Gesunheitslehre

The semicircular canals are responsible for detecting rotational movements, head tilting, and the position of the body in space.

The utricle and saccule are responsible for detecting linear acceleration and gravity, informing the brain about changes in head position and overall body movement.

Damage to the utricle and saccule can result in:

• Misjudging spatial orientation
• Loss of control over body posture
• Dizziness, nausea
• Sensations of spinning or falling
• Visual disturbances

Information from the vestibular system is processed in the brain. Inconsistencies between visual input and vestibular input can lead to motion sickness.

The olfactory bulb receives signals from the olfactory receptors, processing odors and transmitting information to the brain via olfactory nerves.

Olfactory information affects emotions, decision-making, and motivation.

Olfaction impacts a wide range of behaviors, including:

• Identifying prey and predators
• Recognizing mates
• Navigating and locating specific places
• Distinguishing food sources
• Recognizing offspring and family members
• Determining group affiliation.

Microsmats have a less developed olfactory system with fewer olfactory receptor cells compared to macrosmats.

Humans and birds are examples of microsmats, having a less developed sense of smell.

Rats and dogs are examples of macrosmats, having a highly developed sense of smell.

Anosmats lack the ability to smell because they have poorly developed olfactory systems, as seen in whales and manatees.

The surface of the tongue is covered in taste buds grouped into taste papillae, allowing for taste perception.

Taste buds, also called taste papillae, contain receptor cells that detect different tastes such as sweet, salty, sour, bitter, and umami.

Taste is essential for identifying nutritious and potentially hazardous foods.

The ciliary muscle is responsible for changing the shape of the lens in the eye.

The ciliary muscle allows the lens to adjust its curvature, changing its refractive power to focus on objects at varying distances. This process is called accommodation.

Nearsightedness (myopia) occurs when incoming light focuses in front of the retina, while farsightedness (hyperopia) occurs when light focuses behind the retina.

Sound is produced by vibrations that travel through the air as sound waves.

The outer ear, specifically the pinna, catches sound waves and directs them into the ear canal.

The eardrum vibrates in response to incoming sound waves, transmitting these vibrations further into the ear.

The ossicles (malleus, incus, stapes) transfer vibrations from the eardrum to the oval window of the inner ear. The stapes amplifies the vibrations before delivering them to the oval window.

The inner ear contains the cochlea, a spiral-shaped structure filled with fluid. Sound waves travel through the fluid, stimulating hair cells in the organ of Corti.

The cochlea converts sound vibrations into electrical signals that are transmitted to the brain via the auditory nerve.

The auditory nerve transmits electrical signals from the cochlea to the auditory cortex in the temporal lobe of the brain, where sounds are processed and understood.

Sound waves travel through the ear as follows:

• Sound waves → eardrum → ossicles (malleus, incus, stapes) → cochlea → auditory nerve → brain.

Hair cells in the cochlea move due to fluid displacement, generating electrical impulses.

The eardrum, a thin membrane, vibrates in response to sound waves, transferring these vibrations to the ossicles (hammer, anvil, stirrup). The stirrup amplifies the vibrations and transmits them to the oval window of the inner ear.

The skin is the largest sensory organ, responsible for detecting pressure, temperature, touch, pain, and vibration.

Tactile perception is the ability to detect touch and pressure through specialized sensory cells in the skin.

Haptic perception involves actively exploring objects through touch, movement, and pressure, often using the hands.

The three layers of skin from inside to outside are:

• Subcutis (hypodermis)
• Dermis
• Epidermis

Temperature is detected by specialized sensory cells called thermoreceptors located in the skin. There are separate receptors for heat and cold.

Sensory nerves connect the specialized sensory cells in the skin to the central nervous system (including the spinal cord and brain), conveying information about touch, pressure, temperature, and pain.