Neuro Basis Test 1

Relay center

Relay center

the thalamus processes and relays sensory signals to cortical areas

Sensory seperation

different thalamic nuclei handle distinct sensory information, preserving sensory integrity

Homeostatic control

regulates body functions ( temperature, hunger, thirst, and circadian rhythms)

Autonomic nervous system

it influences ANS, impacting heart rate, digestion, and other essential processes

where is the pineal gland

epithalamus

pineal gland

secretes melatonin, influencing sleep-wake cycles

what does the subthalamus do

is involved in motor control and functions within the basal ganglia circuitry

thalamus can be thought of as

the central hub that has connections to all other brain structures

the thalamus has 3 essential operations

relay station, modulates incoming sensory information, learning of complex motor actions

thalamic structures are

more important for sensory rather than motor

where is the hypothalamus located

below the thalamus; comprises the floor of the 3rd ventricle

the hypothalamus is the chief regulatory center that

maintains the body’s homeostasis and autonomic functions

the hypothalamus is a massive integrator of informations

that gauges the nature of the body w/i an environmental context and creates an autonomic behavioral response

the hypothalamus influences behavior via 4 other systems

homeostatic mechanisms, endocrine, autonomic nervous system, limbic system

the thalamus and hypothalamus

share their location within the diencephalon

subthalamus is located

at the base of the diencephalon, underneath the thalamus and above the midbrain

what does the subthalamus form

part of the neural circuits that connect the cerebral cortex, thalamus, and basal ganglia

2 aspects of movement

starting and continuation

what is the basal ganglia

a group of nuclei in the brain

what are the basal ganglia responsible for

primarily involved in the control of voluntary movements, procedural learning, routine behaviors, emotional movements, and cognition

the basal ganglia receive input from

the cerebral cortex

the basal ganglia send out put

back to the cortex via the thalamus

the BG subcortical structures are

striatum (made up of the caudate and putamen), globus pallidus, subthalamic nucleus, substantia, nigra

substantia nigra

consists of 2 parts, the pars compacta and pars reticula, providing dopaminergic input

4 major neurotransmitters

GABA, glutamate, acetylcholine, and dopamine

GABA

inhibitory; prevents overactive muscle contractions

glutamate

dopamine

inhibitory and excitatory; promotes voluntary movement and inhibits involuntary movements

hypokinesia

decreased movements and dynamics: PD, others

hyperkinesia

increased movements and dynamics: HD, others

the brainstem consists of

midbrain, pons, and medulla oblongata

the brainstem controls

breathing, heart rate, and blood pressure

the brain stem serves as a conduit for

sensory and motor information between the brain and higher brain centers

reticular formation is

a network of neurons extending through the brainstem

the reticular formation is responsible for

maintaining wakefulness, attention, and consciousness ( crucial for alertness during speech and comm)

reticular formation connects

the ANS, influencing functions like heart rate, blood pressure, and digestion

motor pathways

pyramidal and extrapyramidal tracts and speech control

pyramidal tract

controls precise voluntary movements

extrapyramidal tract

modulates posture, balance, and automatic movements

sensory pathways

ascending pathways and auditory processing

ascending pathways

sensory information from the body travels through the brainstem before reaching higher brain centers for perception and response

auditory processing

auditory pathways involving the brainstem nuclei contribute to sound localization, auditory reflexes, and sound discrimination

the midbrain is responsible for

processing auditory and visual data, maintains consciousness and alertness, involves with reflexive somatic motor responses to stimuli

the midbrain is also known as the

mesencephalon

the midbrain gives rise to

CN nuclei III and IV

the midbrain is a critical center for

CN functions associated with motion of the eyes and visual reflexes to light

the midbrain houses nuclei that

are closely associated with motor control functions of the cerebellum and BG and w/ sound and visual processing

the functional areas of the midbrain

cerebral peduncles, tectum, and tegmentum

cerebral peduncles

pathways for the corticobulbar and corticospinal tracts descending from M1 of the cortex as well as connections to the BG

