Lip is an important visible body part that can help us to hold, suck and swallow food. The muscles of the lips allow us to easily communicate our emotions through facial expressions. It also helps us to play various wind instruments such as flute and saxophone by regulating airflow. The color and size of lips play a crucial role in sexual attraction in both men and women.
What are lips and why do they exist?
Have you ever wondered why do we have lips or what are the functions of lips?
Lip is a soft and visible part at the entry of the mouth. The skin of the lip typically has 3-5 cellular layers compared to the facial skin that has 16 layers. The lip skin doesn’t have hair and sweat glands. Lips are generally red in color due to the presence of very few melanocytes (that are responsible for skin color). In the absence of melanin, the color of blood vessels can easily appear through the skin and hence they look red. We know that not all living organisms have lips. For example, birds don’t have lips as humans do. Then why do humans need lips? Well, the lip plays an important role in the intake of food, facial expressions, as a tactile organ, and erogenous zone. Let’s understand the lip functions in detail below.

Why do we need lips?
Here are few reasons why mammals such as humans have lips.
Helps In Food Intake
Lips play an important role in the intake of food because they are soft, flexible, and can be moved easily. They allow us to hold, chew and swallow food. We can make our mouth air sealed with the help of lips. They can also help in creating a suction effect to drink liquids using straws. We often see newborns sucking their thumb which is only possible due to the presence of lips.
Facial Expressions
Lips are an important part of facial expression. Emotions can be easily expressed with the movement of lips. When we are happy and smiling, lips form a parabolic curve facing upwards, and in the case of a sad mood, the parabolic curve facing downwards. Lips also allow humans to lip-read to understand and communicate without the need for sound.
Regulates the air flow
The presence of lips helps us to regulate the flow of air for various purposes. Lips allow us to perform various wind instruments such as flute, harmonica, and saxophone. Lips also help us to blow air in order to cool down hot beverages.
Act as Tactile Organ
Lips can generally sensitive to touch due to the presence of many nerve endings in the lips. In the case of newborns, it can be used a tactile organ to explore new things such as cold and warm.
Erogenous zone
Lip is one of the erogenous zones due to the presence of a high number of nerves. They can play role in kissing and may swell during sexual arousal. In humans, lip size and color can help to sexually attract the opposite gender.