Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy 300L > ANA 303 Meninges, Synapses & Blood Supply To The Brain > Flashcards

ANA 303 Meninges, Synapses & Blood Supply To The Brain Flashcards

1
Q

The cranial meninges are composed of 3 membranous connective tissue layers namely:

A

Dura mater (dura): tough, thick external fibrous layer
Arachnoid mater (arachnoid): thin intermediate layer
Pia mater (pia): delicate internal vasculated layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Dura mater is also called the__________

A

pachymeninx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The dura mater is adherent to the internal table of the_________

A

calvaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Layers of the dura mater

A

external periosteal layer
an internal meningeal layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the epidural space?

A

The internal meningeal layer is intimately fused with the external periosteal layer, but separation can occur pathologically creating an actual (blood or fluid filled) space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The____________forms dural infoldings which divide the cranial cavity into compartments, forming partial partitions (dural septa) between certain parts of the brain

A

internal meningeal layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

list the dural infoldings of the internal meningeal layer

A

Cerebral falx (falx cerebri)
Cerebellar tentorium ( tentorium cerebelli)
Cerebellar falx ( falx cerebelli)
Sellar diaphragm (diaphragma sellae)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the falx cerebri (shape, size and location)

A

is a sickle shape structure
the largest dural infolding
lies in the longitudinal cerebral fissure and separates the right and left cerebral hemispheres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Attachments of falx cerebri

A

Anteriorly: median plane from the frontal crest of the frontal bone and crista galli of the ethmoid bone
posteriorly: to the internal occipital protuberance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Boundaries of the cerebri falx

A

The superior sagittal sinus runs in its upper fixed margin
the inferior sagittal sinus runs in its lower concave free margin
It ends by becoming continuous with the cerebellar tentorium
and the straight sinus runs along its attachment to the tentorium cerebelli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Discuss the size and shape of the Cerebellar tentorium

A

the 2nd largest dural infolding
is a wide crescentic septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cerebellar tentorium separates the__________ from the cerebellum

A

occipital lobes of the cerebral hemispheres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cerebellar tentorium it covers the____________ and supports the occipital lobe

A

upper surface of the cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The cerebellar tentorium divides__________

A

the cranial cavity into supratentorial and infratentorial compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The supratentorial compartment is divided into right and left halves by the__________

A

cerebral falx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the Cerebellar falx and its role

A

is a vertical dural infolding that lies inferior to the cerebellar tentorium in the posterior part of the posterior cranial fossa
It is attached to the internal occipital crest
partially separates the cerebellar hemispheres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the Sellar Diaphragm and its role

A

the smallest dural infolding
is a circular sheet of dura that is suspended between the clinoid processes
forms a partial roof over the hypophysial fossa in the sphenoid
The sellar diaphragm covers the pituitary gland in this fossa and has an aperture for passage of the infundibulum and hypophysial veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The arterial supply to the dura mater travels in the_________ of the dura

A

outer periosteal layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The arterial supply to the dura mater consists of:

A
  • anterior meningeal arteries in the anterior cranial fossa
  • middle and
  • accessory meningeal arteries in the middle cranial fossa
  • posterior meningeal artery and other meningeal branches in the posterior cranial fossa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

All are small arteries except for the__________

A

middle meningeal artery which is much larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which artery supplies the greatest part of the dura?

A

middle meningeal artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The anterior meningeal arteries are branches of the___________

A

ethmoidal arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The middle meningeal artery is a branch of the __________

A

maxillary artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The middle meningeal artery enters the middle cranial fossa through the_____________
divides into;

A

foramen spinosum
anterior branch
posterior branch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the Venous drainage of the dura, particularly the m.m.a and where it drains

A

The veins of the dura accompany the meningeal arteries
The middle meningeal veins accompany the middle meningeal artery, leave the cranial cavity through the foramen spinosum and drain into the pterygoid venous plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe the innervation of the dura in the anterior cranial fossa

meningeal branches from the ethmoidal nerves (branches of the ophthalmic nerve [V1]) supply______________

