This chapter provides an abundant display of gross hippocampal anatomy with related diagrams as needed. Anatomy, embryology, arterial supply and function normal hippocampal anatomy the hippocampus is a bilaminar gray matter structure located medially in the temporal lobe that protrudes over the temporal horn of the lateral ventricle and occupies the medial region of its floor figs. It has a head posterior to the amygdala, a body, and a tail which follows the upwardly curving lateral ventricle although there is a lack of consensus relating to. Anatomy of parts that defines hippocampal function. This feature of the hippocampus means that in magnetic resonance mr brain images, the hippocampus has relatively low contrast and no distinguishable boundaries along significant portions of its surface. The hippocampus is a small gm structure that is adjacent to other gm structures e. The hippocampus lies in the hippocampal sulcus immediately below the floor of the temporal horn of the lateral ventricle, and in cross section coronal has appearances that are reminiscent of a seahorse. The hippocampus, which is located in the inner medial region of the temporal lobe, forms part of the limbic system, which is. A good example that shows the involvement of the hippocampus with our memories concerns the peculiar case of a man named henry molaison, also known as patient h. Humans and other mammals have two hippocampi, one in each side of the brain. The purpose of this anatomic moment is to highlight the appearance of the hippocampus. The hippocampus is also called ammons horn because the two hippocampi bend around in the form of the horns of a ram.
Hippocampal physiology, structure and function and the. We compared differences in anatomy before, and after, correcting for whole brain size. In this chapter, the term hippocampal formation refers to the dentate gyrus, hippocampus, subicular complex, and entorhinal cortex. There were a total of 140 arteries supplying the hippocampi, for an average of 4. The hippocampus is one of several brain regions that together comprise the hippocampal formation. The hippocampus is a complex and fascinating region of the brain that has enormous clinical significance. The hippocampus is an anatomical subdivision of the brain. The complexity of this phylogenetically ancient structure, at both the gross and cellular level, has encouraged study by generations of anatomists. Anatomy and aging of the amygdala and hippocampus in. The hippocampus is part of the limbic system, and plays important roles in the consolidation of information from shortterm memory to longterm memory, and in spatial memory that. The other regions that together comprise the hippocampal formation consist of the dentate gyrus, the subicular complex, and the entorhinal cortex.
The third section chapter 5 is devoted to the vascularization of the hippocampus. Before we discuss these various features of hippocampal. Pdf the hippocampus is a complex and fascinating region of the brain that has enormous clinical significance. In this lateral view of the human brain, the frontal lobe is at left. The hippocampus proper consists of three major subfields ca1ca3. Microsurgical anatomy of the hippocampal arteries in. The hippocampus is located in the medial temporal lobe of the brain. The second section chapter 4 is a description of the anatomy of the hippocampus and adjacent structures. Since hippocampus is a part of allocortex archicortex, there is a zone that separates it from neocortex. The hippocampal formation is an important component of the limbic system, along with the amygdala and septal area although some also include the cingulate gyrus and prefrontal cortex as part of this system. Measuring size and shape of the hippocampus in mr images. Specifically, small imaging abnormalities may cause major symptoms. We believe that the detection of these lesions will be improved if imaging clinicians have an organized reference that facilitates identification of the cellular zones that comprise the hippocampus.
It describes the extensive cortical connections of the entorhinal cortex in the macaque monkey and the emerging prominence of adjacent related brain regions. The hippocampal formation is a prominent cshaped structure bulging in the floor of the temporal horn of the lateral ventricle. The hippocampus is a horseshoe shaped structure, with an arching band of nerve fibers fornix connecting the hippocampal structures. However, the healthy function of the hippocampus can be affected by. Hippocampus seahorse curved shape which resembles a shape of a seahorse. Normal anatomy and pathology article pdf available in american journal of roentgenology 1714. Nisslstained coronal section of the brain of a macaque. Hippocampus, region of the brain that is associated primarily with memory. The hippocampus is composed of the dentate gyrus, the hippocampus proper separated into ca1, ca2, ca3 regions. Here is a neural landscape, alluring in its intricacy and beauty, not only to the anatomist on histological section, but. The full text of this article is available in pdf format. Hippocampus the hippocampus is located in the medial temporal lobe of the brain. Ammon was an egyptian god, near whose temple ammonia or the salt of ammon was prepared.
