| Rectum | |
|---|---|
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| Anatomy of the anus and rectum | |
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| The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx. | |
| Gray's | subject #249 1183 |
| Artery | superior rectal artery (1st two-thirds of rectum), middle rectal artery (last third of rectum) |
| Vein | superior rectal veins, middle rectal veins |
| Nerve | inferior anal nerves, inferior mesenteric ganglia[1] |
| Lymph | inferior mesenteric lymph nodes, pararectal lymph nodes, internal iliac lymph nodes |
| Precursor | Hindgut |
| MeSH | Rectum |
| Dorlands/Elsevier | r_05/12697487 |
The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. Gray's Anatomy the Respiratory apparatus ( Apparatus Respiratorius Respiratory system Respiratory apparatus Arteries are Blood vessels that carry blood away from the Heart. The superior rectal artery ( superior hemorrhoidal artery) is an artery that descends into the Pelvis to supply blood to the Rectum. The middle rectal artery is an Artery in the pelvis that supplies blood to the Rectum. In the Circulatory system, a vein is a Blood vessel that carries Blood back toward the Heart (as opposed to Artery, a blood vessel The middle rectal veins (or middle hemorrhoidal vein) take origin in the Hemorrhoidal plexus and receive tributaries from the bladder, Prostate A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. The Inferior rectal nerves ( inferior anal nerves, inferior hemorrhoidal nerve) usually branch from the Pudendal nerve but occasionally arises directly from The inferior mesenteric ganglion is a ganglion located near where the Inferior mesenteric artery branches from the Abdominal aorta. The lymphatic system in Vertebrates is a network of conduits that carry a clear fluid called Lymph. The inferior mesenteric glands consist of (a small glands on the branches of the Left colic and Sigmoid arteries (b a group in the The pararectal lymph nodes are in contact with the muscular coat of the Rectum. The internal iliac lymph nodes (or hypogastric) surround the Internal iliac artery and its branches (the hypogastric vessels) and receive the Lymphatics Embryology (from Greek grc ἔμβρυον embryon, "unborn embryo" and grc -λογία -logia) is the study of the development The Hindgut (or epigaster) is the Posterior ( Caudal) part of the Alimentary canal. Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Elsevier, the world's largest Publisher of Medical and Scientific literature, forms part of the Reed Elsevier group The large intestine is the last part of the Digestive system: the final stage of the Alimentary canal in Vertebrate Animals Its function is to Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The anus is an opening at the opposite end of an Animal 's Digestive tract from the Mouth. The human rectum is about 12 cm long. At its commencement its caliber is similar to that of the sigmoid colon, but near its termination it is dilated, forming the rectal ampulla. The sigmoid colon ( pelvic colon; sigmoid flexure) forms a loop which averages about 40 cm The rectal ampulla is the dilated section of the Rectum where Feces are stored until they are eliminated via the Anal canal.
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Role in human defecation
The rectum intestinum acts as a temporary storage facility for feces. As the rectal walls expand due to the materials filling it from within, stretch receptors from the nervous system located in the rectal walls stimulate the desire to defecate. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract If the urge is not acted upon, the material in the rectum is often returned to the colon where more water is absorbed. The colon is a storage tube for solid wastes The main function of the colon appears to be extraction of Water and salts from Feces. If defecation is delayed for a prolonged period, constipation and hardened feces results. Constipation, costiveness, or irregularity, is a condition of the Digestive system in which a person (or animal experiences hard Feces that
When the rectum becomes full the increase in intrarectal pressure forces the walls of the anal canal apart allowing the fecal matter to enter the canal. The anal canal is the terminal part of the Large intestine. It is situated between the Rectum and Anus, below the level of the Pelvic diaphragm The rectum shortens as material is forced into the anal canal and peristaltic waves propel the feces out of the rectum. In the Esophagus After food is chewed into a bolus it is swallowed to move it into the esophagus The internal and external sphincter allow the feces to be passed by muscles pulling the anus up over the exiting feces. A sphincter is a structure usually a circular Muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological
Medical procedures
For the diagnosis of certain ailments, a rectal exam may be done. Illness (sometimes referred to as ill-health or ail) can be defined as a state of poor Health. A rectal examination or rectal exam is an internal examination of the Rectum such as by a Physician or other healthcare professional
