Lecture 21: Mammalian Brain Anatomy

Question 1

anatomical divisions of brain (embryonic)

Answer 1

forebrain = telencephalon, diecenephalon
midbrain = mesecephalon
hindbrain = metencephalon, myelencephalon

Question 2

telencephalon =

Answer 2

cerebral hemispheres
forebrain

Question 3

diencephalon

Answer 3

forebrain
thalamus, hypothalamus

Question 4

mesecephalon =

Answer 4

midbrain
cerebral peduncles and tectum

Question 5

metencephalon =

Answer 5

hindbrain
pons and cerebellum

Question 6

myeloncephalon =

Answer 6

hindbrain
medulla

Question 7

which brain division contains cranial nerve nuclei

Answer 7

brainstem= pons, medulla, cerebellum, midbrain

Question 8

brainstem is a conduit of

Answer 8

functions between spinal cord and forebrain

Question 9

sulcus =

Answer 9

indentations within gyri

Question 10

longitudinal fissure: cerebrum

Answer 10

divides right and left sides of cortex (vertical down the middle)

Question 11

transverse fissure: cerebrum

Answer 11

divides cerebrum from cerebellum

Question 12

cruciate sulcus: cerebrum

Answer 12

contains motor cortex

Question 13

cerebral lobes (5)

Answer 13

frontal
parietal
occipital
temporal
olfactory

Question 14

cortex aka

Answer 14

gray matter

Question 15

cortex definition

Answer 15

outer layer of cerebrum/cerebellum that contains CELL BODIES of neurons (why it’s gray matter)

Question 16

how are functions distributed across cortex ( how are they named)

Answer 16

AREAS
primary visual area, auditory area

Question 17

homunculi

Answer 17

model of sensorimotor specializations
represents the innervation of body regions in cortex proportional to biological relevance (how much info reaches that region)

Question 18

human homunculus (which regions are largest)

Answer 18

tongue and fingers receive most sensorimotor info

Question 19

what composes white matter

Answer 19

large bundles of myelinated axons deep to cortex

Question 20

6 layers of cortex based on

Answer 20

layered densities of neurons

Question 21

6 layers of cortex

Answer 21

I - Molecular
II - external granular
III - external pyramidal
IV - internal granular
V - internal pyramidal
VI - multiform

Question 22

which cortex layer is a major input layer and why

Answer 22

IV = internal granular
smaller cells

Question 23

which cortex layer is a major output layer and why

Answer 23

V - internal pyramidal
larger neurons/longer axons

Question 24

primary sensory cortical areas will have what cortex layer larger

Answer 24

layer 4

Question 25

primary motor cortical areas will have which cortex layer larger

Answer 25

layer 5

Question 26

3 types of cortical connections/fibers in white matter

Answer 26

association commissural projection

Question 27

association fibers in white matter

Answer 27

connect different areas of cortex in SAME hemisphere (right or left)

Question 28

commissural fibers in white matter

Answer 28

connect corresponding structures BETWEEN hemispheres

Question 29

projection fibers in white matter: 2 types

Answer 29

corticopetal - fibers ENTERING cortex corticofugal - fibers EXITING cortex

Question 30

corpus callosum

Answer 30

axonal tract that allows communication between lobes on right and left sides

Question 31

axons that communciate between left and right sides are called (hint: similar to fibers in white matter)

Answer 31

commissural axons

Question 32

which type of nuclei relay info to and from the cortex

Answer 32

thalamic

Question 33

functions of hypothalamus (3)

Answer 33

regulate nervous and endocrine systems to maintain stasis of internal environment release hormones regulate heart rate, BP, body temp, water balance, appetite, circadian rhythms, emotion

Question 34

subarachnoid space

Answer 34

deep to arachnoid mater and superficial to pia mater surrounds brain and spinal cord filled with CSF

Question 35

falx cerebri

Answer 35

fold of dura between right and left hemispheres

Question 36

tentorium cerebelli

Answer 36

fold of dura and bone between cerebrum and cerebellum

Question 37

2 dural folds between cerebral hemispheres and cerebellum

Answer 37

falx cerebi tentorium cerebelli

Question 38

dural venous sinuses: location, function

Answer 38

between folds of dura and skull receive venous blood draining from brain and orbit --> drain to vertebral and internal jugular veins

Question 39

what other fluid will drain into dural venous sinuses

Answer 39

CSF

Question 40

what vessel primarily supplies blood to dura mater

Answer 40

maxillary artery

Question 41

maxillary artery is a branch of what main artery

Answer 41

external carotid

Question 42

brach of maxillary artery that is the largest of the blood vessels to the dura and calvaria

Answer 42

middle meningeal

Question 43

middle meningeal artery enters cranial cavity via

Answer 43

oval foramen

Question 44

mandibular portion of maxillary artery supplies (2)

Answer 44

muscular branches to temporalis, masseter supply to TMJ and ear

Question 45

2 main branches of maxillary artery

Answer 45

inferior alveolar middle meningeal

Question 46

4 spaces in brain where CSF in produced and circulates

Answer 46

2 lateral ventricles third ventricle fourth ventricle

Question 47

choroid plexuses: definition/function

Answer 47

high density capillary beds that produce/release CSF into right and left ventricles also release ultrafiltrate from blood plasma

Question 48

functions of CSF (5)

Answer 48

Buoyancy transport nutrients flush away waste products medium for diffusion of neuroendocrine/neurotransmitters

Question 49

pathway of CSF

Answer 49

choroid plexus in ventricles --> subarachnoid space (brain and cord) --> arachnoid granulations --> back to venous system

Question 50

what is the connection between 3rd and 4th ventricles

Answer 50

cerebral aqueduct

Question 51

subarachnoid cisterns: definition, importance

Answer 51

widest subarachnoid areas can extract CSF via cisternal puncture

Question 52

arachnoid granulations/villi: definition, function

Answer 52

outpockets from subarachnoid space into dural venous sinus that drains CSF into venous system

Question 53

vertebral artery is branch of

Answer 53

subclavian

Question 54

pathway of vertebral artery

Answer 54

pass through transverse foramina of C6-C1 branches to cervical vertebral muscles and spinal cord

Question 55

which 2 arteries form a shared circle of anastamostic blood supply to brain

Answer 55

internal carotid vertebral

Question 56

2 branches of internal carotid that contribute to anastamosis

Answer 56

rostral cerebral middle cerebral

Question 57

4 branches of vertebral artery that contribute to anastamosis

Answer 57

basilar rostral cerebellar caudal cerebellar caudal cerebral

Question 58

blood supply to cerebral hemispheres (3)

Answer 58

middle, rostral and caudal cerebral aa.

Question 59

blood supply to pons

Answer 59

basilar artery

Question 60

blood supply to caudal cerebellum (1)

Answer 60

caudal cerebellar

Question 61

caudal cerebral artery supplies what brain structures (2)

Answer 61

cerebral hemispheres midbrain

Question 62

rostral cerebellar artery supplies what brain structures (3)

Answer 62

midbrain pons rostral cerebrellum