endocrine system, nervous system and homeostatic control review for unit test #1
TRANSCRIPT
Endocrine System, Nervous System and Homeostatic Control
Review for Unit Test #1
Endocrine system
Information signaling system
Glands produce hormones
Circulate through blood vessels
Regulate:– mood,
growth and development, tissue function, and metabolism
Hypothalamus
The hypothalamus controls body temperature, hunger, thirst, fatigue, anger, and circadian cycles.
Secretes hormones that tell other glands to create their hormones
– GHRH
Pineal Body
Secretes Melatonin Melatonin may help
regulate sleep patterns
Pituitary Gland
Growth Blood Pressure Sex Organ Functions Conversion of food into
energy Water regulation
Thyroid
Controls how quickly the body burns energy, makes proteins, and how sensitive the body should be to other hormones.
Parathyroid
The sole function of the parathyroid glands is to maintain the body's calcium level within a very narrow range.
Pancreas
Regulates blood sugar by producing Insulin
Adrenal gland
Produces Adrenaline Fight or Flight
Response– Dilate pupils– Increase heart rate– Suppress non
emergency process– Boost oxygen and
glucose supply
Testes and Ovaries
Both produce hormones to support body function
Testes– Testosterone
Ovaries– Progesterone– Estrogens
Nervous system
Made up of two major parts
– Central Nervous System (CNS)
– Peripheral Nervous System (PNS)
Neurons
Central Nervous System
Brain and Spinal Cord– Nerves– Ganglion
Brain
Consists of lobes, Each lobe having different functions.
Function
Process information Dictate reactions and behaviors
Peripheral Nervous system
Nerves from spinal cord to rest of body Create locomotion Etc…
Feedback Loops
Your nervous system is involved in almost all homeostatic control loops.
Reflex arc Sensory Vs Motor Affector Vs Effector
Neuron Function
Dendrites Myelin Schwann Cells Axon Node of Ranvier
Threshold
Before a neuron can send out a signal the stimuli has to pass the threshold
Action Potential
An action potential is a nerve impulse
An electrical shock sent down the axon
Action Potential
Synapse
A synapse occurs where ever the action potential meets the end of the axon
It needs to propagate across that gap
It does this through chemical messengers
Neurotransmitter= Acetylcholine
Enzyme that destroys it = Acetylcholinesterase
Synapse
When Acetylcholine jumps across the gap, it tells the next neuron to fire it’s action potential and the process continues
Homeostasis Summary
Homeostasis is the maintenance of a stable internal state within an organism.
Organisms must respond and maintain homeostasis in relation to many factors.
Organisms detect changes in their environment and respond to these changes in a variety of ways.
These changes may occur at the cellular or organism level.