Brain Flashcards
1
Q
What are the three regions of the brainstem?
A
- midbrain
- pons
- medulla oblongata
2
Q
What is found within the ciencephalon?
A
- thalamus and the hypothalamus
3
Q
What is the largest portion of the brain?
A
- cerebrum
4
Q
What is a gyrus?
A
- elevated ridge of folded grey matter
5
Q
What is the core of the cerebrum made of?
A
- white matter
6
Q
What is a sulcus?
A
- a depression in the grey matter of the cerebrum
7
Q
Which fissure divides the brain into left and right hemispheres?
A
- the longitudinal fissure
8
Q
What is found at the floor of the longitudinal fissure?
A
- corpus callosum
9
Q
What is the corpus callosum?
A
- a mass of transversely
running axons that connect the left and right hemispheres
10
Q
The cerebral white matter consists of several tracts of axons that transmit signals
between the various portions of the cerebrum. What are the names of these tracts?
A
- association tracts
- commissural tracts
- projection tracts
11
Q
What do the association tracts do?
A
- connect regions of the same hemisphere
12
Q
What do the commissural tracts do?
A
- connect analogous regions of the two hemispheres (the
largest of these tracts is the corpus callosum)
13
Q
What do the projection tracts do?
A
- carry signals between the cerebrum and other portions of the brain and spinal cord
14
Q
What are the names of the four lobes in each hemisphere of the cerebral grey matter cortex?
A
- parietal
- frontal
- temporal
- occipital
15
Q
How are the lobes separated?
A
- prominent sulci
16
Q
What lobes does the parieto-occipital sulcus divide?
A
- the parietal and occipital lobe
17
Q
What lobes does the central sulcus divide?
A
- the parietal and frontal lobe
18
Q
What lobes does the lateral sulcus divide?
A
- the temporal lobe from the frontal lobe
- the temporal lobe from the parietal lobe
19
Q
Why is the frontal lobe important? MOTOR HOMUNCULUS
A
- primary motor area – initiation of voluntary movements
- premotor area – a “memory bank” of learned movements
- prefrontal cortex – “higher functions” (intellect, learning, memory, planning, judgment, personality, mood)
- articulation of speech
- recognition of olfactory stimuli
20
Q
Why is the parietal lobe important? SENSORY HOMUNCULUS
A
- primary somatosensory area – perception of somatic sensations
- common integrative area – receives and integrates information from a variety of sensory inputs (somatic, visual, smell)
- object recognition based on touch (shape, texture)
21
Q
Why is the temporal lobe important?
A
- primary auditory area – perception of auditory sensations
- primary olfactory area – perception of olfactory sensations
- recognition of auditory stimuli
- recognition of faces
22
Q
Why is the occipital lobe important?
A
- primary visual area – perception of visual sensations
- recognition of visual stimuli
23
Q
What are the major functions of the cerebellum?
A
- monitors and adjusts voluntary movements
- assists in the coordination of complex movements
- regulates muscle tone, posture, and balance
24
Q
What is the second largest portion of the brain?
A
- cerebellum
25
What are the major functions of the thalamus?
- relays sensory impulses from the spinal cord, brain stem, and cerebellum to
the cerebral cortex
- helps maintain consciousness
26
What is the thalamus made up of?
- a mass of nuclei (grey matter) and tracts (white matter) located in the walls of
the diencephalon
27
Where is the hypothalamus located?
- mass of nuclei located in the “floor” of the diencephalon
| - connected to the pituitary gland via a narrow stalk called the infundibulum
28
What are the major functions of the hypothalamus?
- regulates the release of hormones from the pituitary gland
- regulates activity in the ANS
- regulates emotions, behaviour, hunger, thirst, body temperature
29
What is the midbrain made up of and where is it located?
- a mass of nuclei and tracts located at the cranial end of the brain stem
30
What are the major functions of the midbrain?
- generates motor reflex responses to visual and auditory stimuli
- assists in the control of voluntary movements
31
What is the pons made up of and where is it located?
- a mass of nuclei and tracts located in the middle of the brain stem
32
What are the major functions of the pons?
- relays motor signals from the cerebral cortex to the cerebellum
- helps control breathing
33
What is the medulla oblongata made up of and where is it located?
- funnel shaped mass of nuclei and tracts located at the caudal end of the brain
stem that is continuous with the spinal cord
34
What are the major functions of the medulla oblongata?
- relays sensory signals for certain somatic sensations from the spinal cord to
the thalamus
- helps control breathing, heart rate, and blood vessel diameter
- controls reflexes related to swallowing, sneezing, coughing, and vomiting
35
Each part of the brain stem contains....?
- nuclei that give rise to specific cranial nerves
| - sensory and motor tracts that carry signals between the brain and spinal cord
36
What is the blood brain barrier?
- special barrier is present around the vessels that carry blood to the brain
- consists of: tight junctions between the endothelial cells of the blood vessels
- processes extending out from astrocytes that wrap around the blood vessels
- allows certain substances to pass through the brain tissue
37
What are the four ventricles of the brain?
- lateral ventricles (2)
- third ventricle
- fourth ventricle
38
Where do the lateral ventricles form?
- within the cerebral hemispheres
39
Where does the third ventricle form?
- within the diencephalon
40
Where does the fourth ventricle form?
- between the brain stem and the cerebellum
41
What connects the ventricles in the brain?
- a series of canals and continuous inferiorly
| with the central canal of the spinal cord
42
What type of cells line the ventricles in the brain?
- ependymal cells
43
What do the ependymal cells produce?
- cerebrospinal fluid
44
What are the functions of cerebral spinal fluid?
- physically supports the brain in space (it floats within the fluid)
- acts as a cushion for nervous tissue
- maintains the ionic environment
- transport and exchange of nutrients and wastes
45
What are the three layers of connective tissue that surround the brain and spinal cord?
- dura matter
- arachnoid mater
- pia mater
46
What is dura mater?
- tough fibrous outer layer of connective tissue
- has an outer and inner layer in the brain
- the outer layer is fused to the overlying cranial bones
- in certain locations, a cavity forms between the
layers that holds a venous sinus (helps drain blood
from the brain)
47
What is arachnoid mater?
- trabecular (i.e., mesh-like) middle layer
48
What is pia mater?
- thin inner layer that is firmly bound to the underlying nervous tissue
49
What is the purpose of meninges?
- provide physical stability and shock absorption to
the brain and spinal cord
- also extend out and are continuous with the epineurium of
the emerging spinal and cranial nerves
50
What are the inward extensions of the dura mater in the cranial cavity?
- falx cerebri – separates the cerebral hemispheres
- falx cerebelli – separates the cerebellar hemispheres
- tentorium cerebelli – separates the cerebrum and cerebellum
51
What is between the arachnoid mater and pia mater?
- sub-arachnoid space
| - continuous with the fourth ventricle and contains CSF
