The Brain

Loss of the Myelin Sheaths can be attributed to Multiple Sclerosis (MS)

Cells of the Nervous System

Neurons (Info Processors)

Soma (Body of Cell)

Electrical signals cross Soma. and down extension called Axon

Axon ends at Terminal Buttons

Terminal Buttons discharge neurotransmitters into Synapse

Neurotransmitters pass across Synapse, merge with Receptor of adjacent Neuron

Certain neurotransmitters fit into certain Receptors, often called "lock and key" relationship

Synapse: Tiny space between two neurons

Contains synaptic vesicles that hold neurotransmitters

Dendrites: Branches that extend outward

Outer surface: Semipermeable membrane Contains nucleus of neuron

-Allows small molecules, and molecules with smaller charge. -Larger molecules and molecules with higher charge unable to permeate cell

Glial Cells

Inside Axons, Glial cells form Myelin Sheaths that act as insulation to Axon

This increases signal speed

Provides "building blocks" of nervous system

Mediates immune responses

Moves nutrients and waste products

Provides insulation to neurons

Helps neurons align for neural communication

Medulla, Pons, & Midbrain: Together referred to as the brain stem

The Brain

Assoc. w/ Endocrine System

Important Glands

Gonads

Excretes sexual hormones important for sexual motivation, reproduction

Male: Testes

Female: Ovaries

Pancreas

Abdominal internal organ, secretes hormones to regulate body's blood sugar

Glucagon (raises blood sugar)

Insulin (lowers blood sugar)

Adrenals

Glands sit on top of kidneys, produce hormones associated w/ stress response

Norepinephrine (noradrenaline)

Epinephrine (adrenaline)

Thyroid

Located in neck: Responsible for growth, metabolism, appetite, etc

Pituitary

"Master Gland"; Controls all other glands in endocrine system

Body temp., growth hormones, regulates body fluid levels

Produces hormones ("chemical messengers")

Hormones pushed into blood stream

Lobes

Occipital

Back of brain

Primary visual cortex: Processes visual info

Temporal

Sides of brain

Wernicke's Area: Speech understanding

Auditory Cortex: Processes auditory (hearing) info

Parietal

Behind frontal lobe

Somatosensory Cortex: Processes sensory data

Touch, temperature, pain, etc

Frontal

Front of brain

Broca's Area: Langauge

Motor cortex: Plans, coordinates movement

Prefrontal cortex: Manages high-level functioning

Appearance/2 Hemispheres

-Left hemisphere controls right side of body -Right hemisphere controls left side of body

Connected by Corpus Callosum

Band of neural fibers, allows communication between 2 hemispheres

Longitudinal Fissure

Long cleft that separates 2 hemispheres

Surface=Cerebral Cortex

Grooves=Sulci

Bumps=Gyri

Hindbrain

Cerebellum: Controls movement, balance, motor skills

Helps process certain kinds of memories

Pons: Connects brain to spinal cord

Helps manage brain activity during sleep

Medulla: Helps control autonomic nervous system

Ex: breathing, heart rate, blood pressure, etc.

Midbrain

Substantia Nigra & Ventral Tegmental Area: -Critical for movement -Hold cells that produce Dopamine

Help manage mood, reward, addiction

Reticular Formation: Manages sleep/wake cycle

Forebrain

Largest part of brain

Contains

Limbic System

3 Most Imp. Parts

Hypothalamus: Regulates a number of homeostatic processes

Used as connection between endocrine system & nervous syst.

Ex: Body temp, appetite, blood pressure, etc.

Amygdala: Manages emotion and memory, and the relationship between the two

Hippocampus: Learning & memory

Pituitary Gland

Produces growth hormones, endorphins, and manages fluid levels

"Messenger hormones": Control all endocrine glands

Thalamus

All senses other than smell processed here

"Sensory relay"

Spinal Cord

Protected by vertebrae

Connects to brain stem, extends to around the edge of ribcage

Nerves extend out

Motor nerves: Send messages out

Sensory nerves: Take messages to brain