Nervous and Endocrine Systems/Behavior

Simple nervous systems, very basic nerve net modified neurons that allow impulses to travel up and down body (simple movement)

• Primitive brains (ganglia) fuses groups of neuron cell that extend axons down length of worm
• Ventral nerve cod, segmented ganglia down body

• Sensory Input
• Motor output
• integration

Basic functional unit of mammal nervous systems

contains nucleaus

• extension of cytoplasm from cell body that recieve chemical sign and maintain signal as electrical signal
• highly branched and receive signals from many neurons at once

• Seperate cells from the neurons, secrete myelin as insuation for nerve cells that help signals move faster down axon
• In CNS the equivalent of schwann is oligodendrocyte, which send off myelinated sheets all at once

• Insulation for nerve cells that help signals move faster down axon
• Complex of containing membrane of nearby schwann cells 
• Nerves that loose myelin cannot transport messages fast enough

space along myelinated axons where schwann cells have not laid covering

main elongated extension of the cell body through electrical signal travels one direction from cell body toward synaptic knob

Release neurotransmitters

Chemicals that communicate with surrounding nerve cells

• In CNS are more numerous than neurons
• These cells stick to various parts of neurons and break down and remove neurotransmitters
• Chemically engulf debris

Line the fluid filled cavities of the brain and spinal cord and secrete cerebrospinal fluid

• DNA is negatively charged, negative charged phosphate groups
• many proteins are negative
• Sodium potassium pumps kick out three positive sodiums, and bring in two positive potassiums

Positive

Negative ion

• Outflow of positive charge, return to negative charge
• Reestablishment of separation of charge across a membrane
• Sodium channel gets inactive, and cell is impermeable to sodium
• Potassium gates open, allowing potassium to move out

• Polarized at resting, meaning there is a seperation of charge across a membrane
• Outside: high sodium concentration, low potassium concentration
• Inside:low sodium concentration, HIgh potassium

• A reduction in the seperation of charge across a membrane
• Sudden permeability of the membrane to sodium ions via opening of voltage gated channels
• Rapid influx of sodium ions
• Rapid depolarization of the membrane that produces a reversal in the internal charge from negative to positive

• so many potassium ions flow out, that the cell goes below -70milivolts and becomes more negatively charged than usual
• An increase in separation of charge across a membrane

• Stimilus to a neuron that causes the opening of voltage gated channels
• Causes depolarization but must depolarize to a certain level (threshold) to fire

once action potential flows down the axon, it slowly becomes negatively charged. Once sodium channels are inactive for a period--> Refractory perio

Larger signals use more neurons, to produce a large response, but have same action potential

before and after synapse

Becomes a chemical signal in synapse and then back to electrical in new neuron

• charge difference across membrane
• Electrochemical gradient that accompanies the wave of depolarization along the membrane
• i.e. nerve impulse
• Happens when stimulus reaches a threshold

voltage gated calcium channels open and rapid influx of calcium ions cause membrane bound vesicles filled with neurotransmitters merge to presynaptic membrane and release contents in to synapse

• Will bind to membrane receptors on the postsynaptic dendrites or cell body and cause opening of ligand gated channels  on post synaptic cell
• starts action potential all over again

• Are used in pain pathways to moderate amount of pain you feel
• Hyperpolarize the cell to stop action potential from reaching post synaptic membrane

• Motor Neurons -CNS to PNS
•    Only excite 
• Sensory Neurons-PNS to CNS 
•    Inhibit and excite

Carry info about external and internal environment to brain and spinal cord

Carry commands from brain/spinal cord to muscles or glands ect

Bundles of axons covered with connective tissue

• Sensory nerves carry only sensory fibers
• Motor nerves carry only motor fibers
• mixed nerves are both

nuclei

• Somatic and autonmic
• Autonomic is sympatheic and parasympatheic
• Volunary movement

interpret sensory info forming motor plans, cognitive functions

Telenecephalon and diencephalon

• Right and left hemispheres
• Each hemispheres contains (frontal, parietal, temporal, occipital lobe)

• High convoluted gray matter that can be seen on surface of the brain
• Processes sensory input
• R and L communicate wit each other through corpus callosum of cortex

R and L communicate wit each other through

Thalamus and hypothalamus

Relay and integration center for spinal cord and cerebral cortex

• Controls visceral functions
• Hunger, thirst, sex
• Plays important role in endocrine system
• Secretes releasing hormones which pushes pituitary to release stimulating hormones

