Trace the hippocampal mammillary projection through fimbria, crus, body and the postcommissural fornix. Precommissural fibres instead reach basal forebrain structures, including the septal region; these subdivisions are not separately identified here. The displayed F family is population-averaged tractography and does not encode conduction direction.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
F, Fornix
Hippocampus
Compare
Set the medial view and show F with the gross hippocampal reference. Describe the postcommissural course, distinguish the precommissural projection towards basal forebrain structures, and identify which subdivisions are not separately shown.
Read the neighbours
The hippocampal mammillary projection passes through fimbria, crus, body and the postcommissural fornix.
Precommissural fibres instead reach basal forebrain structures, including the septal region; these subdivisions are not separately identified here.
The septum and foramen of Monro are anatomical landmarks that are not rendered as scene objects.
The displayed tract geometry does not identify subdivision boundaries or encode conduction direction.
Explain before revealing
Can this render establish conduction direction or identify every named fornix subdivision?
Explanation
No. It shows a reconstructed course, while subdivision boundaries and conduction direction require separate evidence.
In a surgical discussion
For resident teaching, distinguish the postcommissural and precommissural courses from a separate sectional description of ventricular landmarks. This display does not show the subdivisions or supply an operative plan.
Anatomical accounts trace the hippocampal mammillary projection through fimbria, crus, body and the postcommissural fornix. Precommissural fibres instead reach basal forebrain structures, including the septal region; these subdivisions are not separately identified here. The viewer shows a population F sample and a gross hippocampal reference.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. It shows a reconstructed course, while subdivision boundaries and conduction direction require separate evidence.
This relationship draws on 4 cited sources.
Relationship 2 of 6 · conceptual model
Place the Papez model beside the rendered tracts
Orient
The Papez model places the fornix and cingulum within a proposed route linking hippocampal, diencephalic and cingulate structures. Limbic reviews revise the classic account and treat it as one model, not a complete inventory of memory function. This scene shows only selected population tract families and gross HIP and THA references. TR_A is shown as a broad thalamic-radiation reference. This scene does not isolate the anterior thalamic nuclei or their specific cingulate connections.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
F, Fornix
C_PH, parahippocampal cingulum
TR_A, anterior thalamic radiation
Hippocampus
Thalamus
RSC, retrosplenial reference
EC, entorhinal reference
Compare
Show F, C_PH and TR_A with HIP and THA visible. Describe TR_A as a broad thalamic-radiation reference, then identify the mammillary bodies and mammillothalamic tract as links that need an external anatomical reference.
Read the neighbours
The model relates hippocampal, fornical, thalamic, cingulate and parahippocampal anatomy.
TR_A is a broad thalamic-radiation reference; it does not isolate anterior thalamic nuclei or their specific cingulate connections.
The mammillary bodies and mammillothalamic tract are not rendered as scene objects, and the gross THA mesh does not identify anterior thalamic nuclei.
Co-displayed pathways are separate population samples, not a demonstrated closed or directionally encoded circuit.
Explain before revealing
Do F, C_PH and broad TR_A identify the specific thalamic-cingulate links in the Papez model?
Explanation
No. The mammillary bodies and mammillothalamic tract are not displayed. Broad TR_A and the gross THA mesh do not isolate anterior thalamic nuclei or their specific cingulate connections. The classic circuit remains an external model rather than a closed pathway in this viewer.
In a surgical discussion
For residents, use the loop to ask which links are represented and which require another anatomical source. The label alone does not localise an individual memory difficulty.
The Papez model brings fornix and cingulum relationships into a broader account of limbic anatomy and memory. Several named links and relay structures are absent from the scene, so the model is not a closed circuit rendered by this atlas.
Anatomical accounts trace the hippocampal mammillary projection through fimbria, crus, body and the postcommissural fornix. Precommissural fibres instead reach basal forebrain structures, including the septal region; these subdivisions are not separately identified here. The viewer shows a population F sample and a gross hippocampal reference.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. The mammillary bodies and mammillothalamic tract are not displayed. Broad TR_A and the gross THA mesh do not isolate anterior thalamic nuclei or their specific cingulate connections. The classic circuit remains an external model rather than a closed pathway in this viewer.
This relationship draws on 6 cited sources.