Anatomy of hippocampus radiology linkedin slideshare. Nevertheless, hippocampus anatomy is complex, due to a deep location, and a complex structure. This general layout holds across the full range of mammalian species, from hedgehog to human. The hippocampus is a part of the brain that plays a key role in memory and how knowledge is obtained. In this didactic paper, we propose a description of the hippocampus that should help neurosurgeons to feel at ease in this region. The anatomy of the hippocampus is relatively complex, but a few rules may help for surgical practice. The amygdala is part of the limbic system, amygdala, region of the brain primarily associated with the processing of memory, decisionmaking, and emotional responses. There was no significant between group differences in whole brain volume. This ana tomic moment will highlight some features of the hippocampus to.
Hippocampal anatomy1214 hippocampus contains two parts. It has a distinctive, curved shape that has been likened to the seahorse monster of greek mythology and the rams horns of amun in egyptian mythology. Hippocampectomy is an efficient procedure for medial temporal lobe epilepsy. March 22, 2020 the hippocampal formation is an important component of the limbic system, along with the amygdala and septal area although some also include the cingulate gyrus and prefrontal cortex as part of this system. Both of these parts are separated by hippocampal sulcus and curve into each other. The name hippocampus is derived from the greek hippokampus hippos, meaning horse, and kampos, meaning sea monster, since the structures shape resembles that of a sea horse. Hippocampal anatomy and hippocampal sclerosis neupsy key. Hippocampal anatomy and hippocampal sclerosis imad najm henri duvernoy stephan schuele hippocampal anatomy because the hippocampal formation is frequently involved in patients with focal epilepsy, a thorough knowledge of this structure and its connections is critical to an understanding of the pathology and clinical semiology of temporal lobe epilepsy caused by hippocampal disease. In this lateral view of the human brain, the frontal lobe is at left, the occipital lobe at right, and the temporal and parietal lobes have largely been removed to reveal the hippocampus underneath. Hippocampus anatomy describes the physical aspects and properties of the hippocampus, a neural structure in the medial temporal lobe of the brain. Introduction the hippocampus has been a source of fascination from the very origins of neuroscience as a modern discipline.
It compares and contrasts the picture of hippocampal anatomy obtained from studies of the rat with that of the monkey. Also, there is evidence that the hippocampus plays a role in finding. Cornu ammonis hippocampus proper and dentate gyrus. The amygdala is one of two almondlike shapes of nuclei positioned deep and medially within the temporal lobes of the brain, just anterior to the hippocampus. The hippocampus is the part of the brain that is involved in forming, organizing, and storing memories. The general function of the hippocampus is to encode new information or memories, without it we wouldnt be able to learn. The dorsal fornix which runs close to the midline beneath the corpus callosum is not shown in. Hippocampal function, anatomy and physiology as it relates to schizophrenia. However, individuals with asperger syndrome had a significantly larger raw bulk volume of total p amnesia or loss of memory can eventually lead to alzheimers when only one half is damaged in one hemisphere, the brain is still able to retain nearnormal memory functioning can affect ability to learn new cognitive skills. This chapter outlines the anatomy of the hippocampal formation, beginning with issues of nomenclature and definition. Hippocampal anatomy and pathologic alterations on conventional mr images leighton p. The hippocampus proper can clearly be divided into two major regions, a largecelled proximal region and a smallercelled distal region. Anatomic moment hippocampal anatomy and pathologic.
An anatomical study of the vascularization of the hippocampus was performed on 30 hemispheres. Increasing knowledge of the avian hippocampal formation hippocampus and parahippocampal area suggests that it plays a role in a variety of behaviors, such as homing, cache retrieving, visual discrimination, imprinting, and sexual behavior. It is a limbic system structure that is particularly important in forming new memories and connecting emotions and senses, such as smell and sound, to memories. The role of the hippocampus in relational declarative memory. In humans, the hippocampus is an elongated structure buried deep.
1474 1449 602 50 1207 1313 1098 1307 707 934 1047 958 978 1491 1380 1 864 1 350 395 726 132 868 558 1310 829 682 515 417 1065 966 1246 572 1182 181