O. Osko. Loyola College, Baltimore.
Drawing on your knowledge of the functions of the urinary A second major function of the urinary system is the excre- system buy colospa 135 mg line muscle relaxer sleep aid, list the basic substances that compose normal urine purchase 135mg colospa visa muscle relaxant hamstring. Explain the role of the renal vessels in maintaining home- elimination of toxic wastes that may result from bacterial action ostasis. Approximately how much blood is processed in the and the removal of various drugs that have been taken into the kidneys each minute? All of these functions are accomplished through the forma- tion of urine by the kidneys. The urinary system consists of two kidneys, two ureters, the urinary bladder, and the urethra (fig. Tubules in the kidneys KIDNEYS are intertwined with vascular networks of the circulatory system The kidney consists of an outer renal cortex and an inner renal to enable the production of urine. After the urine is formed, it is medulla that contains the renal pyramids. Urine is formed as a fil- moved through the ureters to the urinary bladder for storage. Blood to be processed by a kidney enters through the large Objective 3 Describe the gross structure of the kidney. After the filtration process (see chapter 3), it exits Objective 4 Describe structure of a nephron and explain through the renal vein. The importance of filtration of the blood how its components are oriented within the kidney. Every minute, the kidneys process approximately juxtamedullary nephrons with respect to the gross structure 1,200 ml of blood. Urinary System © The McGraw−Hill Anatomy, Sixth Edition Body Companies, 2001 Chapter 19 Urinary System 677 Although the kidneys are firmly supported by the renal adi- Twelfth pose capsule, renal fascia, and even the renal vessels, under thoracic certain conditions these structures may give in to the force of gravity vertebra and the kidneys may drop a bit in position. It also may affect victims of anorexia nervosa, who suffer from extreme weight loss. The potential danger of renal Minor ptosis is that the ureter may kink, blocking the flow of urine from the calyx affected kidney. Renal pelvis Kidney Gross Structure of the Kidney Ureter A coronal section of the kidney shows two distinct regions and a major cavity (figs. The outer renal cortex, in contact with the renal capsule, is reddish brown and granular in appearance because of its many capillaries. The deeper renal medulla is darker, and the presence of microscopic tubules and blood vessels gives it a striped appearance. The renal medulla is Urinary composed of 8 to 15 conical renal pyramids. Portions of the bladder renal cortex extend between the renal pyramids to form the renal columns. In turn, the major calyces The reddish brown kidneys are positioned against the posterior join to form the funnel-shaped renal pelvis. The renal pelvis col- wall of the abdominal cavity between the levels of the twelfth lects urine from the calyces and transports it to the ureter. Microscopic Structure of the Kidney The kidneys are retroperitoneal, which means that they are located behind the parietal peritoneum (fig. The lateral more than a million nephrons surrounded by associated small border of each kidney is convex, whereas the medial border is blood vessels. The hilum is also the site for drainage of lymph vessels and Renal Blood Vessels innervation of the kidney. The superior border of each kidney is capped by the adrenal gland (see figs. The kidneys have an extensive circulatory network to allow for Each kidney is embedded in a fatty fibrous pouch consisting the continuous cleansing and modification of large volumes of of three layers. Arterial blood enters the kidney at the hilum layer, is a strong, transparent fibrous attachment to the surface of through the renal artery, which divides into interlobar (in'ter- the kidney. Small interlobular arteries radiate from the arcuate arter- dense irregular connective tissue. It is a supportive layer that an- ies and project into the renal cortex.
