Transcript Neuroanatomy - Kelley Kline

Neuroanatomy
The Human Brain
I. Directional Terms

Dorsal- “toward the back.”

Ventral- “towards the stomach or bottom.”

Anterior – “towards the front.”

Posterior- “towards the rear or back.”
Terms contd.
Rostral – “towards front nostrils.”
 Caudal- “towards the tail.”

Superior- “top of head”
 Inferior- “bottom of head”

Lateral – “to the side”
 Medial – “to the middle”

Ipsilateral – “same side”
 Contralateral – “opposite side”

Anterior view of brain
Posterior view of the brain
Lateral view of Right side of
brain
Lateral view of Left Side of
brain
Dorsal (Superior) view
Ventral (inferior) view
II. Brain Slices:

1. Coronal – slices brain from front to
back. Resembles a butterfly in most slices.
Brain slices (contd)

2. Sagittal (midsagittal) – slices the brain
down the midline so you can see what’s on
each half.
Brain slices

3. Horizontal – slices the brain from top to
bottom.
III. Planes of brain:
IV. Cortical Landmarks

1. Gyrus (gyri) – bulges on the brain’s
surface.

2. Sulcus (sulci) – a small ridge in the
cortex.

3. Fissure (s) – a large ridge in the cortex.
A. Gyri:
B. SulciCentral sulcus- separates frontal lobe from
parietal lobe.
C. Fissures
1. Sylvian (Lateral Fissure)- Large ridge
that separates temporal lobe from other
lobes.
Fissures (contd.)

2. Longitudinal fissure – separates left &
right hemispheres.

Left
Right
V. CNS & PNS terms

Nuclei – cell bodies in the CNS.

Ganglion – cell bodies in the PNS

Tracts – Axon bundles in the CNS

Nerves – Axon bundles in the PNS
Terms contd.

White matter –composed of axon bundles.
Is white because of the myelin sheaths
(white fatty tissue) that cover the axons.

Gray matter – composed of clusters of cell
bodies, have dark gray appearance from cell
body structures.
VI. Three Divisions of the Brain

1. Hindbrain – oldest part of brain,
governs basic functions (breathing,
regulates heart beat).

2. Midbrain – involved in some perceptual
& motor functions.

3. Forebrain – governs all higher-order
level functions (problem solving, planning,
emotion regulation, language).
VII. The Hindbrain
consists of the medulla, pons, & cerebellum.
A. Medulla (oblongata):


a structure just above spinal cord. Controls
& regulates vital reflexes for survival
(respiration, HR, vomiting, salivation,
coughing, & sneezing).
Damage to the
Medulla is almost always
fatal.
B. Pons:

An enlarged protrusion anterior to the
medulla. Both pons & medulla form
reticular formation & raphe system.

Plays a role in arousal & dreaming.
C. Cerebellum: (means little brain)

Large hindbrain structure that is posterior to
the brainstem.
 Governs motor functions, motor memory.
VIII. The Midbrain
Most obvious feature is the tectum (“roof”).
Two pairs of bumps on tectum:
Superior colliculi (vision)
Inferior colliculi (audition)
Substantia nigra—part of basal ganglia,
involved in movement (Parkinson’s disease).
IX. The Forebrain

Consists of subcortical and cortical
structures.

1. Subcortical structures include the
thalamus, hypothalamus, limbic system, &
basal ganglia.
A. Thalamus
A large two-lobed structure that sits on top of the
brainstem. Is brain’s sensory relay station.

Several nuclei receive sensory input & send that
input to parts of the cortex.

Nuclei: Lateral geniculate nuceli (visual),
medial geniculate nuceli (auditory) & ventral
posterior nuclei (somatosensory)
Thalamus
B. Hypothalamus


Is ventral to the thalamus. Receives
projections from the fornix in its
mammilary bodies.
Function: regulation
 Of basic motivational
 Drives (sex, hunger,
 thirst, fighting).
C. Limbic system

Comprised of the fornix, hippocampus,
amygdala, septum, & cingulate gyrus.
Limbic system

Fornix (“arch”) is the major pathway of the
limbic system; projects in an arc from the
hippocampus into mammilary bodies of the
hypothalamus.

Hippocampus “seahorse” is the structure
that lies in between the cortex & thalamus,
rests in the temporal lobe; plays a large role
in LTM storage.
Limbic system

Amygdala – “almond” lies anterior to the
hippocampus, is involved in basic emotions
(fear, anger).
2. Cortical structures
Lobes of the brain
A. Occipital lobe

Most posterior portion of brain. Processes
visual sensory information.

Houses primary visual cortex (striate
cortex).

Damage to PVC can cause
 “cortical blindness.”
B. Parietal lobe


Is posterior to the frontal lobe & dorsal to
temporal lobe. Processes visual & tactile
sensory information.
Houses primary
 Somatosensory cortex
 Which receives sensory
 Info from skin.
C. Temporal lobe


Processes auditory and visual information.
Houses primary auditory cortex—the
primary projection site for auditory stimuli.
Language, face recognition,
 & processing of sounds
 Occurs here.
D. Frontal lobe:

Processes information for planning,
executive control, fine movement, emotion
regulation, higher-order cognitive functions.