Download Regulation: Chemical and Nervous

Regulation:
Chemical and Nervous
So Far…
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Nutrition
Transport-Blood and Immunity
Respiration
Excretion
Support and Locomotion
How do we coordinate all these activities?
How do we maintain Homeostasis?
• Regulation
– Chemical
• Hormones and Glands of Endocrine System
• Slow-Snail Mail (travel via blood long distance)
• Long-lasting effects and hormones can remain active
in blood from minutes to days
– Nervous
• Neurons and Neurotransmitters of Nervous System
• Fast-E-mail (travel through wires 100m/s)
• Short-lived effects
Endocrine System
• Glands
– Organs that secrete
chemicals
– Glands of the
Endocrine System are
Ductless
Gland
• Secretion goes right
into blood stream
• Blood brings it to target
Blood Vessels
Other types of Glands
• Exocrine Glands
– Secretions delivered to target through ducts
Gland that is Endocrine and
Exocrine:
Pancreas
Makes
Digestive Enzymes
And
Hormones
Hormones
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Secreted by Endocrine Glands
Chemicals
Travel via blood to target
Regulate processes at target
How do Hormones act on target?
• One Messenger Model:
– Hormone crosses target cell membrane
– Binds cytoplasmic receptor protein
– Hormone-Receptor Complex interacts with
DNA
– Effect produced
– Ex. Steroids (Lipid-like)
Steroid Model
How do Hormones act on target?
• 2 Messenger Model:
– Hormone binds receptor on membrane
– Binding activates a second chemical in
cytoplasm (ex. cAMP, cGMP, Calcium)
– 2nd Chemical leads to cell response
– Protein Hormones
2nd Messenger Model
The Glands
1. Pituitary Gland
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In Head
“Master Gland”
Two Sections
(Anterior and
Posterior)
Regulated by the
Hypothalamus (Part
of Brain)
Pituitary Gland
Releasing Factors
Makes &
Secretes
Hormone
Stores &
Secretes
Neuropeptides
of
Hypothalamus
Hormones of Anterior Pituitary
Hormone
TSH
ACTH
GH
FSH
LH
Prolactin
Target
Response
Thyroid
Adrenals
Many cells
Ovary
Ovary
Mammary
Glands
Thyroxin Release
Hormone Release
Bone Growth
Follicle Growth
egg release
Milk Production
Hormones of Posterior Pituitary
Neuropeptide
Target
Oxytocin
Uterus
Vasopressin (ADH) Kidney
Response
Contractions
More H20
Reabsorption
The Glands
2. Thyroid Gland
– In neck
Hormones of Thyroid
• Thyroxine (T3,T4)
– Has iodine
– Regulates protein, carb and fat metabolism
– Regulates cellular respiration
• Calcitonin
– Regulates blood calcium levels
– Lowers blood calcium levels
The Glands
3. Parathyroid Glands
– Four glands embedded in thyroid gland
Hormone of Parathyroid Gland
• Parathormone
– Regulates Calcium and Phosphate
metabolism
– Increases blood calcium levels by taking
Calcium out of bone
The Glands
4. The Adrenal Glands
– On surface of kidneys
– Has two layers (inner medulla and outer cortex)
Hormones of Adrenal Medulla
• Epinephrine (Adrenalin) and “Fight or
Flight Response”
– Nervous System regulation
– Increase: Heartbeat, blood pressure,
respiration, clotting rate, glucose levels
• Norepinephrine
– Released in response to low blood pressure,
causes for an increase.
