Anatomy (intro to Neuroanatomy) Flashcards
describe the term motor homoculus?
Describe the sensory homoculus?
Each cerebral hemisphere includes somatosensory cortex that is located just posterior to the central sulcus (a.k.a., postcentral gyrus) and extends down to the sylvian fissure. This area is histologically known to be Brodmann’s Areas 1, 2, 3.
The topographical representation of the homunculus arranged in an anatomical fashion and represents the tactile representation of the contralateral side.
It is important to recognize 2 main things about the somatosensory cortex:
That the density of receptors for various parts of the body are not the same which is why the homunculus represents different sizes as it extends over the cortex.
The surface area of the anatomical body part also does not influence the amount of the cortex dedicated to that body part, but rather reflects the density of cutaneous tactile receptors dedicated to that body part. For example, the lips make up a small surface area compared to other body parts but yet has a greater density of receptors compared to the shoulder or forearm.
Define the term Anterior.
nearer the front, especially in the front of the body, or nearer to the head or forepart.
Define the term posterior.
further back in position; of or nearer the rear or hind end.
Define the term Superior(cranial).
toward the head end of the body; upper.
Define the term Inferior (caudal).
away from the head; lower.
Define the term Superficial.
structures that are closer to the exterior surface of the body.
Define the term Deep.
structures closer to the interior centre of the body.
Define the term Medial.
means toward the middle or centre.
Define the term lateral.
means to the side of, or away from, the middle of the body.
Define the term Proximal.
means nearer to the center (trunk of the body) or to the point of attachment to the body.
Define the term Distal.
it refers to parts of the body further away from the center.
Define the term Ipsilateral.
On the same side, as opposed to contralateral.
Define the term Contralateral.
refers to structures on opposite sides of the body.
What is the Coronal plane?
is an anatomical term describing an imaginary division between an organism’s dorsal and ventral halves. Dorsal indicates an area toward the back or spine, while ventral indicates the direction away from the spine, typically toward the ground.
What is the Sagittal plane?
is an anatomical plane which divides the body into right and left parts. The plane may be in the center of the body and split it into two halves (mid-sagittal) or away from the midline and split it into unequal parts (para-sagittal).
What is the horizotal plane?
is an imaginary plane that divides the body into superior and inferior parts. It is perpendicular to the coronal plane and sagittal plane.
Define the term Abduction?
Abduction is any motion of the limbs or other body parts that pulls away from the midline of the body.
Define the term Adduction?
the movement of a limb or other part towards the midline of the body or towards another part
Define the term Flexion.
Flexion is the medical term for bending an arm or leg. Techically speaking, it’s a physical position that decreases the angle between the bones of the limb at a joint. It occurs when muscles contract and move your bones and joints into a bent position.
Define th term Extension.
Extension refers to a movement that increases the angle between two body parts. Extension at the elbow is increasing the angle between the ulna and the humerus. Extension of the knee straightens the lower limb.
Define the term Rotation?
Rotational movement is the movement of a bone as it rotates around its longitudinal axis. Rotation can be toward the midline of the body, which is referred to as medial rotation, or away from the midline of the body, which is referred to as lateral rotation.
What is meant by lateral flexion?
For example, when you move your head toward one of your shoulders or bend your body sideways, you’re performing a lateral flexion.
What is the pre-gyri?
An important functional area of the frontal lobe is the precentral gyrus, which is located rostral to the central sulcus. The precentral gyrus is called the somato-motor cortex because it controls volitional movements of the contralateral side of the body
What is the post-gyri?
The postcentral gyrus is a prominent gyrus in the lateral parietal lobe of the human brain. It is the location of the primary somatosensory cortex, the main sensoryreceptive area for the sense of touch.
What is the corpus callosum and why is it important?
The corpus callosum is a large, C-shaped nerve fiber bundle found beneath the cerebral cortex. It stretches across the midline of the brain, connecting the left and right cerebral hemispheres. It makes up the largest collection of white matter tissue found in the brain.
It allows us to perceive depth and enables the two sides of our brain to communicate
What is the function of the Olfactory Nerve?
It conveys the sense of smell.
Where does the Olfactory nerve orginate?
The olfactory nerve originates in the nasal mucosas. They are formed by th eolfactory neurons that merge into olfactory nerve bundles.
What is the Olfactory Bulb?
A rounded mass of tissue that contains several types of nerve cells that are involved in the sense of smell.
What is the cribriform plate?
The cribriform plate, a horizontal segment of the ethmoid bone, forms a major portion of the nasal roof separating it from the anterior cranial fossa.
What is the cavernous sinus?
The cavernous sinus is a paired dural venous sinus located within the cranial cavity.
What is the pons?
The pons is a major division of the brainstem. It is found above the medulla and below the midbrain, and is anterior to (in front of) the cerebellum.
What are orbits?
The orbits are bony structures of the skull that house the globe, extraocular muscles, nerves, blood vessels, lacrimal apparatus, and adipose tissue.
The image highlights the subarachnoid space – what type of fluid will be found within this space and what is its purpose?
Cerebrospinal fluid is a clear, watery fluid.
First, CSF acts as a shock absorber, cushioning the brain against the skull. Second, CSFallows the brain and spinal cord to become buoyant, reducing the effective weight of the brain from its normal 1,500 grams to a much lesser 50 grams.
What are arachnoid granulations?
Arachnoid granulations are structures filled with cerebrospinal fluid (CSF) that extend into the venous sinuses through openings in the dura mater and allow the drainage of CSF from subarachnoid space into venous system. Usually they are asymptomatic but can be symptomatic when large enough to cause sinus occlusion.