Relationship 3 of 6 · reconstruction
Compare the cingulum route families
Orient
Human dissection and diffusion tracking describe the cingulum in subdivisions rather than as one undifferentiated cable. Hodos displays five families, C_FP, C_PO, C_PH, C_FPH and C_PHP; their names are route labels, not microscopic partitions or proof that one tract follows the full arc.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
C_FP, frontal-parietal cingulum
C_PO, Cingulum, parolfactory
C_PH, parahippocampal cingulum
C_FPH, Cingulum, frontal-parahippocampal
C_PHP, parahippocampal-parietal cingulum
25, subgenual cingulate reference
23d, posterior cingulate reference
RSC, retrosplenial reference
EC, entorhinal reference
PHA1, parahippocampal reference
Compare
Show all five cingulum families in the medial view. Compare their broad courses with the selected cortical references, without treating a parcel outline as a tract endpoint.
Read the neighbours
The five displayed cingulum families are C_FP, C_PO, C_PH, C_FPH and C_PHP.
Diffusion tracking identifies modelled subdivisions; it does not supply histological borders for these five names.
Areas 25, 23d, RSC, EC and PHA1 provide cortical reference points; their boundaries do not establish tract endpoints.
Displayed line continuity is not an axon count or proof that each fibre follows the entire arc.
Explain before revealing
Do the five installed cingulum families represent five histologically separated tracts?
Explanation
No. They distinguish the atlas route categories. They do not establish separated tissue compartments, the fibre course of any one person or a function for the nearby cortex.
In a surgical discussion
Use the family names to describe a group-scale medial pathway before proposing a functional interpretation. Do not turn a tract label into an individual tissue border or a direct symptom explanation.
Dissection and diffusion studies describe subdivisions along medial and parahippocampal cingulum routes. The installed families are population tractography categories, not histological compartments or endpoints registered to one person; PHA1 is a cortical reference rather than a tract endpoint.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. They distinguish the atlas route categories. They do not establish separated tissue compartments, the fibre course of any one person or a function for the nearby cortex.
This relationship draws on 5 cited sources.
Relationship 4 of 6 · reconstruction
Follow the posterior cingulum towards medial temporal cortex
Orient
Posterior cingulum reconstructions include a medial course and routes towards parahippocampal territory. Compare C_PH and C_PHP with RSC, EC and PHA1 references, while remembering that these parcels and tract samples come from population atlases. Their proximity does not establish exact endpoints or a connection in one individual.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
C_PH, parahippocampal cingulum
C_PHP, parahippocampal-parietal cingulum
RSC, retrosplenial reference
EC, entorhinal reference
PHA1, parahippocampal reference
Compare
Show C_PH and C_PHP together, select RSC, EC and PHA1, and rotate through medial and posterior views. Describe the named reference parcels separately from the displayed tract course.
Read the neighbours
RSC orients retrosplenial cortex, EC entorhinal cortex, and PHA1 part of the parahippocampal cortex. These references do not establish exact cingulum terminations.
The cingulum families are reconstructed routes, not registrations of fibres in any one person to those parcel boundaries.
The posterior projection is not a sectional dissection of the isthmus or neighbouring structures.
The scene does not establish a functional role from spatial proximity alone.
Explain before revealing
Do the RSC, EC and PHA1 parcels mark the exact endpoints of the highlighted cingulum families?
Explanation
No. RSC, EC and PHA1 are group cortical references, and the cingulum families are group tractography samples. Their proximity can orient an anatomical hypothesis, but it does not register the pathway in one person.
In a surgical discussion
For resident anatomy discussion, describe the posterior tract and its cortical references separately from any cognitive claim. The population view cannot define an individual corridor or the function of a nearby parcel.
Dissection and diffusion studies describe subdivisions along medial and parahippocampal cingulum routes. The installed families are population tractography categories, not histological compartments or endpoints registered to one person; PHA1 is a cortical reference rather than a tract endpoint.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. RSC, EC and PHA1 are group cortical references, and the cingulum families are group tractography samples. Their proximity can orient an anatomical hypothesis, but it does not register the pathway in one person.
This relationship draws on 5 cited sources.
Relationship 5 of 6 · schematic
Keep the fornix and cingulum distinct in a limbic account
Orient
The fornix and cingulum appear together in classic limbic accounts, but they have distinct courses: F is a hippocampal output family, while the cingulum contains medial association routes. Showing them together does not make them one continuous cable or demonstrate fibres between the families.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
F, Fornix
C_FPH, Cingulum, frontal-parahippocampal
C_PH, parahippocampal cingulum
Hippocampus
Compare
Show F with C_FPH and C_PH, then compare each route with the gross hippocampal reference. Name the source that supports each anatomical description before opening the answer.
