Ch. 13: Special Senses; ch.15: endocrine system; ch.20: immune system; ch.19 lymphatic system
What is the difference between sensation and perception?
Sensation is the awareness of a stimulus. Examples would include changes in internal (being thirsty or hungry) and external (cold or warm outside) environments.
Perception is the interpretation of the meaning of a stimulus. In other words, the understanding of what we are sensing so that we as humans can decide to either stop it or not. An example would be sensing that you are thirsty, so your perception is telling you to go and drink some water.
What are the different types of receptors?
There are exteroceptors (external), proprioceptors (skeletal muscle, joints, tendons, etc.), and interoceptors (internal).
What is the difference between tonic and phasic receptors? Give an example of each.
Phasic receptors are fast-adapting receptors that send signals at the beginning or end of a stimulus. An example would be receptors for pressure, touch, or smell. For pressure or touch, you place your finger on your arm and forget it is there until you lift it. For smell, you tend to go nose-blind after smelling it so much at a given time.
Tonic receptors are receptors that adapt slowly or not at all. These receptors are constantly sending signals. It builds and grows until the problem is solved. An example would be pain receptors; you are in pain until the cut or problem is over.
What is the difference between visceral and referred pain?
Visceral pain results from stimulation of visceral organ receptors. This would be if one were to feel vague, aching, or burning.
Referred pain is pain from one body region perceived as coming from a different region. An example would be someone having pain in their left arm during a heart attack.
What is the pathway from visual sensation and perception (from light waves to occipital lobe)?
Light waves go to the cornea, then scattered throughout the lens, then focus on the fovea, then to the optic nerve, and to the CNS (central nervous system), which is the occipital lobe (primary visual cortex)
What is the function of the anatomy of the eye (external and internal)?
External:
Eyebrows protect the eye from sweat and dirt.
The eyelids protect the eye from debris and keep it lubricated.
The conjunctiva is the mucus coat of the eyeball.
The lacrimal apparatus is the tear ducts.
Then, finally, the extrinsic eye muscles control how the eye moves and how to focus light.
Internal:
The fibrous layer is the outermost layer and contains the…
Sclera, which protects and shapes the eyeball, and the
Cornea, which forms a clear window which bends light as it enters the eye,.
The vascular layer is the pigmented layer of the eye and is also called the uvea. This contains the…
Choroid region, which supplies blood to all layers of the eyeball
ciliary body, which consists of ciliary muscles that control the shape of the lens
Iris, which is the colored part of the eye; dark colors do not have good dark vision but do not get headaches during the eye, and vice versa with those with lighter colored eyes.
What are the different layers of the eye?
The inner layer is the retina.
This consists of the pigmented layer, which absorbs light and prevents its scattering (meaning it focuses light to make things clearer) and stores vitamin A that is sent to the brain.
The neural layer contains the optic disc, which lacks photoreceptors, meaning the blind spot, and rods and cones
What is the electromagnetic spectrum?
The electromagnetic spectrum is the range of all types of electromagnetic radiation. It organizes electromagnetic radiation by wavelength or frequency. It includes from longest to shortest wavelengths.
What is visible light?
Visible light is the range of wavelengths in the electromagnetic spectrum that humans can see.
What are wavelengths of light?
Light has wavelengths between 400 and 700 nm
What are the photoreceptors of the inner eye?
Rods and cones
Rods help with night vision and shape of the eye.
Cones make the color vision. The fovea has the highest concentration of cones.
What is the auditory pathway from sound waves to the temporal lobe?
Starting at the external ear, sound waves enter the tympanic membrane, then amplified by auditory ossicles, then sound moves oval window to cochlear organ, which then soundwaves disturb/move intracellular fluid and moves inner hair, which generates AP, which then moves along the cochlear nerve and joins the vestibular nerve and is finally transmitted into the temporal lobe.
What is the function of the anatomy of the external, middle, and internal ear?
The external ear’s function is to transmit sound waves. It consists of two parts: The auricle funnels sound waves into the auditory canal. The external acoustic meatus (auditory canal) transmits sound waves to the eardrum, which is the tympanic membrane, which vibrates in response to sound. The external ear is cartilage.
