WEEK 6: Nervous System 2 Flashcards
(91 cards)
1
Q
Describe the wegiht/volume/size of brain
A
- contains almost 97% of body’s nervous tissue
- average weight is 1.4 kg
- volume is typically 1200 ml
- ranges from 750 to 2100 ml in functionally normal individuals
- brains of males are ± 10% > females
- no correlation between brain size and intelligence
2
Q
What are the 4 regions of the brain
A
- cerebrum
- cerebellum
- diencephalon
- brainstem
3
Q
What is the cerebrum and functions
A
- largest part of adult brain
- controls higher mental functions
->conscious thoughts, intellect, memory, etc. - divided into left and right cerebral hemispheres
4
Q
What is the cerebral cortx of cerebrum and functions
A
- surface layer of gray matter
- rounded elevations (gyri) increase surface area available for cortical neurons
- gyri are separated by shallow depressions (sulci) or deep grooves (fissures)
5
Q
What 2 matters make up cerebrum, and locations
A
- Gray matter
->in cerebral cortex and basal nuclei - White matter
->deep to cerebral cortex+around basal nuclei
6
Q
What are the longitudinal cerebral fissure
A
separates cerebral hemispheres
7
Q
What is the central sulcus
A
divides anterior frontal lobe from posterior parietal lobe
8
Q
What is the precentral gyrus of frontal lobe
A
forms anterior border of central sulcus
9
Q
What is the postcentral gyrus of parietal lobe
A
forms posterior border of central sulcus
10
Q
What is the lateral sulcus
A
separates frontal lobe from temporal lobe
11
Q
What is the insula
A
(“island” of cortex)
lies medial to lateral sulcus
12
Q
What is the parieto-occipital sulcus
A
separates parietal lobe from occipital lobe
13
Q
What 4 fibers does the white matter contain
A
association fibers
longitudinal fasciculi
commissural fibers
projection fibers
14
Q
What are association fibers, contains?
A
- form connections within one hemisphere
- arcuate fibers
->short fibers
->connect one gyrus to another
15
Q
What are longitudinal fasciculi, function
A
- longer bundles
- connect frontal lobe to other lobes in same hemisphere
16
Q
What are commissural fibers
A
- bands of fibers connecting two hemispheres
- make up corpus callosum and anterior commissure
17
Q
What are projection fibers
A
- link cerebral cortex to diencephalon, brainstem, cerebellum, and spinal cord
- pass through diencephalon
- make up internal capsule
->all ascending and descending projection fibers
18
Q
What is basal nuclei,+ functions + 3 main components
A
- masses of gray matter
- embedded in white matter of cerebrum
- direct subconscious activities
- caudate nucleus
- lentiform nucleus
- claustrum
19
Q
What are caudate nucleus
A
large head and slender, curving tail
20
Q
What is lentiform nucleus
A
putamen (lateral)
globus pallidus (medial)
21
Q
What is claustrum
A
thin layer of gray matter close to putamen
22
Q
What are the 2 functions of the basal nuclei
A
- subconscious control of skeletal muscle tone
- coordination of learned movement patterns (walking, lifting)
23
Q
What casues Parkinsons disease symptoms?
A
symptoms caused by increased activity of basal nuclei
24
Q
What are the 2 Functional principles of the cerebrum
A
- cortex of each cerebral hemisphere
->receives somatosensory information from, and sends motor commands to, the opposite side of the body - correspondence between a specific function and specific area of the cerebral cortex is imprecise
25
What are the 2 motor areas, locations
- primary motor cortex
->surface of precentral gyrus
- pyramidal cells
->neurons of primary motor cortex
26
What are the sensory areas and location
-primary somatosensory cortex
->surface of postcentral gyrus
27
What are the 4 Special sensory cortices and function
Visual cortex
- receives visual information
Auditory cortex
- receives information about hearing
Olfactory cortex
- receives information about smell
Gustatory cortex
- receives information from taste receptors
28
What are association areas and function
- connected to sensory and motor regions of cortex
- interpret incoming data or coordinate a motor response
29
What is premotor cortex function
- also called somatic motor association area
- coordinates learned movements
30
What are the 3 Sensory association areas and function
- Somatosensory association cortex
->monitors activity in primary somatosensory cortex
->example: it recognizes touch
- Visual association area - interprets activity in visual cortex
- Auditory association area - monitors auditory cortex
31
What are Integrative centers locations and 3 functions
- in lobes and cortical areas of both cerebral hemispheres
- receive information from association areas
- direct complex motor activities
- perform analytical functions
32
What is the wernickes area location and 3 functions
- primarily associated with left cerebral hemisphere
- language comprehension
- receives information from sensory association areas
- coordinates access to visual and auditory memories
33
What is the Broca’s area (motor speech area) location and 2 functions
- primarily associated with left cerebral hemisphere
- speech production
- regulates patterns of breathing and vocalization
34
What are the 2 functions of the Prefrontal cortex of frontal lobe
- coordinates information relayed from all cortical association areas
- performs abstract intellectual functions
35
What is prefrontal lobotomy
procedure to “cure” mental illnesses
36
What is Hemispheric lateralization
- refers to the functional differences between left and right cerebral hemispheres
- each performs certain functions not ordinarily performed by the opposite hemisphere
37
What is the function of the left cerebral hemisphere
reading, writing,speech and language, decision making
38
What is the function of Right cerebral hemisphere
- analyzes sensory information - touch, smell, sight, taste
- recognition of faces and voice inflections
39
What is the cerebellum
- second-largest part of brain
- two hemispheres
- covered by gray matter (cerebellar cortex)
40
What are the 2 functions of the cerebellum
- adjust postural muscles
- program and fine-tune conscious and subconscious movements
41
What are the 8 structures of the cerebellum
- cerebellar cortex
- folia
- anterior and posterior lobes
- cerebellar hemispheres
- vermis (“worm”)
- flocculonodular lobe
- Purkinje cell layer
- arbor vitae (“tree of life”)
42
What is the cerebellar cortex
- gray matter of convoluted surface
43
What is the folia
folds in cerebellar cortex
44
What is the anterior and posterior lobes
separated by primary fissure
45
What is the vermis (“worm”)
- narrow band of cortex
separates cerebellar hemispheres at midline
46
What is flocculonodular lobe
lies above roof of fourth ventricle
47
What is Purkinje cell layer
consists, location
- consists of large, branched neuron cell bodies
- in cerebellar cortex
- each cell receives input from up to 200,000 synapses
48
What is arbor vitae (“tree of life”),+ function
- highly branched, is the internal white matter of cerebellum
- cerebellar nuclei embedded in arbor vitae
- relay information to Purkinje cells
49
What is the Cerebellar peduncles and 3 types
- tracts that link cerebellum with brainstem, cerebrum, and spinal cord leave the cerebellum as:
->superior cerebellar peduncles=link cerebellum to midbrain/diencephalon/cerebum
->middle cerebellar peduncles=carry communications between cerebelum+pons
->inferior cerebellar peduncles=link cerebellum to medulla oblongata/spinalcord
50
What is ataxia and caused by?
Disorder of the cerebellum
- disturbance in muscular coordination
- caused: damage from trauma or stroke +intoxication (temporary impairment)
51
What is the diencephalon location, 3 parts
- integrates sensory information with motor commands
- located under cerebrum and cerebellum
- epithalamus, thalamus+ hypothalamus
52
What is the thalamus function
- filters and relays sensory information
- from spinal cord and cranial nerves
to cerebral cortex
53
What 3 functions is hypothalamus involved in
emotions
autonomic function
hormone production
54
What is the pineal gland location, secretion?
- in posterior portion of epithalamus
- secretes melatonin
55
What is the pituitary gland
- major endocrine gland
- connected to hypothalamus via infundibulum (stalk)
- integrates nervous and endocrine systems
56
What is the hypothalamus 3 structures
mammillary bodies
infundibulum
tuber cinereum
57
What is mammillary bodies function
control reflex eating movements
58
What is the infundibulum and function
a narrow stalk
connects hypothalamus to pituitary gland
59
What is the tuber cinereum and function
between infundibulum and mammillary bodies
produces hormones that affect pituitary gland
60
What is the brainstem function and 3 parts
- relays information between spinal cord and cerebrum or cerebellum
- midbrain, pons, medulla oblongata
61
What is the midbrain 2 functions
- processes sight, sound, and associated reflexes
- maintains consciousness
62
What is pons and 3 parts
- connects cerebellum to brainstem
-> tracts (collections of CNS axons)
->relay centers
->nuclei for somatic and visceral motor control
63
What is medulla oblongata+ functions
- connects brain to spinal cord
- inferior portion has a narrow central canal
- relays sensory information
- regulates autonomic functions
heart rate, blood pressure, and digestion
64
What are the 3 functions of limbic system
- establishes emotional states
- links conscious functions of cerebral cortex with autonomic functions of brainstem
- facilitates memory storage and retrieval
65
