LOBES/FISSURES/MENINGES

Question 1

Frontal lobe

Answer 1

Frontal lobe- controls judgment, thinking, foresight (the consequences of right and wrong), sexual behavior, some smell, voluntary movements, abstract reasoning & planning. The frontal lobe contains the Broca’s area, which is responsible for the ability to speak and write. The frontal lobe also contains the motor strip, which sends messages to the body to allow it to move. If you can’t speak, your speech is said to be “broken”. The lip and tongue area of the motor strip are very close to the Broca’s area.

Question 2

Temporal lobe

Answer 2

Temporal lobe- controls memory, emotion, auditory, smell and taste. The temporal lobe contains the Wernicke’s area which is responsible for the ability to understand other people’s speech and to read. On the surface of the temporal lobe is the transverse gyri of Heschl which is the primary auditory cortex also called Brodmann’s area #41. So, Wernicke’s and the auditory center are very close together. The temporal lobe also contains the uncus which is the primary olfactory (smell) cortex.

Question 3

Parietal lobe-

Answer 3

Parietal lobe- controls orientation (where your at/proprioperception/position), interpretation of sensation (feeling) and contains the sensory strip. It also contains the association areas necessary for the recognition of familiar objects. A lesion in the parietal area could cause agnosia which is the loss of the ability to recognize sensory inputs.

Question 4

Occipital lobe-

Answer 4

It contains the primary visual cortex also known as Brodman’s area # 17. It is responsible for the analysis of visual information for orientation, position, movement and recognition and identification of objects.
Certain parts of the brain such as cranial nerves run through several different lobes. For example: emotions are associated with the temporal lobe, if we saw a snake, our emotion might be fear. The optic nerve runs all through the brain including the temporal lobe so that what we see (Occipital lobe) and our emotions (Temporal lobe) are connected.
In about 98% of the population, the left hemisphere is thought to be the dominant hemisphere. Usually, if you are right handed, your dominant hemisphere would be the left. The left or dominant hemisphere is considered very analytical and the right hemisphere is considered to be more creative. The dominant hemisphere also contains speech and language abilities.

Question 5

Broca’s area-

Answer 5

is located in the frontal lobe of the dominant hemisphere. It controls the ability to write, form words and communicate. Lesions in this area would result in the inability to articulate, although ability to understand is intact, this is known as expressive aphasia (unable to speak or write). It is Brodmann’s area #44. (Named after a French neurologist who discovered that speech was in the left hemisphere.)

Question 6

Wernicke’s area-

Answer 6

Wernicke’s area- is located in the temporal lobe of the dominant hemisphere and is responsible for receptive speech. A lesion here would result in the inability to understand written or spoken language, this is known as receptive aphasia (cannot comprehend written or spoken words).

Question 7

Gyri-

Answer 7

Gyri- raised areas of the brain (bumps), the bumps contain information all coiled up

Question 8

Sulci-

Answer 8

Sulci- shallow indentations or valleys (convolutions) in the brain

Question 9

Fissure –

Answer 9

Fissure – deep indentations or valleys

Question 10

Longitudinal cerebral fissure-

Answer 10

Longitudinal cerebral fissure- separates the two hemispheres of the brain

Question 11

Lateral cerebral/Sylvian fissure-

Answer 11

Lateral cerebral/Sylvian fissure- separates the temporal lobe from the frontal and parietal lobes

Question 12

Central sulcus/Rolandic fissure-

Answer 12

Central sulcus/Rolandic fissure- separates the frontal lobe from the parietal lobe. There is a type of seizures known as Sylvian and or Rolandic seizures. These two fissures (Sylvian & Rolandic) are close to each other but they are not the same. The true origin of the seizures is along the Rolandic fissure at C3, C4 and Cz.

Question 13

Parieto-occipital fissure-

Answer 13

Parieto-occipital fissure- separates the parietal lobe from the occipital lobe

Question 14

Calcarine fissure-

Answer 14

Calcarine fissure- separates the occipital lobe from the rest of the brain

Question 15

Skull-

Answer 15

Skull- this is the bony framework of the head and includes both the cranial and facial bones.

Question 16

Cranium-

Answer 16

Cranium- this is the skeleton of the head and includes only the bones of the head or cranium not the bones of the face.

Question 17

Foramen-

Answer 17

Foramen- this is a natural opening or hole in a bone. The foramen magnum is the opening at the base of the skull where the spinal cord connects to the brainstem.