The middle ear (tympanic cavity) functions in hearing but more so in amplifying sound. It contains the pharyngotympanic (auditory) tube, which connects the middle ear to the nasopharynx (throat). The middle ear has 3 bones called auditory ossicles, including the malleus, incus, and stapes.
The internal ear (labyrinth (maze)) functions in hearing and equilibrium. This has 2 major divisions: the bony labyrinth, which is a system of tortuous channels and cavities that worm through the bone and is filled with perilymph fluid, and the membranous labyrinth, which is a series of membranous sacs and ducts that are contained in the bony labyrinth and are filled with potassium-rich endolymph. It also has the vestibule (in the bony labyrinth), which responds to gravity and changes the position of the head.
Define frequency
Frequency is the number of waves that pass a given point in a given time
What are the auditory receptors of the inner ear?
The cochlea, which extends the vestibule and contains cochlear hair cells that function in detecting high and low pitch sounds.
What is the difference between static and dynamic equilibrium and what are the receptors that detect them?
Static equilibrium means maintaining equilibrium with no change (no movement/motion. Standing still). Dynamic equilibrium means maintaining an equilibrium with continuous changes (lots of movement. Moving your head from side to side).
Macula receptors monitor static equilibrium and Crista ampullaris receptors monitor dynamic equilibrium.
Where is the equilibrium determined?
The maculae (biaxial movement) are a sensory receptor organ that monitors static equilibrium. This responds to linear acceleration (nodding yes), not rotation.
The cristae ampullaris is a receptor that monitors dynamic equilibrium. This responds to rotational acceleration (spinning, nodding no).
What is the pathway for olfactory sensation and perception?
Air is sent through the nares (nostrils), then to the nasal conchae, which then goes to the olfactory epithelium. Once it is there, it will reach the olfactory bulb, which then will travel via the olfactory nerve to the olfactory cortex in the front lobe.
Sometimes information will be brought to various parts of the brain like the thalamus, hypothalamus, amygdala, and regions of the limbic system.
What is the function of the anatomy of the nasal passages?
The olfactory epithelium is the organ of smell. This contains olfactory sensory neurons and olfactory stem cells that send receptors to cerebral cortex. This olfactory epithelium is covered in mucus (solvent for odors).
What is the pathway for gustatory sensation and perception?
There are two cranial nerve pairs that carry taste impulses from the tongue to the brain: the facial nerve VII, which carries impulses from the fungiform taste buds and the glossopharyngeal nerve X, which carries impulses from the folate taste buds. The signals are then transmitted to the gustatory cortex in the insula (the hidden cortex in the cerebral).
What is the function of the anatomy of the taste passages?
Taste buds are sensory organs for taste; most taste buds are located on the tongue in papillae, which are peg-like projections of the tongue mucosa.
There are three types of papillae: fungiform papillae, which are mushroom-shaped structures that house most taste buds; these are scattered across the tongue. Vallate papillae are the largest taste buds that form an upside down “V” at the back of the tongue. The foliate papillae are on the side walls of the tongue.
There are also gustatory epithelial cells that are taste receptor cells that have microvilli (gustatory hairs) that project into taste pores, bathed in saliva.
What anatomical feature of the eye contains the highest concentration of pigmented cells and photoreceptors?
Fovea
Which receptor is responsible for detecting the sensation of pain?
Nociceptors
Which receptor is responsible for detecting the sensation of stretching, vibration, and pressure?
Mechanoreceptors
Define pitch
Pitch is the perception of different frequencies. Higher the frequency, higher the pitch.
Define wavelengths
Wavelengths are the distance between two consecutive waves. Shorter the wavelength, higher the frequency of sound.
Define tone
Tone is 1 frequency, meaning no changes.
Compare and contrast the endocrine system with the nervous system
The endocrine system influences metabolic activities via hormones transported in the blood. The responses are slower but longer lasting than nervous system responses. The endocrine system acts over longer distances (bloodstream from head to toe) while the nervous system acts over shorter distances.
What are the ten endocrine organs?
Adrenal glands
Pineal gland
Hypothalamus
Ovaries (female)
Pancreas
Parathyroid glands
Pituitary gland
Testis (male)
Thymus
Thyroid gland
What is the difference between exocrine and endocrine glands?
