CorpusHuman Anatomy
NervousSpace

Lateral ventricles

Ventriculi laterales

Also known as: first and second ventricles

The largest ventricles: a C-shaped CSF cavity in each cerebral hemisphere, with a frontal horn, body, atrium and occipital and temporal horns, communicating with the third ventricle through the interventricular foramen.

Show on body map Brain — Midsagittal Section

Overview

Each lateral ventricle follows the C-shaped growth of the hemisphere. Its parts are:
• the frontal (anterior) horn, in front of the interventricular foramen;
• the body, beneath the corpus callosum and above the thalamus;
• the atrium (trigone), where the body, occipital horn and temporal horn meet;
• the occipital (posterior) horn, extending back into the occipital lobe;
• the temporal (inferior) horn, curving down and forward into the temporal lobe.

Its walls are formed by surrounding structures:
• roof: the corpus callosum;
• medial wall of the frontal horn and body: the septum pellucidum, a thin double membrane separating the two lateral ventricles;
• lateral wall and floor of the frontal horn: the head of the caudate nucleus;
• floor of the body: the thalamus and the body of the caudate, with the choroid plexus along the choroidal fissure between thalamus and fornix;
• floor of the temporal horn: the hippocampus; its roof carries the tail of the caudate.

The choroid plexus runs from the interventricular foramen along the body into the temporal horn. It forms a large tuft, the glomus, in the atrium, which commonly calcifies in adults and is a useful CT midline marker. The frontal and occipital horns contain no choroid plexus.

Location

Within each cerebral hemisphere, extending into the frontal, parietal, occipital and temporal lobes.

Parts & subdivisions

  1. Frontal (anterior) horn
    Bounded by the corpus callosum (roof and front), septum pellucidum (medially) and caudate head (laterally); no choroid plexus.
  2. Body
    Under the corpus callosum; floor = thalamus and caudate body; choroid plexus at the choroidal fissure.
  3. Atrium (trigone)
    Junction of body, occipital and temporal horns; contains the choroid glomus.
  4. Occipital (posterior) horn
    Variable in size; calcar avis (bulge of the calcarine sulcus) on the medial wall; no choroid plexus.
  5. Temporal (inferior) horn
    Hippocampus in its floor, tail of caudate and stria terminalis in its roof, amygdala at its tip.
  6. Septum pellucidum
    Thin double sheet separating the two frontal horns; a cavum septi pellucidi between its layers is a normal variant.

Function

  • Main site of CSF production (choroid plexus)
  • Reservoir of CSF that buffers changes in intracranial volume

Clinical significance

Germinal matrix haemorrhage in preterm infants

The fragile germinal matrix beneath the ependyma at the caudothalamic groove bleeds in premature infants (<32 weeks), especially with fluctuating cerebral blood flow. Blood may rupture into the lateral ventricles (intraventricular haemorrhage, graded I–IV) and cause post-haemorrhagic hydrocephalus and periventricular venous infarction.

Midline shift

Asymmetry or compression of the lateral ventricles and displacement of the septum pellucidum on CT quantify midline shift from a mass lesion, an important indicator of herniation risk.

Compiled from standard anatomy and physiology references — see the Nervous System sources. For education only; not medical advice.