Homeostasis Flashcards
Ultimate purpose of hormones
Maintain homeostasis
What are the two major groups of hormones
Steroid (fat soluble) and protein hormones (not fat soluble)
Explain the exocrine glands
Glands that have tubes where stuff are either emptied out of the body (sweat) or into the digestive tract.
Explain endocrine glands
Don’t have tubes and stuff are released from the cells right into the blood stream (thyroid + adrenal gland)
Four major classes of hormones
Modified amino acids- ex. thyroxin, synthesized from SINGLE amino acids
Proteins- ex. insulin, glucagon, synthesized from CHAINS of amino acids
Steroids- ex. testosterone, estrogen, synthesized from cholesterol.
Prostaglandins- ex. prostaglandin, synthesized from fatty acids.
The hypothalamus
It’s connected to the anterior pituitary through the circulatory system and it’s also connected directly to the posterior pituitary.
What is the purpose of excretion? Also what are the two main metabolic wastes?
It removes metabolic waste products so homeostasis can be maintained. Metabolic waste products are formed from catabolic rxn’s to make energy.
Main metabolic waste= co2 + water
Fates of ammonia
- Can be super diluted w/ fresh water
- Convert to urea
- uric acid -> solid paste -> birds reptile
Define the following: Stimulus Receptor Regulator Action
Stimulus- The thing that stimulates the feedback loop
Receptor- Where it happens
Regulator- What keeps it at bay
Action- What happened
Example of a feedback loop: Ovulation
Stimulus- Estrogen+ progesterone
Receptor- Hypothalamus/pituitary
Regulator- ovaries
Action- Before ovulation, low estrogen levels inhibit FSH but stimulate LH. After ovulation, high levels of estrogen and progesterone inhibit FSH and LH
Difference between negative and positive feedback loops.
Negative- Rxn produced that reduces the stimulus meaning change in an opposite direction occurs to bring conditions back to normal
Positive- increases the stimulus
What happens during negative feedback
Constant body temp is maintained.
What is vasodilation and vasoconstriction?
vasodilation= blood vessels widen=body temp rises vasoconstriction= blood vessels narrow= body temp falls
What is resting potential?
Neuron not transmitting a signal
Inside a neuron during active potential is? Outside?
Inside= negative Outside= positive
What causes a neuron to go from resting to active potential?
Diffusion of ions that changes the charge
What causes a neuron to go back to resting?
Repolarization
How is a signal transmitted through a neuron
Action potential
What is a neurotransmitter?
Chemical that carries info from one nerve cell to the other
How are neurotransmitters secreted into the synaptic cleft?
Vesicles fuse w/ cell membrane, releasing the neurotransmitter into the synaptic cleft using the exocytosis process
How does a neurotransmitter cause an action potential in a receiving neuron?
The influx of Na+ ions
Cerebrum
Stores info and initiates sensory motor activates
Cerebral cortex
Increases surface area (grey matter)
Corpus callosum
Joins the 2 cerebral hemispheres
