2110 Final Review.pptx

Final Review 2110  Classification by Stimulus Type – named according to the activating stimulus. 1) Mechanoreceptors – generate nerve impulses when they, or adjacent tissues, are deformed by a mechanical force such as touch, pressure (including blood pressure), vibration, stretch, and itch. 2) T...

Final Review 2110  Classification by Stimulus Type – named according to the activating stimulus. 1) Mechanoreceptors – generate nerve impulses when they, or adjacent tissues, are deformed by a mechanical force such as touch, pressure (including blood pressure), vibration, stretch, and itch. 2) Thermoreceptors – sensitive to temperatures changes. 3) Photoreceptors – those of the retina of the eye, respond to light energy. 4) Chemoreceptors – respond to chemicals in solution (molecules smelled or tasted, changes in blood chemistry). 5) Nociceptors – respond to potentially damaging stimuli that result in pain. • Proprioceptors – responds to internal stimuli. • Occurs in skeletal muscles, tendons, joints, and ligaments and in connective tissue coverings of bones and muscles. • They advise the brain of our body movements by monitoring how much the organs are stretched. • Each axon is surrounded by an endoneurium, a delicate layer of loose connective tissue that also encloses the fiber’s associated myelin sheath or neurilemma. • Those carrying impulses only toward the CNS are sensory (afferent) nerves; those carrying impulses only away from the CNS are motor (efferent) nerves. Twelve pairs of cranial nerves.              Olfactory – nerves of smell. Optic – nerve of vision. Outgrowth of the brain Oculomotor – means “eye mover”. Supplies four of the six extrinsic muscles that move the eyeball in the orbit. Trochlear – innervates an extrinsic eye muscles that loops through a pulley-shaped ligament in the orbit. Trigeminal – 3 branches, largest of the cranial nerves. Sensory fibers to the face and motor fibers to the chewing muscles. Abducens – controls the extrinsic eye muscles that abducts the eyeball (turns it laterally). Facial – innervates muscles of facial expression. Vestibulocochlear – sensory nerve for hearing and balance, formerly the auditory nerve. Glossopharyngeal – means “tongue and pharynx” and helps to innervate these structures. Vagus – only cranial nerve to extend to the abdomen. Accessory – accessory part of the vagus nerve. Formerly called the spinal accessory nerve. Hypglossal – runs inferior to the tongue and innervates some tongue-moving muscles  Brachial plexus gives rise to virtually all the nerves that innervate the upper limb.  There are four major groups of branches.  From medial to lateral they are:  1) ventral rami (called roots) which forms 2) trunks, which forms 3) divisions, which form 4) cords. To remember the branching sequence, think of the saying “Really tired? Drink coffee”. • 31 pairs of spinal nerves • Arise from the spinal cord and supply all parts of the body except the head and some areas of the neck. • There are: • 8 pairs of cervical spinal nerves (C1-C8) • 12 pairs of thoracic nerves (T1-T12) • 5 pairs of lumbar nerves (L1-L5) • 5 pairs of sacral nerves (S1-S5) • 1 pair of coccygeal nerves (C0).  Each spinal nerve connects to the spinal cord by a dorsal root and a ventral root. The ventral roots contain motor (efferent) fibers extend to and innervate the skeletal muscles. Dorsal roots contain sensory (afferent) fibers.  Conduct impulses from peripheral receptors to the spinal cord. Exaggerated, distorted, or absent reflexes indicate degeneration or pathology of specific nervous system regions, often before other signs are apparent. • The stability of our internal environment depends largely on the autonomic nervous system (ANS) that innervates smooth and cardiac muscle and glands. • Involuntary nervous system and the general visceral motor system. • Norepinephrine (NE) secreted by most sympathetic fibers, • ACh released by parasympathetic fibers. • Those carrying impulses only toward the CNS are sensory (afferent) nerves; those carrying impulses only away from the CNS are motor (efferent) nerves. • The sympathetic division promotes a number of metabolic effects. • • • • 1) increases the metabolic rate of body cells 2) raises blood glucose levels 3) mobilizes fats for use as fuels 4) increases mental alertness by stimulating the reticular activating system of the brain stem. • Visceral pain afferents travel along the same pathways as somatic pain fibers helps explain the phenomenon of referred pain, where stimuli arising in the viscera are perceived as somatic in origin. • Main integration center of the ANS is the hypothalamus. • Hypothalamus contains centers that coordinate heart activity, blood pressure, body temperature, water balance, and endocrine activity. • Contains centers that mediate various emotional states (rage, pleasure) and biological drives (thirst, hunger, sex). • The “fight-or-flight” system in sympathetic. Involves E activities – exercise, excitement, emergency, and embarrassment. • Most sympathetic postganglionic axons release NE and care classified as adrenergic fibers. • Sympathetic division innervates more organs. • Emmetropic eye – normal eye with light focused properly • Myopic eye (nearsighted) – the focal point is in front of the retina. Can’t see far. • Corrected with a concave lens • Hyperopic eye (farsighted) – the focal point is behind the retina. Can’t see close. • Corrected with a convex lens • The pinna is a shell-shaped projection surrounding the opening of the external acoustic meatus. • Three semicircular canals that each define two-thirds