Special Senses and Lymphatic System PDF

 SPECIAL SENSES AND THE LYMPHATIC SYSTEM Consider this… Leslie woke up with eyes swelling and irritated. She complains of a rough feeling in the eyes and the white portion becomes reddish and itchy. 1. What would you do if this happens to you? 2. What would you suggest to Leslie? SPECIAL S...

 SPECIAL SENSES AND THE LYMPHATIC SYSTEM Consider this… Leslie woke up with eyes swelling and irritated. She complains of a rough feeling in the eyes and the white portion becomes reddish and itchy. 1. What would you do if this happens to you? 2. What would you suggest to Leslie? SPECIAL SENSES  Special Senses The Special senses are the senses that have specialized organs devoted to them. It includes: 1. Sight 2. Hearing and Equilibrium 3. Taste 4. Smell I. SIGHT  I. Sight The eye is our organ of sight. They are the organs that allow you to see. They take in light from the world around you and send visual information to your brain. - Nearly 70% of all the body receptors are in the eyes - a sphere that measures about 1 inch in diameter  IMPORTANT PARTS OF THE EYE 1. Sclera 7. Macula 2. Cornea 8. Vitreous Humour 3. Retina 4. Iris 5. Pupil 6. Lens  SCLERA - thewhite of the eye or the white outer layer of the eyeball. - functions as the supporting wall of the eyeball. - helps maintain your eyeball's shape, and protects it from injury.  CORNEA - acts as the eye's outermost lens. - It functions like a window that controls and focuses the entry of light into the eye. - the cornea contributes between 65-75 percent of the eye's total focusing power.  RETINA -athin layer of tissue that covers approximately 65 percent of the back of the eye, near the optic nerve. - Its job is to receive light from the lens, convert it to neural signals and transmit them to the brain for visual recognition.  IRIS - thecolored part of the eye which helps regulate the amount of light entering the eye. - When there is bright light, the iris closes the pupil to let in less light. - And when there is low light, the iris opens up the pupil to let in more light.  PUPIL - its function is clearly that of controlling the amount of light entering the eye, and hence the light reflex.  LENS is located in the eyeball.- - By changing its shape, the lens changes the focal distance of the eye. - In other words, it focuses the light rays that pass through it (and onto the retina) in order to create clear images of objects that are positioned at various distances.  MACULA - located near the center of the retina; - its function is to process sharp, clear, straight-ahead vision.  VITREOUS HUMOR - is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. - helps maintain the round shape of the eye and can also help with vision clarity and shock absorbance. - Most importantly, it helps it to hold its 'spherical' shape. - responsible for about 80% of the volume of your eye  AQUEOUS HUMOR - transparent, colorless, gelatinous mass - flows in and out of the front of your eye. - its job is to keep proper ocular pressure (eye pressure) in your eye. -  EXTERNAL and ACCESSORY PARTS 1. Eyelids 2. Eyelashes 3. Conjunctiva 4. Lacrimal Gland  EYELIDS - arethin soft tissue structures that cover and protect the anterior surface of the eyeball. -The main role of the eyelids is to protect the eye. - It's vital that the surface of the eye (the cornea) remains constantly moist, so the eyelid is responsible for spreading the tear film evenly across the surface. - When we sleep, the eyelids don't simply block out light, they keep the cornea from drying out.  EYELASHES - the short hairs that grow along the edge of our eyelids - are our first line of defense for your eyes, keeping airborne dirt, dust, lint and other debris from reaching the delicate eye tissues. With eyes open, eyelashes catch some airborne debris, but when closed, eyelashes form a nearly impenetrable barrier against foreign irritants in the eye.  CONJUNCTIVA - is a transparent mucous membrane that lines both the inner surface of the eyelids and the anterior surface of the eyeball (except the cornea). - provides protection and lubrication of the eye by the production of mucus and tears. - prevents microbial entrance into the eye and lines the inside of the eyelids and provides a covering to the sclera. - has 2 parts: 1. Bulbar - lining the anterior eye 2. Palpebral – lining the eyelids  LACRIMAL GLAND - situated on lateral end of each eye. - - produces lacrimal fluid (tears);  TEARS is a clear liquid secreted by the lacrimal glands. Tears contain: Dilute salt solution Mucus Antibodies Lysozyme (enzyme that destroys bacteria)  Function of Tears 1. Cleanse 2. Protect 3. Moisten 4. Lubricate the eye II. HEARING AND BALANCE  THE EARS - the organ of hearing and balance. - are paired organs, located on each side of your head, - divide into 3 sections: a. External ear b. Middle ear c. Internal Ear  ANATOMY OF THE EAR 1. External Ear 2. Middle Ear 3. Internal Ear  External Ear External ear is involved only in collecting sound waves. It is composed of the following: 1. Auricle - shell shaped structure surrounding the auditory canal opening. 2. External Acoustic Meatus - narrow chamber in the temporal bone. Lined with skin and ceruminous (earwax) glands. Ends at the tympanic membrane (eardrum).  MIDDLE EAR CAVITY An Air-filled, mucosa-lined cavity within the temporal bone. It is Involved only in the sense of hearing. Located between tympanic membrane and oval window and round window. - made up of auditory ossicles  AUDITORY OSSICLES 1. Malleus (hammer) 2. Incus (anvil) 3. Stapes (stirrup) Function: Transmit vibrations from tympanic membrane to the fluids of the inner ear.  