A

the floor and the anterior part of the falx cerebri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Additionally a meningeal branch of the ophthalmic nerve [V1] supply____________

A

the tentorium cerebelli and the posterior part of the falx cerebri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the innervation of the middle cranial fossa

A

the middle cranial fossa is supplied

medially by meningeal branches from the maxillary nerve [V2]
laterally by meningeal branches from the mandibular nerve [V3]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the innervation of the posterior cranial fossa

A

The posterior cranial fossa is supplied by
meningeal branches from the 1st , 2nd , and sometimes, 3rd cervical nerves

27
Q

The arachnoid mater and pia mater are together refer to as_____________

A

leptomeninges

27
Q

Clinical significance of the pterion

A

The pterion is an important area because it overlies the middle meningeal artery
Fracture to the pterion can rupture the anterior branch of this artery resulting in hematoma which exerts pressure on the underlying cerebral cortex
An untreated meningeal artery can cause hemorrhage which can lead to death in a few hours

28
Q

The pia and arachnoid mater develop from a single layer of mesenchyme surrounding the embryonic brain, becoming the________________

A

parietal part (arachnoid mater) and visceral part (pia mater) of the leptomeninx

29
Q

Describe the arachnoid mater

A

is a thin, avascular membrane
It is not adherent to the inner surface of the dura mater

30
Q

From its inner surface thin processes called____________arise and cross the subarachnoid space

A

trabeculae

31
Q

In between the arachnoid and the pia, is a real space called the___________
What does the space contain?

A

subarachnoid space
This real space contains CSF, trabecular cells, arteries, and veins

32
Q

Describe the subarachnoid space

A

The subarachnoid space surrounds the brain and spinal cord and in certain locations it enlarges into expanded areas called subarachnoid cisterns

33
Q

The arachnoid and pia enter the grooves of the brain T/F

A

FALSE
Unlike the pia, the arachnoid does not enter the grooves or fissures of the brain

34
Q

Describe the pia mater

A

is an even thinner membrane
that is highly vascularized by a network of fine blood vessels
The pia is difficult to see, but it gives the surface of the brain a shiny appearance
The pia adheres to the surface of the brain and follows all its contours

35
Q

Define a synapse

A

A synapse is described as a special zone of contact at which one neuron communicates with another
It is a specialized junction where axon terminals contact another neuron or cell type

36
Q

Describe electrical transmission

A

In electrical transmission between nerve cells, the current generated by an impulse in one neuron spreads to another neuron through a pathway of low electrical resistance via gap junctions
In an electrical synapse, ion channels
connect the cytoplasm of the presynaptic and postsynaptic cells

36
Q

Several neurons may take part in forming complex synapses encapsulated by neuroglial cells to form__________

A

synaptic glomeruli

36
Q

The importance of electrical synapses

A

In the adult mammalian CNS, electrical synapses are present where the activity of neighboring neurons needs to be highly synchronized.
For example, hormone-secreting neurons in the mammalian hypothalamus are connected with electrical synapses so that they fire almost simultaneously and secrete a burst of hormones into the circulation.

36
Q

Two types of synaptic transmission

A

electrical and chemical

37
Q

Directionality of electrical synapses

A

Most electrical synapses
in the mammalian nervous system are believed to be the non-rectifying or bidirectional type of synapse.

37
Q

What is a gap junction?

A

The area where the two neurons are
apposed to each other, at an electrical synapse

38
Q

The channels that connect neurons at the gap junction are called

A

gap junction channels

39
Q

The extracellular space between
presynaptic and postsynaptic neurons at an electrical synapse is___________
Compare it to the usual extracellular space

A

3 to 3.5 nm, which is much smaller than the usual extracellular space (about 20–50 nm) between neurons.

