Animal Lesson 3 Flashcards
The endocrine and nervous systems are what?
specialized for different functions and both signal info form one place to another.
Endocrine system: signal type?
Hormone
Endocrine system: Transmission?
Blood
Endocrine system: speed?
Fast/slow.
Fast: adreniain rush
Slow: next step in puberty.
Endocrine system: Duration?
Short/long.
Short: adreniain rush
long: next step in puberty.
Endocrine system: Specificity (how to know where to go)?
is achieved by hormone/receptor interaction. The hormone needs to lock onto the correct receptor then it has a specific response (lock and key).
Nervous system: signal type?
Electrical impulse and chemical neurotransmitter.
Nervous system: Transmission?
Neuron
Nervous system: Speed?
Very fast
Nervous system: Duration?
Short. It ends quickly. So you’ll need to have another kind of signal in order to create another kind of response, through the nervous system.
Nervous system: Specificity?
is achieved by close connection of neurons and target
cells (e.g. neurons, muscle, endocrine cells). The end of neurons is very close to the cell it targets (chemical).
Endocrine system functions
specialized for coordinating gradual changes that affect the entire body. E.g. growth and development, reproduction, metabolic processes (food), and digestion (nutrients absorbing).
Nervous system functions
is specialized for directing immediate and rapid responses to the environment to move and effect behaviour quickly. E.g. rapid locomotion and behaviour.
Nervous systems are composed of what?
Neurons and gila
Neurons
cells responsible for generating and transmitting the electrochemical impulses of the nervous system. Long axons with dendrites.
GIla
cells that maintain homeostasis, form myelin, nourish, and provide support and protection for neurons in the central and peripheral nervous systems. They are interconnected with the axon.
Parts of neuron
Dendrites, cell body, axon.
Dendrites
The branch out to feel any response. ready to receive signals and tells neurons to produce a signal.
Axon
connects to other end of neuron.
How do neurons send a signal?
- Electrical impulses are triggered at the dendrites.
- With sufficient stimulus to the cell body, a new electrical impulse is generated and sent down the axon.
- Neurotransmitter is released and crosses the synapse to bind to receptors on the postsynaptic cell.
Synapse
The gap between neurons.
Neurotransmitters
The chemicals the travel between the synapse.
2 parts of the nervous system?
Central and peripheral.
Central nervous system
Brain and spinal cord
Peripheral nervous system
Cranial nerves (face nerves), ganglia outside (concentration of neuron cell bodies), spinal nerves (bundles of axons).
The 3 stages of nervous system info processing?
Sensor organ senses something wrong. Then goes through PNS (sensory input) to CNS, where it receives a signal in the brain. Then integration. Then brain sends a signal to PNS (motor output) then to the effector where it does something about it.
Reflex
The quadriceps muscle band shortens muscle and it notices it and sends it to the ganglia around your spinal cord. Then in the grey matter of your spinal cord it goes to the interneuron (they process info very quickly). The from interneuron it goes to the motor neuron and tells the hamstring to relax causing a kick and quadriceps to contract.
Endocrine cells secrete hormones into the bloodstream, affecting what?
target cells to regulate physiology and behaviour
Where are the endocrine cells?
In major endocrine glands.
Major endocrine glands
Hypothalamus
Pineal gland
Pituitary gland
Thyroid gland
Parathyroid glands
Adrenal glands
Pancreas
Ovaries (female)
Testes (male)
Organs containing endocrine cell?
Thymus
Heart
Liver
Stomach
Kidneys
Small intestine
What makes hormones?
endocrine cells
Hypothalamus
a brain region that acts as the “master regulator” of the endocrine system, primarily through the pituitary gland.
Two parts of the pituitary gland?
Posterior and anterior. Made up of slightly different tissue.
Posterior pituitary
Is made up of the axons of neurosecretory cells of the hypothalamus. Hypothalamus secrets neurohormone that travels through the neurosecretory cell to the posterior then into the blood stream.
neurosecretory cell
Is a neuron that produces a hormone and secretes it directly into the bloodstream. It’s very long one part I hypothalamus and one in posterior. i.e., Functional overlap between nervous and endocrine systems.
