common pathways for food and air are the (1), which connects to the mouth, and (2), which connects to the larynx. Epithelium in this region is (3), which provideds good protection from friction. Three bands of skeletal muscle, the (4) propel food into the (5). Entrance to the stomach is guarded by the (6).
1. pharynx
2. Epiglottis
1. pharynx
2. nose
3 stratified squamous
To answer the question, let's break it down and refer to the given numbers:
1. The common pathway for food and air is the **pharynx**. The pharynx is a tube-like structure located behind the nasal cavity, mouth, and larynx.
2. The pathway for air specifically that connects to the larynx is the **trachea**. The trachea is commonly known as the windpipe and serves as the passage for air to enter and exit the lungs.
3. The epithelium in this region is **stratified squamous epithelium**. Stratified squamous epithelium is a type of tissue composed of multiple cell layers that provides protection against friction and mechanical stress.
4. The three bands of skeletal muscle that propel food into the esophagus are the **pharyngeal constrictor muscles**. These muscles contract in a coordinated manner to push the food bolus from the pharynx to the esophagus during swallowing.
5. The entrance to the stomach is guarded by the **lower esophageal sphincter** (LES) or **cardiac sphincter**. It is a muscular ring located at the junction of the esophagus and the stomach, preventing the backflow of stomach acid into the esophagus.
In summary, the common pathways for food and air are the pharynx (1) and the trachea (2), respectively. The epithelium in this region is stratified squamous epithelium (3), providing protection. The three bands of skeletal muscle, the pharyngeal constrictor muscles (4), propel food into the esophagus (5). The entrance to the stomach is guarded by the lower esophageal sphincter (LES) or cardiac sphincter (6).