40
Q

connexons

A
41
Q

connex

A
42
Q

Describe chemical synapse and its directionality

A

There is no continuity between the cytoplasm of the presynaptic terminal and the postsynaptic neuron at chemical synapses. Instead, the cells are separated by synaptic clefts, which are fluid-filled gaps (about 20–50 nm). The presynaptic and postsynaptic membranes adhere to each other due to the presence of a matrix of extracellular fibrous protein in the synaptic cleft.

unidirectional

43
Q

What is a neurotransmitter?

A

Neurotransmitters are substances which neurons use to communicate with one another and with their target tissues in the process of synaptic transmission (neurotransmission).

Neurotransmitters are synthetized in and released from nerve endings into the synaptic cleft. From there, neurotransmitters bind to receptor proteins in the cellular membrane of the target tissue. The target tissue gets excited, inhibited, or functionally modified in some other way.

44
Q

What is the active zone?

A

Active zones are the specialized release sites in the presynaptic terminal. The vesicles containing the neurotransmitter
are aggregated near the active zones.

45
Q

Types of synapses

A

axodendritic
axosomatic
axoaxonic
dendrodendritic
symmetrical
asymmetrical

46
Q

Axodendritic synapse

A

A synapse in which the postsynaptic membrane is on a dendrite of another neuron. This type of synapse can occur at the spine or shaft of the dendrite. About 30% of the synapses in the CNS are estimated to be axodendritic type.

47
Q

Axosomatic synapse:

A

A synapse in which the postsynaptic membrane is on the cell body (soma) of another neuron. About 6% of the synapses in the CNS are estimated to be axosomatic type.

48
Q

Axoaxonic synapse

A

A synapse in which the postsynaptic membrane is on the axon of another neuron
This type of synapse is rare.

49
Q

Dendrodendritic synapse

A

A synapse in which dendrites of specialized neurons form synapses with each other.

50
Q

Symmetrical synapse

A

A synapse in which the postsynaptic and presynaptic membranes are similar in thickness.
This type of synapse is usually inhibitory

51
Q

Asymmetrical synapse

A

A synapse in which the postsynaptic membrane of a synapse is thicker than the presynaptic membrane. This type of synapse is usually
excitatory

52
Q

The brain is supplied by

A

two internal carotid
two vertebral arteries

53
Q

The four arteries lie within the_____________and their branches anastomose on the inferior surface of the brain to form the_________________

A

subarachnoid space
Circle of Willis

54
Q

Internal carotid arteries arise in the neck from which artery?

A

the common carotid artery

55
Q

Terminal branches of the ICA

A

Anterior cerebral arteries
Middle cerebral arteries

56
Q

The anterior cerebral arteries are joined together by the__________

A

anterior communicating artery

57
Q

The internal carotid arteries are joined by the posterior communicating arteries to the________________

A

posterior cerebral arteries

58
Q

the cortical branches of each cerebral artery supply

A

branches to deeper parts of the brain, the supply a surface and a pole of the cerebrum

59
Q

The cortical branches of the:
Anterior cerebral artery supply

A

most of the medial and superior surfaces of the brain and the frontal pole

60
Q

The cortical branches of the:
Middle cerebral artery supply

A

the lateral surface of the brain and the temporal pole

61
Q

The cortical branches of the:
Posterior cerebral artery supply

A

the inferior surface of the brain and the occipital pole

62
Q

Describe the vertebral arteries
Where is arises from, what it forms etc.

A

•They arise from the first part of subclavian arteries
•They unite at the lower border of the pons to form the basilar artery
•The basilar artery ends by dividing into two posterior cerebral arteries
•Other branches such as the anterior inferior cerebellar arteries, several small pontine arteries, and the superior cerebellar arteries arise from the basilar artery

63
Q

What does the basilar artery supply?

A

The basilar artery supply the brainstem, cerebellum and cerebrum

64
Q

What’s the main blood vessel that forms the posterior circulation of the brain?

A

Basilar artery

Anatomy 300L (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions