The adrenal (suprarenal) glands are trianglular glands situated above the kidneys. They are retroperitoneal and are surrounded by a capsule and renal fascia. The adrenal glands have a cortex (this makes mineralcorticoids (aldosterone), glucocorticoids (cortisol), and sex hormones). The adrenal glands also have a medulla that secretes epinephrine and norepinephrine. 

Type 1 pneumocytes (alveolar cells) are responsible for gas exchange between the alveoli and blood. They have a thin cytoplasm. Type 2 pneumocytes also reside in the alveoli, but they produce surfactant which prevents the alveoli from collapsing. Macrophages and neutrophils can be present in the alveoli or lung blood vessels, but they do not participate in gas exchange,but are involved in the response against microbial infections. Oligodendrocytes are neuroglia in the central nervous system that produce myelin sheets.

The adrenal gland functions purely as an endocrine gland, while the other choices do not. The pancreas and stomach contain endocrine cells, but they also function in digestion; they are not  purely endocrine glands. The ovary also contains endocrine cells, but it also functions in reproduction and is thus not a purely endocrine gland.

Oxygen and carbon dioxide are exchanged across the thin walls of the air sacs, or alveoli. The nasal cavity, bronchi, and trachea are responsible for filtering, humidifying, and warming the air passing through them. They do not function in gas exchange.

Of the pneumocytes, type II cells are responsible for secreting pulmonary surfactant, serve as precursors to type I cells, proliferate during lung damage and decrease alveolar surface tension.

Type I cells, on the other hand, line the aveoli and consist of 97% of the alveolar surface. The cells are squamous and thin for optimal gas diffusion. 

An easy way to differentiate between the two types of lung cells is to remember that type I cells are responsible for the physical lining and makeup of pneumocytes, while type II cells are responsible for the functioning of the pneumocytes.

The right lung has 3 lobes: superior lobe, middle lobe and inferior lobe.

The left lung has 2 lobes: superior lobe and inferior lobe. There is no middle lobe in the left lung because this space in the left lung is occupied by the heart. 

The respiratory tract is divided into the upper and lower tracts. The upper respiratory tract consists of the nose (including nasal sinuses) and pharynx. The lower respiratory tract consists of the larynx, trachea, bronchi, and lungs. 

The larynx, also known as the voice box, connects the pharynx to the trachea. The larynx is formed from folds of laryngeal mucous membrane lined with stratified squamous epithelium. The epiglottis is a flap of cartilage located in the throat that prevents food and water from entering the larynx (and airway) when swallowing.  

The epiglottis is a flap of cartilage located at the base of the tongue that prevents food and drink from entering the larynx (and further into the airway). This ensures that food and drink enter the esophagus and gastrointestinal tract. The diaphragm is a muscle involved in respiration. Alveoli are small sacs located in the lungs (at the end of brochioles) that allow for oxygen and carbon dioxide exchange. Nasopharynx is the upper part of the pharynx. 

The epididymis, which is on the posterolateral aspect of the testes, gives rise to the vas deferens. The vas deferens travels superiorly in the spermatic cord, furthermore joining with the seminal vesicles (located posterior to the urinary bladder). 

The bulbourethral gland is located inferior to the prostate and posteriolateral to the membranous urethra. The gubernaculum (scrotal ligament) is located inferior to each teste, attaching them to the scrotum.