Sensory information from the periphery of the animal ascends through the spinal cord and enters the higher levels of the brain. There are numerous pathways which allow different types of information to be passed to the brain. Types of general somatic sensation include pain, touch, temperature and kinaesthesia (conscious proprioception). This sensory information is sent to one of two destinations; the cerebral cortex or the cerebellum.

The epidermis is a stratified squamous epithelium and is composed of 4 cell layers anchored to a basal lamina of connective tissue. Keratinocytes migrate through the epidermis from the basal layer. This migration begins in the stratum basale, then moves up through the stratum spinosum, stratum granulosum and the stratum corneum.

Hormones have a large effect on the skin, details of which can be found at endocrine and nutritional influences on the skin. As a result, endocrine associated skin pathology is relatively common.

The small intestine extends from the pylorus of the stomach to the caecum. The small intestine recieves chyme from the stomach. It is the main site of chemical degradation and absorption of chyme. Fats are exclusively broken down in this part of the alimentary tract. Carbohydrates and proteins that are not degraded in the small intestine are available for microbial fermentation in the large intestine. The small intestine produces enzymes for digestion of protein, carbohydrate and fat and absorbs the products of their digestion. Enzymes are produced by glands in the intestinal wall and the pancreas. The gall bladder produces bile which emulsifies fats for digestion. Absorption is facilitated by ridges in the small intestine and by the presence of villi and microvilli.

n the verterbrate embryo, as the primitive streak is regressing, the paraxial mesoderm divides into blocks of cells called somites. These divisions can be seen either side of the notochord. Somites are transient structures that will give rise to cells of the vertebrae and ribs, dermis of the dorsum, skeletal muscle of the body wall, back and limbs. Somites begin to develop at the anterior of the embryo first, and appear at regular intervals.

Fusion of the two plates of the thyroid cartilage is incomplete forming a rostral pointing notch which is a good site for surgical entry into the larynx. The thyroarytenoid muscle is divided into 2 parts; the rostral and caudal vocalis, which are situated within the vocal folds and vestibular folds. The cuneiform processes are attached to the epiglottis.

The spinal cord is constructed of the marginal layer which has axons and white matter, the mantle which contains cell bodies and grey matter and the spinal canal. This canal conducts sensory information from the peripheral nervous system (both somatic and autonomic) to the brain, conducts motor information from the brain to various effectors and acts as a minor reflex center.

Epidemiological studies can be described as belonging to one of two categories: descriptive or analytical. Descriptive studies involve detailed investigations of individuals in order to improve knowledge of disease. Descriptive studies often have no prior hypotheses and are opportunistic studies of disease whereas analytical studies are used to test hypotheses by selection and comparison of groups. However, data obtained from analytical studies can be used in a descriptive manner and vice versa.

This page explains superficial anatomy through a guide to the superficial anatomy of a dog, including the head, forelimb, and hindlimb. Detailed Illustrations open in new tab.

Monitoring of the epidemiological patterns (animal, place, time) of diseases and pathogens within populations provides a vital system for the identification of changes in disease status within this population (whether this relates to all animals worldwide, or those within a single country, region, village or farm). For this reason, most countries have systems in place for the intermittent collection and collation of data relating to disease. Monitoring of production levels also provides a method of informing farmers about the productivity of their animals. These processes can be described as monitoring systems.

T cells are so named as they differentiate in the thymus. They are long lived and are involved in cell mediated immunity. They represent 60-80% of the circulating lymphocytes and all express the markers CD2, CD3 and CD7 as well as having T cell receptors (TCR). Each T cell has 30,000 TCRs each of which is identical and recognises antigens and major histocompatability complex (MHC) II.

Thermoregulation is the ability of an endothermic organism to maintain a relatively constant body temperature, despite fluctuations in temperature of the external environment. This is a vital part of homeostasis.

Thrombocytes are small anuclear fragments of megakaryocytes. They are membrane bound portions of the megakaryocyte cytoplasm and have a finely granular cytoplasm; they are much smaller than other blood cells at 2-3ľm and have a lifespan of around 10 days in the circulation.

As with erythrocytes, thrombocytes are derived from multipotential myeloid stem cells (CFU-GEMM). In the bone marrow CFU-GEMM cells differentiate into the megakaryocyte precursor cell the megakaryocyte CFU (CFU-Meg), under the influence of cytokines CFU-CSF and IL-3. Unlike other blood cells which undergo mitosis in the first few developmental stages, once the CFU-GEMM has differentiated into the CFU-Meg there is no further mitosis. The CFU-Meg then develops into the megakaryoblast.

The thyroid gland lies in the neck, in front of the upper part of the trachea. Two types of hormones are produced, which are the iodine containing hormones; tri-iodothyronine(T3) and thyroxine (T4). Thyroid hormones regulate the basal metabolic rate and are important in the regulation of growth of tissues, particularly nervous tissue. Release stimulated by TSH from the pituitary. The second type of hormone produced from the thyroid gland is calcitonin, which regulates blood calcium levels along with parathyroid hormone and acts to reduce blood calcium by inhibiting its removal from bone.

Teeth develop differently in different regions of the mouth in most species, a process called heterodonty. In some animals, teeth develop identically in different regions of the mouth, a process called homodonty. Different species will have varying numbers of teeth and different shapes depending largely on their diet. Not all species possess teeth and there is huge variation in dental formulae between the species that have teeth. Teeth are mainly used for mastication - chewing and grinding food particles, but are also used for seizing prey and tearing. The occlusion surface is where opposing teeth touch. The contact surface is where adjacent teeth touch.

The trachea is the tube linking the cricoid cartilage of the larynx to the bronchi, forming part of the conducting system which transports air from the external environment to the lungs. The oesophagus lies dorsally to the trachea. The cervical part of the trachea lies generally in the median position, although this varies slightly depending on the position of the head. The thoracic part of the trachea crosses the aortic arch, thus its positioning is moved slightly to the right at this level. The trachea bifurcates to form the two bronchi at the level of the 4th-6th intercostal space.

Hydrophillic ions and molecules are unable to diffuse across the lipid bilayer. However if concentration gradients allow it they are sometimes able to diffuse across the membrane using water filled protein channels. These tend to be only large enough for small ions to pass through and so are perhaps more commonly known as ion channels.

The urinary system includes the kidneys, the ureters which join the kidneys to the bladder, the bladder itself and the urethras which permit urine collecting in the bladder to be excreted - a process termed micturition. Understanding the physiology of kidney function is key when looking at the diseases that occur in this organ, and the anatomy of all the structures within the urinary sytem is significant as a foundation to understanding the pathology which affects them.