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Ella graduated in June 2025 from the University of California, Irvine with a Bachelor of Arts in Psychological Sciences. With an interest in both therapy and administrative work, she was drawn to Mind Health Institute, Orange County. Ella is excited to make connections with patients and give them the best possible experiences at Mind Health Institute, Orange County.

I have been in practice for 25 years. During that time I have treated thousands of clients with High Blood Pressure, Elevated Cholesterol and Diabetes as well as Depression and Anxiety and Painful Conditions. Like most physicians I would briefly recommend diet and exercise and then prescribe medication. Most of the time one medication was not enough and their conditions usually worsened over time. Now I offer a different approach. I emphasize the lifestyle changes that actually get to the root of these problems. I personally have been adjusting my lifestyle. I still take medications when my doctors prescribe them but through my Eating Habits, some moderate Activity and practicing Mindfulness I am decreasing rather than increasing medications. I lost 40 pounds, improved my Blood Pressure, corrected my Cholesterol and most importantly improved my Pain and Mood. I am passionate to help others achieve the results of their goals as well.

Joanna Ayala, MD, is a board-certified physician with over a decade of experience in family medicine. She proudly leads the team at Murrieta Primary Care Clinic in Murrieta, California.

Dr. Ayala earned her medical degree from the University of Guadalajara School of Medicine in Jalisco’s capital city of Guadalajara in Mexico. She served the community of Guadalajara for four years before completing a three-year residency in family medicine at the University of Texas Health Science Center in Houston.

After completing her residency in 2011, Dr. Ayala gained experience practicing in Texas and New Mexico. She moved to Southern California in 2017 and established Murrieta Primary Care Clinic.

Dr. Ayala is proud to offer comprehensive health care services to adults and children over the age of 5. The team takes an open, personalized approach to wellness. Dr. Ayala specializes in primary care and managing chronic conditions, while also offering skin treatments and the latest cosmetic services. 

To better serve the Murrieta, California, community, Dr. Ayala is fluent in Spanish and English. She is affiliated with Temecula Valley Hospital in California and prioritizes patient comfort at every stage of the health care journey. 

Schedule a consultation online or on the phone to meet Dr. Ayala and the team at Murrieta Primary Care Clinic.

David Zebrack, DO, is a conscientious and friendly primary care physician and founder of Temecula Valley Primary Care Physicians. He has been in practice for more than 20 years and has cared for patients in Temecula, California, since 2004.

Dr. Zebrack began his education at UCLA where he earned his bachelor’s degree in psychobiology. He then went on to complete his medical education at the College of Osteopathic Medicine of the Pacific in Pomona, California. After earning his doctorate, Dr. Zebrack completed a one-year rotating internship at Rio Hondo Hospital in Downey, California, and a three-year family practice residency at San Bernardino County Medical Center in San Bernardino, California.

During his postgraduate training, Dr. Zebrack served as the president of his residency program. He has held various leadership positions over the years and has enjoyed mentoring medical students. Upon earning his board certification in family medicine, Dr. Zebrack joined a multispecialty medical group in Torrance, California.

In 2004, Dr. Zebrack relocated with his family to Temecula, California, where he joined Dr. Douglas Wise and eventually founded Temecula Valley Primary Care Physicians. In addition to his primary care practice, Dr. Zebrack has acted as a preceptor to train medical students, participated in research and clinical trials, and served as the department chief of family medicine at Southwest Healthcare System in Wildomar, California.

When he is out of the office, Dr. Zebrack has been a fundraiser for the United Jewish Welfare Fund and served multiple terms on the board of his homeowners' association. Dr. Zebrack enjoys spending time  time withife and three children. He stays active through tap dancing, golfing and traveling.

Dr. Zebrack is currently accepting new patients.

 

Credentials

Board-Certified: Family Practice

Residency: San Bernadino Medical Center
DO: College of Osteopathic Medicine of the Pacific
BS: University of California, Los Angeles
Member: AMA, American Academy of Family Physicians, California Academy of Family Physicians

 

Primary care physician Douglas Wise, DO, is dedicated to ensuring patients in Temecula, California, have access to high-quality health care. He provides a comprehensive range of general health services at Temecula Valley Primary Care Physicians. 

Dr. Wise grew up in the suburbs of Philadelphia. After studying at the Philadelphia College of Osteopathic Medicine, he completed his residency in general practice at the Osteopathic Medical Center of Philadelphia. 

In 1981, Dr. Wise started his own private practice in Swedesboro, New Jersey. He moved to the Temecula Valley area in 1987, where he has continued practicing medicine ever since. He has worked with Dr. Zebrack for 10 years and is proud to partner with him in providing care for the residents of Temecula. 

Dr. Wise is an active member of his church and community. He volunteers annually for musical productions, and when he’s not in the office, he enjoys jogging and other fitness activities.

Born in the small rural ski resort town of Show Low, Arizona, Cristal Sumerlin is a dedicated Physician Assistant specializing in Internal Medicine. With a strong passion for patient care and a desire to play an active role in their treatment and well-being, she chose the professional career path of a Physician Assistant after working as an X-Ray Technician. Cristal fell in love with medicine and recognized the need to further her education to better serve her patients and the community.

Cristal takes great pride in both her personal and professional accomplishments. As a mother and military spouse, she has successfully balanced the demands of family life while pursuing her professional goals. Her commitment to her patients and dedication to her work make her a source of pride and inspiration.

In the field of Internal Medicine, Cristal's strengths lie in managing complex disease processes such as diabetes. Her previous experience as an orthopedic technician and x-ray tech in an orthopedic practice has also honed her skills in orthopedics. She finds fulfillment in working with patients facing orthopedic conditions and providing comprehensive care.

Beyond her career, Cristal enjoys spending time outdoors and engaging in activities such as camping, hiking, and traveling. She cherishes these moments with her friends and family, as they provide a source of rejuvenation and happiness outside of her job.

With her unwavering dedication, clinical expertise, and compassionate approach, Cristal Sumerlin is an invaluable asset to Dr. Richard Lam's office. She strives to make a positive impact on her patients' lives and is committed to providing comprehensive and personalized care to improve their overall well-being.

Through active listening and thoughtful questioning, I am able to deliver high quality care that utilizes the most recent advancements in medicine. I take pride in providing urgent care and primary care needs to the under-served areas of Inland Empire for the last 30 years.