tectum

location of the colliculi, which consists of nuclei critical for processing sound localization and timing

tegmentum

CN III and IV nuclei, and nuclei that comm w/ the cerebellum, contributing to coordinated movements

the pons are responsible for

relays information to the cerebellum and the thalamus and regulates somatic and visceral motor centers

where is the pons

between the midbrain and the medulla

the pons is an anatomical bridge between

the cerebrum, spinal cord, and cerebellum

the pons is a critical center for

cranial nerve functions related to control of the facial muscles, mandible, and motion of the eye

the pontine nuclei

mediate sensory inputs from the skin of the face, oral mucosa, and the mandibular region

pontine nuclei are involved with

involuntary control of breathing

apneustic center

promotes inspiration by exciting cells of the medullary respiratory center

pneumotaxic center

limits inspiratory activity by inhibiting those same medullary centers

the medulla is responsible for

relaying information to the thalamus and brainstem and regulates heart pressure, and digestion

where is the medulla

the base of the brainstem

the medulla gives rise to

CN nuclei VIII- XII

the medulla is a critical center for CN functions

associated with hearing and balance, swallowing, voice, head movement, and tongue motion

what is pyramidal decussation

crossing over of sensory and motor fibers, takes place in the medulla

dorsal respiratory group

neurons modulate the depth of breath through the monitoring

ventral respiratory group

neurons controls and coordinates the rhythm or breathing

the cerebellum has an important role in

coordination of movements, timed movements and precise movements

the cerebellum is responsible for

coordinating skilled movements of skeletal muscles; motor learning, and adjusts output of somatic motor centers resulting in smooth movements

components of the cerebellum

lobes, vermis and hemispheres, grey matter, and white matter

feedback loop

the cerebellum compares intended movements with actual movements, adjusting to achieve accuracy

fine-tuning

it refines motor skills and ensures smooth, and coordinated movement

non motor roles

the cerebellum contributes to attention, working memory, and language processing

cerebro-cellular loops

connections with the cerebral cortex support cognitive tasks

the nervous system controls

all body functions, maintains homeostasis, allows body to respond to changing conditions

nerve tissue is made up of

neurons

sensory receptors provide

sensory input

sensory receptors are located

at the ends of peripheral neurons

what do sensory receptors do

detect changes in the bodys internal environment and relay information

what do motor neurons do

act on the information by sending a message to muscles, organs, or glands to contract/relax

CNS is made up of

brain and spinal cord

PNS is made up of

12 pairs of cranial nerves, 31 pairs of spinal nerves

CNS is responsible for

integrating, processing, and coordinating sensory input and motor output

CNS is the seat of

intelligence, memory, learning, and emotion

PNS provides

sensory information to the CNS and carries motor commands away from the CNS

PNS can be divided into

afferent and efferent division

afferent division

brings sensory information to the CNS

efferent division

carries motor commands to muscles and glands

afferent division can be divided into

somatic and visceral portions

somatic portion

information from skeletal muscles and joints

visceral portion

information from smooth muscles, cardiac muscles, and other internal organs

efferent division can be divided into

somatic and autonomic nerves

somatic nerves

control skeletal muscle contractions

autonomic nerves

controls internal organ activities

the autonomic and somatic nerves can be further divided into

sympathetic and parasympathetic divisions/nerves

somatic nervous system

axons innervate the skeletal muscles, has afferent and efferent neurons, afferent pathways originate in the skeletal muscles

autonomic nervous system

axons innervate the visceral organs, has afferent and efferent neurons, afferent pathways originate in the visceral receptors

somatic nervous system is associated with

the voluntary control of body movements via skeletal muscles

autonomic nervous system is associated with

regulating body temperature and coordinating cardiovascular, respiratory, digestive, excretory, and reproductive functions

parasympathetic division (nerves)

rest and digest

sympathetic division (nerves)

fight or flight