1. Welcome to PHCorner Forums. Take a moment to Sign up and gain unlimited access and extra privileges that guests are not entitled to, such as:

    All that and more! Registration is quick, simple and absolutely free. Join our community today!

Three Types of Tears

Discussion in 'Off-Topic' started by Soul Surfer, Sep 8, 2015.

  1. 1. basal Tears

    Throughout the day, the eye produces tears to protect itself and keep from drying out. Depending on the size of the eye, the average human makes anywhere from just over one-half to just over one cup of Please or Register to view links every day.
    These Please or Register to view links:

    Contain water, nutrients and antibacterial components such as glucose, mucin (sticky stuff), lysozyme (antibacterial), lactoferrin (antibiotic), lipocalin (protein transporter), urea, potassium and sodium.

    So many basal tears are required because during the day:

    Some of the fluid evaporates between blinks and some is drained through small permanent openings at the nose end of each eyelid

    2.Reflex Tears

    Protecting the eye from irritants, Please or Register to view links result from a message sent from the cornea to the brain stem, which then “sends a hormonal signal to [the] lachrymal glands causing the tear response to kick in.” Intended to Please or Register to view links, unlike basal tears, reflex tears:

    Are designed to break down and eliminate eyeball-intruders like airborne dust [so] these tears tend to flow in greater amounts and probably contain a greater concentration [when compared to basal tears] of antibodies and enzymes that target micro-organisms.

    3.Emotional Tears

    Humans are the only species Please or Register to view links, and unlike the other two, Please or Register to view links involve nerve impulses that stimulate the cerebrum:

    Where sadness is registered. The endocrine system is then triggered to release hormones to the ocular area, which then causes tears to form.

    Many scientists believe that emotional crying helps eliminate Please or Register to view links from the body.

    Bonus Crying Facts:
    Women cry (emotionally) “ Please or Register to view links.” Some attribute this difference, at least in part, to the prolactin in tears – a female hormone and protein that enables women to produce *phcorner* milk. Others believe the difference is explained by cultural forces and expectations.
    taroroy likes this.
  2. taroroy

    taroroy Eternal Poster Established

    thanks for sharing. (y)
Tags / Keywords: