Chapter Thirteen: Brain and Cranial Nerves Flashcards
What is this?
- part of the CNS contained in the cranial cavity
- control center for many of body’s functions
Brain
What are the four parts of the brain?
Brain stem
Cerebellum
Diencephalon
Cerebrum
What part of the brain is this?
- connects spinal cord to brain; integration of reflexes necessary for survival
Brain stem
What part of the brain is this?
- involved in control of locomotion, balance, posture
Cerebellum
What part of the brain is this?
- involved in many relay and homeostatic functions
Diencephalon
What part of the brain is this?
- conscious thought, control
Cerebrum
What are these?
- part of PNS arise directly from brain
- two pairs arise from cerebrum
- ten pairs arise from brain stem
Cranial Nerves
What are the three regions of the brainstem?
Midbrain
Pons
Medulla Oblongata
What part of the brainstem?
- continuous with spinal cord, but different in that grey matter is organized into discrete nuclei
- regulates vital reflexes: heart rate, blood pressure, respiratory rate, swallowing, sneezing, coughing, vomiting
- decussation: fibers decussate (cross over) at inferior portion of the medulla so that each half of the brain controls the opposite half of the body
Medulla Oblongata
What part of the brainstem?
- possesses ascending and descending tracts that relay information between cerebrum and cerebellum
- possesses sleep center associated with REM sleep
Pons
What part of the brainstem?
- also called mesencephalon
- receives auditory and visual input - involved in visual reflexes
- assists in regulation and coordination of motor activities
- affected by Parkinson’s disease
Midbrain
What part of the brainstem is affected by Parkinson’s disease?
Midbrain
What part of the brain?
- cortex folded in ridges called folia; white matter resembles a tree (arbor vitae)
- regulates and coordinates motor movement
- coordinates with cerebrum to learn, practice, and plan complex movements
Cerebellum
What part of the brain?
- located between brainstem and cerebrum
- involved in many relay and homeostatic functions
- components: thalamus, sub-thalamus, epithalamus, hypothalamus
Diencephalon
What part of the Diencephalon?
- sensory relay center
- all sensory information synapses here before projecting to cerebrum
- involved in motor functions, mood modification, emotion regulation
Thalamus
What part of the Diencephalon?
- involved in controlling motor function
- several ascending and descending nerve tracts
Subthalamus
What part of the Diencephalon?
- Habenula: emotional and visceral responses to odors
- Pineal gland: many be involved in modulation of sleep/wake cycles
Epithalamus
What part of the Diencephalon?
- major coordinating center of autonomic nervous system
- mammillary bodies: olfactory reflexes and emotional responses to odors
- Infundibulum: stalk extending from floor; connects hypothalamus to posterior pituitary gland
- link between nervous and endocrine system
Hypothalamus
What part of the brain?
- largest part of the brain
- composed of right and left hemispheres each of which has the following lobes: frontal, parietal, temporal, insula
Cerebrum
What part of the epithalamus?
- emotional and visceral responses to odors
Habenula
What part of the pithalamus?
- may be involved in modulation of sleep/wake cycles
Pineal Gland
What part of the hypothalamus?
- olfactory reflexes and emotional responses to odors
mammillary bodies
What part of the hypothalamus?
- stalk extending from floor; connects hypothalamus to posterior pituitary gland
- link between nervous system and endocrine system
Hypothalamus
What fissure of Cerebrum?
- separates the two hemispheres
Longitudinal Fissure
What fissure of Cerebrum?
- separates temporal lobe from frontal and parietal lobes
Lateral Fissure
What sulcus of the Cerebrum?
- separates frontal and parietal lobes
Central Sulcus
What is the outer surface of the cerebrum called?
Cortex
What are the folds of the cortex called?
Gyri
What are the depressions of the cortex called?
Sucli
What is this called?
- between the precentral gyrus (primary motor cortex) and postcentral gyrus (primary somatic sensory cortex)
Central Sulcus
What lobe?
- voluntary motor function, motivation, aggression, send of smell, mood, personality and decision making
Frontal Lobe
What lobe?
- reception and evaluation of sensory information
Parietal Lobe
What lobe?
- reception and integration of visual input
Occipital lobe
What lobe?
- reception and evaluation for smell and hearing; memory, abstract thought, judgment
- insula is within this lobe
Temporal Lobe
What system?
- basic survival functions such as memory, fight or flight response, reproduction, satisfying hunger/thirst, etc
- involved in emotions
- circulate gyrus and hippocampus
Limbic System
The…is necessary for forming new memories
hippocampus
Damage to what area is seen in Alzheimer’s disease?
Hippocampus
What are the three types of connective tissue membranes?
Dura Mater
Arachnoid Mater
Pia Mater
What connective tissue membrane?
- superficial layer
Dura Mater
What connective tissue membrane?
- thin, wispy layer
Arachnoid Mater
What connective tissue membrane?
- thin, delicate connective tissue membrane closely adhered to brain
Pia Mater
What are the two types of spaces?
Subdural and Subarachnoid
What space?
- contains serous fluid
Subdural
What space?
- contains blood vessels and CSF
Subarachnoid
What part of the Dura Mater?
- in longitudinal fissure between the two cerebral hemispheres
Falx Cerebri
What part of the Dura Mater?
- between cerebellum and cerebrum
Tentorium Cerebelli
What part of the Dura Mater?
