The Brain

The Medulla Oblongata

derived from the myelencephalon It serves as a communication pathway between the brain and the spinal cord.

Pons

connects the medulla oblongata to the cerebellum and regulates sleep, respiration, and facial movements.

Midbrain

contains nuclei that process visual and auditory information and generate reflexive responses to these stimuli

Cerebral peduncle

ascending and descending nerve fiber layers

Diencephalon

consists of the thalamus, hypothalamus, and epithalamus

Thalamus

surrounds the 3rd ventricle

Hypothalamus

link between neurological and endocrine systems

Epithalamus

includes the pineal gland

Lateral Ventricles

connection between each of the lateral ventricles and the 3rd ventricle

Anterior cerebral artery

supplies the frontal and parietal lobes

Middle Cerebral artery

supplies the midbrain and the lateral surfaces of the cerebral hemispheres

Posterior Cerebral artery

Anterior communicating artery

a connection between branches of the anterior cerebral arteries and forms part of the circle of Willis

Posterior communicating artery

a connection between branches of the posterior cerebral arteries and the internal carotid arteries, forms a part of the circle of Willis

The Circle of Willis

interconnection between the internal carotid and basilar arteries, reducing chances for serious vascular interruption

Important Nuclei

portions located in the spinal cord, medulla oblongata, pons, mesencephalon, parts of thalamus and hypothalamus

Somatic motor control

reticulospinal tracts of the spinal cord, adjust muscle tension to maintain balance and posture. Relays signals from the eyes and ears to the cerebellum to integrate motor coordination.

Cardiovascular control

cardiac and vasomotor centers

Pain modulation

one route pain signals reach the cortex, but descending analgesic pathways from the RF can block transmission of signals

Cortical alertness

sleep and consciousness

Habituation

ignoring inconsequential stimuli while remaining sensitive to others 

Cardiovascular centers

adjust heart rate, the strength of cardiac contractions, and the flow of blood through peripheral tissues.

Respiratory rhythmicity centers

set the basic rate for respiratory movements

Pyramids

are on anterior, inferior surface of medulla. Where the corticospinal fibers come close to the surface, and the lateral tract fibers cross here

Olives

oval enlargement on lateral sides

Olivary nuclei

relay info from the spinal cord, cerebral cortex, diencephalon, and brain stem to the cerebellar cortex

Nucleus gracilis

where primary neurons from the lower extremities synapse with secondary neurons on their way to the thalamus

Nucleus cuneatus

where primary neurons from the upper extremities synapse with secondary neurons on their way to the thalamus

Autonomic nuclei reflex centers

cardiovascular and respiratory centers

Red nucleus

connects the cerebral hemispheres and the cerebellum, functioning in reflexes concerned with motor coordination and maintenance of posture. Involuntary motor commands.

Substantia nigra

thought to inhibit forced involuntary movements. Produces dopamine, which inhibits the excitatory motor neurons.

Vermis

the central constricted area that separates the cerebellar hemispheres

Flocculonodular lobes

lie anterior and inferior to the cerebellar hemisphere. It is important in the maintenance of balance and eye movement control

Superior cerebellar peduncle

tracts that link the cerebellum with nuclei in the mesencephalon, diencephalon, and cerebrum

Middle cerebellar peduncle

tracts that cross the ventral surface of the pons, and connect the cerebellar hemispheres with sensory and motor nuclei in the pon

Inferior cerebellar peduncle

tracts that allow communication between the cerebellum and the nuclei in the medulla oblongata, and carry ascending and descending cerebellar tracts from the spinal cord.

Gyri

elevated folds of the convolutions

Sulci

depressed folds of the convolutions

Fissure

longitudinal fissure is a deep groove that incompletely separates the cerebral hemispheres

Association fibers

are confined to each cerebral hemisphere and conduct impulses within the hemisphere

Longitudinal fasciculi

connect the frontal lobe to other lobes of the same cerebral hemisphere

Commissural fibers

connect the neurons and gyri between areas of similar structure and function in the 2 hemispheres

Projection fibers

form the ascending and descending tracts from the cerebrum to other parts of the brain: the midbrain, brainstem, cerebellum, as well as the spinal cord. In gross dissection, the collection of fibers is called the internal capsule

The Basal nuclei

specialized masses of gray matter located deep within the white matter of the cerebrum. control unconscious movements of skeletal muscle, and coordinates learned movement patterns and controls muscle tone

Caudate nucleus

the most superior of the nuclei, and follows the curve of the lateral ventricle. They do not initiate movement, but once it is underway, they determine pattern and rhythm

Lentiform nucleus

so named because it is lens-shaped

Globus pallidus

controls and adjusts muscle tone, especially in the appendicular muscles

The Limbic System

a complex set of structures involved in emotion, behavior, and memory, located deep within the brain.

Primary motor cortex

 directs voluntary movements. It allows us to control precise or skilled voluntary movements

Premotor cortex

It is responsible for coordination of learned motor activities, especially of a repetitious or patterned nature. It coordinates several muscle groups simultaneously or sequentially. It is the memory bank for skilled motor activities. It may be involved in planning movements, like moving a hand around objects to grasp something that is hidden

Postcentral gyrus

receives somatic information from touch, pressure, pain, taste, and temperature receptors. It identifies the part of the body that is stimulated: spatial discrimination.

Somatosensory association cortex

It integrates different sensory inputs – texture, temperature, and pressure, to assemble an understanding of it

Thalamus

provides switching and relay centers for sensory and motor pathways. Ascending sensory information from the spinal cord and cranial nerves (except the olfactory) is processed here before it is relayed to the cerebrum. It is also a relay station that coordinates the pyramidal and extrapyramidal systems

Medial geniculate nucleus

relays auditory information to the primary auditory cortex from the inner ear

Lateral geniculate nucleus

are relay stations for the parietal lobe, and have an impact on emotional states, and integration of sensory information

Ventral nuclei

relay information between the cerebral cortex and the basal nuclei d) The anterior nuclei: part of the limbic system

Medial nuclei

provide conscious awareness of emotional states, and relay information between the basal nuclei, hypothalamus, and the frontal lobes

The posterior nuclei

integrate sensory information for projection to the appropriate association area of the cerebral cortex

Lateral nuclei

integrate sensory information

Paraventricular

secretes oxytocin which stimulates smooth muscle contractions in the uterus and mammary glands

Suprachiasmatic

coordinates the day/night cycles

Preoptic

regulates body temperature via autonomic centers in the medulla

Tuberal area

releases hormones that control endocrine cells of the anterior pituitary gland

Supraoptic

regulates water loss at the kidneys by secreting ADH

Mamillary bodies

control feeding reflexes

Autonomic centers

control medullary nuclei that regulate heart rate and blood pressure

Pineal gland

secretes melatonin which helps regulate the circadian rhythm: day/night cycles