Exocrine glands produce nonhormonal substances (sweat, saliva, etc.) and have ducts to carry secretion to the membrane surface (ex. Mammary glands produce milk for mammalian infants).
Endocrine glands produce hormones and lack ducts. It is embedded with capillaries and blood vessels because it is duct-less
What is the difference between autocrine and paracrine?
Autocrine are local chemical messengers that exert effects on the same cells that secrete them.
Paracrine are locally acting chemical messengers that affect cells other than those that secrete them. It has a gap junction
What is the difference between water-soluble, fat-soluble, and thyroid hormone?
Water-soluble hormones (all amino acid-based hormones except thyroid hormones) act on plasma membrane receptors and cannot directly enter the cell. Water-based hormones use G-protein to enter and exit the cell.
Fat (lipid)-soluble hormones (steroid and thyroid hormones) act on intracellular receptors that directly activate genes and can directly enter the cell because of the phospholipid bilayer.
Thyroid hormone (“master hormone.”) It is a water-based hormone but acts like a fat-based that directly influences genes.
What is the pathway for cAMP hormone signaling?
The hormone (first messenger) 1binds to a receptor, which then 2activates a G-protein. The G-protein 3activates or inhibits the effector enzyme adenylate cyclase. Adenylate cyclase then 4converts ATP to cAMP (second messenger). 5cAMP activates protein kinases that 6add phosphate (phosphorylate) to other proteins. 7Phosphorlyated proteins are then either activated or inactivated. 8cAMP is rapidly degraded by enzyme phosphodiesterase (cell can go back to its resting state), which stops cascade.
What is PIP2 hormone signaling used for?
This pathway is not as common as cAMP but is used for smooth muscle contraction, calcium balance in skeletal system, and for the parathyroid hormone.
What is direct gene activation?
Direct gene activation is when lipid-soluble steroid hormones and thyroid hormones can 1diffuse into target cells and 2bind with intracellular receptors. A 3receptor-hormone complex enters the nucleus and 4binds to region of DNA (receptors are found on DNA). This helps start DNA transcription to produce mRNA.
How does negative and positive feedback work specifically for the thyroid gland?
When there are low levels of thyroid hormones in target cells, the hypothalamus sends thyrotropin-releasing hormones (TRH) to the anterior pituitary. The anterior pituitary then sends thyroid-stimulating hormones (TSH) to the thyroid gland to increase the level of thyroid hormones in target cells. This process of making TRH and TSH increases until there are high enough levels for the target cells, making it a positive feedback loop. Once there are enough thyroid hormones in the target cells, thyroid hormones tell the hypothalamus that there are enough thyroid hormones so GHIH, dopamine, or cortisol are released to inhibit the production of any more thyroid hormones. This process creates the negative feedback loop.
What hormone does the pineal gland produce?
Melatonin
What hormones do the 2 parts of the adrenal gland produce?
Aldosterone
The adrenal cortex produces corticosteroids (mineralocorticoids, glucocorticoids, and gonadocorticoids).
The adrenal medulla produces epinephrine and norepinephrine. Mostly epinephrine (adrenaline).
What hormone does the hypothalamus produce?
Produces thyrotropin-releasing hormone
What hormones do the 2 parts of the pituitary gland produce?
The posterior pituitary produces neurohormones (oxytocin and ADH).
The anterior pituitary produces the growth hormone (GH), thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin
What hormone does the thyroid gland produce?
Produces T3 and T4 hormones. Thyroxine
What hormone does the parathyroid gland produce?
Produces parathyroid hormone (PTH)
What hormone does the thymus produce?
Produces thymosin, thymopoietin, and thymulin
What hormones do the 2 pancreas cells produce?
Alpha cells produce glucagon (hyperglycemic)
Beta cells produce insulin (hypoglycemic)
What hormone does the ovaries produce?
Produces estrogen
What hormone do the testes produce?
Produces testosterone
Mucin
This is in the first line of defense. It is a sticky mucus that lines digestive and respiratory tract and traps microorganisms. It clogs the respiratory tract to trap microorganisms to cough it out so it does not enter the body.
Defensins
This is in the first line of defense. It is antimicrobial peptides (proteins) that inhibit growth. It breaks up/destroys the buildup of microorganism growth.
Antigens
Antigens are substances that trigger a response (trigger B and T cells). They target all adaptive immune responses.