Question 19

Fossa-

Answer 19

Fossa- this is a shallow or depressed area

Question 20

Sinuses-

Answer 20

Sinuses- cavity or hollow space. There are venous sinuses that carry venous blood and cranial sinuses that have air cavities.

Question 21

Dentate nuclei-

Answer 21

Dentate nuclei- (dentate means toothed) It’s in the cerebellum, receives axons of purkinje cells, major source of fibers composing the massive superior cerebellar peduncle (stalk like fibers that connect the hemispheres to the brainstem). They are the largest of the subcortical gray nuclei in the cerebellar hemispheres. It contributes most of outgoing efferent messages from the cerebellum to the cerebral cortex.

Question 22

CNS- Central nervous system-

Answer 22

CNS- Central nervous system- contains the brain, brainstem, cerebellum and the spinal cord.

Question 23

Cerebrum or brain -

Answer 23

Cerebrum or brain - are the four lobes together (frontal/temporal/parietal/occipital). It is divided into two cerebral hemispheres (left/right) by the longitudinal cerebral fissure.

Question 24

Cortex-

Answer 24

Cortex- the outer surface of the brain (which is where our EEG electrode record from). It has an area of about 2.5 square feet but only about 1/3 of it is found on the surface. The rest of it is hidden in the depths of the sucli. It may contain as many as 14 billion neurons.

Question 25

Cerebellum-

Answer 25

Cerebellum- (means little brain) a large striated mass lying above the pons and medulla (part of the brainstem) and beneath the occipital lobe. It consists of a left and a right hemisphere separated by the vermis. It is responsible for coherent control of movement (the planning and coordination of movement). Diseases of the cerebellum do not often affect the EEG. Alcohol effects the cerebellum and causes people to be uncoordinated which is why cops try to make drunks touch their nose. The left motor cortex connects to the right cerebellum.

Question 26

Vermis-

Answer 26

Vermis- narrow middle zone between the two hemispheres of the cerebellum

Question 27

Corpus callosum-

Answer 27

Corpus callosum- is the largest band of commissural (means to join together, a seam) fibers, it connects the main cerebral hemispheres and forms the roof of the lateral and 3rd ventricles. If it were cut, the two hemispheres would not be able to work together. It is thought to contain as many as 200 million individual fibers which could carry up to 4 billion impulses per second. (It looks like a big white C.)

Question 28

Gray matter-

Answer 28

Gray matter- non-myelinated nerve fibers and neuronal cell bodies (somas). It is found in outer layers and deep within the cerebrum and cerebellum.

Question 29

White matter-

Answer 29

White matter- are myelinated nerve axons that send nervous impulses from one region to another.

Question 30

Meninges-

Answer 30

Meninges- are the 3 coverings of the brain and central nervous system that protect and guard against injury (the pia, arachnoid and the dura or PAD). They are membranes made up of connective tissue.

Question 31

Pia-

Answer 31

Pia- innermost and thinnest covering of the brain, and closely adheres to the brain. It is rich with blood vessels.

Question 32

Arachnoid-

Answer 32

Arachnoid- is the web like covering (spider) that encloses the pia. The space between the pia and arachnoid is filled with cerebrospinal fluid (CSF). The arachnoid is a delicate nonvascular membrane that gives off extensions one of which is the arachnoid villi. The arachnoid villi go up through the dura to create a canal between the subarachnoid space and the intradural venous sinuses. These canals are considered the major site of absorption of CSF.

Question 33

Dura-

Answer 33

Dura- (also called the pachymenix) is the outermost, durable and toughest (dura is Latin for hard) layer of the brain (CNS). It surrounds the arachnoid and prevents leakage of CSF

Question 34

CSF- Cerebrospinal fluid-

Answer 34

CSF- Cerebrospinal fluid- protects, baths and nourishes the brain

Question 35

Leptomeninges-

Answer 35

Leptomeninges- the pia and arachnoid together are known as this, they are the soft membranes. There is an extension (trabeculae) of the arachnoid that goes down to connect with the pia. At one time the two layers were considered one and referred to as the leptomeninges.

Question 36

Tentorium cerebelli-

Answer 36

Tentorium cerebelli- fold of dura forming a roof over the posterior cranial fossa, It separates the cerebellum from the basal surface of the occipital and temporal lobes