Anterior pituitary
is made up of endocrine cells that respond to hormones from the hypothalamus by secreting
their own hormones. Hypothalamic hormones arrive via portal vessels. The neurosecretory cells are shorter and not in pituitary. The portal vessel then this will release its own hormones into the blood.
Endocrine hierarchial organization
Hypothalamus sends signal to Posterior and Anterior
Pituitary that release hormones to Other Endocrine Glands (e.g. thyroid, adrenals, testes, ovaries) where they can set up their own set of hormones as well. It’s slower because of all the steps.
The short-term stress response (AKA Fight or Flight) involves what systems?
nervous and endocrine systems
Hypothalamus controls what in fight and flight?
the connection between nervous and endocrine systems. ie. neuron that secrete hormones and send electrical impulses. In this example, the hypothalamus affects the endocrine system without acting through the pituitary gland. Instead, via spinal cord→adrenal glands (on top of kidneys).
Flight or fight
Hypothalamus sends nerve signals to spinal cord to adrenal medulla in adrenal gland. Adrenal medulla secretes epinephrine and norepinephrine. They then go into the blood and cause the response.
epinephrine and norepinephrine effects
- Increased heart rate
- Increased breathing rate
- Increased metabolic rate
- Increased blood glucose
- Change in blood flow pattern
Hormones differ in what?
structure and solubility
Water-soluble (hydrophilic)
Polypeptides like insulin. They go into the blood stream easily. Amines: epinephrine it’s hard to transport across membranes.
Lipid-soluble (hydrophobic)
Steroids like cortisol, it means it needs a protein to transport through the fluid system. Amines: thyroxine easy to cross membranes.
The pathway of a water-soluble hormone
Stored for a while in a secretory cell (vacuole) within the cell. It then fuse with the phospholipid membrane to release it. It then goes into the blood and out onto a signal receptor of cell it targets (lock and key). Then it either creates a cytoplasmic response or goes into the nucleus with the help of the protein, where it goes through gene regulation then creates the cytoplasmic response.
The pathway of the lipid-soluble hormone
It made in the cell only when needed and it’s not in a vacuole because it can easily pass through the membrane. It then goes through the blood with the help of the transport protein. Then it easily goes through the membrane of the target cell. Then to goes through the membrane of the nucleus where it attaches to signal receptor, then it goes through gene regulation where it triggers certain genes to turn on and off. So then proteins are released in the cytoplasm where there is a cytoplasmic response.
A single hormone can produce what?
different effects in different cells.
The response of a target cell to a hormone
depends on what?
– The signaling pathways within the target cell
– The type of receptor on the target cell is different and can have may types of receptors for one cell.
Same receptors but different intracellular proteins example?
Liver cell: Glycogen deposits then epinephrine attaches to beta receptor. Then glycogen breaks down and glucose is released from the cell because we need sugar in the blood.
Skeletal muscle blood vessel: epinephrine attaches to beta receptor, then the vessel dilates to get blood to the arms and legs.
Different receptors on same vessel example?
Skeletal muscle blood vessel: epinephrine attaches to beta receptor, then the vessel dilates to get blood to the arms and legs.
Intestinal blood vessel: epinephrine attaches to alpha receptor. Then the vessel constricts because blood away from digestive and to limb to more.
Antagonistic hormones
– Pairs of hormones whose actions oppose each other.
– Maintain a physiological parameter within an
acceptable range (homeostasis).
– Example: Insulin and Glucagon are antagonistic
hormones that regulate blood glucose concentration in the blood (negative feedback loop).
Insulin loop
Homeostasis: Blood glucose level (70–110 mg/100 mL) then stimulus: Blood glucose level rises (E.g., after eating a carb-rich meal). Then Beta cells of pancreas
release insulin (a hormone) into the blood. The insulin then tells body cells to take up more glucose and the liver to take up glucose and store it as glycogen. Then Blood glucose level declines, and back to normal.
Glucagon loop
Homeostasis: Blood glucose level (70–110 mg/100 mL) then stimulus: Blood glucose level falls (for instance, after skipping a meal). Then Alpha cells of pancreas
release glucagon (hormone) into the blood. Then the glucagon tells the liver to break down glycogen
and releases glucose into the blood. Then blood glucose level rises and back to homeostasis.
Hormone solubility affects what?
properties of secretion, transport, and signaling.
Antagonistic hormones are commonly used to what?
Maintain homeostasis.