What is the difference between innate and adaptive immunity?
The innate defense system is the system you are born with, while adaptive defense system is humans learn as we age. However, both systems work together to keep organisms healthy.
The innate responses release proteins that alert cells of the adaptive system to foreign molecules. Both also release and recognize many of the same defensive molecules.
The adaptive immune system eliminates almost any pathogen or abnormal cell in the body. It amplifies inflammatory response and picks up where complement system left off. It is specific, meaning It recognizes and targets specific antigens, it is systemic meaning is it not restricted to the initial site, and it has memory, meaning every time you are exposed, your immune system will be stronger because it remembers how to fight off the specific illness.
What is the function of Peyer’s patches and the appendix and where are they located?
Peyer’s patches are clusters of lymphoid follicles in the wall of the small intestine.
The appendix is an offshoot of the first part of the large intestine.
They destroy bacteria, preventing them from breaching the intestinal wall. They also generate “memory” lymphocytes.
What are lines of defense for the innate system?
The first line of defense are the surface barriers (skin and mucous membranes), along with their secretions. The acid mantle inhibits the growth of foreign microorganisms by dissolving them once they fall onto the skin. Enzymes help kill microorganisms as well (ex. enzymes in stomach kill many microorganisms).
The second line of defense is used when the foreign microorganism has invaded into the deeper tissues. It has pattern recognition receptors that recognize and bind tightly to the microbes, disarming them before they do harm.
What is the line of defense in the adaptive system?
Humoral immunity (B cells-triggered with antigens) is when antibodies circulate freely in body fluids and then eventually bind temporarily to a target cell and make it inactive (making it not reproduce and destroy it).
Cellular immunity (T cells- NO antigens) are not antibodies and is when lymphocytes (white blood cells) act against a target cell directly (by killing infected cells by engulfing them, injecting chemicals to activate cell death, or signaling macrophages to eat it) or indirectly (releasing chemicals that enhance inflammatory response.)
What are T cells and B cells?
T and B cells protect against antigens and originate in bone marrow. T cells mature into the thymus while B cells stay in the red bone marrow.
B cells produce plasma cells, which secrete antibodies. The antibodies mark antigens for destruction.
T cells manage immune responses, and some also attach and destroy infected cells.
What are natural killer cells (NK)?
Natural killer cells (NK) are nonphagocytic but are large lymphocytes that “police” blood and lymph. This kills cells before adaptive immune system is activated. It attacks cells that lack “self” cell-surface receptors; this helps cells identify cells within the body
What are macrophages?
Macrophages are developed from monocytes and are chief phagocytic cells. There are free macrophages (move around through tissue spaces) and fixed macrophages (stay in specific area).
What are phagocytes and neutrophils?
Phagocytes are white blood cells that ingest and eat foreign invaders.
Neutrophils are also white blood cells that consumes the foreign invader and kills itself. The body makes a lot because it is one time use.
What are the stages of inflammation?
Inflammation is triggered whenever body tissues are injured. It alerts the immune system to an injury/infection. It increases blood flow to the site of injury/infection and mobilizes immunocytes. The stages are:
Inflammatory chemical release is when chemicals are released into extracellular fluid by injured tissues or immune cells. An example would be histamine released by mast cells to trigger inflammatory response (attracts cells to help clean up injured area)
Vasodilation and increased vascular permeability. Vasodilation causes hyperemia (high amounts of blood) which causes swelling (edema).
Phagocyte mobilization (eating cells—think of Pac-Man) is when neutrophils flood the area first and macrophages follow.
What are antimicrobial proteins?
Antimicrobial proteins are proteins that prevent microorganism growth by enhancing innate defenses. There are 2 important proteins:
Interferons (IFN) are a family of immune-modulating proteins that activate or inhibit our immune system. They warn healthy neighboring cells when secreted by entering them and block virus production. IFNS can activate natural killer cells (NK) and macrophages.
Complement proteins (system) consist of ~20 blood proteins that circulate in blood in inactive form. It enhances inflammation by increasing macrophages.
What are complete antigens?
Complete antigens have 2 function properties: immunogenicity, which is the ability to stimulate the increase of specific lymphocytes, and reactivity, which is the ability to react with activated lymphocytes and antibodies released by immunogenic reactions.
