Human Head and Neck Anatomy: Structures and Functions

Posted on Sep 17, 2026 in Biology

Concept of the Head

The head is the uppermost part of the body, connected to the neck. It contains the brain, the organs of the senses, and the structures for speech, facial expressions, and chewing.

Parts of the Head and Face

  • Head (cabeza): The upper part of the body that contains the brain.
  • Hair (cabello): Strands that grow from the scalp.
  • Forehead (frente): The flat area between the eyebrows.
  • Eyes (ojos): Organs for seeing.
  • Iris (iris): The colored part of the eye.
  • Pupil: The black circle in the center of the iris.
  • Eyelids (párpados): Folds of skin that protect the eyes.
  • Eyelashes (pestañas): Short hairs on the eyelids.
  • Eyebrows (cejas): Strips of hair above the eyes.
  • Nose: Organ for smelling and breathing.
  • Nostrils (fosas nasales): Openings of the nose.
  • Cheeks (mejillas): Fleshy areas below the eyes.
  • Ears (orejas): Organs for hearing and balance.
  • Earlobe (lóbulo de la oreja): The soft lower part of the ear.
  • Mouth (boca): Opening for eating, speaking, and breathing.
  • Lips (labios): Soft edges of the mouth.
  • Teeth (dientes): Hard structures for chewing food.
  • Tongue (lengua): Muscle for tasting and speaking.
  • Chin (barbilla): Lower part of the face below the mouth.
  • Jaw (mandíbula): Bone structure for chewing and speaking.

The Skull

The skull is the bony structure that forms the head in humans and other animals. It supports the structures of the face and protects the brain.

Main Functions of the Skull

  1. Protection (Protección): The skull protects the brain, eyes, inner ear, and other delicate structures from injury.
  2. Support (Soporte): It provides a framework that supports the face and gives shape to the head.
  3. Attachment for Muscles (Inserción de Músculos): The skull serves as an attachment point for muscles involved in chewing, facial expressions, and head movement.
  4. Formation of Cavities (Formación de Cavidades): The skull forms cavities (cranial cavity, orbits, nasal cavity, oral cavity) that house and protect organs.
  5. Passage for Nerves and Blood Vessels: Openings (foramina) in the skull allow the passage of blood vessels and nerves to and from the brain and face.

The Neck

The neck is a flexible structure that supports the head and allows its movement. It contains vital structures such as the cervical spine, major blood vessels, nerves, the trachea, the esophagus, and important glands.

Functions of the Neck

  • Supports and moves the head.
  • Protects vital structures.
  • Provides passage for air and food.
  • Contains important glands such as the thyroid and parathyroid.
  • Plays a role in speech, breathing, and swallowing.

Anatomical Structures and Functions

  • Cervical spine (columna cervical): Supports the head and protects the spinal cord.
  • Cervical vertebrae (vértebras cervicales): Provide mobility and stability to the neck.
  • Atlas (C1): Allows the head to nod (“yes” motion).
  • Axis (C2): Enables head rotation (“no” motion).
  • Hyoid bone (hueso hioides): Supports the tongue and aids in swallowing.

Muscles of the Neck

  • Sternocleidomastoid
  • Trapezius
  • Scalene muscles
  • Platysma
  • Infrahyoid muscles
  • Suprahyoid muscles

Nerves of the Neck

  • Cervical nerves (nervios cervicales): Provide sensation and movement to the neck and upper limbs.
  • Vagus nerve (nervio vago): Controls voice, swallowing, and visceral functions.
  • Accessory nerve (nervio accesorio): Innervates sternocleidomastoid and trapezius muscles.
  • Hypoglossal nerve (nervio hipogloso): Controls tongue movement.
  • Phrenic nerve (nervio frénico): Controls the diaphragm for breathing.

Organs of the Neck

  • Trachea
  • Esophagus
  • Larynx
  • Pharynx
  • Thyroid gland
  • Parathyroid glands
  • Lymph nodes

The Larynx

The larynx, commonly called the “voice box,” is a cartilaginous structure located in the neck, between the pharynx and the trachea.

Functions of the Larynx

  • Voice production
  • Airway protection
  • Breathing
  • Cough reflex

The Pharynx

The pharynx is a muscular tube located behind the nasal cavity and the mouth, and above the esophagus and larynx.

Functions of the Pharynx

  • Respiration
  • Digestion
  • Swallowing
  • Voice resonance
  • Protection

The Thyroid

The thyroid gland is an endocrine gland located in the front of the neck, just below the larynx, and shaped like a butterfly.

Functions of the Thyroid

  • Hormone production
  • Growth and development
  • Energy regulation
  • Temperature control
  • Heart and nervous system regulation