Special nerurons that send enhanced messages to the brain to be analyzed
Why do we call them special senses?
Because they only occur in one place in the body
What kind of cells are special senses?
What senses do your special senses include?
Taste, smell, hearing and sight
Why do we stop smelling after a certain period of time?
We have what is called olfactory fatigue where you only smell things a few times and then the messages no longer get sent to the brain
What part of the nerve picks up sensory information?
Where do the axons of the neurons go in the special sense of smell?
They project through the small holes in the cribriform plate to the olfactory bulbs
Where do the olfactory tracts go to?
the Cerebral cortex
Each different smell is considered what?
What does the chemical message (scent) do in regards to the brain?
Opens the sodium doorway which creates an electrical message to go to the brain.
Explain the process of how we smell.
Airborne molecules enter the nasal cavity and are dissolved in the fluid of the epithelium. Molecules then bind to a chemoreceptor. This allows gates to open allowing NA+ into the cell causing depolarization of the neuron
What is a chemoreceptor?
It is a receptor that only chemicals will bind to.
What is another term for the sense of taste?
What do you have to have in order to taste?
1. Have olfactory input 2. Has to be in a liquid state (dissolved) 3. Papillae 4. Taste buds
What are papillae?
Little bumps (neurons) found on the tongue.
What are the 4 types of Papillae?
1. Vallate-V shaped/big
2. Fungiform-dark red, mushroom shaped
3. Foliate-Look like leaves (has best taste receptors)
4. Filiform-Most abundant, no taste receptors here, looks like a filament in a light bulb
___________ are not found on majority of papillae.
Acts like a funnel and pulls in soundwaves (outter ear)
External auditory canal
Takes soundwaves down toward the middle ear
Ear drum, vibrates
What are the three parts of the external ear?
Pinna, external auditory canal, tympanic membrane
What are the parts of the middle ear?
Ear ossicles, Oval window, Eustacian tube
Malleus, incus, stapes
Where is the malleus located?
Closest to membrane
How do you describe the stapes?
Looks like Sturrup
Oval hole that leads soundwaves into the cochlea
Where are all receptors for hearing?
In the Cochlea
Where does the eustacian tube lead?
Back of the throat (leads fluids here)
Why do children need to have tubes put in their ears?
The Eustacian tube is flat so all water stays behind the eardrum and puts a lot of pressure on the eardrum until it breaks. The eardrum can heal on its own.
When do children no longer need tubes in their ears?
As they grow taller the eustacian tube begins to angle downward.
What can effect hearing after your eardrum has broken, then healed?
Scar tissue on ear drum will effect hearing because the eardrum will vibrate differently so we may not be able to hear certain sounds or pitches.
What can you get if you eardrum doesnt heal on its own?
Skin graft of th ear, it is a difficult surgery and hearing would also be different.
Contains nerves for eyesight called photorecepters
What are the two types of photoreceptors and describe them.
Rods-Work in low light, black/white, crude images (no fine detail) Has rhodopsin
Cones-Color, lots of light. Has Iodopsin
Has highest number of photoreceptors. If lens reflects light to hit this place exactly, you will have 20/20 vision.
Neurons will degenerate and will cause blindness (deals with the macula lutea)
Explain a detached retina.
It detaches from the choroid so we do not absorb as much light so we see stars and brights spots when we should not
Lets you see, takes message to occipital lobe
blind spot (no photoreceptors)
(Front) Anything in front of the lens
What kind of fluid is in the Anterior Cavity?
(Back) Anything behind the lens
What kind of fluid is in the posterior cavity?
Vitrious fluid (jellylike)
Bending of light
How much aqueoud fluid is in front of the eye. If there is more fluid there will be an increase in pressure
Cloudy lens, cannot easily bend light
What occurs during cataracts surgery?
You replace your lens with another
Opsin with retinal inside of it. When light enters the eye, retinal is released, opens the sodium doorway, so we get message of what we are seeing
What is rhodopsin derived from?
What makes iodopsin and rhodopsin different?
They use different proteins
Part of photoreceptors; it is the light sensitive part of the rod and has 700 double layered membraneoud discs that just continue to fold over and over
Have different amino acids so they are different proteins so rods see black/white, cones are color
What causes the sodium channels to open for vision?
At rest the retinal is bound to the inside of the opsin. When light strikes the cone, the retinal changes shape and detaches from the opsin. This causes the NA+ channels to open
Endocrine Glands (technically speaking)
Endocrine glands are secreted and picked up by the blood.. But in actuality this is not what happens. Not all hormones enter the blood, so we can give them different names
True endocrine glands (endocrine glands)
Hormone gets secreted and goes into the blood and travels that way
Paracrine (endocrine glands)
When you have tissue making it, it works on a neighbor cell
Autocrine (endocrine glands)
Makes it and works on itself
Phermones (endocrine glands)
Secrete hormones into the environment, women release hormones into environemtn and sync up period, dogs secrete hormones to let other dogs know they are in heat
What are the chemial classification of hormones?
How are hormones classified by?
What they look like
What is a difference between a protein hormone or a fat hormone?
How it finds its receptor
Explain proteins as a hormone
ex. insulin. Long chain of amino acids and folds into a ball
Explain peptides as a hormone
ex. oxytocin, still a protein but it doesn't fold
Explain BiogenicAmines as a hormone
ex. Thyroid, one single amino acid
Explain lipids as a hormone
ex. testerone, estrogen, stored to make food for later
1. Keeps lipids from clumping together (cell will surround lipid to prevent clumping)
2. Keep biogenicAmines from going directly into urine since they are so small
3. Keep hormone levels constant in the blood (Make sure you do not have extreme high/low levels)
Membrane bound receptors
Receptor is on the membrane. Proteins attach to it (through a door)
holes in the capillaries to allow proteins to get out
Receptor is on the inside of the cell. Lipids attach to it (through the membrane)
How are hormones controlled?
Negative feedback loop
What are the 3 ways a gland is told to secrete?
Nonhormonal regulation of hormone secretion
Neural regulation of hormones
One hormone influences the release of another hormone. Anterior pituitary tells the thyroid gland to release its hormone
Non hormonal regulation of hormone secretion
We look at concentrations in the blood. Change the extra-cellular concentration of a substance other than a hormone. When levels move, we have receptors watching it. ex. glucose
Neural Regulation of hormones
The neuron synapses with the gland, nervous system influences hormone secretion and the gland produces a hormone (sympathetic nervous system, adrenal gland)
Tropic (One hormone influences the release of another hormone)
Anterior pituitary tells the thyroid gland to release its hormone
What is the direct link to the endocrine gland?
What are the two major sites where the nervous system and the endocrine system interact?
Hypothalamus and the pituitar gland
Releasing hormone-secrete a hormone to make pituitary work
Inhibitory hormone-secrete a hormone to make pituitar work
Oxytocin-Hypothalamus makes this and sends it to pituitary to store and use later
Anti-diuretic-makes people retain water within the body, regulates blood pressure. Hypothalamus makes and sends to pituitary to store and use later
called neurohypophsis. It is an extension of the nervous system. The hypothalamus is connected to the posterior pituitary by the hypothalamopophysial tract (nervous tract). Sends all info by nervous system
What are the hormones of the posterior pituitary?
Anti-diuretic and oxytocin (Made in the hypothalamus, secreted by the pituitary)
The anterior pituitary gland
Also called hypothalmohypophysial. Portal system. Endocrine system, capillary network.
What are the hormones that are secreted by the anterior pituitary gland
TSH(thyroid stimulating hormone)
FSH(Follicle stimulating hormone)
grows tissues and cells
Goes to thyroid and tells it to work (tropic)
Triggers a woman to ovulate
Matures sperm and egg
What are the two reproduction hormones?
FSH and LH
goes to outside portion of the adrenal gland to release its hormone
Helps women in formulating milk
What are some parts of the thyroid gland?
Follicles and parapollicular cells
What are two parts associated with the Follicles?
T3 (triiodothyronine) and T4 (thyroxine)
Cell shaped like nice palls
Cells that surround the follicle
What do we see on parafollicular cells
Calcitonin (regulates calcium levels)
Where are the parathyroid glands usually found?
Embedded in the posterior part of each lobe of the thyroid gland. On back of thyroid
What does the parathyroid gland secrete
What does the parathyroid gland do?
Brings calcium levels back up from food and drink and works hand in hand with calcitonin
The pancreas is both ____________ and ___________
endocrine and exocrine
What is the exocrine part of the pancreas
The acini which produces pancreatic juices. It makes digestive enzymes into small intestines to break down food.
What is the endocrine part of the pancreas?
The islets of langerhans
Beta cell-insulin (brings sugar into cell)
What are some characteristics of someone who has diabetes?
Glucose in urine
Drinks and eats a lot
Explain why diabetics pee and drink a lot
Because there is sugar in the kidneys there is more water in the blood. Since water automatically flows from high to low water moves into the kidneys which means we have to get rid of some of those fluids so they will pee a lot and since the blood volume is going down they need to replenish that fluid into the blood so they drink a lot
Where is the adrenal gland located?
On top of the kidneys
What are the two parts of the Adrenal Gland?
Adrenal medulla and adrenal cortex
What is secreted by the adrenal medulla?
Epinephrine (speeds everything up)
What is the opposite of epinephrine?
Norepinephrine (comes from sympathetic nervous system. Not secreted by the adrenal gland)
What is secreted by the adrenal cortex?
Aldosterone-tells your body to put sodium back into capillary. Regulates blood pressure. Where sodium goes, water will follow.
Steroids-increase levels of testosterone in the body