What are incomplete antigens?
Incomplete antigens are also called haptens (half), which involve molecules too small to be seen, meaning they are harmless until they react with the body. It causes the immune system to mount an attack that is harmful to a person. Examples include poison ivy, detergents, etc.
What are antibodies?
B cells produce and secrete antibodies. They first bind to antigens, activating them to trigger an immune response.
Double binding is called complement fixation.
What is immunological memory?
Has the primary immune response which increases and differentiation of cells upon exposure to antigen for the first time. The lag period is between 3-6 days, but it decreases the more times you are exposed to.
It also has the secondary immune response, which means the re-exposure to the same antigen gives a faster, more prolonged, and more effective response, making the lag period shorter. This response sensitized memory cells that provide immunological memory.
What is the lymphatic system?
The lymphatic system role is to return fluids that were leaked from the blood vessels back to the blood (circulatory system). There are 3 parts: lymphatics, lymph, and lymph nodes.
What are lymphatics?
Lymphatics, which are the network of lymphatic vessels that return leaked fluids from the blood back to the blood. It is a one-way system, ensuring lymph flows only towards the heart. It is also permeable, meaning it can take up larger molecules and particles that blood capillaries cannot.
What are lymph?
Lymph are fluid in the lymphatic vessels
What are lymph nodes and what is their function?
Lymph nodes are embedded deep in connective tissue in clusters along lymphatic vessels. It is the smallest lymphoid organ. Their function is to cleanse the lymph by sending macrophages to remove and destroy microorganisms and debris that enter the lymph to prevent unwanted substances from being delivered to the blood.
How is lymphatic fluid transported?
A low-pressure system transports lymph fluid.
Pressure changes in thorax during breathing
Pulsation of nearby arteries
Contractions of smooth muscle in the walls of lymphatics can help push lymph fluid up the heart.
Physical activity increases the flow of lymph with valves to prevent backflow to continue muscle contraction
What are the lymphatic cells?
Reticular cells produce reticular fibers called stroma in lymphoid organs. Stroma is a network-like support that acts as structure for immune cells.
Immune system cells: lymphocytes are cells of the adaptive immune system and are with T cells or B cells
What is the function of the spleen?
Spleen is a blood-rich organ and is the largest lymphoid organ. The splenic artery and vein supply it. Its function is to be the site of lymphocyte increase and immune surveillance and response. It also cleans the blood of aged blood cells and platelets by having macrophages remove the debris from them.
Where are the white pulp and red pulp and what do they do?
The white pulp and red pulp are in the spleen.
The white pulp is where white blood cell response is going to be.
The red pulp is where old red blood cells are destroyed/broken down
What is the function of the tonsil?
The tonsils form a ring of lymphatic tissue around the pharynx and appear as swellings of mucosa. Its function is to gather and remove pathogens in food or air because is it open.
What is the function of the thymus?
The thymus functions as a lymphoid organ where T cells mature. It is the most active and largest during childhood but eventually shrinks and becomes inactive as we age and becomes a secondary fat storage
What is inflammation and what does it do?
Inflammation is triggered whenever the body tissues are injured.
It alerts the immune system to an injury/infection by increasing blood flow to that site of injury/infection and mobilizes immunocytes
What hormone is responsible for calcium homeostasis?
Parathyroid hormone (PTH)
What hormone regulates systemic water levels?
Antidiuretic hormone (ADH)
What hormone regulates cellular metabolism?
Thyroxine
What hormone controls cellular growth and development?
Growth hormone (GH)
What hormone regulates the sleep/wake cycle?
Melatonin
What is the sex hormone that is responsible for triggering the onset of male puberty and sperm production?
Testosterone
What is the sex hormone that is responsible for triggering the onset of female puberty and menstruation?
Estrogen
What hormone regulates salt or ion and water balance?
Aldosterone
What hormone is responsible for converting glucose into glycogen for storage?
Glucagon
What hormone controls the release of thyroid-stimulating hormone or thyrotropin?
Thyrotropin-releasing hormone
Which line of defense is natural killer cells (NK), antimicrobial proteins, inflammation, and fever?
Second line of defense
What line of defense do B and T cells occur in?
Third line of defense
What cellular component triggers or causes the onset of fever?
Pyrogens