The pia in reflexes colospa 135 mg low price skeletal muscle relaxants quiz, and peripherally located ascending and descending mater contains an extensive vascular network cheap 135 mg colospa overnight delivery muscle relaxant on cns. The gray matter of the spinal cord is centrally located and Objective 25 Describe the structure of the spinal cord. It is composed of nerve cell bodies, neuroglia, and unmyelinated association neurons (interneurons). Objective 26 Describe the arrangement of ascending and The white matter consists of bundles, or tracts, of myelinated descending tracts within the spinal cord. The relative size and shape of the gray and white matter The spinal cord is the portion of the CNS that extends through varies throughout the spinal cord. The amount of white matter the vertebral canal of the vertebral column (fig. It is con- increases toward the brain as the nerve tracts become thicker. It provides a means of neural com- The core of gray matter roughly resembles the letter H munication to and from the brain through tracts of white (fig. Ascending tracts conduct impulses from the pe- cord are called horns, and are named according to the direction ripheral sensory receptors of the body to the brain. The paired posterior horns extend pos- scending tracts conduct motor impulses from the brain to teriorly and the paired anterior horns project anteriorly. Lateral horns are prominent only in Specific nerve pathways allow for reflexive movements the thoracic and upper lumbar regions. The transverse bar of rather than those initiated voluntarily by the brain. Move- gray matter that connects the paired horns across the center of ments of this type are not confined to skeletal muscles; re- the spinal cord is called the gray commissure. Within the gray flexive movements of cardiac and smooth muscles control commissure is the central canal. It is continuous with the ven- heart rate, breathing rate, blood pressure, and digestive ac- tricles of the brain and is filled with cerebrospinal fluid. Spinal nerve pathways are also involved in swal- lowing, coughing, sneezing, and vomiting. Spinal Cord Tracts Impulses are conducted through the ascending and descending Structure of the Spinal Cord tracts of the spinal cord within the columns of white matter. The spinal cord extends inferiorly from the position of the fora- men magnum of the occipital bone to the level of the first lum- bar vertebra (L1). It is somewhat flattened posteroventrally, making it oval in cross section. Nervous Tissue and the © The McGraw−Hill Anatomy, Sixth Edition Coordination Central Nervous System Companies, 2001 Chapter 11 Nervous Tissue and the Central Nervous System 385 Medulla oblongata C1 C2 Cervical spinal nerve C3 Cervical plexus C4 Cervical spinal C5 enlargement C6 C7 C8 T1 Brachial plexus T2 Arachnoid T3 T4 T5 Dura mater T6 Cervical enlargement T7 T8 Thoracic spinal nerve T9 Dura mater T10 Lumbar enlargement Lumbar spinal T11 enlargement Dura mater Conus medullaris T12 Filum terminale Conus medullaris L1 Cauda equina Lumbar spinal L2 Cauda equina nerve L3 Filum terminale L4 L5 Lumbar plexus S1 S2 S3 (b) S4 Sacral plexus S5 (a) FIGURE 11. Nervous Tissue and the © The McGraw−Hill Anatomy, Sixth Edition Coordination Central Nervous System Companies, 2001 386 Unit 5 Integration and Coordination Posterior horn Posterior funiculus Posterior median Lateral funiculus sulcus Gray commissure Posterior root of spinal nerve Central canal Lateral horn Spinal ganglion Paras Anterior horn Anterior root Anterior median Anterior funiculus fissure Spinal nerve of spinal nerve (a) Posterior horn Central canal Anterior horn Spinal ganglion Spinal nerve (b) FIGURE 11. The spinal cord has six columns of white matter called funiculi ated and are named according to their origin and termination. The two anterior funiculi are lo- brain and spinal cord or cross over within the medulla oblongata cated between the two anterior horns of gray matter, to either or the spinal cord. The crossing over of nerve tracts is referred to side of the anterior median fissure (fig. Each funiculus consists of both ascending and descending Descending tracts are grouped according to place of origin as tracts. The nerve fibers within the tracts are generally myelin- either corticospinal or extrapyramidal. Corticospinal (pyramidal) tracts descend directly, without synaptic interruption, from the cerebral cortex to the lower motor neurons. Nervous Tissue and the © The McGraw−Hill Anatomy, Sixth Edition Coordination Central Nervous System Companies, 2001 Chapter 11 Nervous Tissue and the Central Nervous System 387 Cerebrum Sensory cortex Motor cortex of cerebrum of cerebrum Cerebrum Corticospinal tract Thalamus Midbrain Sections of brain Midbrain Sections of brain Pons Pons Sensory fibers decussate Medulla oblongata Medulla Motor fibers oblongata decussate Section of cervical spinal cord Section of cervical spinal cord Motor impulse to skeletal muscle Sensory impulse from skin receptors FIGURE 11. Most (about 85%) of The corticospinal tracts appear to be particularly important in the corticospinal fibers decussate in the pyramids of the medulla voluntary movements that require complex interactions between the motor cortex and sensory input. The remaining 15% do not cross from ample, is impaired when the corticospinal tracts are damaged one side to the other. The fibers that cross compose the lateral in the thoracic region of the spinal cord, whereas involuntary breath- corticospinal tracts, and the remaining uncrossed fibers compose ing continues. Damage to the pyramidal motor system can be de- the anterior corticospinal tracts.