Hormones of Adrenal Cortex
Corticosteroids:
• Cortisol (Glucocorticoid)
– Affects carb, protein and fat metabolism
• Aldosterone (Mineraolcorticoid)
– Affects Sodium and Potassium levels at
kidney level
The Glands
5. Pancreas
– Islets of Langerhan cells:
• Alpha cells= secrete the hormone Glucagon
• Beta cells=secrete the hormone Insulin
Hormones of Pancreas
• Glucagon
– raises blood glucose levels
• (Glycogen to glucose)
• Insulin
– Lowers blood glucose levels
• (Glucose to Glycogen)
The Glands
6. Gonads:
• Ovaries
– Located in female
abdominal cavity
• Testes
– Located in male
scrotum
Hormones of Ovaries
• Estrogen
– Stimulates female reproductive system
– Female secondary sexual characteristics
– Regulates menstrual cycle
• Progesterone
– Regulates menstrual cycle
Hormones of Testes
• Testosterone (an Androgen)
– Stimulates male reproductive system
development
– Male secondary sexual characteristics
The Glands
7. Thymus
• In upper chest
• More important in
early years than
adulthood
Hormones of Thymus
• Thymosin
– Stimulate T cell development
The Glands
8. Pineal Gland
– At base of brain
Hormone of the Pineal Gland
• Melatonin
– Involved in daily rhythms and biological clock
– Much still unknown
Digestive System Hormones
• Gastrin from Stomach
• Secretin, CCK, GIP from Small Intestine
“Local Hormones”
• Prostaglandins
– Don’t travel far from production site (unlike
other hormones)
– Wide range of functions
Problems
• Diabetes:
– Excess glucose in blood
– Low Insulin (Hyposecretion) or too much
glucagon (Hypersecretion)
– Type 1= don’t make insulin (autoimmune against beta
cells)
– Type 2= Diet related sugar management problem,
liver doesn’t respond to insulin)
– Gestational= Pregnancy related
• Hypoglycemia
– Too low blood glucose
– Too high insulin or too low glucagon
Problems
• Giantism
– In kids
– Normal proportions
– Too much GH
• Acromegaly
– In adults
– Too much GH
– Large body parts
• Dwarfism
– In kids
– Small but proportional body
– Low GH
Problems
• Hyperthyroidism
– Too much thyroxine
– Hyper, eye bulging , may include Goiter
condition
Problems
• Cushing’s Disease
– Hypersecretion of
Aldosterone and
Cortisol
– Fat deposits
– High blood glucose
• Addison’s
Disease
– Low amount of
aldosterone
and cortisol
– Glucose
metabolism
problems
– Sluggish,
weak, weight
loss
– Increased skin
pigmentation
Problems
Problems
• Hypothyroidism
– In infant: becomes
dwarf with
disproportionate body
and mental retardation
(cretinism)
– In adult: sluggish,
heavy person
How are hormone levels normally
regulated?
Homeostatic Feedback Regulation
1) Baby Suckling
nerves signal Hypothalamus to
release Oxytocin
Breast Milk
2) Temp. drop
nerves signal Hypothalamus to
release TSH-releasing factor
TSH release
from Pituitary
Thyroid Gland release Thyroxin
3) Hot
nerves signal Hypothalamus to release
ADH
kidney releases less urine
Negative Homeostatic
Feedback
• Too much Thyroid
hormones in blood
• Shut down anterior
pituitary and
hypothalamus
related to Thyroid
hormones
Nervous Regulation
• Like E-mail
• Fast but short-lived response
Basic Unit of Nervous Regulation
• Neuron (They don’t divide!)
Parts of Neuron
• Dendrite
– Branched
– Short
– Receives signals
– Sends signals towards axon
Parts of Neurons
• Cell Body (Cyton)
– Contains organelles of neuron
– Does metabolic activities
Parts of Neuron
• Axon
– Long
– Single fiber 1cm to 1 meter in length
– Carries electrical signals towards terminal
branches
– Can be wrapped with 2 types of glial cells
• Schwann Cells that may produce Myelin (Fatty
insulating material) on axons, PNS
• Oligodendrocytes, CNS
– Myelination progresses as we grow into adult
Spots of exposed axon
between Schwann
Cells=Nodes of
Ranvier
Parts of Neuron
• Terminal Branches
– Sends electrical
signals towards
synaptic knobs
(terminal knobs)
Parts of Neuron
• Synaptic Knobs
– Electrical signal
causes release of
neurotransmitter
(chemical) from
vesicles
•Neurotransmitters cross Synapse (Space)
•Bind to receptors on dendrites of other neurons or receptors on muscles
Types of Neurons
• Sensory
– Send messages from receptors to brain and spinal
cord
• Receptors: ex. Eye, Ear, Skin
• Interneurons (associative neurons)
– Relays messages from one neuron to another
– Usually short
• Motor Neuron
– Send messages from brain and spinal cord to
Effectors
• Effectors: ex. Muscles and Glands
Neurons vs. Nerves
• Nerves=bundles of
neurons
The Message=Impulse
• A neuron at rest:
– Outside neuron positively charged
– Inside neuron negatively charged (-70mV)
– Membrane is “Polarized”
Cell at Rest
Negative Chlorine also outside
What starts an Impulse?
• Stimulus
– Ex. Light, heat, sound, pain
An impulse will lead to a
“Response”
What happens during an impulse?
• Wave of depolarization and repolarization
along neuron=Action Potential
How do we get the depolarization?
Action Potential
At Rest (Polarized)
Need to reach “Threshold” to open
enough Na gates to start impulse
(All or none Response)
Na Gates Open-Positive Na rushes in,
Positive K stays in (Depolarization),
More positive entering than leaving
Na gates close, K gates open,
more positive leaving than
coming in (Repolarization)
Undershoot Resting Potential, Very
negative inside, REFRACTORY
PERIOD-Unresponsive
Wave travels along membrane
Gates are voltage regulated
Na rushing through one gate will move towards the right and
open downstream gates
What regulates the speed of the
wave?
