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Specified risk material (SRM) is any of various tissues of ruminant animals that cannot be inspected and passed for human food because scientists have determined that BSE-causing prions concentrate there. The term was referred to in the United Kingdom's Specified Risk Material Order 1997 (S.I. 1997/2964), in the United States Department of Agriculture's, and in the Canadian Food Inspection Agency's regulatory response to the first confirmed U.S. BSE case in December 2003. [1] [2] [3]
These can include brains, eyes, spinal cord, and other organs; the exact definition varies by jurisdiction. Under the new US regulations (69 FR 1862, January 12, 2004), SRMs are: the brain, skull, eyes, trigeminal ganglia, spinal cord, vertebral column (with some exclusions), dorsal root ganglia (DRG) of cattle 30 months of age and older, the tonsils and distal ileum of the small intestine of all cattle.[ citation needed ]
The BSE infective agent has been found to concentrate in specific tissues of BSE-infected cattle.
BSE SRMs |
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The United States (U.S.) is considered as negligible BSE risk country and Canada is considered as controlled BSE risk country, SRMs are defined as: skull, brain, trigeminal ganglia (nerves attached to brain and close to the skull exterior), eyes, spinal cord, distal ileum (a part of the small intestine), and the dorsal root ganglia (nerves attached to the spinal cord and close to the vertebral column) of cattle aged 30 months or older. On January 12, 2004, the Food Safety and Inspection Service of the USDA published new rules banning such materials from the human food supply.[ citation needed ]
In countries classified as undetermined risk, the OIE code recommends SRM removal as follows: tonsils and intestines in cattle at all ages; brains, eyes, spinal cord, skull and vertebral column from animals over twelve months of age.
In the European Union (E.U.), SRMs are excluded by law from the human and animal food chain.
The World Organization for Animal Health (OIE) has established recommendations and guidelines for SRM removal based on the level of risk. In the U.S., tonsils are removed from cattle of all ages. SRMs must be removed at slaughter and disposed as inedible material. The dorsal root ganglia must be removed during the deboning process and in animals older than 30 months, the vertebral column (excluding the vertebrae of the tail, the transverse processes of the lumbar and thoracic vertebrae, and the wings of the sacrum) is removed to be certain the dorsal root ganglia is extracted in its entirety.[ citation needed ]
Cranial nerves are the nerves that emerge directly from the brain, of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and from regions of the head and neck, including the special senses of vision, taste, smell, and hearing.
A body cavity is any space or compartment, or potential space, in an animal body. Cavities accommodate organs and other structures; cavities as potential spaces contain fluid.
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A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the corresponding cervical, thoracic, lumbar, sacral and coccygeal regions of the spine. There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system.
The dorsal column–medial lemniscus pathway (DCML) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception from the skin and joints. It transmits information from the body to the primary somatosensory cortex in the postcentral gyrus of the parietal lobe of the brain. The pathway receives information from sensory receptors throughout the body, and carries this in nerve tracts in the white matter of the dorsal column of the spinal cord to the medulla, where it is continued in the medial lemniscus, on to the thalamus and relayed from there through the internal capsule and transmitted to the somatosensory cortex. The name dorsal-column medial lemniscus comes from the two structures that carry the sensory information: the dorsal columns of the spinal cord, and the medial lemniscus in the brainstem.
In human anatomy, the spinal canal, vertebral canal or spinal cavity is an elongated body cavity enclosed within the dorsal bony arches of the vertebral column, which contains the spinal cord, spinal roots and dorsal root ganglia. It is a process of the dorsal body cavity formed by alignment of the vertebral foramina. Under the vertebral arches, the spinal canal is also covered anteriorly by the posterior longitudinal ligament and posteriorly by the ligamentum flavum. The potential space between these ligaments and the dura mater covering the spinal cord is known as the epidural space. Spinal nerves exit the spinal canal via the intervertebral foramina under the corresponding vertebral pedicles.
Neuromeres are distinct groups of neural crest cells, forming segments in the neural tube of the early embryonic development of the brain. There are three classes of neuromeres in the central nervous system – prosomeres, mesomeres and rhombomeres that will develop the forebrain, midbrain, and hindbrain respectively.
A dermatome is an area of skin that is mainly supplied by afferent nerve fibres from the dorsal root of any given spinal nerve. There are 8 cervical nerves , 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves. Each of these nerves relays sensation from a particular region of skin to the brain.
A pseudounipolar neuron is a type of neuron which has one extension from its cell body. This type of neuron contains an axon that has split into two branches. A single process arises from the cell body and then divides into an axon and a dendrite. They develop embryologically as bipolar in shape, and are thus termed pseudounipolar instead of unipolar.
The dorsal root of spinal nerve is one of two "roots" which emerge from the spinal cord. It emerges directly from the spinal cord, and travels to the dorsal root ganglion. Nerve fibres with the ventral root then combine to form a spinal nerve. The dorsal root transmits sensory information, forming the afferent sensory root of a spinal nerve.
The sympathetic trunks are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. They are a major component of the sympathetic nervous system.
The lateral grey column is one of the three grey columns of the spinal cord ; the others being the anterior and posterior grey columns. The lateral grey column is primarily involved with activity in the sympathetic division of the autonomic motor system. It projects to the side as a triangular field in the thoracic and upper lumbar regions of the postero-lateral part of the anterior grey column.
In neuroanatomy, the dorsal column nuclei are a pair of nuclei in the dorsal columns in the brainstem. The name refers collectively to the cuneate nucleus and gracile nucleus, which are situated at the lower end of the medulla oblongata. Both nuclei contain second-order neurons of the dorsal column–medial lemniscus pathway, which convey fine touch and proprioceptive information from the body to the brain. The dorsal column nuclei project to the thalamus.
This article describes the anatomy of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat.
Bovine spongiform encephalopathy (BSE), commonly known as mad cow disease, is an incurable and invariably fatal neurodegenerative disease of cattle. Symptoms include abnormal behavior, trouble walking, and weight loss. Later in the course of the disease the cow becomes unable to function normally. There is conflicting information about the time between infection and onset of symptoms. In 2002, the World Health Organization (WHO) suggested it to be approximately four to five years. Time from onset of symptoms to death is generally weeks to months. Spread to humans is believed to result in variant Creutzfeldt–Jakob disease (vCJD). As of 2018, a total of 231 cases of vCJD had been reported globally.
The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system.
The term Feed ban is usually a reference to the regulations that have prohibited the feeding of most mammalian-derived proteins to cattle as a method of preventing the spread of bovine spongiform encephalopathy (BSE). Feeding of infected ruminant material back to ruminants is believed to be the most likely means of transmission of the disease.
Meat on the bone or bone-in meat is meat that is sold with some or all of the bones included in the cut or portion, i.e. meat that has not been filleted. The phrase "on the bone" can also be applied to specific types of meat, most commonly ham on the bone, and to fish. Meat or fish on the bone may be cooked and served with the bones still included or the bones may be removed at some stage in the preparation.
Each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species.
The mad cow crisis is a health and socio-economic crisis characterized by the collapse of beef consumption in the 1990s, as consumers became concerned about the transmission of bovine spongiform encephalopathy (BSE) to humans through the ingestion of this type of meat.