[PPT]Brain and Cranial Nerves - University of … · Web viewTitle Brain and Cranial Nerves Author...
Transcript of [PPT]Brain and Cranial Nerves - University of … · Web viewTitle Brain and Cranial Nerves Author...
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Brainstem
• Connects spinal cord to brain• Parts
– Medulla oblongata– Pons– Mesencephalon
Fig. 15.1
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Brainstem• Medulla oblongata or medulla
– Regulates: Heart rate, blood vessel diameter, respiration, swallowing, vomiting, hiccupping, coughing, and sneezing
• Pons– Sleep and respiratory center
• Mesencephalon– Integral part of auditory
pathways in CNS
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Cerebellum• Involved in control of:
balance, posture, locomotion, and fine motor coordination producing smooth flowing movements
Fig. 15.22
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Diencephalon• Thalamus
– Largest part of diencephalon
– Most sensory input projects to here
– Influences mood and actions as fear or rage
• Epithalamus– Pineal gland may
influence sleep-wake cycle
• Hypothalamus– Functions
• ANS control• Endocrine control• Muscle control• Temperature
regulation• Regulation of food
and water intake• Emotions• Regulation of sleep-
wake cycle
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Cerebrum• Largest portion of brain• Hemispheres
– Right – Left– Lobes: frontal, parietal,
occipital, temporal, insula• Gyrus• Sulcus
Fig. 15.10
Fig. 15.1
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Meninges• Connective tissue
membranes– Dura mater:
Superficial– Arachnoid mater– Pia mater:
Bound tightly to brain
– Spaces • Subdural:
Serous fluid• Subarachnoid:
Cerebrospinal fluid (CSF)
Fig. 15.4
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Ventricles
• Ventricles: Lateral ventricles (2), third ventricle, fourth ventricle
• Choroid plexuses produce CSF which fills ventricles and other parts of brain and spinal cord
Fig. 15.6
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Cerebrospinal Fluid (CSF)
• Similar to serum with most of proteins removed
• Bathes brain and spinal cord• Provides a protective cushion around CNS• Provides some nutrients to CNS tissues• Produced by ependymal cells in the
ventricles of the brain
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Brain Blood Supply• Brain
– Requires tremendous amount of blood– Receives 15-20% of blood pumped by heart– Interruption can cause unconsciousness and
irreversible brain damage– High metabolic rate and dependence on
constant supply of oxygen and glucose– Receives blood through arteries
• Internal carotid arteries (carotid canal) and vertebral arteries (foramen magnum)
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Review Question
The primary link between the nervous system and the endocrine system (consists of glands that secrete hormones) is the
(a) Hypothalamus(b) Pons(c) Medulla oblongata(d) Cerebellum(e) Midbrain
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Points to Remember• Major parts of brain are: brain stem, cerebellum,
diencephalon and cerebrum.• Injury to medulla oblongata often fatal since it
contains vital parts for control of breathing, heart rate and blood pressure.
• Cerebellum provides important control of skeletal muscles for coordination of movement and posture.
• Diencephalon functions in several emotions and control of sleep-wake cycle.
• Cerebrum is largest part of brain with functions in emotions, higher level thinking, interpretation of sensory data and muscular control.