- between the two cerebellar hemispheres
Falx Cerebelli
What forms at the bases of the three folds in the dura mater?
Venous Sinuses
How many ventricles are within the brain?
4
What is within the four ventricles?
Cerebrospinal Fluid
Cerebrospinal Fluid (CSF) bathes the brain and spinal cord and provides protective cushion for…
CNS
What is this?
- produce CSF which fills ventricles, subarachnoid space, and central canal of spinal cord
Choroid Plexus
What barrier?
- endothelial cells of capillaries attached by tight junctions, so substances cannot pass between cells
- substances must pass through cells, making the barrier very selective
Blood-Cerebrospinal Fluid Barrier
(blood-brain barrier)
What step of flow of CSF?
- CSF is produced in the 4 ventricles
1
What step of flow of CSF?
- CSF flows through ventricles and exits fourth ventricle
2
What step of flow of CSF?
- CSF enters subarachnoid space or central canal of spinal cord
3
What step of flow of CSF?
- CSF flows from subarachnoid space into superior sagittal sinus - venous circulation
4
What percent of blood pumped by the heart goes to brain?
15-20%
Interruption of blood supply to the brain can cause what two things?
Unconsciousness
Irreversible Brain Damage
What two things does the brain receive blood through?
Internal Carotids
Vertebral Arteries
What are the three functions of cranial nerves?
Sensory
Somatic Motor
Parasympathetic Motor
What function of the cranial nerves?
- special or general
Sensory
What function of the cranial nerves?
- control of skeletal muscles
Somatic Motor
What function of the cranial nerves?
- regulation of glands, smooth muscles, cardiac muscle
Parasympathetic Motor
What cranial nerve? Roman numeral?
- sensory
- special senses: smell
- Damage: Lost sense of smell
Olfactory (CN I)
What cranial nerve? Roman numeral?
- sensory
- special senses: vision
- damage: blindness and affected side
Optic (CN II)
What cranial nerve? Roman numeral?
- Somatic Motor and Parasympathetic
- Motor Functions
- 4 muscles that move eyeball
- Levator palpebral - raises eyelid
- Parasympathetic Functions
- Smooth muscle in eyelid
- Regulate pupil size and lens shape
- Damage
- Drooping of the eyelid
- Eye drifts downward and outward
- Loss of pupillary constriction
Oculomotor Nerve (CN III)
What cranial nerve? Roman numeral?
- Somatic Motor
- Function:
- 1 muscle that moves eyeball
- Damage: loss of eye movement control
Trochlear Nerve (CN IV)
What cranial nerve? Roman numeral?
- Somatic Motor and Sensory
- Motor
- muscles of mastication (chewing)
- one middle ear muscle
- one palatine muscle
- two throat muscles
- Proprioception
- temporomandibular joint, tongue, and cheek
- Sensory
- scalp, face, mouth/throat
- Damage
- inhibited chewing
- loss of sensation in face
Trigeminal Nerve (CN V)
What cranial nerve? Roman numerals?
- Somatic Motor
- one eye muscle - lateral rectus
- abducts eye
- Damage: eye deviates medially, often results in double vision
Abducens Nerve (CNS VI)
What cranial nerve? Roman numeral?
- Somatic motor, sensory, and parasympathetic
- Sensory
- taste from anterior two-thirds of tongue
- Motor
- muscles of facial expressions
- two hyoid muscles
- small muscle in the middle ear
- Parasympathetic
- submandibular and sublingual salivary glands
- lacrimal gland
Damage:
- facial palsy
- loss of taste sensation on the anterior two-thirds of tongue
- decreased salivation
Facial Nerve (CN VII)
What cranial nerve? Roman numeral?
- Sensory
- Cochlear nerve - hearing
- Vestibular nerve - balance
- Damage
- loss of hearing (cochlear nerve)
- loss of balance and equilibrium
- nausea, vertigo, vomiting (vestibular nerve)
Vestibulocochlear Nerve (CN VIII)
What cranial nerve? Roman numeral?
- Sensory motor, and parasympathetic
- Sensory
- taste from posterior one-third of tongue
- monitors blood pressure and CO2/O2 levels
- Motor
- pharyngeal muscle
- Parasympathetic
- parotid salivary gland
- Damage
- difficulty swallowing
- loss of taste sensation in posterior one-third of tongue
- decreased salivation
Glossopharyngeal Nerve (CN IX)
What cranial nerve? Roman numeral?
- Sensory, motors and parasympathetic
- Sensory
- inferior pharynx, larynx, thoracic and abdominal organs
- sense of taste from posterior tongue
- Motor
- soft palate, pharynx, intrinsic laryngeal muscles (voice production), and tongue muscle
- Parasympathetic
- abdominal and thoracic viscera
- Damage
- Difficulty swallowing
- Hoarseness and loss of normal speech
- Uvula deviates away from side of the dysfunction
Vagus Nerve (CN X)
What cranial nerve? Roman numeral?
- Motor
- sternocleidomastoid and trapezius muscles
- Damage
- difficulty elevating the scapula or rotating the neck
Accessory Nerve (CN XI)
What cranial nerve? Roman numeral?
- Motor
- intrinsic tongue muscles
- three of the four extrinsic tongue muscles
- thyrohyoid and the geniohyoid muscles
- Damage
- when protruded, tongue deviated toward the side of the damaged nerve
Hypoglossal Nerve (CN XII)
