Staff at Your Service

Our team prides itself in providing quality care and treatments. While our providers are friendly, caring physicians that come to you, our friendly staff is prepared to help patients, care facilities and families with any customer service, new patient registration, insurance, paperwork, questions and necessities.

Ralph Flores, Chief Executive Officer

Ralph has extensive financial, operational and administrative management healthcare experience serving in various roles prior to joining Cholla. He has been an Executive Vice President, Chief Financial Officer, and Consultant of various privately held companies in Arizona and has held financial management roles in the personnel and real estate finance services industries.


Dr. Roselavender Richards

Dr. Roselavender Richards, MD

Dr. Richards knew from a very young age that she would someday become a doctor. She began her education at Georgetown University where she earned her B.A. in Sociology. She went on to receive her Medical Degree from Georgetown University School of Medicine, followed by her residency in Internal Medicine at Franklin Square Hospital in Maryland.

In her 30+ years as a physician, Dr. Richards has filled various roles such as Primary Care Provider, Community Physician as well as Medical Director. She has worked in diverse areas of the medical field as well, from preventive medicine to hospice care.

Dr. Richards’ passion for helping people has guided her not only through her work experiences, but in a volunteer capacity as well. She has assisted refugees in finding the help they need and to regain control of their futures. Dr. Richards’ objective has always been to provide care and services that enable people to lead better lives.

Dr. Robert Kasa, MD

Dr. Kasa comes out of retirement as an Orthopedic Surgeon and joins our practice as Associate Medical Director and General Practitioner. He is from Chicago and attended University of Illinois at Chicago for undergraduate and medical school. He attended the University of Illinois affiliated hospitals for a general surgery rotating internship and Orthopedic Residency Program. He completed his training in 1984 and practiced in Arizona from 1984 through 2014. He is a member of American Academy of Orthopaedic Surgeons (AAOS) and was formally board-certified with the American Board of Orthopaedic Surgery (ABOS).

Dr. Kasa’s continued passion for medicine; to promote, maintain, supervise, and restore health, identify health risks, and assess, diagnose, and manage acute and chronic illnesses are his main objectives.

When he is not seeing patients, Dr. Kasa plays music in a classical rock band and Latin jazz band and also plays classical piano.

Mackenzie Morrow, FNP-C

Mackenzie is a Family Nurse Practitioner with a Master of
Science in Nursing from the University of Phoenix and
completed her undergraduate nursing education at Grand
Canyon University.

Her background as a Registered Nurse includes five years of
experience working in Intensive Care, Outpatient Surgery, and
Cardiac Units. She also enjoys teaching for Arizona State
University in their nursing program part-time.

Mackenzie was inspired to pursue her education as a Nurse
Practitioner to better serve her patients with an evidence-based,
holistic, patient-centered approach. She is particularly
passionate about women’s health and geriatric medicine.

In her free time, Mackenzie enjoys camping, kayaking, and
hiking with her fur baby- Parker, an 80 lb. Golden doodle.

Heather Jordan, FNP-C

Heather joins Cholla Medical Group after completing her Doctorate of Nursing Practice at the University of Washington in Seattle and is a Board Certified Family Nurse Practitioner through the American Academy of Nurse Practitioners. She received her Bachelor of Science in Nursing from the University of Northern British Columbia in 2007.

Her 15 years of emergency and critical care nursing experience in hospitals across Canada and the US have given her a unique perspective on preventative health care and the importance of exceptional primary care.

She looks forward to partnering with patients and families to optimize health through the management of chronic illness, health care maintenance and support of acute illnesses. By fostering a strong and open patient-provider relationship she aims to support patient’s long-term health care goals.

Outside of her NP practice, Heather enjoys being active with her husband and daughter in the gorgeous Arizona sunshine, cooking and traveling. A true Canadian she loves to watch hockey and is looking forward to playing here in the Valley.

Ethan Nguyen, FNP-C

Ethan was born in Saigon, Vietnam and at a very young age fled communism then immigrated to the United States. Arizona has been his home ever since. Ethan completed his Bachelor of Science degree in Biology at Arizona State University then continued on to University of Phoenix, where he obtained his Masters of Science in Nursing, through the Family Nurse Practitioner program. His background includes 6 years of delivering comprehensive and compassionate nursing care to diverse populations including neurology at Barrows Neurological Institute, emergency room at Banner Desert, and resource nurse for HonorHealth. As a certified family nurse practitioner through the American Academy of Nurse Practitioners, Ethan is very excited to join the Cholla Medical family. Having cared for acute patients in emergent and inpatient settings, he is convinced that an even greater challenge is to keep patients out of hospitals in the first place. Of course, the task is easier said than done. With diligence and patience coupled with the acute patient care, Ethan is compelled to make a difference and beat this challenge.
During this past year, Ethan had the privilege to be on a mission trip to aide the victims of child sex trafficking in Cambodia. The traumatic, yet unforgettable experience of a lifetime, not only opened his eyes to some of the incomprehensible tragedies that exists but also how much more there is to be done. He intends to continue these impactful missions as a part of his career.
Ethan’s hobbies include the outdoors such as hiking and biking. He also loves to travel and spend time with his family and the adorable yet handful maltipoo, Benjamin Latte (Benji).
Terri Noyes

Terri Noyes, RN BSN

Terri is an Arizona native who has over 20 years of nursing experience, providing care to patients of all ages in a variety of settings. She served 10 years of active duty service for the U.S. Army caring for patients all over the world to include military soldiers and their family members. Prior to joining the Cholla family, she worked as an academic counselor and nursing instructor at both the University of Phoenix and Penn Foster College. Terri earned her Bachelor’s Degree in Nursing from the University of Texas while stationed in San Antonio. She is currently working towards her Master’s degree at the University of Phoenix – Family Nurse Practitioner program. Outside of work, Terri dedicates her free time to rescuing and fostering homeless cats and dogs until they can be placed in their forever homes.

Jocelyn Guillen

Jocelyn Guillen, PM

Jocelyn was born and raised in Phoenix. She attended the University of Arizona in Tucson where she obtained her Bachelor’s degree in Business Management. Upon graduation, she moved back to Phoenix and has been with Cholla Medical Group since late 2017. As Project Manager, she manages multiple projects that have a direct impact on improving medical operations. In her spare time, she enjoys the company of family and friends, reading, and exploring new places.


Alyssa Aguilar, PSS

Alyssa was born and raised in Mesa, AZ. She joins Cholla Medical Group as part of our Patient Services Specialists. She has been in the medical field for 6 years and was previously a caregiver at assisted living homes. She has a passion for working with the elderly because she feels that they become like family. Alyssa wants to go back to school to study natural medicines and also has a big interest in marine biology. When she’s not at work, she likes spending time with her family, listening to music, and exploring new places with friends.


Briana Ponce

Briana Ponce, MA-TL

Briana leads the Back Office Clinical Team. She attended Pima Medical Institute and graduated in 2015 with a Medical Assistant Certificate and has been with Cholla Medical Group for a year and half. Briana’s hands-on approach to caring for her patients is a passion that has been with her since an early age. She makes a daily personal goal to bring smiles to all her patients. When not assisting doctors, she enjoys spending time with family and being outdoors, especially camping with all her family.


Tania Venzor, MA

Tania graduated in 2017 from the National Healthcare Association, where she received her Medical Assistant certification. Tania has worked in the mobile doctors setting since then and joins Cholla as a medical assistant where she brings her prior expertise in the field to support our clinical team. She’s motivated to gain more years of experience and knowledge of the medical field before continuing to pursue her nursing career. In her spare time, Tania loves to spend time with her family and friends.