• Size of neuron
• Myelin presence
A large myelinated neuron impulse speed=
100 meters/sec
Why so fast?
• Saltatory Conduction:
Skipping is faster than walking!
What happens when impulse
reaches the knobs?
• Signal must cross Synapse!
• Change electrical signal to a
chemical signal
• Neurotransmitter
• Diffuse across synapse
• Bind receptor on next
dendrite-cause the
generation of action
potential
• Enzymes breakdown
transmitters
Neurotransmitters
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Acetylcholine
Norepinephrine
Serotonin
Glutamic Acid (MSG in foods)
Strength of Stimulus?
• Relate to frequency of action potentials
• Different neurons have different thresholds
Why can’t we smell through our
ears?
How is a response produced?
• Neuromuscular Junctions
• Neurons end with Motor End Plates
• Neurotransmitters like acetylcholine bind
to muscle cells
• Muscle contracts
Drugs and Poisons
Interfere with Neuromuscular Junctions
• Nerve Gas
• Curare
• Botulin toxin
• Insecticides
Interfere with synaptic transmission
• Uppers and Downers
• Caffeine
Nervous Regulation in Protists
• No Neurons
• No Nervous System
• Can respond to stimuli like chemicals,
light, obstacles
• They have “irritability”=Whole organism
response to stimuli
Nervous Regulation in Hydra
• Neurons
• No Brain
• 2 way transmission
along neuron, not 1
way
• Nerve net
• Whole body
responses to stimuli
Nervous Regulation in Worm
• Has Central Nervous System
– “Brain”-fused ganglia
– 2 Nerve cords
• Has Peripheral Nervous System
– Branching sensory, motor and associative
nerves off of CNS
• One way transmission
Two, ventral nerve cords
Periodically there are bulges of
cell called ganglia that relay info
Peripheral nerves branch off of
nerve cord
Nervous Regulation in
Grasshopper
• Central and Peripheral Nervous System
• Sensory Receptors like antennae, eyes,
tympana
• Brain
• 2 ventral nerve cords that have ganglia
Nervous Regulation in Humans
• Central Nervous System
– Brain
– Dorsal Spinal nerve cord
• Peripheral Nervous System
– Nerves to and from receptors and effectors
Brain
• Protected by cranium
• You might not realize it, but your brain is a
code-cracking machine.
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Brain
• Covered by Meninges Membranes
• Bathed in Cerebrospinal Fluid
Parts of Brain
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Cerebrum
Cerebellum
Medulla Oblongata
Thalamus
Hypothalamus
Pons
Parts of Brain
• Cerebrum
– Largest part
– Divided down the middle
into the right and left
cerebral hemispheres
• Rt Art/Music
• Lt Math/Analytical
– The nerves that cross the
hemispheres are the
“corpus callosum”
Brain
• Cerebrum
– Outer Gray Matter ( Cerebral Cortex)
• motor neuron cytons and
interneurons
• Many unmyelinated cells
• Processing area of brain
• Sensory, motor and associative
functions
– Speech, thought, hearing,
vision, voluntary body
movements, memory, smell
• Many folds=increase surface area
– Inner White Matter region
• Mostly region of myelinated
axons
• Communication of data
between sides of cortex
• Communication from cortex
region and rest of body
• Crossed “wires”:Lt side of
brain controls Rt side of
body and vise versa
Compartmentalization
Memory
Stored in Hippocampus Region
Tiered circuits of impulses
• Momentary
– Lasts minutes
• Short-term
– Lasts several hours
• Long-term
– Lasts years
– Stored in Cortex
Why do casinos stay open all night
and have no clocks?
Naps boost memory
(J. Sleep Research)
• As much as a 6 min.