• relay center for visual and auditory impulses
• motor control

• posterios part of brain
• consists of cerebellum, pons, and medulla

Motor impulses, balance, and hand eye cordniation

relay center for cortex communication with cerebellum

Vital functions like breathing, heart rate

Mid brain, pons, medulla

• incorperates all sensory info below head
• Simple motor responses
• (top) cervical, thoracic, lumbar, and sacral (bottom)

innervates skeletal muscles, body system

• reflex involves one neuron
• Ex: knee jerk reaction

• More than one neuron, withdrawal reflex
• ex: step on nail, one leg pulls up and other extends to retain balance

• involuntary nervous system
• Parasympathetic and sympathetic NS
• Regulates body internal environment without conscious control
• Regulates blood pressure, gastrointestinal, respiration and reproduction

• Fight of flight
• Increase blood pressure, decrease gut activity, release adrenaline

• Rest and digest, conserve energy and resotre body to resting state
• Lower heart rate, and increase gut activity

Transmit info regarding position of body in 3d space, also in inner ear

Sense thing in external environment (light sounds taste pain temp)

Detects photons and transmits info about shape, intensity, color, and shape to brain

White of eye

Behind sclera, helps supply retina with blood

inner most layer of eye that contains photoreceptors

Transparent layer at front of eye that bends and focuses light onto lens

• Muscle that controls opening and closing of pupil
• Responds to intensity of  light

Control shape of lense, and focus image onto retina

• Respond to high intensity light
• Sensitive to color

• Low intensity light
• Night vision

• Axons of ganglion cells bundle together to conduct visual info into brain
• Where optic nerve exits eye there is a blind spot

• Desly packed with cones
• Important for high acuity vision on retina

• Converts sound E, i.e. pressure waves into impulses perceived by brain as sound
• maintains balance

Pinna, auditory cannal

• Eardrum, separates outer and middle ear
• Vibrates at same frequency as incoming sound

• Amplify the stimulus and transmits it through oval window, to fluid of inner ear
• Three bonds, malieus, incus, and stapes

Cochlea and semi circular canals

• Contains organ of corti, has hair cells
• Vibrations of ossicles exert pressure on fluid in cochlea and stimulate hair cells
• Pressure turns into action potential which travels into auditory nerve to brain

• are three perpendicular canals  that are filled with fluid an hair cells
• the fluid covers hair cells on one side and the brain can determine where the head is

• Outer surface of taste bud is taste pore which has microvili
• Taste are sour salty sweet bitter and brothy

• Olfactory receptors are in upper aret of nostril and have olfactory hairs, or cilia
• substance enters nose and binds to cillia

• gland synthesize and secrete chemical hormones which enter blood stream
• Hormonal signaling can last for days
• Work mostly vis negative feed back loops

• Anterior and posterior have different hormones
• Most travel in blood and cause other glands to release their hormones
• Master Gland

• Anterior pituitary
• Stimulates bone and muscle growth

• Anterior pituitary
• Stimulates milk production and secretion

• Anterior Pituitary
• Stimulates adrenal cortex to synthesize glucorticoids

• Anterior pituitary
• thyroid to produce thyroid hormone

• Anterior pituitary
• Stimulates ovolulation, and testosterone in men

• Anterior pituitary
• Stimulates follicule maturation in females and spermatogenesis in males

• Produced in Hypothalamus
• Stored in posterior pituitary
• Uterine contractions during labor and milk secretion

• Hypothalamus
• Stored in posterior pituitary
• Water reabsorbed in kidneys

• Thyroid
• Stimulates metabolic activity

• Thyroid
• Decreases calcium in blood

• Parathyroid
• Increases calcium in blood

• Adrenal 
• increase blood glucose

• Adrenal
• Increase water reabsorption in kidney

• Adrenal Medula
• Increase blood glucose and heart rate

• Pancreas
• stimulates conversion of glycogen to glucose in liver

• Innate behaviors not learned 
• neurologically wired 
• Triggered by a sign stimulus

Environmental patterns or objects presented become stamped in to an animals behavioral response

• Repeated stimulation results in decrease in responsiveness
• Allows constant stimui to become ignored 
• ex: background noise

Repeated stimulation results in more responsiveness

• Animal links two events or stimuli as related
• Conditioned reflex

• Established innate reflex (ex food make you salivate)
• Neutral stimulus (bell)
• Conditioned reflex (bell makes you salivate)

Uses reward, can be positive or negative conditioning