A&P Chapter 12.

Cerebrum

Makes up 40% of brains mass.

Sulci and Gyri increases its surface area

Cerebellum

Processes information from the cerebrum cortex

Provides instruction for the cerebral motor cortex. Therefore, resulting in smooth coordinated skeletal muscle movements

Responsible for balance & posture

Brainstem

Composed of the: Midbrain, Pons, and Medulla Oblongata

Midbrain

Contains visual and auditory reflex centers

Contains subcortical reflex centers

Contains nuclei for cranial nerves 3&4

Contains projection centers

Pons

Relays information from cerebrum to the cerebellum

Controls respiratory rate and depth

contains nuclei for cranial 5-7

Contains projection fibers

Medulla Oblongata

Controls heart rate, blood vessel diameter, respiratory rate, vomiting, coughing, etc. (autonomic activities)

Relays sensory information to the cerebellum through inferior olivary nuclei

Contains cranial nerves 8,9,10 & 12

Contains projection fibers

Site where pyramids cross

Frontal Lobe

Primary motor cortex, premotor cortex, Broca’s area, and the frontal eye field

Parietal Lobe

Contains the Primary somatosensory cortex

Is an area that is concerned with conscious awareness of sensation, the sensory areas of the cortex

Temporal Lobe

Primary auditory cortex, primary olfactory (smell) cortex, and gustatory (taste) cortex

Is an area that is concerned with conscious awareness of sensation, the sensory areas of the cortex

Occipital Lobe

Is an area that is concerned with conscious awareness of sensation, the sensory areas of the cortex

Primary visual cortex, visual association area, and posterior association area

Blood Brain Barrier

Astrocytes facilitate this formation

Prevents many substances in the blood from entering the brain tissue.

Contains tight junctions that ensure substances pass through and not around the endothelium wall

Pituitary Gland

An endocrine organ that is connected to the hypothalamus

White Matter

Myelinated fibers bundled into large tracts; provides for communication between cerebral areas and lower CNS centers

Limbic System

Contains cerebral and diencephalon

Mediates emotional response

Involved in memory processing

Corpus Callosum

Connects left to right cerebral hemispheres

Arbor Vitae

The cerebellar white matter inside the cerebellum

Has a resemblance to the branches of a tree.

Hypothalamus

Chief integration center of autonomic nervous system (involuntary)

Regulates body temperature, food intake, water balance, thirst, and biological rhythms and drives

Regulates hormonal balance through the pituitary gland (Acts as endocrine organ)

Thalamus

Relays impulses to the cerebral cortex

also Relays impulses to the motor centers & cerebellum

Memory Processing

Epithalamus

most dorsal/posterior portion of diencephalon

forms roof of third ventricle

Contains pineal gland: important for secreting melatonin regulates sleep

Association Fibers

Connect different parts of the same hemisphere

Commissural Fibers

Connect corresponding gray areas of the two hemispheres.

Allow the two hemispheres to function as a coordinated whole.

Projection Fibers

A type of white matter tract that connects the cortex with other areas in the CNS

Run horizontally

They tie the cortex to the rest of the nervous system

Grey Matter

Localizes and interprets sensory inputs

Controls voluntary and skilled skeletal muscle activity

Functions in intellectual and emotional processing

Unmylienated

Inner layer in spinal cord

Outer layer in cerebrum & cerebellum

Dura Mater

Outermost and toughest of the three meninges & covers the brain and spinal cord

Double fussed layer and meningeal layer

Arachnoid Mater

Middle meningeal layer. Separated from dura mater by subdural space

Pia Mater

Clings tightly to the brain

Is the last meninge and composed of delicate connective tissue

Subarachnoid Space

Spiderweb like extensions that secure the arachnoid mater to the Pia mater

Filled with CSF

Meninges

Three membranes that surround and protect the brain

Brocas Area

Anterior to the inferior region of the premotor area

Speech production

Activates when we prepare and think about speech

Wernickes Area

Understanding spoken and written language

Primary Somatosensory cortex

Conscious awareness of sensation

Somatosensory association cortex

helps understand objects ex: size, tempature, texture, shape

Processes information with touch

Ex: feeling into your pocket and being able to identify keys or coins

Primary visual (striate) cortex

Posterior tip of occipital lobe

receives visual information from retinas

Visual association area

Communicates with the Primary visual cortex to Interpret visual stimuli

Looking at words and being able to understand their meaning

Primary auditory cortex

Located in the superior margin of temporal lobe

Interprets information from the inner ear

ex: pitch, loudness, location

auditory association area

Perception of sound stimulus

Stores memories of sounds from the past

vestibular cortex

Important for balance and the position of our head in space

Being conscious of surrounding and obstacles

olfactory cortex

Medial aspect of temporal lobe

Conscious awareness of different odors

gustatory cortex

Locates in insula, deep to temporal lobe

Perception of taste

visceral sensory area

Located posterior to gustatory cortex

Conscious perception of visceral sensation

ex: upset stomach, bladder being full, being thirsty

Primary motor cortex

Located in the pre central gyrus of the frontal lobe of each hemispheres

Conscious and precise control of voluntary movement

Premotor cortex

Anterior to pre-central gyrus

Controls movement

Damage to this area causes muscle paralysis

Frontal eye field

Anterior to pre-motor cortex & superior to Broca’s area

Controls voluntary eye movements

Hearing a door open and looking in its direction

Thinking about the sounds around you and responding to them

Pyramidal (corticospinal) tracts

Send information down motor tracts to the spinal cord

Spinocerebellar Tracts

Motor tracts that relay conscious information of the lower limbs and trunk to the cerebellum

