impulses (cont.)
Many of the na+ ions that entered the axon in step 1 flow in both directions and would cause depolarization of adjacent regions of the axon. The presence of cleaved fusion proteins prevents the fusion of synaptic vesicles with the presynaptic membrane and inhibits the release of acetylcholine, resulting in weak paralysis of the affected muscles.
Peripheral Nerves
It progresses to flails of the joints, including deformities associated with dementia and motor dysfunction. It is thought to result from the loss of the cells that produce γ-aminobutyric acid (GABA), an inhibitory neurotransmitter.
Somatic Motor and Autonomic Nervous Systems
The autonomic innervation is divided into two functionally different divisions: the sympathetic nervous system and the parasympathetic nervous system. Norepinephrine is the neurotransmitter between the postganglionic neuron and the effector organ in the sympathetic nervous system.
Ganglia
Broadly defined, the sympathetic system is considered vasoconstrictor in function, while the parasympathetic system is considered secretomotor in function. Norepinephrine is the neurotransmitter between the postganglionic neuron and the effector organ in the sympathetic.
Somatic Motor and Autonomic Nervous Systems (cont.)
126 central Nervous System
Vaccines are now available to protect against some of the common bacteria that cause meningitis. Although the cause is not clearly understood, it is characterized by the loss of neurons and synapses mainly within the cerebral cortex followed by gross atrophy of the individual cerebral lobes.
Nerve Regeneration
Granular layer – composed of tightly packed nuclei of small granule cells and glomeruli (cerebellar islands) that represent synapses between axons entering the cerebellum and the resident granule cells. Purkinje cells release only gABA as their neurotransmitter substance, and they are the only cells of the cerebellum whose processes and reactions extend outside the cerebellum.
HEMAToPoIESIS
Most of the CO2 is transported as hco3− ions (formed by the action of carbonic anhydrase on h2o and co2, forming h2co3 which immediately dissociates into h+ and hco3−). T cells constitute 80% of the lymphocyte population and are responsible for the cell-mediated immune response.
142 bone Marrow
CFU-GM gives rise to CFU-G and CFU-M, cells that give rise to neutrophils and monocytes. IL-6, IL-11, IL-12, macrophage inhibitory protein-a, and erythropoietin induce Phsc, cFU-geMM, and cFU-ly to form progenitor cells (see Table 10.7).
Pressure against the luminal aspect of the vessel wall as blood flows to the heart. Skin discoloration is the result of abnormal spasms of the blood vessels and of a reduced blood supply to the local tissues.
166 Lymphatic vascular System
Primary lymphedema is rare and is caused by the absence of certain lymphatic vessels at birth, or may be caused by abnormalities in the lymphatic vessels. During their journey within the lymphatic vessels, these tumor cells enter a lymph node where their spread can be inhibited.
Occasionally, the immune system develops a dysfunction, as in Graves' disease, in which thyroid follicular cell receptors for thyroid-stimulating hormone are no longer recognized as part of themselves. Alternatively, ctl's Fas ligand (the CD95L molecule, a death ligand) can bind to the transformed cells' Fas protein (CD95, a death receptor), which drives the transformed cells into apoptosis.
Lymphoid organs
The newly differentiated cells migrate to the medulla of the lymph node and form marrow cords. About 90% of plasma cells leave the lymph node via the efferent lymphatic vessels and migrate to the bone marrow, where they end up.
Hormones
Pituitary Gland (Hypophysis)
