ANAPHY

• Muscle tissue is responsible for movement of the body and its parts and for changes in the size and shape of internal organs.
• Muscle tissue is composed of contractile cells called Myocytes.
• Muscle tissue is classified according to their appearance as striated muscle, in which the cells exhibit cross striations, and smooth muscle, in which the cells do not exhibit cross striations.
• Skeletal muscle is responsible for movement of the axial and appendicular skeleton, maintenance of body position and posture, and help maintain a constant body temperature.
• Skeletal muscle is characterized as tubular, multinucleated, and striated, and is the longest of muscle types.
• Myoblast are mononucleate precursor cells of skeletal muscle, can differentiate to form multinucleated muscle fibers capable of muscle contraction.
• Muscle fiber contains the usual cellular components, but special names have been assigned to them: Sarcolemma, Sarcoplasm, Sarcoplasmic reticulum, T (for transverse) system, Endomysium, Perimysium, Fascicle, Epimysium, Myofibrils, Sarcomeres, Z disk, A band, I band, M line.
• Action potential travels down the motor neuron to presynaptic terminal causing Ca2+ channels to open.
• Ca2+ causes synaptic vesicles release acetylcholine into synaptic cleft.
• Acetylcholine binds to receptor molecules on Na+ channels, Na+ channels open, and Na+ rushes into the postsynpatic terminal (depolarization).
• Na+ causes sarcolemma and T-tubules to increase permeability of sarcoplasmic reticulum and stored Ca2+ is released.
• Ca2+ binds to troponin which is attached to actin.
• The pia mater attaches directly to the brain.
• The substantia nigra and the red nucleus help regulate body movements.
• The pineal body, which may play a role in the onset of puberty and secretes the hormone melatonin, is located in the epithalamus.
• The hypothalamus is the main visceral control center of the body and is vitally important to overall body homeostasis.
• Diencephalon consists of the thalamus, which functions as an integration center, and the subthalamus and epithalamus, which are involved in motor function.
• The brainstem consists of the medulla oblongata, pons, and midbrain.
• The hypothalamus is an autonomic control center, a center for emotional response/behavior, involved in body temperature regulation, regulation of food intake, water balance, and control of endocrine system functioning.
• The midbrain is superior to the pons and consists of the corpora quadrigemina, which consists of four colliculi, two inferior colliculi involved in hearing and two superior colliculi involved in visual reflexes.
• The dura mater attaches to the skull and has two layers that can separate to form dural folds and dural venous sinuses.
• The medulla oblongata is continuous with the spinal cord and contains ascending and descending tracts.
• The pons connects the cerebrum and the cerebellum and the pontine nuclei regulate breathing, swallowing, balance, chewing, and salivation.
• The lateral hemispheres are involved with the planning, practice, and learning of complex movements.
• The pyramids are tracts controlling voluntary muscle movement.
• Vermis and medial part of the lateral hemispheres control posture, locomotion, and fine motor coordination.
• Beneath the arachnoid mater the subarachnoid space contains CSF that helps cushion the brain.
• Diencephalon is a region that encircles the third ventricle located between the brainstem and cerebrum.
• Cerebrospinal Fluid is produced from the blood in the chronoid plexus of each ventricle by ependymal cells, moves from the lateral to the third and then to the fourth ventricle, from the fourth ventricle, CSF enters the subarachnoid space through three aperture, and leaves the subarachnoid space through arachnoid granulations and returns to the blood in the dural venous sinuses.
• The pons is superior to the medulla and ascending and descending tracts pass through the pons.
• The medullary nuclei regulate the heart, blood vessels, breathing, swallowing, vomiting, coughing, sneezing, hiccupping, balance and coordination.
• The cerebral peduncles are the major descending motor pathways.
• The meninges cover the brain and spinal cord and consist of the dura, arachnoid, and pia mater.
• Ca2+ binding to troponin cause tropomyosin to move exposing attachment sites for myosin.
• Cervical, lumbar, sacral, and coccygeal ventral rami supply sympathetic nerves.
• The brain receives about 15-20% of the blood pumped by the heart.
• The dorsal rami supply the muscles and skin near the middle of the back.
• The cranial nerves consist of 12 pairs of cranial nerves: most of the cranial nerves belong to the somatic system, some are sensory nerves that contain only sensory fibers, some are motor nerves, containing only motor fibers, and others are mixed nerves, so called because they contain both sensory and motor fibers.
• Fascicles form the nerve and are held together by the epinerium.
• The ventral rami in the thoracic region form intercostal nerves, which supply the thorax and upper abdomen.