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Endocrine System and Nervous System

Biology class
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endocrine system
regulation (maintain homeostasis)
-works by using chemicals formed by special cells to regulate processes throughout the body.
-responses are slower, but last longer.
the endocrine system works very closely with...
the circulatory system
hormones
the chemicals that are involved in regulation in the the endocrine system.
-released directly into the bloodstream
target cell
hormones travel in the blood until they reach this. which contains compatible receptors on its surface
receptor molecules
are chemically specific , they can only bind to hormones meant for that receptor (same shape, lock and key)
response
after a hormone binds to a receptor molecule, this occurs. can occur in the target cell
responses of the endocrine system regulate:
growth, blood pressure, immune responses, the rate of metabolism, muscle contraction, responses to stress, digestion, the development and function of the reproductive system
glands
what hormones are produced in and released from
exocrine glands
release secretions through tubes or ducts.
-examples: sweat from glands, digestive enzymes from pancreas
endocrine glands
release secretions directly into the bloodstream
-examples: hormones
hypothalamus
a gland that controls secretions of other glands such as the pituitary
pituitary
regulates the function of other glands
thyroid
gland that regulates metabolism
parathyroid
gland which regulates blood calcium levels
thums
controls T-cell production
adrenal
gland which regulates responses to stress
ovaries
regulates secondary sex characteristics of females and egg production
testis
regulates secondary sex characteristics of males and sperm production
feedback
what the endocrine system uses to maintain homeostasis
uses this for body temp. regulation, regulation of water & blood sugar regulation
- cause-effect mechanism
cause-effect mechanism
a change detected in the body causes an action in the appropriate area, which will return the body to its original condition
-example "A" causes a change in "B" which than causes a change back in "A"
diabetes
the body doesn't produce enough insulin (type 1) or the body doesn't respond to the insulin (type 2) and blood glucose remains high
hypoglycemia
the body doesn't produce enough glucagon and the blood glucose remains low
dwarfism
extremely small stature due to a deficiency of human growth
acromegaly (giantism)
extremely large stature due to a surplus of human growth hormone
nervous system
it function is to maintain homeostasis by controlling and coordinating functions throughout the body and responding to the internal and external stimuli
stimulus
a detectable change in the internal or external environment
neuron
are cells of the nervous system
-transmit electrical impulses throughout the body
cell body
contains the nucleus and most of the cytoplasm of the cell. the site of metabolic activity
bendrites
branched extensions off of the cell body which carry impulses from other neurons to the cell body
axon
long fiber that carries the impulses away from the cell body to other neurons
-covered in a myelin sheet for insulation
nerves
bundles of neurons branching from the central nervous system to all parts of the body
-long axons of neurons bundle together
sensory
a type of neuron , carries impulses from the sense organs to the central nervous system
motor
a type of neuron, carries impulses from the central nervous system to muscles and glands
interneuron
a type of neuron, located in the central nervous system, carries impulses between sensory and motor neurons
nerve impulses are formed when...
there is a change in change of the cell membrane of a neuron
impulse
caused by a flow of ions (potassium and sodium)
once an impulse occurs...
neurons stimulate other neurons in with they are connected
threshold
the minimum level needed to activate s neuron
synapse
at what impulses travel from neuron to neuron is
axon terminal
at the end of each neuron an impulse reaches this
neurotransmitters
what impulses travel across the synapse as
neurotransmitters
chemicals used by neurons to transmit impulses across a synapse to other neurons
the nervous system is divided into these to major divisions...
central nervous system, peripheral nervous system
central nervous system
control center of the body which processes, analyses and relays info.
peripheral nervous system
includes the nerves which branch from the CNS
brain and spinal cord
CNS
-protected by 3 layers of connective tissue called meninges.
-space between the protective layers contains cerebra spinal fluid (CSF):
fluid acts as an absorber. allows exchange of nutrients and waste products between the blood and nervous tissue.
brain
separated into 3 parts: cerebrum, cerebellum, brain steam.
-each part contains a pacific function of the body
cerebrum
controls voluntary or conscious activities of the body including intelligence and learning.
hemispheres
brain divided into this.
-left controls the right side of the body, while right controls the left side of the body.
lobes
hemispheres is divided into this.
-frontal, occipital, parietal and temporal
thalamus
receives messages from the sensory organs and relays the info to the cerebrum which causes a response.
hypothalamus
recognizes hunger, thirst, fatigue, anger and the body temp.
cerebellum
controls coordination and balance
-located at the bottom back of the skull
brain stem
connects the brain and spinal cord.
- controls involuntary body functions including blood pressure, heart rate, breathing and swallowing
-contains the pons and the medulla oblongata
spinal cord
main communication link between the brain and the rest of the body
-reflexes are produced directly here
vertebrae
the bones that protect the spinal cord
reflex
a quick automatic response to a stimulus
-allows for an immediate response to danger
peripheral nervous system
all nerves extending off of the brain and spinal cord
-sensory and motor function
sensory function
transmits impulses from the sense organs to the central nervous system
motor function
transmits impulses from the central nervous system to the muscles or glands.
- two divisions: somatic and automatic
somatic
voluntary.
- controls activities that are under conscious control
-movement of skeletal muscles
automatic
involuntary.
- controls activities not under conscious control
-heartbeat, movement of smooth muscles in organs and blood vessels.
-further divided: sympathetic and parasympathetic