Alpha Waves

Awake but relaxed

Frequency 8-13

Beta Waves

Awake, alert

Frequency 14-30, Rapid

Theta Waves

Common in Children

Frequency 4-7

Delta Waves

Deep Sleep

Frequency less than 4

Sleep Stages

Cortical activities are depressed

Brainstem activity is still active (heart rate & breathing)

After abt 90 minutes it will repeat itself

REM sleep

Rapid Eye Movement

Most dreaming occurs

Skeletal muscles are inhibited

Eye muscles & diagram are still moving

NREM Stage 1

Non Rapid Eye Movement

EEG alpha waves, easily awoken

NREM Stage 2

Non Rapid Eye Movement

Irregular EEG patterns, waking up is harder

NREM Stage 3

Non Rapid Eye Movement

Theta & Delta waves, deep sleep occurs…change in breathing

NREM Stage 4

Non Rapid Eye Movement

Delta waves, not waking up to alarms, sleepwalking, night terrors, and bed-wetting may occur

Declarative Memory

Fact memory

Ex: names, faces, words, dates

Short term memory & Long term Memory

Procedural Memory

Memory of skills

Ex: Mariano Rivera

Motor Memory

Muscle memory

ex: riding a bike

Emotional Memory

How we link experiences to emotions

Ex: racing heart after after hearing a rattlesnake

Short Term Memory

Working memory

Can hold 7-8 pieces of information

Long Term Memory

Has limitless amount of memory storage

Hippocampus

Area of brain associated with Memory

Retrograde Amnesia

Can’t remember the past

Anterograde Amnesia

Can’t retain new memories

ex: 50 First Dates

Absence Seizure

Expressions going blank for a moment

Mild seizure

Tonic-Clonic Seizure

Severe seizure

Patients lose consciousness leading to falls, broken bones, and biting of tongue

Can last a few minutes

Aura

Warning signs before a seizure

Reticular Formation

Sleep Cycle

Wakefulness & Consciousness

Insomnia

Chronic inability to obtain the amount or quality of sleep

Orexins

Wake up chemicals

Pre central gyrus

Section of the brain associated with motor activity

Post central gyrus

Part of the brain that is associated with sensory activity

Posterior association area

Allows for the ability to recognize faces

Anterior association area

Higher cognitive functioning such as reasoining, problem solving, and decision making

Prosencephalon (forebrain)

Telencephalon (cerebrum) & Diencephalon

Mesencephalon

Mesencephalon (midbrain)

Rhombencephalon

Metacephalon (pons + cerebellum) & Myelencephalon (medulla oblongata)

Parkinson’s Disease

Dopamine deprived

Basal nuclei become overactive because of the lack of dopamine

Tremors at rest

Huntington’s Disease

High levels of dopamine cause involuntary jerking movements

Contusion

permanent damage to brain

Concussion

Temporary alteration in function

Most common head trauma

Mild/temporary damage

Subdural Hemorrhage

Pressure from blood forces the brainstem through the foramen magnum

Can be fatal

Cerebral Edema

swelling of the brain

How many hours of sleep does a School Age Child Need?

9-12 hours

How many hours of sleep does a Teen Need?

8-10 hours

How many hours of sleep does a Adult Need?

7 or more hours

infundibulum

Stalk of pituitary gland connects the hypothalamus to the posterior portion of pituitary gland

What effects the transferring of memory from short term to long term memory?

Association, Rehearsal, Emotional state, Automatic memory

Damage to the premotor cortex may cause?

Loss of coordination

Lateral Horn

Automatic motor neurons are located

Located in thoracic and lumbar regions

Posterior horns

Contains sensory neurons

Anterior horns

Contains motor neurons

Falx Cerebri

Separates the right and left cerebral hemisphere and houses the dural senses

In longitudinal fissure

Falx Cerebelli

Continues inferiorly from the falx cerebri

Separates cerebellar hemisphere

Tentorium cerebelli

Membranous roof over cerebellum

In transverse fissure

Decussation

Crossing of motor fibers in the medulla oblongata

Emotional State

We learn best when we are alert, motivates, surprised, or aroused

Rehearsal

Repeating the material enhances memory

Association

Tying new information to old information stored in the LTM (Long-Term Memory) helps remember facts

Automatic Memory

Information that we do not store purposely and is unintentionally memorized