Read the neighbours
F and the cingulum are separate installed pathway families.
The fornix anatomy and cingulum subdivisions come from different anatomical and reconstruction evidence.
The hippocampus is shown at gross scale; the mammillary bodies and fine cingulum endpoints are absent.
A single view cannot establish which fibres are intact in an individual.
Explain before revealing
If both pathways appear in one limbic model, are they one tract?
Explanation
No. F and the cingulum are distinct anatomical systems that can be placed in a broader circuit model. The scene shows their population geometry and does not establish a continuous fibre connection between them.
In a surgical discussion
A resident explanation should name the pathway under discussion before attaching it to a broader memory model. This group render does not show whether either route is intact in a person.
Anatomical accounts trace the hippocampal mammillary projection through fimbria, crus, body and the postcommissural fornix. Precommissural fibres instead reach basal forebrain structures, including the septal region; these subdivisions are not separately identified here. The viewer shows a population F sample and a gross hippocampal reference.
Dissection and diffusion studies describe subdivisions along medial and parahippocampal cingulum routes. The installed families are population tractography categories, not histological compartments or endpoints registered to one person; PHA1 is a cortical reference rather than a tract endpoint.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. F and the cingulum are distinct anatomical systems that can be placed in a broader circuit model. The scene shows their population geometry and does not establish a continuous fibre connection between them.
This relationship draws on 8 cited sources.
Relationship 6 of 6 · conceptual model
Bound what a highlighted route says about memory
Orient
Use the Papez model to retrieve links that are not represented in this scene. The mammillary bodies, mammillothalamic tract and identified anterior thalamic nuclei remain unrepresented.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
F, Fornix
C_PH, parahippocampal cingulum
TR_A, anterior thalamic radiation
Hippocampus
Thalamus, gross
RSC, retrosplenial reference
EC, entorhinal reference
Compare
Show F, C_PH and TR_A with HIP and THA visible. Compare the displayed pathways with the named Papez links and identify which structures remain absent.
Read the neighbours
F and TR_A are displayed pathway references, not a complete hippocampal-diencephalic route.
The mammillary bodies are not separate scene objects.
The mammillothalamic tract is not rendered.
The gross THA mesh does not identify anterior thalamic nuclei.
Explain before revealing
Which links in the hippocampal–diencephalic route remain unrepresented?
Explanation
The mammillary bodies, mammillothalamic tract and identified anterior thalamic nuclei remain unrepresented.
In a surgical discussion
A highlighted route does not measure memory; in resident teaching, pair any memory claim with a named test and its result.
The Papez model brings fornix and cingulum relationships into a broader account of limbic anatomy and memory. Several named links and relay structures are absent from the scene, so the model is not a closed circuit rendered by this atlas.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: The mammillary bodies, mammillothalamic tract and identified anterior thalamic nuclei remain unrepresented.
This relationship draws on 4 cited sources.
Recap
How do the fornix and cingulum enter the Papez model, and what does the atlas leave unresolved?
Name the fornix waypoints from anatomical sources, not from the F render alone.
Compare cingulum families as reconstructed routes rather than histological compartments.
Identify the mammillary bodies, mammillothalamic tract and anterior thalamic nuclei as links absent from the displayed route.
Review the final explanation
The mammillary bodies, mammillothalamic tract and identified anterior thalamic nuclei remain unrepresented.
Rhoton lineage fibre dissection relating callosal and deep white matter structures to the transcallosal ventricular corridor. This is anatomical context, not operative instruction.
Provenance for the HCP1065 population-averaged bundles rendered here. Every displayed line is an average-space reconstruction sampled for display; it is not a patient’s pathway and carries no direction of conduction.
Provenance for the Melbourne Subcortex Atlas scale-1 meshes rendered here. Scale 1 is the coarsest level: anterior and posterior thalamus are merged and no brainstem nucleus is included.
This review proposes a revised model of limbic relationships across memory, emotion and behaviour. It supports treating Papez as one historical framework, not as a complete circuit or a single-function map.
Diffusion MRI fibre tracking describes subdivisions within the cingulum bundle. It supports a model-based account of regional courses, not histological boundaries or an individual endpoint map.
HCP population reference built from converging cortical features. A parcel boundary here is a group boundary; it does not locate one person’s functional border and it has not been registered to any individual in this viewer.