The most complicated part of the brain is the
a. brain stem.
c. thalamus.
b. cerebellum.
d. cerebrum.

Cerebrum is the most complicated part of the brain.

Explanation:

Cerebrum is the largest and upper most portion of the human brain. It contain cerebral cortex. It made up two cerebral hemisphere and their subcortical structure include hippocampus, basal ganglia and olfactory bulb. Cerebral hemisphere is divided by the medial longitudinal fissure into two cerebral hemispheres the right and left. Cerebral cortex is classified into four lobes:

Frontal, pariental, occipital and temporal lobes.

The cerebrum is divided into two parts:-

1.Left cerebral hemispheres

2.Right cerebral hemispheres

Hippocampus is a major component of the brain. Hippocampus is located under the cerebral cortex. The hippocampus is a small region of the brain and contain unique shape similar to horseshoe.

stridor can't collapse a lung.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.