nap improves recall
– Brain extracts the gist
of learned info
– Brain files info and
combines info with
previously learned info
– Brain adds meaning to
info learned
Brain
• Cerebellum
– Outside has gray matter
– Inside has white matter
– Coordinates movements
Brain
• Medulla Oblongata
– Lowest brain part
– Outside is white matter
– Inside is gray
– Controls involuntary activities
Brain
• Thalamus
– Relay center
– pain
• Hypothalamus
– Controls body temperature, blood pressure,
sleep, emotions
– Regulates pituitary gland
• Pons
– Relay center
Brain Waves
EEG
Behaviors
• Reflex
– No thought
– Response is inborn
– Unlearned
– Protection or survival-related
Behaviors
• Instinct
– Inborn
– Unlearned
– Sequence of reflexes with each one triggering
the next reflex
Behaviors
• Conditioned Reflex
– Learned behavior together with a reflex
Behaviors
• Conditioned Response
– Associate one stimulus with another
Child will
associate
fear with mice
Behaviors
• Habit
– Behavior requiring no thought
– Performed quickly
– Not inborn
– Desire, Repetition and Satisfaction
Behaviors
• Imprinting
– Behavior patterns developed soon after birth
– learned from what ever it thinks to be its
parent
Spinal Cord
• Extends from medulla down through the
vertebral column
Spinal Cord
• Protected by vertebral
column
Spinal Cord
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Covered by the menenges and CSF
Outer White Matter
Inner Gray Matter
Connects Peripheral Nerve with Brain
Controls Reflexes
Simple Reflex Arc
Peripheral Nervous System
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Nerves not of brain and spinal cord
– 31 pairs of spinal nerves
– 12 pairs of cranial nerves serving eyes,
ears, nose, mouth…
Two Divisions of Peripheral Nervous System
1. Somatic Nervous System
2. Autonomic Nervous System
Somatic Nervous System
• Sensory and Motor Neurons dealing with
activities that are voluntary (ex. Pick up a
book)
Autonomic Nervous System
• Nerves that facilitate events that are not
under voluntary control (ex. Gland
contraction)
Two Divisions of Autonomic System
1. Parasympathetic Nervous System
2. Sympathetic Nervous System
Parasympathetic System
Causes impulses for:
– Slow heartbeat
– Increase peristalsis of digestion
– Dilate blood vessels
– Constrict urinary bladder
– Constrict bronchi
– Pupil constricted
Sympathetic Nervous System
Causes impulses for:
– Speed up heart rate
– Slow digestion peristalsis
– Constricts blood vessels
– Relax bladder
– Widen bronchi
– Dilate pupils
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Problems
Multiple Sclerosis
Schizophrenia
Dyslexia
Autism
ADHD
Paralysis
Bipolar Syndrome
Alzheimer's Disease
Cerebral Palsy
Parkinson's Disease
Headaches
Muscular Dystrophy
Encephalitis, Meningitis
Stroke / "Brain Attack"
Epilepsy and Seizures
Brain Tumors
Polio
Addiction/Anxiety/Depression
Pinched nerves
Headaches
Receptor Organs
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Eye
Ear
Tongue
Nose
Skin
Eye
Eye
Sclera
• Outer layer
• White of eye
• Provide shape and
protection
Cornea
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Front of sclera
Bulges outward
Thin
Transparent
Light enters
Provides focus
Choroid Coat
• Beneath Sclera layer
• Blood Vessels
• Stops reflection inside
eye
Iris
• Front of Choroid coat
• Colored
• Controls amount of
light entering eye like
camera shutter
• Muscle controlled
• Autonomic control
Pupil
• Hole at center of iris
• Light enters
Lens
• Behind iris
• Focuses light on retina
• Muscles change shape of lens
Retina
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Inner layer
Image screening
Light receptors
No receptors where
optic nerve exits
eye=“blind spot”
Retina
• Vision:
– Rod cells=black and white, low light vision
– Cone cells (Red, Green, Blue)=color vision
– Cells have Retinal Pigment (Need Vit. A)
– Send info out through optic nerve
Cavities of Eye
• Fluid-filled
– Aqueous Humor
• Between cornea and
lens
– Vitreous humor
• Jelly
• Provides shape
• Behind lens
Ear
• Outer Ear
– Pinna
• Funnel sound
– Auditory Canal
• wax
Ear
• Middle Ear
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Tympanic membrane
Hammer
Anvil
Stirrup
Oval Window
Membrane
– Eustachian Tube
Ear
• Inner Ear
– Cochlea
• hearing
– Semicircular canals
• Balance
– Auditory Nerve
Skin
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Touch receptors
Pressure Receptors
Pain Receptors
Temperature Receptors
Tongue
• Taste Receptor
– “Taste bud”
– Substance needs to
be in solution to taste
– Much of flavor comes
from smell
Tongue
• Tastes and receptor
localization (old view)
• Evidence shows taste
receptors detect all
flavors
• More sugar binding,
more impulses to
brain
Old Model!
• Olfactory cells
• Adaptation
Nose
Problems
• Eye
– Farsightedness=Can’t see near (Hyperopia)
• Eyeball too short
Problems
• Eye
– Nearsightedness=Can’t see far (Myopia)
– Eyeball too long
Problems
• Eye
– Astigmatism=Misshaped cornea
• Focus problem
Problems
• Glaucoma
– Increased eye
pressure
– Damage to optic nerve
Glaucoma Vision
Problems
• Cataracts
– Lens turns cloudy
Cataract Vision
Problem
• Colorblindness
– Problem with cones
Stare at center dot for 20sec