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Mechanoreceptors

• Types of Mechanoreceptors:

  • Ruffini Corpuscles: Sensitive to pressure and sustained touch, located in the dermis.

  • Merkel's Discs: Touch-sensitive receptors also in the epidermis.

  • Meissner's Corpuscles: Responsible for light touch discrimination.

  • Pacinian Corpuscles: Onion-shaped corpuscles sensitive to deep pressure and vibration, found in the dermis.

  • Free Nerve Endings: Primarily responsible for pain, itch, and temperature sensations.

Fun Activity

• Activity Description:

  • One partner closes their eyes while the other uses a pen to mark their palm.

  • The person with their eyes closed must then point to the same spot marked on their palm.

  • Repeat the activity on the back of the hand and forearm to see how accurate the sense of touch is.

Pain Receptors

• Nociceptors (Pain Receptors):

  • Free nerve endings that detect pain, itch, and temperature, mainly located in the epidermis and dermis.

  • Examples include Ruffini and Meissner's corpuscles for different sensations.

Chemoreceptors

• Taste Receptors (Gustatory Epithelium):

  • Found in taste buds located on the tongue and associated structures (e.g., epiglottis, tonsils).

  • Types of taste receptors include those for sweet, sour, salty, bitter, and umami, with contributions from Vallate and Fungiform papillae.

• Olfactory Receptors (Smell):

  • Located in the olfactory epithelium lining the nasal cavity, playing a crucial role in the olfactory process.

Thermoreceptors

• Function: Respond to temperature changes.

  • Located in the epidermis and dermis, capable of detecting pain, heat, and cold through various nerve endings such as:

    • Krause End Bulbs: Cold sensitivity.

    • Ruffini Endings: Warmth sensitivity.

    • Pacinian Corpuscles: Detect pressures.

Proprioceptors

• Role: Sense body position and movement.

  • Located in muscles and tendons, detecting stretch and tension for coordination of movement and balance.

  • Include muscle spindle fibers and Golgi tendon organs.

Ear Anatomy

• Parts of the Ear:

  • Outer Ear: Includes the helix, auricle, and external acoustic meatus.

  • Middle Ear: Contains malleus, incus, stapes (ossicles), and the tympanic membrane (eardrum).

  • Inner Ear: Comprised of structures like the cochlea and vestibular apparatus, responsible for hearing and balance.

Anatomy of the Eye

• Key Structures:

  • Cornea, Lens, Iris: Essential for focusing light.

  • Retina: Contains photoreceptor cells responsible for converting light into neural signals.

  • Optic Nerve: Transmits visual information from the retina to the brain.

Brain Anatomy

• Major Regions:

  • Cerebral Cortex: Divided into lobes (frontal, parietal, occipital, temporal) responsible for various sensory processes.

  • Brain Stem: Involved in basic life functions and relaying signals between the brain and spinal cord.

  • Cerebellum: Key player in motor control, coordination, and balance.

Cerebrum Functions

• Frontal Lobe: Controls voluntary movements and higher cognitive functions.

• Parietal Lobe: Processes sensory information related to touch, taste, and temperature.

• Temporal Lobe: Engaged in auditory processing and memory.

• Occipital Lobe: Primarily dedicated to vision.