Sense Organs PDF

SENSE ORGANS LIFE SCIENCE MAYA SUJITH KRISHNAN  SENSE ORGANS Sense organs are the organs that respond to external stimuli by conveying impulses to the sensory nervous system. 5 Sense Organs are 1. Nose- Smell 2. Ear- Hear 3. Tongue- Taste 4. Eyes- Vision 5. Skin-...

SENSE ORGANS LIFE SCIENCE MAYA SUJITH KRISHNAN  SENSE ORGANS Sense organs are the organs that respond to external stimuli by conveying impulses to the sensory nervous system. 5 Sense Organs are 1. Nose- Smell 2. Ear- Hear 3. Tongue- Taste 4. Eyes- Vision 5. Skin- Touch EARS- HEARING Maya Sujith Krishnan Subject Expert  EARS 1. Study of Ear: Otology 2. Otolaryngology : Focuses on the ears, nose, and throat: ENT 2 functions 1. Hearing : 20-20,000 Hz range 2. Maintaining balance of the body  EARS Parts of Ear: 3 Regions: ➔ Outer Ear, ➔ Middle Ear, ➔ Inner Ear  TEST YOUR KNOWLEDGE MEMBRANE THAT SEPARATES THE OUTER EAR FROM THE MIDDLE EAR BY__________? A. Auditory canal B. Tympanum C. Pinna  EARS- OUTER EAR a. Pinna: Outer funnel shaped structure made up of cartilage. Vestigial organ b. Ear Canal/Auditory Canal: Fine hair and Ceruminous glands (wax gland) and Carries the soundwaves to the middle ear c. Ear Drum (Tympanum): Separates the outer ear from the middle ear  TEST YOUR KNOWLEDGE MEMBRANE THAT SEPARATES THE OUTER EAR FROM THE MIDDLE EAR BY__________? A. Auditory canal B. Tympanum C. Pinna  TEST YOUR KNOWLEDGE WHICH IS THE SMALLEST BONE IN OUR BODY? A. Malleus B. Incus C. Stapes  EARS MIDDLE EAR: Air filled cavity. 3 bones called ear ossicles concentrate the sound and passes it to the inner ear a. Malleus (Hammer shaped) b. Incus (Anvil shaped) c. Stapes (Stirrup): Smallest bone of body Smallest Muscle- Stapedius EUSTACHIAN TUBE (Auditory Tube): Connects the middle ear to the nasopharynx. It helps in equalising the pressures on either sides of the eardrum  TEST YOUR KNOWLEDGE WHICH IS THE SMALLEST BONE IN OUR BODY? A. Malleus B. Incus C. Stapes  TEST YOUR KNOWLEDGE WHICH PART OF THE INNER EAR RESPONSIBLE FOR HEARING? A. Semicircular canals B. Vestibule C. Cochlea  EARS INNER EAR: Fluid filled cavity called Labyrinth. It consists of two parts, 1. the bony Labyrinth and 2. the membranous labyrinths. Membranous Labyrinth is present inside the bony labyrinth and is surrounded by a fluid called perilymph. The membranous labyrinth is filled with a fluid called endolymph.  EARS INNER EAR: a. Semicircular canals: Balancing b. Vestibule: Balancing c. Cochlea: Hearing: it has Organ of Corti which has hair-like cells on its basilar membrane. When the fluid in the cochlea moves and vibrates due to the sound waves, the hair cells also vibrates. AUDITORY NERVE: Electrical signals to the brain HEARING  TEST YOUR KNOWLEDGE WHICH PART OF THE INNER EAR RESPONSIBLE FOR HEARING? A. Semicircular canals B. Vestibule C. Cochlea SKIN- TOUCH Maya Sujith Krishnan Subject Expert  SKIN Largest organ- Skin Study of skin- Dermatology Pigment that gives colour to skin- Melanin Melanin protects against the harmful effect of UV rays of the Sun Albinism: Genetic disorder which causes low production of melanin Function: General receptors to detect touch, pain,pressure, temperature and also in excretion 2 types of glands in skin: 1. Sweat gland 2. Sebaceous gland  SKIN Outer layer- Epidermis- No nerves or blood vessels. Function: Protection Middle Layer- Dermis- Has blood vessels, nerves, hair follicles, sweat gland and sebaceous glands. Blood vessels in the dermis provide nutrients to the epidermis Innermost: Subcutaneous layer: Made of fat and connective tissue. Helps in temperature regulation NOSE- SMELL Maya Sujith Krishnan Subject Expert  NOSE The nose is an olfactory organ. Study of Nose: Rhinology Nasal mucosa and the epithelium is called olfactory epithelium Nasal cavity is lined with olfactory cells (Chemoreceptors) which conducts nerve impulse to the brain by olfactory nerve. Inability of sense smell: Anosmia THANK YOU