Download Rising blood glucose level - Grosse Pointe Public School System

What’s the function???
Nervous systems contain neural cells and glial cells
Types of neurons
• Sensory neurons
• Interneurons
• Motor neurons
Fig. 28-1b
1 Sensory
2 Sensory neuron
Reflex Arc
receptor
Brain
• Simplest example
• Does not send
message to brain
Motor
neuron
Spinal
cord
3
4
Quadriceps
muscles
Interneuron
Nerve
Flexor
muscles
PNS
CNS
Fig. 28-2
Signal direction
Dendrites
Cell Body
Cell
body
Layers of
myelin sheaths
Signal
pathway
Nucleus
Axon
Schwann
cell
Nucleus
Schwann
cell
Myelin sheath
Synaptic terminals
Neurons work by sending an electrical impulse (action
potential) from one end of the neuron (cell body) to the
other (synaptic terminal)
-works in ONE DIRECTION only
Resting Potential
There is a difference in the distribution of charges
inside the cell compared to outside
-inside is negative; outside is positive
There is a difference in the concentration of certain
ions inside compared to outside
outside high concentration of Na+
inside high K+
Animation link
Action Potential
A stimulus to a neuron causes Na+ gates to open (Na+ rushes
into the cell) reversing the charge
cell is DEPOLARIZED
Charge distribution is reestablished when K+ is allowed to
leave the cell
Cell is Repolarized
Na+/K+ pump reestablishes the ion concentrations (expends
the most energy in your body)
Sending the message on
Signal reaches synaptic terminal causing vesicles containing neurotransmitters to be
released into synapse
Neurotransmitters diffuse across the synapse and bind to receptors on receiving cell
These receptors are also gated channels
-may be Na+  effect?
-may be K+ effect?
1
Sending neuron
Action
potential
arrives
Vesicles
Axon of
sending
neuron
Synaptic
terminal
Synapse
2
Vesicle fuses
with plasma
membrane
3
Neurotransmitter
is released into
synaptic cleft
Synaptic
cleft
Receiving
neuron
4
Receiving
neuron
Ion channels
Neurotransmitter
molecules
Neurotransmitter
binds to receptor
Fig. 28-7a
Dendrites
Synaptic terminals
Inhibitory
Excitatory
Myelin
sheath
Receiving
cell body
Axon
Fig. 28-7b
Synaptic
terminals
Acetylcholine
motor neurons /
muscles
Serotonin & dopamine in brain affect sleep/mood
Botulinum toxin
-inhibits release of acetylcholine
Neurotransmitter
Receptor
Neurotransmitter broken
down and released
Ions
5 Ion channel opens
6 Ion channel closes
Fig. 28-12
Peripheral
nervous system
Somatic
nervous
system
Autonomic
nervous
system
Sympathetic
division
Parasympathetic
division
Enteric
division
Fig. 28-13
Parasympathetic division
Brain
Sympathetic division
Eye
Constricts
pupil
Dilates
pupil
Salivary
glands
Stimulates
saliva
production
Inhibits
saliva
production
Lung
Dilates
bronchi
Constricts
bronchi
Slows
heart
Spinal
cord
Accelerates
heart
Heart
Adrenal
gland
Liver
Stomach
Stimulates
stomach,
pancreas,
and intestines
Stimulates
epinephrine
and norepinephrine release
Pancreas Stimulates
glucose release
Inhibits
stomach,
pancreas,
and intestines
Intestines
Bladder
Stimulates
urination
Promotes
erection of
genitals
Inhibits
urination
Genitalia
Promotes ejaculation and vaginal
contractions
• Sensory receptors
– Specialized cells or neurons that detect stimuli
• All senses trigger the same type of action
potential
• The brain distinguishes the type of stimulus
• Perception is the brain’s integration of
sensations
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Cerebral
hemisphere
Midbrain
Hindbrain
Diencephalon
Midbrain
Pons
Cerebellum
Medulla
oblongata
Forebrain
Embryo (one month old)
Spinal cord
Fetus (three months old)
Embryonic
Brain Regions
Forebrain
Brain Structures
Present in Adult
Cerebrum (cerebral hemispheres; includes
cerebral cortex, white matter, basal ganglia)
Diencephalon (thalamus, hypothalamus,
posterior pituitary, pineal gland)
Midbrain
Midbrain (part of brainstem)
Pons (part of brainstem), cerebellum
Hindbrain
Medulla oblongata (part of brainstem)
Cerebral
cortex
Cerebrum
Forebrain
Thalamus
Hypothalamus
Pituitary gland
Midbrain
Hindbrain
Pons
Medulla
oblongata
Cerebellum
Spinal
cord
Left cerebral
hemisphere
Corpus
callosum
Right cerebral
hemisphere
Basal
ganglia
Frontal lobe
Parietal lobe
Frontal
association
area
Speech
Taste
Somatosensory
association
area
Reading
Speech
Hearing
Smell
Auditory
association
area
Visual
association
area
Vision
Temporal lobe
Occipital lobe
The hypothalamus “master controller”
influences many hormones
• The hypothalamus
– Links the endocrine and nervous systems
– Receives input from nerves about body
conditions
– Responds by sending out appropriate nervous
or endocrine signals
– Uses the pituitary gland to exert master control
over the endocrine system
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Brain
Hypothalamus
Posterior pituitary
Anterior pituitary
(Bone)
Hypothalamus
Hormone
Neuron
cell
Posterior
pituitary
Blood
vessel
Oxytocin
Anterior
pituitary
ADH
Uterine muscles Kidney tubules
Mammary glands
Neuron
cell
Blood
vessel
Releasing hormones
from hypothalamus
Endocrine cells of
the anterior pituitary
Pituitary hormones
TSH
ACTH
FSH
and
LH
Prolactin
(PRL)
Growth
hormone
(GH)
Thyroid Adrenal Testes or Mammary Entire
body
cortex ovaries
glands
(in mammals)
Endorphins
Pain
receptors
in the brain
HORMONES
AND HOMEOSTASIS
Copyright © 2009 Pearson Education, Inc.
Hypothalamus
Thyroid hormones
-regulate metabolism
Inhibition
TRH
Anterior
pituitary
TSH
Thyroid
Thyroid hormones
Inhibition
• The pancreas secretes two hormones that
control blood glucose
– Insulin—signals cells to use and liver to store
glucose
– Glucagon—causes liver to release stored
glucose into the blood
Copyright © 2009 Pearson Education, Inc.
Body
cells
take up more
glucose
Insulin
3
2
Beta cells
of pancreas stimulated
to release insulin into
the blood
4
Blood glucose level
declines to a set point;
stimulus for insulin
release diminishes
Liver takes
up glucose
and stores it as
glycogen
1 High blood
glucose level
Stimulus:
Rising blood glucose
level (e.g., after eating
a carbohydrate-rich
meal)
Glucose
level
Homeostasis: Normal blood glucose level
(about 90 mg/100 mL)
Glucose
level
Stimulus:
Declining blood
glucose level
(e.g., after
skipping a meal)
5 Low blood
glucose level
Blood glucose level
rises to set point;
stimulus for glucagon
release diminishes
6
Alpha
cells of
pancreas stimulated
to release glucagon
into the blood
8
Liver
breaks down
glycogen and
releases glucose
to the blood
7
Glucagon
Insulin
Body
cells
take up more
glucose
3
2
Beta cells
of pancreas stimulated
to release insulin into
the blood
4
Liver takes
up glucose
and stores it as
glycogen
1 High blood
glucose level
Stimulus:
Rising blood glucose
level (e.g., after eating
a carbohydrate-rich
meal)
Glucose
level
Homeostasis: Normal blood glucose level
(about 90 mg/100 mL)
Glucose
level
Blood glucose level
declines to a set point;
stimulus for insulin
release diminishes
Glucose
level
Homeostasis: Normal blood glucose level
(about 90 mg/100 mL)
Glucose
level
Stimulus:
Declining blood
glucose level
(e.g., after
skipping a meal)
5 Low blood
glucose
level
Blood glucose level
rises to set point;
stimulus for glucagon
release diminishes
6
Alpha
cells of
pancreas stimulated
to release glucagon
into the blood
8
Liver
breaks down
glycogen and
releases glucose
to the blood
7
Glucagon
Reproductive hormones
• Testosterone
– Supports sperm formation
– Promotes development of secondary sex
characteristics
• Estrogen
– Promotes female secondary sex
characteristics
• FHS (folicle stimulating hormone)
– Stimulates production of eggs and sperm
• Progesterone
– Promotes growth of the uterine lining