EEMB 7 wk. 8-10

hypothalamus

master controller of the body

regulatory system

system of the body composed of the nervous and endocrine system

nervous system

signals are sent directly to specific locations in the body via specific pathways of branching neurons

* rapid traveling
* very specific tissues reached by a single signal
* shorter lasting

endocrine system

signals are secreted into the blood stream, where they circulate broadly and can potentially be received by any tissue

* slow to release
* broad range of tissues reached by a single signal
* long lasting (minutes to hours)

ductless glands

hormones are secreted out of these directly into the interstitial fluid

endocrine glands

name of a group of endocrine cells

peptide

protein signaling, water soluble

amine

made from hormone tyrosine, both water and lipid soluble to some degree

steroid

made from cholesterol, lipid soluble

lipid soluble hormone

hormone that needs assistance traveling through the blood, usually with the help of transport proteins. however, it can pass through the cell membrane to reach the receptor in the cell cytosol

\

water soluble hormone

can easily travel through the blood with no assistance needed, but needs help passing through cell membrane with the help of a membrane bound receptor. allows for specificity

negative feedback

insulin and glucagon are part of the ___ ___ system to maintain blood sugar levels, maintaining homeostasis

positive feedback

prolactin and milk production is an example of ___ ___

neuromodulator

a chemical that regulates neurons via stimulation or suppression, etc. also known as neurotransmitters

ghrelin

produced and released mainly by stomach

* termed the hunger hormone
* stimulates appetite
* increases food intake
* promotes fat storage

leptin

produced by fat cells

* termed satiety hormone
* reduces appetite
* makes you feel full
* communicates with hypothalamus to regulate food intake

Estrogen

important for sexual/reproductive development, mainly in women

* female sex hormones
* develops breasts, wider hips, pubic hair, armpit hair
* regulates menstrual cycle
* controls growth of uterine lining

progesterone

released by ovaries

* changing levels of this contribute to abnormal periods
* necessary for implantation of fertilized eggs

testosterone

secreted by testicles and ovaries

* metabolism in males is more pronounced
* plays a role in development of male reproductive organs
* anabolic steroid
* prevention of osteoporosis

hCG (human chorionic gonadotropin hormone)

only made during pregnancy

* made exclusively in placenta
* rises a lot in first trimester
* linked to nausea

hPL (human placental lactogen)

* also known as human chorionic somatomammotropin
* made by placenta
* stimulates milk glands in the breast for feeding

adrenaline

* can slow or stop labor all together
* women who feel threatened may produce high levels of it

endorphins

* produced by the body to give calming and pain relieving effects
* women may have higher levels of it near the end of pregnancy

oxytocin

* hormone of love
* contractions during labor, release of milk
* helps us feel good

prolactin

* mothering hormone
* increases during pregnancy, peaks when labor starts
* central to milk production, high levels with early breastfeeding

gastrin

* stimulates production of gastric acid
* stimulates glands to secrete pepsinogen and hydrochloric acid

secretin

duodenum

* regulates small intestine acidity
* signals secretion of sodium bicarbonate
* stimulates secretion of bile in the liver

CCK (cholecystokinin)

duodenum

* stimulates release of digestive enzymes in pancreas and emptying of bile from gallbladder

GIP (gastric inhibitory peptide)

duodenum

* decreases stomach churning in order to slow emptying of stomach

motilin

duodenum

* increases migrating myoelectric complex of gastrointestinal motility
* stimulates production of pepsin
* big role in fat metabolism

ADH (antidiuretic hormone)

excretory

* water levels are controlled by this
* produced by hypothalamus
* triggers reabsorption of water

aldosterone

excretory

* released by adrenal cortex of kidneys
* enhances Na+ reabsorption from extracellular fluid

melatonin

* helps regulate body’s sleep wake cycle and internal clock

cortisol

* helps regulate body’s sleep wake cycle
* responsive to daylight

serotonin

* found in brain, bowels, and blood platelets
* transmits between nerve cells
* active in smooth muscles
* contributes to well being and happiness
* appears to play a role in maintaining mood balance

dopamine

* produced by hypothalamus
* executive function, moter control, motivation, arousal, reinforcement

thyroxine

respiratory

* stimulates respiration

fight or flight response

begins in the amygdala

triggers neural response in hypothalamus, then pituitary gland

* secretion of adrenocorticotrophic hormone (ACTH)
* activation of adrenal gland
* releases epinephrine
* binds to liver cells produces glucose
* results in production of cortisol
* increases blood pressure and blood sugar
* suppresses immune response

sodium potassium pump

pumps in potassium, pumps out sodium via the use of ATP hydrolysis.

electron motive force

electric potential produced by an electrochemical cell

dendrites

highly branched extensions of a neuron that receive signals from other neurons

axon

part of the neuron that extends and transmits signals to other neurons.

