15 Flashcards
Speech
It is the ability to express thoughts in the form of words in response to visual and auditory stimuli.
Words may be spoken or written.
centers of speech and motor control areas are usually much more developed in one cerebral hemisphere than the other,
Dominant hemisphere
left hemisphere is dominant in 95% of
peoples (right handed people) and in the
remaining 5% the right hemisphere becomes
dominant (left handed people).
Wernicke’s area is more developed in one
hemisphere, responsible for
comprehension of language and related intelligence.
Damage to dominant Wernicke’s area leads to
dementia
Non-dominant side is related to other forms of
Non-dominant side is related to other forms of sensory intelligence (as music, nonverbal visual experiences), spatial relations between the person and their surroundings, the significance of “body language” and intonations of people’s voices.
Mechanism of speech
1- Sensory aspect of speech (input)
A. Visual input
B. Auditory input
C. Wernicke’s area (Junctional area)
2- Motor aspect of speech (output)
D. Broca’s area (word formation area) [areas 44, 45]
E. Exner’s area (hand skills area)
Sensory aspect of speech (input)
Visual input:
• Primary visual area (area 17 in the occipital
lobe) which receives impulses from the eyes. • Visual association areas (area 18 and 19 in
occipital lobe) which understand the meaning of the impulses coming to it from area 17.
Auditory input
• Primary auditory area (area 41 and 42 in temporal
lobe) receives sound impulses from the ear.
• Auditory association area (area 22 in temporal
lobe) which understand the meaning of impulses
coming to it from the primary auditory area.
Wernicke’s area (Junctional area)
• present in the
receives impulses from:
Wernicke’s area (Junctional area)
• present in the posterior part of the superior
temporal lobe. • It receives impulses from:
1- Visual association area. 2- Auditory association area. 3- Somatic association areas.
Motor aspect of speech (output)
A- Broca’s area (word formation area) [areas 44, 45]:
• Present in the lower part of premotor area
(area 6).
• Receives impulses from Wernicke’s area.
• Forms the program for muscles of articulation
(lips, tongue, and larynx) to produce the words
chosen by Wernicke’s area.
• Sends the pattern to face region in the primary
motor area which initiates the appropriate
movements of muscles of articulation.
B- Exner’s area (hand skills area):
• Present in the upper part of premotor area
(area 6).
• Receive impulses from Wernicke’s area.
• Form the program for muscles of the hand
to write the words chosen by Wernicke’s area.
• Sends the pattern to the hand area in
primary motor area which initiates the appropriate movements of muscles of the hand.
Formation of word, thoughts and choice of
words is function o
Wernicke’s area.
Speech disorders
- Aphasia
a. Sensory aphasia
Visual aphasia Auditory aphasia Wernicke’s aphasia
b. Motor aphasia
Broca’s aphasia Exner’s aphasia (agraphia)
c. General (global) aphasia
Dysarthria
Aphasia
- Inability to express thoughts in the
form of spoken or written words in absence of visual or hearing defect or disorders of muscles of speech
means the muscular
movements of the tongue, lips and larynx (muscles of speech) for the actual production of sound.
needs the normal function
Articulation
Of motor cortex, cerebellum & basal ganglia.
inability to speak correctly due to disorders
of the muscles of articulation.
Dysarthria
Causes of dysarthria:
1- Paralysis: resulting from UMNL or LMNL affecting
muscles of articulation.
2- Ataxia: resulting from neocerebellar lesion
leading to staccato speech.
3- Parkinsonism: Resulting from basal ganglia lesion
leading to slow monotonous speech.