MALLEUS - also called hammer - is the largest, and most lateral of the bony chain. - It is a club-shaped structure - functions with the other bones to transmit vibrations from the eardrum to the inner ear.  INCUS - also called Anvil - the middle of three small bones in the middle ear. - The incus transmits vibrations from the malleus to the stapes.  STAPES - Also called stirrup - the smallest bone in the human body. - the innermost (most medial and nearest to the cochlea of the ossicles inside the middle ear.  INNER EAR Also called the Labyrinth of the ear Includes sense organs for hearing and balance. Has 3 parts: 1. Cochlea 2. Vestibule 3. Semicircular canal  Cochlea - a hollow, spiral-shaped bone found in the inner ear - plays a key role in the sense of hearing and participates in the process of auditory transduction. - Sound waves are transduced into electrical impulses that the brain can interpret as individual frequencies of sound.  Vestibule - best described as the area of the inner ear between the tympanic cavity and posterior to the cochlea. - controls our equilibrium and balance.  Semicircular Canal - Your semicircular canals are three tiny, fluid-filled tubes in your inner ear that help you keep your balance. - When your head moves around, the liquid inside the semicircular canals sloshes around and moves the tiny hairs that line each canal.  EQUILIBRIUM Is a state of balance. Equilibrium does not see, hear or feel. What it does is to respond to various head movements. Receptors of the inner ear are called the vestibular apparatus Vestibular apparatus has two functional parts 1. Static equilibrium – no movement 2. Dynamic equilibrium - moving SMELL AND TASTE  SMELL AND TASTE Involves 2 organs: 1. Tongue 2. Nose  OLFACTORY RECEPTOR and the SENSE of SMELL The faculty or power of perceiving odors or scents by means of the organs in the nose. Nose is the organ of smell.  How do we Smell Vaporized odor molecules (chemicals) floating in the air reach the nostrils and dissolve in the mucus (which is on the roof of each nostril). Underneath the mucus, in the olfactory epithelium, specialized receptor cells called olfactory receptor neurons detect the odor The olfactory receptor neurons transmit the information to the olfactory bulbs, which are located at the back of the nose.  The olfactory bulbs has sensory receptors that are actually part of the brain which send messages directly to the brain. These brain centers perceive odors and access memories to remind us about people, places, or events associated with these olfactory sensations.  TASTE - the sensation of flavor perceived in the mouth and throat on contact with a substance. The tongue is the organ of taste. Humans have taste receptors on taste buds and other areas including the upper surface of the tongue and the epiglottis. Taste has Five Types of Receptors 1. Salty 2. Sweet 3. Bitter 4. Sour 5. Umami (delicious and savoury)  TASTE BUDS and the SENSE of TASTE Taste buds are sensory organs that are found on your tongue and allow you to experience tastes that are sweet, salty, sour, and bitter. It houses the receptor organs of taste. Locations of Taste Buds THE LYMPHATIC SYSTEM  The LYMPHATIC SYSTEM The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. It is also a Drainage System because it facilitates the return of the excess fluids from the cells back to the blood vessels. is a network of organs, vessels and tissues that work together to move a colorless, watery fluid (lymph) back into your circulatory system (your bloodstream).  MAIN FUNCTIONS 1. Collecting excess fluid from your body’s tissues and returning it to your bloodstream 2. Helping your body absorb fats 3. Protecting your body against invaders.  LYMPHATIC VESSELS A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system..  LYMPHS - Isthe fluid that flows through the lymphatic system. - Similar but not identical to that of blood plasma. - Lymph that leaves a lymph node is richer in lymphocytes than blood plasma is.  LYMPH NODES -are small glands that filter lymphs through lymph vessels. They become swollen in response to infection and tumors.. Most lymph nodes are kidney-shaped, less than 1 inch long, and buried in connective tissue. Surrounded by a capsule. Nodes are divided into Compartments: a. Cortex (outer part) contains follicles—collections of lymphocytes. Germinal centers enlarge when antibodies are released by plasma cells b. Medulla (inner part) contains phagocytic macrophages Macrophages—engulf and destroy bacteria, viruses, and other foreign substances in lymph Locations of Lymph Nodes in the Body  Other Lymphoid Organs 1. Spleen 2. Thymus 3. Tonsils 4. Peyer’s Patches  Spleen It is a soft organ located on the left side of the abdominal cavity. It filters and cleanses blood of bacteria, viruses and other debris. Most important function is to destroy worn out RBC’s and return some of its breakdown products to the liver. Ex iron – used again in making hemoglobin.  Thymus - a lymphoid mass found in the anterior mediastinum overlying the heart. is responsible for producing and maturing lymphocytes, or immune cells. - these include T cells, a type of white blood cell that defends the body from infections.  Tonsils Small masses of lymphoid tissue deep to the mucosa surrounding the throat. Its job is to trap and remove bacteria entering the throat.  Peyer’s Patches Are found in the wall of the intestine. Captures and destroys bacteria. GOOD LUCK, NURSES!!