synapse

junction between neurons

sensory neurons

transmit information about external stimuli, like light, touch, smell, or internal conditions like blood pressure or muscle tension

interneurons

form the local circuits connecting neurons in the brain or ganglia. responsible for integration of sensory input

motor neurons

transmit signals to muscle cells, causing them to contract.

central nervous system

neurons that make up the brain and the spinal cord. responsible for integration of information.

peripheral nervous system

carries signals in and out of the CNS. bundled neurons form nerves.

membrane potential

charge difference across a plasma membrane of a cell

\-55mv

the threshold value

\-70mv

the resting membrane potential

action potential

chemical and electrical process that consists of chemo-electrical movement of a signal down an axon

upstroke

at threshold, sodium channels snap open. sodium is driven through the channels cause by depolarization of the celld

downstroke

most sodium channels close, with potassium channels opening to permit K+ outflow because EMF is large and positive.

absolute refractory

Na+ channels closed and unable to reopen, K+ channels still open

relative refractory

some Na+ channels can be activated, but K+ conductance is still high. enough stimulus will initiate depolarization

sensory reception

detection of a stimulus

* afferent neurons in the PNS
* initial stimulus can be direct or via a receptor cell

transmission

sensory information travels through the nervous system as Action Potentials

* more direct stimulation due to increased presence of stimulus
* gentle pressure, lower frequency of APs
* high pressure, high frequency of APs

perception

circuits of neurons in the CNS process the information

signal transduction

occurs between sensory reception and transmission

* the conversion of a stimulus to a change in the membrane potential of a sensory receptor cell

chemical synapses

electrical current is carried from neuron to neuron via chemical signals like neurotransmitters

* depolarization of axon causes vesicles to fuse with the membrane
* neurotransmitters are released into the synaptic cleft

amplification

strengthening of a sensory signal during transductions

sensory adaptation

sensory cells decrease receptiveness after prolonged stimulus, helping you focus on important things.

mechanoreceptors

Bending or stretching or the associated external structure (hair or cilia) generates tension that alters the permeability of the neuronal membrane

electromagnetic receptors

respond to electromagnetic energy, most commonly found in our eyes in the form of rods and cones

thermoreceptors

present in human skin and in the hypothalamus to regulate temperature, external and internal

pain receptors

respond to noxious stimuli, with free nerve endings in our skin to respond to tissue damage. can be inhibited by pain medication

chemoreceptors

respond to chemical and concentrations, like solute concentration and individual chemicals

ball and socket joint

joint that allows for near 360 movement, like hips and shoulders

hinge joint

joint that can move in one plane, back and forth or right and left, like the knee or elbow

pivot joint

joint that rotates, like the ulna and radius

myosin

the thick filaments that grab onto the thin filaments and pull them closer for muscle contraction

actin

the thin filaments that are pulled by the thick filaments for muscle contractions

myofibril

bundles of thick and thin filaments in a muscle

troponin complex

blocks myosin binding sights to prevent involuntary contraction in skeletal muscles

tropomyosin

a strand that wraps around actin filaments that hold troponin complexes in place

neuromuscular junction

where motor neurons interface directly with muscle cells

skeletal muscle

striated, made for movement and fine motor skill, voluntary

smooth muscle

non-striated, made for movement of materials through conduits such as blood vessels and the alimentary canal, involuntary

cardiac muscle

contains intercalated discs, structurally resilient, doesn’t fatigue quickly, made for a coordinated and consistent heartbeat, self regulated

myelin sheath

fatty phospholipid barrier that wraps around axons and acts as an electrical insulator, allowing signals to jump and travel quicker.

node of ranvier

depolarized region of an axon that is not covered in a myelin sheath

oligodendrocytes

a cell that can produce multiple bundles of myelin sheath. only found in CNS

schwann cells

a cell that makes a single myelin sheath, so often found in multiples on a single neuron. only in the PNS

astrocytes

cells that clear neurotransmitters from synaptic cleft and wrap around the synapses. also have a function in the blood brain barrier to protect the brain from toxins

microglia

the cell that is the primary immune response to the CNS. can be phagocytic macrophages or respond to inflammation in ameboid form.

frontal lobe

prefrontal cortex, broca’s area, motor cortex

parietal lobe

somatosensory complex, sensory association cortex (integration of sensory information)

temporal lobe

auditory complex, wernicke’s area

occipital lobe

visual association cortex, visual cortex

broca’s area

in the frontal lobe, responsible for forming speech

wernicke’s area

in the temporal lobe, responsible for comprehending language

diencephalon

composed of the thalamus, pineal gland, hypothalamus, and pituitary gland

brainstem

composed of the midbrain, pons, and medulla oblongata

cerebrospinal fluid

found in brain and spinal cord. carries hormones, nutrients, etc from blood plasma to neurons.

motor system

voluntary movement

autonomic system

involuntary movement, made of the enteric, sympathetic, and parasympathetic division.

sympathetic division

division that controls fight or flight responses

parasympathetic division

division that is the resting state, aka “rest and digest”

enteric division

division that controls mostly digestion