Lecture 3 Central nervous system (brain)

what are components of the central nervous system

brain and spinal cord

what are components of the peripheral nervous system

somatic and autonomic

what are components of the somatic periphal nervous system

sensory input (afferent neurons) and motor output (efferent neurons)

what are components of the autonomic periphal nervous system

sympathetic and parasympathetic

efferent neurons are responsible for what

Carries motor information from the brain to the periphery

afferent neurons are responsible for what

Carries sensory information from the periphery back to the brain

motor commands are connected to which neurons in the somatic nervous system?

efferent neurons

sensory signals are connected to which neurons in the somatic nervous system?

afferent neurons

which nervous system is responsible for voluntary movements?

somatic nervous system

which nervous system is responsible for involuntary movements?

autonomic nervous system

somatic nervous system is responsible for what type of movements?

voluntary

autonomic nervous system is responsible for what type of movements?

involuntary

which nervous system is responsible for reacting to situations such as pupil dilating or heart beat increasing?

sympathetic nervous system

which nervous system is responsible for maintaining activities of the day or metabolism?

parasympathetic nervous system

which part of the brain has a large number of neurons to perform functions?

cerebellum

why does cerebellum have more neurons than cerebrum

because it is a safe and secure location to perform daily functions

what are the three main meninges of the brain?

Dura mater, Arachnoid mater, Pia mater

function of the three meninges

protect brain from external injuries

what is the periosteum of the brain?

connective tissue around the skull bone

thickest layer of the Meninges

Dura mater

thinnest layer of the Meninges

Arachnoid mater

which layer of the Meninges is directly attached to the tissue layer

Pia mater

what is the space between Dura mater and Archanoid mater

subdural space

what is the space between Archanoid mater and Pia mater?

subarachnoid space

why does it mean when the dura mater “folds”

implies that the membrane bends inward to create a structural partition

why does the dura mater fold?

it is thick and tough so it can project inward to form supportive partitions

why doesn’t the arachnoid mater fold?

is it not strong enough

why doesn’t the pia mater fold?

it just follows the brain’s outer contours like paint on a surface

what are the two folds of the dura mater

the falx cerebri and tentorium cerebelli

what is the vertical sickle-shaped sheet of the dura mater

falx cerebri

where can we find falx cerebri

it extends from the cranial roof into the great longitudinal fissure between the two cerebral hemispheres

what is the horizontal sheet of the dura mater

tentorium cerebelli

where can we find tentorium cerebelli

it lies between the posterior part of the cerebral hemispheres and the cerebellum

what is the largest portion of the brain

cerebrum

how many lobes does the cerebrum have

five

which part of the cerebrum connect the two hemispheres together and transmit messages from one side to another

corpus callosum

function of corpus callosum

connects the two hemispheres and transmit messages from one side to another

what is the fissure between the left and right hemisphere of the cerebrum

medial longitudinal fissure

what are the five lobes of the cerebrum

limbic lobe, frontal lobe, temporal lobe, parietal lobe, occipital lobe

what is the main function of the frontal lobe of the cerebrum

motor and executive functioning

what is the main function of the parietal lobe of the cerebrum

somatosensory, proprioception, pressure, pain, position

what is the main function of the occipital lobe of the cerebrum

vision

what is the main function of the temporal lobe of the cerebrum

hearing

what is the main function of the limbic lobe of the cerebrum

emotions, memory, learning

which lobe of the cerebrum is responsible for motor and executive functioning

frontal lobe

which lobe of the cerebrum is responsible for somatosensory like pressure and pain

parietal lobe

which lobe of the cerebrum is responsible for vision

occipital lobe

which lobe of the cerebrum is responsible for hearing

temporal lobe

which lobe of the cerebrum is responsible for emotions, memory, and learning

limbic lobe

where do all the higher brain functions take place in our cerebrum?

neocortex

where can we find neocortex and what is it responsible for

cerebrum’s surface, and it is where higher brain functions take place

why is the neocortex convoluted into hundreds of folds?

because it allows to fit more neurons and more executive functions

in teh cerebral cortex, what is the outermost /periphery layer that covers the cerebrum?

grey matter

in teh cerebral cortex, what is the innermost layer that covers the cerebrum?

white matter

the cerebral cortex contains how many % of all neurons?

