The structure indicated by the arrows is the 
Definitions:
Heart Beats
The rhythmic contraction and expansion of the heart, representing each cycle during which the heart pumps blood through the circulatory system.
Aerobics Class
A group fitness program focused on enhancing cardiovascular health, stamina, and flexibility through rhythmic aerobic exercise.
Margin of Error
The margin of error represents the maximum expected difference between the true population parameter and a sample estimate of that parameter.
Population Mean
The average value of a characteristic of the entire population.
Q2: A mosquito bites you on the wrist.
Q7: Which of these terms do not below
Q10: Which endocrine gland is part of the
Q31: Which of the following statements is FALSE
Q38: Sinusitis, nasal congestion, sore throat, coughing as
Q43: "Adam's apple"is the common name for the
Q44: In the wall of the utricle and
Q51: Select the best description of neurotransmitter molecules:<br>A)
Q53: A, B, and Rh(D) are examples of
Q57: The parafollicular cells (C cells) of the