The Body's Senses: Perception & Response Mechanisms

Sensory Perception and Bodily Responses

Sensory Perception

Sensory perception is the process of obtaining information through our senses: sight, hearing, balance, smell, taste, and touch. Receptors also exist that capture the internal conditions within the body.

Bodily Responses

Our body's responses are executed by the locomotor system (formed by bones and muscles) and the endocrine system (which functions through hormones), responsible for movement and regulation.

The Sense of Sight (Vision)

Key components of the eye include:

• Cornea: A transparent layer that covers the front of the eye.
• Iris: A layer that can dilate or shrink, regulating the passage of light through an opening called the pupil.
• Sclera: The layer that gives shape to the eyeball.
• Conjunctiva: A membrane lining the eyeball and the inside of the eyelids.
• Aqueous Humor: Liquid that fills the cavity located between the cornea and the crystalline lens.
• Crystalline Lens: A lens-shaped membrane that permits focusing images exactly on the retina.
• Vitreous Humor: A gelatinous substance that occupies the inside of the eyeball.
• Retina: A layer of cells lining the back inside of the eye, where images are formed.
• Eyelids: Layers of tissue that cover the front of the eye for protection.
• Eyelashes: Hairs on the eyelids that provide shade and protection.
• Eyebrows: Hairs covering the prominences located above the eyes, offering protection.

The Sense of Hearing (Audition)

The ear is divided into three main parts:

• External Ear: Comprises the auricle (or pinna) and the external auditory canal (ear canal).
• Middle Ear: Consists of the eardrum, hammer (malleus), anvil (incus), stapes, and oval window.
• Internal Ear: Consists of the cochlea and the auditory nerve.

The Sense of Balance (Vestibular System)

The vestibular apparatus is the organ of balance, located in the inner ear. It consists of:

• Semicircular Canals: Tubes filled with a liquid called endolymph.
• Otolith Organs: Small sacs called the saccule and utricle, which contain calcareous particles named otoliths.

The Sense of Smell (Olfaction)

The olfactory system includes:

• Nasal Cavity: The orifice through which air enters and communicates with the air cavity.
• Turbinates (Nasal Conchae): Bony structures within the walls of the nasal cavity, covered by mucosa.
• Olfactory Mucosa: Lining the upper parts of the nasal cavity, including the turbinates, containing olfactory receptors.

The Sense of Taste (Gustation)

The primary structures for taste are:

• Taste Buds: Structures containing taste receptors, primarily found on the tongue and other areas of the mouth.

The Sense of Touch (Tactition)

The skin, the primary organ for touch, has two main layers:

• Epidermis: The outer layer, formed by epithelial tissue. It contains receptors that capture sensations like pain.
• Dermis: The inner layer, composed of connective tissue, muscle tissue, capillaries, glands, and various receptors for touch, pressure, temperature, and pain.