It is essential for the absorption tendons and bones or at points of friction atrioventricular valve A cardiac valve located of fats discount 135mg colospa free shipping spasms rib cage area. It includes the embryo or fetus buy 135mg colospa overnight delivery spasms during meditation, as arise from the inferior surface of the brain. An material between the nucleus and the cell origin; the opposite of proximal. One of posterior, portion of a body part; the opposite the convex folds on the surface of the brain. Deciduous teeth are shed and The blood vessel that connects the the epidermis. It stores spermatozoa and expiration The process of expelling air from recording of the electrical impulses or transports them from the seminiferous the lungs through breathing out; also called activity of a muscle; EMG. Van De Graaff: Human Back Matter Glossary © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 808 Glossary middle-ear chamber and through which fibrous joint A type of articulation bound by frontal plane See coronal plane. The anterior aspect of the head not gap between the incompletely formed cranial chromosome containing the information supporting or covering the brain. The bones of a fetus or baby; commonly known as needed to synthesize a particular protein exposed surface of a structure. It extends formed elements The cellular portion of side-to-side and back-and-forth movements. Pertaining to the forehead or frontal extensions that is capable of forming bone. It merges with the cystic duct intestine and large intestine that forms a hormones. It hepatopancreatic ampulla (hep'a˘-to-pan'kre- commonly known as the “anvil. It is covered by portions of extremity, consisting of the carpus, type, occurring at the articular ends of bones, the frontal, parietal, and temporal lobes. It functions in the transport of oxygen control center located below the thalamus enzymes; also called the crypt of Lieberkühn. A secondary cancerous growth the incus; commonly known as the system, composed of the dura mater, formed by transmission of cancerous cells “hammer. The region in the center of the quadrigemina, the cerebral peduncles, and divides the body or an organ into right and thorax separating the lungs; contains the specialized nuclei that help to control posture left halves; also called the median plane. The pelvic floor autonomic nervous system concerned with bone tissue formation. Its cell body is outside the permits light to enter the posterior cavity of shaped endocrine gland situated in the sella central nervous system, and it terminates at the eyeball and be refracted by the lens. Its cell body is thick ring of smooth muscle encircling the pivot joint A synovial joint in which the within the central nervous system, and it opening between the stomach and the rounded head of one bone articulates with terminates on a postganglionic neuron. It regulates the passage of food the depressed cup of another, permitting material into the small intestine and prevents pregnancy The condition in which a female is rotational movement. It controls inspiratory channel of the cochlea that is filled with gray matter of a reddish color located in the and expiratory phases. It contains sac that contains the testes and their neck, thorax, or abdomen. Nerves arising from the sacral plexus of male accessory reproductive organs, lying organism. It is located below the mandible and bone formed in a tendon in response to joint stress (e. It is attached by mesenteries to the or toward the head; also called cephalic. It vestibular (oval) window of the inner ear; of the hand anteriorly; the opposite of contracts in an involuntary, rhythmic fashion commonly known as the “stirrup. A ligament that supports systemic circulation The circuit of blood flow thigh The proximal portion of the lower an organ or a body part, such as that from the left ventricle of the heart to the extremity between the hip and the knee in supporting the lens of the eye.
