Sensory Receptors, Locomotor System, and Injury Prevention

Posted on Feb 11, 2025 in Biology

Sensory Receptors

Sensory receptors are structures formed by nerve cells, specialized to capture and transform stimuli into nerve impulses.

Receptors are classified as:

• Chemoreceptors: Sensitive to chemicals.
• Mechanoreceptors: Sensitive to mechanical stimuli such as touch and pressure.
• Photoreceptors: Light-sensitive.
• Thermoreceptors: Sensitive to temperature variations.
• Nociceptors: Sensitive to intense pressures; responsible for pain.

They are also classified by their location:

• Internal receptors: Located inside the body, in the viscera.
• External receptors: On the surface of the body.

Sight

The sense of sight lies in the eyes, very complex and specialized organs responsible for receiving light stimuli.

The eye is composed of:

Hearing

The ears are the sensory organs of hearing and equilibrium. They permit picking up sounds and converting them into nerve impulses.

The ear has two functions: hearing and balance.

Touch, Smell, and Taste

Touch receptors are found in the skin, smell in the nasal cavity, and taste in the taste buds.

Touch

• Epidermis: The outer layer is made up of epithelial tissue with several cell strata.
• Dermis: The inner layer of connective tissue provides elasticity to the skin.

Smell

The inside of the nostrils are lined by a mucosa called the pituitary. Two regions are distinguished:

• Red pituitary: Interior, occupying the area that heats inspired air.
• Yellow pituitary: Superior, containing the olfactory receptors.

Taste

On the surface of the tongue are numerous projections called papillae; on these are sensitive cells.

Taste buds detect four basic tastes: sweet, salty, sour, and bitter.

The Locomotor System

The locomotor system is responsible for carrying out the motor responses produced by the nervous system. It serves as internal support to the body and facilitates movement and displacement.

• Skeletal system: The passive part of the musculoskeletal system.
• Muscular system: The active part of the musculoskeletal system, formed by muscles and tendons.

Bones

Bones are living organisms that feed and grow. They are composed mainly of calcium, phosphorus, and a fibrous substance called collagen.

Bones are surrounded by connective tissue called periosteum, responsible for bone growth in thickness and where tendons and ligaments attach.

Joints

Joints are structures that connect adjacent bones, preventing their separation.

• Motionless: Do not allow movement between them.
• Semi-mobile: Bind bones tightly but allow a small movement.
• Mobile: Allow a great variety of movements between the bones that form them.

Muscles

Muscles are composed of elongated cells called muscle fibers. These organs can contract and relax, changing their length and enabling movement.

• Smooth muscle: Contraction is rapid and involuntary; formed by smooth muscle fibers.
• Cardiac muscle: Contraction is rapid and involuntary; made up of striated muscle fibers.
• Skeletal muscle: Movements are rapid and voluntary.

Most Frequent Injuries of the Locomotor System

• Fractures: Caused by a broken bone, which can break or shatter.
• Strains and sprains: Both are injuries related to inflammation. Strains affect muscles and tendons from overuse, and sprains affect ligaments and are produced by strains.
• Dislocations: Occur when a bone is displaced from its normal position in a joint.
• Muscle contractures: Involuntary and sustained contraction of a muscle.

Prevention of Injury and Healthy Habits

• Regular physical exercise.
• Have a balanced diet.
• Wear suitable footwear.
• Maintain appropriate posture.
• Do not overload the back with excessive weight.