Suppositories may be inserted into the rectum as a route of administration for medicine. A suppository is a drug delivery system that is inserted either into the Rectum (rectal suppository Vagina (vaginal suppository or Urethra (urethral In Pharmacology and Toxicology, a route Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the
The endoscopic procedures colonoscopy and sigmoidoscopy are performed to diagnose diseases such as cancer. Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an instrument called an endoscope. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic Sigmoidoscopy is the Minimally invasive medical examination of the large Intestine from the Rectum through the last part of the colon Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled
Temperature taking
Body temperature can also be taken in the rectum. Core temperature, also called core body temperature, is the operating Temperature of an Organism, specifically in deep structures of the body such as the Rectal temperature can be taken by inserting a mercury thermometer for 3 to 5 minutes, or a digital thermometer until it "beeps", not more than 25 mm (1 inch) into the rectum via the anus. A mercury-in-glass thermometer, invented by German physicist Daniel Gabriel Fahrenheit, is a Thermometer consisting of mercury in a Glass The thermometer is a device that measures Temperature or Temperature gradient using a variety of different principles it comes from the Greek roots The anus is an opening at the opposite end of an Animal 's Digestive tract from the Mouth. Due to recent concerns related to mercury poisoning, the use of mercury thermometers is outlawed. Mercury poisoning (also known as mercurialism, hydrargyria, Hunter-Russell syndrome, or acrodynia when affecting children is a Disease Normal rectal temperature generally ranges from 36 to 38 °C (97. 6 to 100. 4 °F) and is about 0. 5 °C (1 °F) above oral (mouth) temperature and about 1 °C (2 °F) above axillary (armpit) temperature. The axilla (or armpit, underarm, or oxter) is the area on the human body directly under the joint where the Arm connects to the Shoulder
Many pediatricians recommend that parents take infants and toddler's temperature in the rectum for two reasons:
- (1) Rectal temperature is the closest to core body temperature and in children that young, accuracy is critical. Pediatrics (also spelled paediatrics) is the branch of Medicine that deals with the medical care of Infants Children and Adolescents Toddler is a common term for a young Child who is learning to walk or "toddle", generally considered to be the second stage of development after infancy
- (2) Younger children are unable to cooperate when having their temperature taken by mouth (oral) which is recommended for children, ages 6 and above and for adults.
In recent years, the introduction of ear (tympanic) thermometers and changing attitudes on privacy and modesty have led some parents and doctors to discontinue taking rectal temperatures. Privacy is the ability of an individual or group to seclude themselves or information about themselves and thereby reveal themselves selectively Standards of modesty (also called demureness or reticence) are aspects of the Culture of a Country or people at a given point in time
Sexual stimulation
Due to the proximity of the anterior wall of the rectum to the vagina in females or to the prostate in males and the shared nerves thereof, rectal stimulation or penetration can result in sexual arousal. The vagina (from Latin, literally " Sheath " or " Scabbard " is a fibromuscular tubular tract leading from the Uterus The prostate (from Greek προστάτης - prostates, literally "one who stands before" "protector" "guardian" is a Stimulation is the action of various agents ( stimuli) on Muscles Nerves or a sensory end organ by which activity is evoked especially the nervous For further information on this aspect, see anal sex. Anal sex most often refers to the sex act involving insertion of the Penis into the Rectum.
Additional images
 Organs of the female reproductive system. A sex organ, or primary sexual characteristic, as narrowly defined is any of the anatomical parts of the body which are involved in sexual reproduction and constitute |
 Median sagittal section of pelvis, showing arrangement of fasciæ. |
 The arteries of the pelvis. |
 Section of mucous membrane of human rectum. The mucous membranes (or mucosae; singular mucosa) are linings of mostly endodermal origin covered in Epithelium, which are involved in X 60. |
 The blood vessels of the rectum and anus. The blood vessels are part of the Circulatory system and function to transport Blood throughout the body |
 Median sagittal section of male pelvis. |
 Median sagittal section of female pelvis. |
 Sagittal section of the lower part of a female trunk, right segment. |
 The rectum can be seen on the left of this illustration. |
 Cross section microscopic shot of the rectal wall. |
See also
- Gastrointestinal tract
- Rectal prolapse
- Latus rectum (conic section)
- Semi-latus rectum (conic section)
- pectinate line
References
External links
- Cross section at UV pembody/body15a
- Cross section at UV pelvis/pelvis-e12-15
- SUNY Anatomy Image 7808
- SUNY Labs 43:11-0101 - "The Female Pelvis: The Rectum"
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