Quantcast Accessory structures of the eye - The Sensory System

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
e. Muscles of the Eye. The structure of the eye includes the muscles of the
eye--intrinsic muscles and extrinsic muscles. Intrinsic muscles include the two
involuntary muscles within the eye--the iris and the ciliary muscles. The iris regulates
the amount of light which can enter the eye. The iris does this by dilating (opening
more) and by constricting (opening less). The extrinsic muscles are composed of four
rectus muscles (superior muscles, inferior muscles, medial muscles, and lateral
muscles) and two oblique muscles (superior muscles, and inferior muscles). The
extrinsic muscles move the eye within the orbit. The eye is the only organ with both
voluntary and involuntary muscles.
1-4.
ACCESSORY STRUCTURES OF THE EYE
The site of accessory structures of the eye are as follows: eyebrows, eyelashes,
eyelids, conjunctiva, and lacrimal apparatus.
a. Eyebrows. The eyebrows are made up of several rows of hair above the
upper eyelids. The eyebrows form an arch at the junction of the upper eyelid and the
forehead and structurally resemble the hairy scalp. The hairs are generally coarse and
grow toward the side of the face.
b. Eyelashes. Eyelashes are a row of hairs which project from the border of
each eyelid. Eyelashes coming from the upper eyelid are usually long and turn upward;
eyelashes from the lower eyelid are generally short and turn downward. Sebaceous
glands at the base of eyelash hair follicles pour a lubricating fluid into the follicles.
When these glands become infected, a sty forms.
c. Eyelids. Each eyelid consists of epidermis, dermis, subcutaneous
connective tissue, fibers of oculi muscle, a tarsal plate, tarsal glands, and a conjunctiva.
The epidermis, dermis, and subcutaneous connective tissue make up the skin of the
eyelid. The tarsal plate is a thick fold of connective tissue that forms part of the inner
wall of each eyelid. The tarsal plate gives form and support to the eyelids. The
conjunctiva is a mucous membrane which lines the inner aspect of the eyelids as well
as the visible portion of the cornea (the glossy, transparent part of the cornea).
d. Lacrimal Apparatus. This is the term used for a group of structures that
manufacture and drain away tears. Included are the lacrimal glands, the execratory
lacrimal ducts, the lacrimal canals, the lacrimal sacs, and the nasolacrimal ducts.
(1)  Lacrimal gland. A lacrimal gland is located in the upper outer corner of
each orbit. The lacrimal glands secret lacrimal fluid through small ducts into the space
between the external surface of the eyeball and the upper eyelid.
MD0582
1-6



Medical News
One person’s normal = another person’s heart attack?
Much has been written about calculating your BMI (or body...
scopeblog.stanford.edu
Friday Feedback: Do-It-Yourself Genetic Testing
(MedPage Today) -- What will it mean to clinicians when...
medpagetoday.com
ACIP: 9-Valent HPV Vaccine OK to Use
(MedPage Today) -- Advisers also back meningococcal B vaccines only...
medpagetoday.com
Talent Shortages, 5 Things to Shut Up About: Healthcare Career Insights
(MedPage Today) -- Must reads about the latest news and...
medpagetoday.com
Scientists discover robust evidence that chronic fatigue syndrome is a biological illness
Researchers at the Center for Infection and Immunity at Columbia...
medicalxpress.com
Tweet of the Week: Addressing the Dress that Went Viral
(MedPage Today) -- Science weighs in: Why do people see...
medpagetoday.com
ME/CFS/SEID: It goes by many aliases, but its blood-chemistry signature is a giveaway
It’s the disease that dare not speak its name without...
scopeblog.stanford.edu
Early ART, TB Prevention Improve HIV Outcomes (CME/CE)
(MedPage Today) -- Effects of treating HIV and preventing TB...
medpagetoday.com
New algorithm increases surgical success with advanced ovarian cancer
A surgical algorithm developed and implemented by ovarian cancer specialists...
medicalxpress.com
FDA Approves Antibiotic Combo
(MedPage Today) -- Ceftazidime-avibactam approved for complicated abdominal and urinary...
medpagetoday.com
Mystery of the reverse-wired eyeball solved
From a practical standpoint, the wiring of the human eye...
medicalxpress.com
Neurons controlling appetite made from skin cells
Researchers have for the first time successfully converted adult human...
medicalxpress.com
Drug research and development more efficient than expected
Drug R&D costs have increased substantially in recent decades, while...
medicalxpress.com
Statin Therapy Suppresses Coronary Plaques in HIV Patients (CME/CE)
(MedPage Today) -- Clear benefit versus placebo in a randomized...
medpagetoday.com
New York City Gets Its HIV Act Together (CME/CE)
(MedPage Today) -- Health officials find infected subjects and link...
medpagetoday.com
Exploring the science of decision making
Every day we make decisions that affect our work, personal...
scopeblog.stanford.edu
Novel HIV Prodrug Safer Than Its Predecessor (CME/CE)
(MedPage Today) -- Investigational compound appears to overcome renal and...
medpagetoday.com
Black/blue or white/gold? Dress debate goes viral
Is the dress black and blue, or white and gold?...
medicalxpress.com
Few Women Qualify for 3-Person IVF (CME/CE)
(MedPage Today) -- Fewer than 1,000 U.S. women annually are...
medpagetoday.com
Amsterdam warns tourists white heroin being sold as cocaine
(AP)—Authorities in Amsterdam are warning about potentially lethal white heroin...
medicalxpress.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +