medulla oblongata

(redirected from Medulla oblongada)
Also found in: Dictionary, Thesaurus, Encyclopedia.

medulla

 [mĕ-dul´ah] (L.)
1. the inmost part of a structure or organ.
3. marrow. adj., adj med´ullary.
adrenal medulla the inner portion of the adrenal gland, where epinephrine and norepinephrine are produced.
medulla of bone bone marrow.
medulla oblonga´ta that part of the hindbrain continuous with the pons above and the spinal cord below; it houses nerve centers for both motor and sensory nerves, where such functions as breathing and the beating of the heart are controlled. See also brain.
medulla os´sium bone marrow.
renal medulla the inner part of the substance of the kidney, composed chiefly of collecting tubules, and organized into a group of structures called the renal pyramids.
medulla spina´lis (medulla spina´lis) spinal cord.
medulla of thymus the central portion of each lobule of the thymus; it contains many more reticular cells and far fewer lymphocytes than does the surrounding cortex.

me·dul·la ob·lon·ga·'ta

[TA]
the most caudal subdivision of the brainstem, immediately continuous with the spinal cord, extending from the lower border of the decussation of the pyramid to the pons; its anterior (ventral) surface resembles that of the spinal cord except for the bilateral prominence of the inferior olive; the posterior (dorsal) surface of its upper half forms part of the floor of the fourth ventricle. Motor nuclei of the medulla oblongata include the hypoglossal nucleus, the dorsal motor nucleus, inferior salivatory nucleus, and the nucleus ambiguus; sensory nuclei include the nuclei of the posterior column (gracile and cuneate), the cochlear and vestibular nuclei, the middle and caudal portions of the spinal trigeminal nucleus, and the nucleus of the solitary tract.
See also: medulla.
Synonym(s): myelencephalon [TA], oblongata

medulla oblongata

(ŏb′lông-gä′tə)
n. pl. medulla oblonga·tas or medullae oblongatae (mĭ-dŭl′ē ŏb′lông-gä′tē)
The lowermost portion of the vertebrate brain, continuous with the spinal cord, responsible for the control of respiration, circulation, and certain other bodily functions.

medulla oblongata

a bulbous continuation of the spinal cord just above the foramen magnum and separated from the pons by a horizontal groove. It is one of three parts of the brainstem and mainly contains white substance with some mixture of gray substance. The medulla contains the cardiac, vasomotor, and respiratory centers of the brain. Medullary injury or disease often proves fatal. Compare mesencephalon, pons. Also called, (informal) medulla.

medulla oblongata

The lower half of the brain stem, which is located between the spinal cord and the pons.

Content
• Cardiac centre—Sympathetic, parasympathetic systems. 
• Respiration centre—Contains chemoreceptors.
• Vasomotor centre—Contains baroreceptors.
• Reflex centres—For vomiting, coughing, sneezing, swallowing.

Function
Autonomic and involuntary functions, including breathing, maintaining the heart rate and blood pressure.

me·dul·la ob·lon·ga·ta

(mĕ-dŭl'ă ob-long-gā'tă) [TA]
The most caudal subdivision of the brainstem, continuous with the spinal cord, extending from the lower border of the decussation of the pyramid to the pons; its ventral surface resembles that of the spinal cord except for the bilateral prominence of the inferior olive; the dorsal surface of its upper half forms part of the floor of the fourth ventricle. Motor nucleiof the medulla oblongata include the hypoglossal nucleus, the dorsal motor nucleus, inferior salivatory nucleus, and the nucleus ambiguus; sensory nuclei include the nuclei of the posterior column (gracile and cuneate), the cochlear and vestibular nuclei, the mid and caudal portions of the spinal trigeminal nucleus, and the nucleus of the solitary tract.
See also: medulla
Synonym(s): myelencephalon, oblongata.

medulla

(me-dul'a, dul') plural.medullae [L. medulla, marrow, pith]
1. Marrow (1).
2. In anatomy, the innermost or central portion of an organ in contrast to the cortex.
3. The caudal segment of the hindbrain. Synonym: medulla oblongata; bulb (2)
4. The medulla ossium. medullary (med'ul-er?e, mej?), adjective
Enlarge picture
ADRENAL MEDULLA

adrenal medulla

The central tissue of the adrenal gland. It is filled with pheochromocytes, which are derived from the neural crest and resemble postsynaptic sympathetic ganglion cells. In response to stimulation by presynaptic sympathetic axons, the pheochromocytes secrete epinephrine and norepinephrine into the bloodstream. See: illustration
See: adrenal gland

medulla of hair

The central axis of a hair.

medulla of kidneys

See: pyramid, renal

medulla nephrica

See: pyramid, renal

medulla oblongata

Medulla (3).

medulla ossium

Marrow (1).

medulla of ovary

The central portion of the ovary, composed of loose connective tissue, blood vessels, lymphatics, and nerves.

medulla spinalis

The spinal cord.

medulla oblongata

The part of the BRAINSTEM lying below the PONS and immediately above the spinal cord, just in front of the CEREBELLUM. The medulla oblongata contains the nuclei of the lower four CRANIAL NERVES, the vital centres for respiration and control of heart-beat, and the long motor and sensory tracts running down to and up from the spinal cord. Disease or injury to the medulla is always serious, often fatal.

medulla oblongata

the posterior part of the hindbrain of vertebrates that connects with the spinal cord. It is ventrally thick-walled and contains groupings of nerve cells called nuclei. The thin-walled posterior CHOROID PLEXUS is situated on its dorsal side. The medulla contains several important areas of nervous control not influenced by conscious action. The respiratory and cardiovascular centres control respiration and heartbeat and organs of the LATERAL-LINE SYSTEM. The ear, taste and touch receptors also have their impulses coordinated in the medulla.

Medulla oblongata

The lowest section of the brainstem, located next to the spinal cord. The medulla is the site of important cardiac and respiratory regulatory centers.
Mentioned in: Anesthesia, General

medulla oblongata

lowest subdivision within brainstem, continuous with spinal cord; extends from decussation of pyramids to pons

me·dul·la ob·lon·ga·ta

(mĕ-dŭl'ă ob-long-gā'tă) [TA]
The most caudal subdivision of the brainstem, continuous with the spinal cord, extending from the lower border of the decussation of the pyramid to the pons.
Synonym(s): myelencephalon, oblongata.

medulla oblongata (mədul´ə oblôngä´tə),

n the direct upward extension of the spinal cord that lies at the junction between the cerebrum and the spinal cord and is considered to be in a group with the pons and midbrain because the nuclei of all the cranial nerves except one are situated within this structural group. Its functions are associated with the nuclei of the glossopharyngeal, vagal, spinal accessory, and hypoglossal nerves. It controls the reflex actions of the pharynx, larynx, and tongue, which are related to deglutition, mastication, and speech, as well as the visceral reflexes of coughing, sneezing, sucking, vomiting, and salivating, and other secretory functions.

medulla

pl. medullae [L.] the central or inner portion of an organ.

adrenal medulla
the inner portion of the adrenal gland, where epinephrine is produced.
medulla of bone
bone marrow, contained in the medullary canal of bone.
medulla oblongata
that part of the hindbrain continuous with the pons anteriorly and the spinal cord posteriorly; it houses nerve centers for both motor and sensory nerves, where such functions as breathing and the beating of the heart are controlled. Called also myelencephalon. In animals the principal clinical manifestations of local lesions in the medulla are those of head rotation and circling, and facial and tongue paralysis with resulting difficulty in prehension and swallowing. With diffuse lesions spastic paralysis or a stiff-legged incoordination occurs.
medulla ossium
bone marrow.
renal medulla
the inner part of the substance of the kidney, composed chiefly of collecting tubules, and in some species organized into a group of structures called the renal pyramids.
spinal medulla, medulla spinalis
spinal cord.
medulla of thymus
the central portion of each lobule of the thymus; it contains many more reticular cells and far fewer lymphocytes than does the surrounding cortex.