of a circle and lie in the three planes of space. • Accessory structures include eyebrows, eyelids, conjunctiva, lacrimal apparatus, and extrinsic eye muscles • Rods: • Respond to dim light • Are used for peripheral vision • Cones: • Respond to bright light • Have high-acuity color vision • Pharyngotympanic tube – connects the middle ear to the nasopharynx • Accommodation – changing the lens shape by ciliary muscles to increase refractory power • Pupil – central opening of the iris • Regulates the amount of light entering the eye during: • Close vision and bright light – pupils constrict • Distant vision and dim light – pupils dilate • Ear Ossicles • The tympanic cavity contains three small bones: the malleus, incus, and stapes • Environmental changes are called stimuli. • Sensation (awareness of the stimulus) and perception (interpretation of the meaning of the stimulus) occur in the brain. • The PNS is divided into sensory (afferent) and motor (efferent) divisions. • Those carrying impulses only toward the CNS are sensory (afferent) nerves; those carrying impulses only away from the CNS are motor (efferent) nerves. • Fibers can be classified according to the region they innervate as somatic afferent, somatic efferent, visceral afferent and visceral efferent. • Receptors transmitting impulses from the visceral organs are called visceral afferent fibers. • Components of a Reflex Arc – there are five essential components. • Receptor – site of the stimulus action. • Sensory neuron – transmits afferent impulses to the CNS. • Integration center – in simple reflex arcs, may be a single synapse between a sensory neuron and a motor neuron (monosynaptic reflex). • More complex reflex arcs involve multiple synapses with chains of interneurons (polysynaptic reflex). It’s always within the CNS. • Motor neuron – conducts efferent impulses from the integration center to an effector organ. • Effector – muscle fiber or gland cell that responds to the efferent impulses (by contracting or secreting). • Components of a Reflex Arc – there are five essential components. • Receptor – site of the stimulus action. • Sensory neuron – transmits afferent impulses to the CNS. • Integration center – in simple reflex arcs, may be a single synapse between a sensory neuron and a motor neuron (monosynaptic reflex). • More complex reflex arcs involve multiple synapses with chains of interneurons (polysynaptic reflex). It’s always within the CNS. • Motor neuron – conducts efferent impulses from the integration center to an effector organ. • Effector – muscle fiber or gland cell that responds to the efferent impulses (by contracting or secreting). • Stretch reflex is most important in the large extensor muscles that sustain upright posture and in postural muscles of the trunk.  Cranial Outflow – Preganglionic fibers run in the oculomotor, facial, glosspharyngeal, and vagus cranial nerves.  Oculomotor nerves (III) – innervate smooth muscles in the eyes that cause pupils to constrict and the lenses to bulge, so one can focus on close objects.  Facial nerves (VII) – stimulate many large glands in the head. Fibers that activate the nasal glands and the lacrimal glands of the eyes.  Glossopharyngeal nerves (IX) – activate the parotid salivary glands. • Medial and anterior hypothalamic regions direct parasympathetic functions, lateral and posterior areas direct sympathetic function. • The sympathetic division can override the parasympathetic in times of stress. • These areas have shown specific motor and sensory functions and are localized in discrete cortical areas called domains. • Six levels: 1. Chemical level – where atoms combine together to make molecules. Molecules then combine in specific ways to form organelles. Organelles are the parts of the cell which carries on its functions/life. 2. Cellular level – most cells have the same function, however, cells vary in size and shape, depending on what they do in the body. Like cells combine together to form specific tissues. 3. Tissue level – groups of similar cells which have a common function. There are four different tissue types in the human body: epithelial (skin) muscle connective (ligaments) nervous tissue 4. Organ level - more than one tissue type that performs a specific function for the body makes up an organ. Usually an organ is comprised of four different tissue types. 5. Organ systems – organs which work together to accomplish a common purpose. - Example being the urinary system. This system removes waste from the body in the form of urine. 6. Organismal level – this is the highest level and it’s all the levels working together to carry out the body’s life processes. • A fibroblast is a cartilage cell. 1. Kinetic energy – energy in action. - Constant movement of particles of matter (atoms) as well as in larger objects (a bouncing ball). Works by moving objects, which in turn can do work by moving or pushing on other objects. - Ex. Push on a swinging door sets it in motion. • When a bone develops from a fibrous membrane, the process is intramembranous ossification and the bone is called a membrane bone. • Bone development by replacing hyaline cartilage is called endochondral ossification and the resulting bone is called a cartilage or endochondral bone. • Mitosis – Prophase (1 & 2), Metaphase, Anaphase, Telophase (PMAT) • Intercalated discs – cardiac muscle • Sarcomere – functional unit of muscle • Central nervous system – brain & spinal cord/column • Largest bone in body is the femur • Worst skin cancer is malignant melanoma • Scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate are carpals.