SENSE ORGANS OF HUMAN BODY AND IT'S FUNCTIONS.pptx

This note describes some sense organs such as eye, ear and many more orange.
It first describe the organ and it's function, not only that it also shows all the parts of the organ and it's function.
In addition, it also describes where the organ are located in the body.

1. SENSE ORGANS (SKIN AND TONGUE)

2. INTRODUCTION The sense organs are the body organs by which humans are able to taste, touch or feel. The two sense organs that are been looked at are: Tongue (for tasting), and skin (for touching or feeling). Our two senses are our sense of taste (gustation), and touch ( somatosensation ). A sense is our ability to detect stimuli which are then interpreted and responded to accordingly. Sensory organs are organs of the body that access those sensory capabilities and help us become conscious and respond to our surroundings.

3. The skin The Human Skin Is The Outer Covering Of The Body And It Is The Largest Organ Of The Integumentary System (It Comprises Of The Skin And It’s Appendages Acting To Protect The Body From Various Kinds Of Damage, Such As Loss Of Water Or Damages From Outside). The Skin Has Up To Seven Layers Of Ectodermal Tissue And Guards The Underlying Muscles, Bones, Ligaments And Internal Organs.

4. The skin is made up of three main layers namely; the epidermis, dermis and the subcutaneous . The epidermis The epidermis is the outermost of three layers that make up the skin. the epidermis provides a barrier to infection from environmental pathogens and regulates the amount of water released from the body into the atmosphere through transepidermal water loss. There are five layers of the epidermis: Stratum basale : This bottom layer, which is also known as the basal cell layer, has column-shaped basal cells that divide and push older cells toward the surface of the skin. As the cells move up through the skin, they flatten and eventually die and shed.

5. Stratum spinosum : This layer, which is also known as the squamous cell layer, is the thickest layer of the epidermis. It contains newly formed keratinocytes, which are strengthening proteins. It also contains Langerhans cells that help prevent infection. Stratum granulosum: This layer contains more keratinocytes moving toward the surface. Stratum lucidum : This layer exists only on the palms of the hands and soles of the feet. Stratum corneum : This is the outermost or top layer of the epidermis. It's made of dead, flat keratinocytes that shed approximately every two weeks . The epidermis contains three specialized cells : Melanocytes that produce pigment (melanin) Langerhans cells that act as the first line of defense in the skin's immune system Merkel cells that have a function that is not yet fully understood.

6. The dermis The dermis is tough and elastic. It is formed from connective tissue and the matrix contains collagens fibers. Fibroblast, macrophages and the mast cells are the main cells found in the dermis. the dermis supports the epidermis and enables the skin to thrive. It also plays a number of others roles due to the presence of nerve endings, sweat glands, sebaceous gland, hair follicles and blood vessels

7. The dermis is home to three different types of tissues that are present throughout: Collagen Elastic tissue Reticular fibers The dermis contains several specialized cells and structures, including: Hair follicles Sebaceous glands Apocrine and endocrine glands Blood vessels and nerve endings Meissner corpuscles and lamellar corpuscles that transmit the sensations of touch and pressure.

8. The Subcutaneous Tissue Subcutaneous tissue is the deepest and innermost layer of the three layers of skin. It's mostly made up of fat, connective tissue, and larger blood vessels and nerves. The thickness of this layer varies depending on where it's located on the body—for example, it's thickest on the buttocks, the soles of the feet, and the palms of the hands. Subcutaneous tissue is a vital component of body temperature regulation. It also acts as a cushion, so if you ever fall or hit something with your body, it protects your insides and makes the injury hurt less.

9. The skin has eight main functions: • Heat regulation: cools and warms body. • Absorption: of drugs or essential oils. • Protection: keeps out bacteria and creates a barrier against rays of the sun. • Elimination: of waste products. • Sensation: skin is the organ of touch. • Vitamin D production. • Melanin production.

10. THE HUMAN TONGUE

11. The tongue A fleshy, movable muscular organ in the floor of the mouth of most vertebrates that contains sensory end organs and small glands and functions in taking and swallowing food, and also as a speech organ in humans. The tongue is covered with moist pink tissue called MUCOSA. It consists of the tiny bumps called papillae which gives a rough texture. The tongue is divided in three major parts namely; the apex, the main body and the root.