If the vertigo is the eyes to dilate the pupils and temporarily inactivate the ciliary sufficiently severe quality colospa 135mg uterus spasms 38 weeks, or if the person is particularly susceptible 135mg colospa zma muscle relaxant, the autonomic nervous system may become involved. This can pro- muscles; (2) a Snellen’s chart, which is used to determine the vi- duce dizziness, pallor, sweating, and nausea. List the structures of the outer ear, middle ear, and measure ocular tension, important in detecting glaucoma. Explain how movements of the basilar membrane can code conditions of the ear, nose, and throat. Explain how the vestibular organs maintain a sense of bal- examine the ears to determine auditory function: (1) an otoscope ance and equilibrium. Some of these occur during the sensitive period of prenatal de- velopment; others, some of which are avoidable, can occur at any time of life. Still other sensory impairments are the result Developmental Problems of changes associated with the natural aging process. The loss of the Eyes and Ears of a sense frequently involves a traumatic adjustment. Fortu- nately, however, when a sensory function is impaired or lost, Although there are many congenital abnormalities of the eyes the other senses seem to become keener to lessen the extent of and ears,most of them are rare. A blind person, for example, compensates some- riod of development is between 24 and 45 days after conception. Most congenital disorders of the eyes and ears are caused Entire specialties of medicine are devoted to specific sen- by genetic factors or intrauterine infections such as rubella virus. It is beyond the scope of this text to attempt a com- prehensive discussion of the numerous diseases and dysfunctions of these organs. Some general comments will be made, however, Snellen’s chart: from Herman Snellen, Dutch ophthalmologist, 1834–1908 Van De Graaff: Human V. Sensory Organs © The McGraw−Hill Anatomy, Sixth Edition Coordination Companies, 2001 Developmental Exposition mesoderm,and endoderm—are involved in the formation of the The Ear ear. Both types of ectoderm (neuroectoderm and surface ecto- derm) play a role. The ear of an adult is structurally and functionally divided EXPLANATION into an outer ear, a middle ear, and an inner ear, each of which The ear begins to develop at the same time as the eye,early dur- has a separate embryonic origin. All three embryonic germ layers—ectoderm, from deep embryonic tissue as one might expect,but rather be- (a) (a1) (a2) (b1) (b2) (b) (c) (d) (e) EXHIBIT II The development of the inner ear. Toward the end of the fourth week,the outer edges of the invaginated otic fovea come together and fuse to form an otocyst. The otocyst further differentiates to form a dorsal utricular portion and a ventral saccular portion. Three separate diverticula extend outward from the utricular por- tion and develop into the semicircular canals, which later func- tion in balance and equilibrium. A tubular diverticulum called the cochlear duct extends in a coiled fashion from the saccular portion and forms the membranous portion of the cochlea of the ear (exhibit II). The spiral organ, which is the functional por- tion of the cochlea,differentiates from cells along the wall of the cochlear duct (Ex. The sensory nerves that innervate the inner ear are derived from neuroectoderm from the developing brain. The differentiating otocyst is surrounded by mesodermal tissue that soon forms a cartilaginous otic capsule (exhibit III). As the otocyst and surrounding otic capsule grow, vacuoles con- taining the fluid perilymph form within the otic capsule. The vacuoles soon enlarge and coalesce to form the perilymphatic space, which divides into the scala tympani and the scala vestibuli. Eventually, the cartilaginous otic capsule ossifies to form the bony (osseous) labyrinth of the inner ear. The middle- ear chamber is referred to as the tympanic cavity and derives from the first pharyngeal pouch (exhibit IV). The auditory ossi- cles, which amplify incoming sound waves, derive from the first and second pharyngeal arch cartilages.