What are the 3 primary brain vesicles of the rostral position of neural tube
- prosencephalon (“forebrain”)
- mesencephalon (“midbrain”)
- rhombencephalon (“hindbrain”)
66
What are the 5 secondary brain vessciles
telencephalon
- forms cerebrum
diencephalon
mesencephalon
metencephalon
- forms cerebellum and pons
myelencephalon
- forms medulla oblongata
67
What are the 3 structures that protect the brain
bones of the cranium
cranial meninges
cerebrospinal fluid
68
What are the 3 layers of cranial meninges
dura mater
arachnoid mater
pia mater
- continuous with spinal meninges
69
What are the 2 layers of dura mater
inner fibrous layer (meningeal cranial dura)
outer fibrous layer (periosteal cranial dura)
70
Where is the dural folds, functions
- extensions of meningeal cranial dura into cranial cavity
- stabilize and support brain
- contain collecting veins(dural venous sinuses)
71
What are the 3 largest dural folds
falx cerebri - projects between cerebral hemispheres
-> contains superior sagittal sinus and inferior sagittal sinus
tentorium cerebelli - separates cerebrum from cerebellum
-> contains transverse sinus
falx cerebelli - divides cerebellar hemispheres
72
What is arachnoid mater
- covers brain
- it attaches to dura mater
73
Where is the subarachnoid space
lies between arachnoid & pia mater
74
What is the pia mater
attached to brain surface by astrocytes
75
What is the spinal cord + function
- housed within meninges and vertebral column
- carries sensory and motor information between brain and most other parts of body
76
Describe the gross anatomy of the spinal cord (length, 4 regions, segments)
- 45 cm long & 14 m wide
- from brain to vertebrae L1 and L2
- stops groing age 4, but vertebral column still growing
- 4 regions (cervical, thoracic, lumbar, sacral)
- 31 segments; give rise to spinal nerves
- central canal= filled with CSF
- anterior median fissure/posterior median sulcus
77
What are the 2 branches that form spinal nerves
- Anterior [ventral] root - axons of motor neurons
- Posterior [dorsal] root - axons of sensory neurons
- spinal nerve roots divide into rootlets before entering or leaving the spinal cord
78
What is the spinal ganglia
- (also called dorsal root ganglia)
- contain cell bodies of sensory neurons that form the posterior root
79
What are Enlargements of the spinal cord and 2 types+ their funtions
- areas of spinal cord that supply limbs have more gray matter and are visibly wider.
- cervical enlargement
->supplies skin & muscles of shoulder and upper limb
- lumbosacral enlargement
-> supplies pelvis and lower limb
80
What is contained in mixed spinal nerves
contain both afferent (sensory) and efferent (motor) fibers
81
Afer mixed spinal nerves, hat does each spinal nerve divide into? and their function
- posterior ramus supplies skin/muscles of back
- anterior ramus supplies most of body wall, skin, limbs
82
What are the 2 functions of the spinal mengines
protect spinal cord
carry blood supply
83
Describe the functional orgnaization of grey matter
- cell bodies of neurons, neuroglia, and unmyelinated axons
- masses of gray matter within CNS are called nuclei and are organized into regions called horns
84
Describe the three horns in grey mater
posterior horns - somatic and visceral sensory nuclei (incoming information from receptors)
anterior horns - somatic motor nuclei (outgoing information to effectors)
lateral horns - thoracic and lumbar segments; visceral motor nuclei
85
What are gray comissures
narrow bands of gray matter around central canal
axons cross here to the other side of spinal cord
86
What are the 3 collumns(Regions) of the white matter
- posterior white columns - between posterior horns and posterior median sulcus
- anterior white columns - between anterior horns and anterior median fissure
-> anterior white commissure - where axons cross from one side of spinal cord to the other
- lateral white columns - on each side of spinal cord, between anterior and posterior columns
87
What are tracts? And the 2 types in white matter
- bundle of axons in CNS
- relay same type of information in same direction
- ascending tracts - sensory information up toward brain
- descending tracts - motor commands down to spinal cord
88
What are nerve plexuses
- complex, interwoven networks of nerve fibers
- formed from blended fibers of anterior rami of adjacent spinal nerves
- allows multiple spinal nerves to supply same structures
89
What are the 4 major nerve plexuses
Cervical plexus
Brachial plexus
Lumbar plexus
Sacral plexus
90
What does the brachial plexus innervate and location
innervates pectoral girdle, upper back, upper limb
anterior rami of C5–T1
91
What does the lumbosacral plexus innveravte and location
innervates pelvic area and lower limb
includes anterior rami of spinal nerves T12–L4