12. The Tip or Apex The tip or apex of the tongue accounts for one-third of the anterior surface of tongue. It is highly movable and rests against the incisor teeth in the mouth cavity. The taste buds for “sweet” are present on this part. The tip also plays its role in the production of labiodental and alveolar sounds. The Body or Main Part The anterior two-thirds of the tongue form its body. The pres-ence of lingual papillae on the upper side makes the surface rough. A layer of mucosa, on the other hand, keeps it moist. It is this part of the tongue where the tongue taste buds for salt, bitter and sour taste are present. The Root or Base The root is that part of the tongue which attaches it to the bottom or floor of the mouth cavity. It appears between the mandible and the hyoid bone. The pri-mary job of the hyoid bone is to provide anchorage to the tongue. The dorsal portion of the root lies in the oropharynx (It is the part of the pharynx lying between the soft palate and epiglottis).

13. Surface Features of the Tongue 1. lingual papillae contain the taste buds and are located on the anterior surface (body and tip) of the tongue : 2. Vallate papillae are large and flat papillae arranged in a V-shaped row just in front (anterior) of the terminal sulcus. 3. Foliate papillae are poorly developed folds on the side of the tongue. 4. Filiform papillae are long, conical, pinkish gray projections that are sensitive to touch. 5. Fungiform papillae are pink to red spots distributed between the filiform papillae and are most dense at the apex and margins of the tongue. 6 . The posterior surface of the tongue has no lingual papillae but has a rough surface due to the presence of lymphoid nodules. 7 . midline groove divides the anterior part of the tongue into the left and right parts. 8 . inferior surface is connected to the floor of the mouth by a fold known as the frenulum. A visible vein on either side of the frenulum is known as the deep lingual vein. 9 . sublingual papillae (caruncle) is located on either side of the base of the frenulum and it is the opening for the ducts of the submandibular gland ( salivary glands ).

14. 1 . Taste Food Different types of receptor cells help distinguish between various sorts of differently tasting substances, such as sweet, sour, bitter, spicy and salty. On the tip, you will find taste buds for sensing sweet. Behind the apex and along the sides, there are receptors for tasting bitter, sour and salty things. Dorsum – the upper surface of the tongue – contains lots of lingual papillae. The papillae house the taste buds and the taste receptors. These receptors assist in the sensation of taste of different types of dietary components which come into contact with them. The taste receptors are of five main types – sweet taste receptors, bitter taste receptors, salty taste receptors, sour taste receptors and umami taste receptors. The umami taste receptors help you detect the taste of amino acids in the food. Functions of the tongue

15. 2 . Mastication & Chewing Tongue facilitates the process of mastication and chewing. Particularly, it helps in the positioning of food between the teeth. 3 . Removal of Hard and Ill-Tasting Substances Tongue has also a role in separating, sorting out and removing unsuitable particles that may accidently come with the food, such as bones and the ill-tasting soft or hard substances. 4. Swallowing Food The masticated food forms a rounded mass, the bolus, with the help of tongue. The task of this fantastic muscular organ does not end here. Its next duty is to expel the bolus into esophagus at the back of the mouth cavity.

16. 5 . Tongue as an Organ of Speech You produce different speech sounds as a stream of air coming from the lungs leaves body through mouth. Your mouth cavity is home to various organs of speech. Different speech organs include tongue, teeth, lips, palate and uvula, etc. Here, tongue is of incredible importance. The tip of the tongue, the body and the back significantly contribute to the production of vowel and other sounds. Different parts of tongue play their own part in producing and modifying sounds. For example, labiodental sounds are produced while the tip of tongue touches the upper teeth. To produce the /k/ and /g/ sounds, the back of the tongue raises against the roof top.Composed of a set of extremely movable tongue muscles, it can quickly assume various shapes for the efficient performance of all the assigned tasks. 6 . An Organ for Sucking Almost all the mammals suck milk from the breasts of their mother parent in infancy. They do so with the help of their tongue by creating negative pressure within their oral cavity.