20%

how much total brain weight does the cerebellum account for?

10%

What percentage of all neurons in the brain are located in the cerebrum

80%

what is the main functions of the cerebellum

maintaining balance, coordinating movement, vision, motor learning

what are the deep structures of the brain

diencephalon, the limbic system, the ventricles, brainstem

what are the four main parts of the diencephalon?

thalamus, hypothalamus, epithalamus (pineal gland), subthalamus

what is the main function of the thalamus in the diencephalon?

acts as the relay station and sends sensory signals (vision, touch, hearing, taste) to the cerebral cortex

what is the main function of the hypothalamus in the diencephalon?

the control center for homeostasis that regulates temp, hunger, thirst, sleep, hormones, and autonomic functions

what is the main function of the epithalamus in the diencephalon?

helps regulate biological rhythms, sleep wake cycles, and produce melatonin

what is the main function of the subthalamus in the diencephalon?

involved in movement control and works with basal ganglia

which structure in the brain is responsible for sending sensory signals to the cerebral cortex

thalamus

which structure in the brain is responsible for controlling homeostasis such as temp, hunger, thirst, and autonomic functions

hypothalamus

which structure in the brain is responsible for regulating biological rhythms?

epithalamus (pineal gland)

which structure in the brain is responsible for producing melatonin

epithalamus (pineal gland)

which structure in the brain is responsible for movement control?

subthalamus

what are the main structures of the limbic lobe

cingulate gyri, amygdala, hypothalamus, hippocampus

function of cingulate gyri in the limbic lobe

emotional and behaviour

function of amygdala in the limbic lobe

emotional reactions

function of hypothalamus in the limbic lobe

homestasis and stable state

function of hippocampus in the limbic lobe

memory

what are hollow-fluid cavities of the brain called?

ventriclces

what is the ribbonlike structure in the venctricles?

chorooid plexus

functions of choroid plexus (3)

produce clear and colour colourless CSF that maintains pressure in the brain, cushion brain structure, prevent injury

what structure in our brain produce cerebrospinal fluid

choroid plexus

what structure in our brain cushion the brain structure and prevent us from injury

choroid plexus

where does the cerebrospinal fluid travel to?

inside the brain and spinal cord, and outside to the subarachnoid space

what are the structures that connect fluid-filled cavities (ventricles) of the brain? (3)

foramen of Monro, aqueduct of Sylvius, obex

which meninges does the cerebrospinal fluid follow through?

arachnoid mater and pia mater

which space of the meninges does the cerebrospinal fluid follow through?

subarachnoid space

cerebrospinal fluid is absorbed or recycled by what structures

arachnoid villi/granulations in the superior sagittal (dural venous) sinus

what is filtering system that drains cerebrospinal fluid into the superior sagittal (dural venous) sinus?

arachnoid villi/granulations

what is the role of arachnoid villi/granulations in the brain

to recycle or absorb cerebrospinal fluid

why do veins absorb excessive cerebrospinal fluid?

to maintain balance and volume in the skull and maintain circulation throughout the body

what is the condition due to enlargement of ventricles in the brain?

hydrocephalus

what is the condition due to collection of fluid in the spinal cord

syringomyelia

define hydrocephalus

enlargement fo ventricles due to buildup of cerebrospinal fluid

define syringomyelia

collection of cerebrospinal fluid in the spinal cord

three regions of the brainstem

midbrain, pons, medulla oblongata

location of the brainstem

at the beginning of the foramen magnum

functions of the brainstem

connects the narrow spinal cord with forebrain

function of midbrain

produce dopamine and involved in movement, planning, excitation, and motivation

which structure is responsible for producing dopamine and being involved in movement, planning, excitation, and motivation

midbrain

function of pons

stimulation of breathing and controlling sleep cycles

which structure is responsible for stimulation of breathing and controlling sleep cycles

pons

function of medulla oblongata

control of respiration, the cardiovascular system and consciousness

which structure is responsible for controlling respiration, the cardiovascular system and consciousness

medulla oblongata