Info

Supraorbital incisure

Perpendicular lamina of ethmoid bone

Greater wing of sphenoid bone

Temporal bone

Infraorbital foramen

Zygomatic bone

Anterior nasal spine

Mastoid process

Intermaxillary suture

Angle of mandible

Mental foramen

Parietal bone

Lambdoid suture

Temporal squama

Mastoid process

External acoustic meatus

Zygomatic process of temporal bone

Parietal bone

Lambdoid suture

Temporal squama

Mastoid process

External acoustic meatus

Zygomatic process of temporal bone

Hyoid bone

Vertex Bregma Coronal suture Frontal bone

Pterion

External side of the greater wing of sphenoid bone

Nasal bone

Frontal process of maxillary bone Zygomatic bone Anterior nasal spine Alveolar process

Hyoid bone

Lambdoid suture Occipital-mastoid suture

Occipital external protuberance Odontoid process of axis Vertical ramus of mandible

Atlas

Parietal bone

Occipital bone Occipital condyle

Styloid process

Angle of mandible

Posterior ci moid process Sella turcica

Internal acoustic meatus

Medial plate of pterygoid process Hook of pterygoid process

Anterior clinoid process

Frontal sinus

Nasal bones

Anterior nasal spine

Palatine process

Hyoid bone

Anterior clinoid process

Frontal sinus

Nasal bones

Anterior nasal spine

Palatine process

Hyoid bone

Crista galli Floor of sella turcica Posterior clinoid process Greater wing of sphenoid bone Foramen lace rum Petrous pyramid of temporal bone Internal acoustic meatus Jugular foramen Clivus

Odontoid process of axis Occipital foramen

Dorsum sellae

Dorsum sellae

Lesser wing of sphenoid bone

Anterior clinoid process

Foramen rotundum

Carotid groove

Foramen spinosus and groove of the middle meningeal artery

Meckel's cave

Foramen ovale

Hypoglossal canal

Lesser wing of sphenoid bone

Anterior clinoid process

Foramen rotundum

Carotid groove

Foramen spinosus and groove of the middle meningeal artery

Meckel's cave

Foramen ovale

Hypoglossal canal

Superior sagittal sinus groove

Optic canal ^

Anterior dinoid process

Tuberculum sellae

Posterior clinoid process

Spheno-ocdpital suture

Internal acoustic meatus '

Oivus

Superior sagittal sinus groove

Optic canal ^

Anterior dinoid process

Tuberculum sellae

Posterior clinoid process

Spheno-ocdpital suture

Internal acoustic meatus '

Oivus

Lesser wing of sphenoid bone

Chiasmatic groove

Greater wing of sphenoid bone

Superior orbital fissure

Foramen rotundum

Petrous pyramid of temporal bone

Short Introduction pp. 25-27 _

The Brain

The brain or encephalon is the cranial part of the neuraxis, distinguished from the spinal cord (medulla spinalis).

The average weight of the brain is about 1380 g in the adult male and about 1250 g in the adult female. The brain increases rapidly during the first four years of life and reaches its maximum weight by about the twentieth year. As age advances, the brain decreases slowly in weight.

It is composed of a rostral portion, the forebrain (prosencephalon), and the truncus cerebri (brainstem). The prosencephalon is formed by two hemispheres (telencephalon) and an impair and median structure. The latter has an anterior part named telencephalon impair, and a posterior part consisting of the diencephalon.

The brainstem is formed by the mesencephalon (midbrain) and the rhombencephalon. The latter is divided into metencephalon (pons and cerebellum) and myelencephalon (medulla oblongata).

The surface of the cerebral hemisphere is characterized by the presence of furrows of two different types: fissures, more prominent and relatively constant in their relationships, and sulci, less deep and more subject to individual variations.

The interhemispheric fissure separates the two hemispheres and hosts the great cerebral falx, a thick meningeal membrane. The sylvian or lateral fissure, quite deep, divides the frontal and parietal lobes from the temporal one. The rolandic or central fissure separates the frontal and parietal lobes. On the medial surface the parieto-occipital fissure divides the precuneus (parietal) from the cuneus (occipital). It extends on the outer aspect of the hemisphere. The border between occipital and temporal lobes on the lateral surface of the brain is less sharp and the division is somewhat arbitrary, passing through the parieto-occipital fissure and the preoccipital notch, in the inferior aspect of the temporal lobe. The preoccipital notch is difficult to identify and it is conventionally located 4 cm frontal to the occipital pole.

The insula is hidden inside the sylvian fissure. In order to see it, the frontal and temporal opercula must be opened.

The most relevant feature in the medial aspect of the brain hemisphere is the corpus callosum (see also p. 275). This is the most important interhemispheric commissure, made of 5 parts: the most anterior and inferior one is the ros trum, immediately dorsal to the anterior commissure (connects portions of middle and inferior temporal gyri): above the rostrum, the genu continues posteriorly with the body of the corpus callosum, which ends in correspondence with the frontal lobe, followed by a notch, the isthmus, and finally the splenium. The corpus callosum is cranially covered by the cingulate gyrus, separated from it by the callosal sulcus. Immediately below its posterior aspect, the fornix is found. This peculiar structure is an interhemispheric commissure (hypothalamic commissure) comprising two columns that originate from the mammillary bodies. They extend forwards and upwards, toward the center of the corpus callosum, where the columns travel together to form the body of the fornix, while maintaining their fibers separate. Afterwards, they become separate by the commissure of the fornix, and continue backward and then down and forward, towards the anterior commissure and hippocampus, ending in the region of the uncus. The parieto-occipital fissure separates the precuneus and cuneus. The medial aspect of the temporal lobe offers the clear distinction of the uncus of the hippocampus, followed posteriorly by the parahippocampal and the fusiform gyri.

FT = Superior frontal gyrus

F2 = Middle frontal gyrus

F3 = Inferior frontal gyrus

Fa = Ascending frontal gyrus

Pa = Ascending parietal gyrus

PI = Superior parietal gyrus

P2 = Inferior parietal gyrus

Central fissure of Rolando

Frontal lobe

Parietal lobe

Parietooccipital fissure

Occipital lobe

Parietal lobe

Parietooccipital fissure

Occipital lobe

Central fissure of Rolando

Frontal lobe

Centrai fissure of Rolando

Parietal lobe

Lateral fissure of Sylvius

Frontal lobe

Parieto-occlpital fissure

Occipital lobe

Preoccipital notch

Temporal lobe

Centrai fissure of Rolando

Parieto-occlpital fissure

Lateral fissure of Sylvius

Frontal lobe

Parietal lobe

Superior frontal gyrus Middle frontal gyrus Inferior frontal gyrus Pars orbitalis of F3 Pars triangularis of F3 Pars operculars of F3 Ascending frontal gyrus Ascending parietal gyrus Superior parietal gyrus Inferior parietal gyrus Superior temporal gyrus Middle temporal gyrus Inferior temporal gyrus

Temporal lobe

Occipital lobe

Preoccipital notch

Interhemispheric fissure

Orbital gyri Gyrus rectus Superior temporal gyrus Middle temporal gyrus Inferior temporal gyrus

Interhemispheric fissure

Orbital gyri Gyrus rectus Superior temporal gyrus Middle temporal gyrus Inferior temporal gyrus

2 Sectional Anatomy of the Telencephalon

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Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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