Bio 30 Final review unit A1/2 Flashcards
What are the divisions of the nervous system
The Peripheral system is further divided into the somatic and autonomic systems, and the Central nervous system.
What is a neuron and its function
A neuron is a single electrically excitable cell that transmits information through electrical and chemical signals
What is the somatic nervous system and its function
The somatic nervous system is the voluntary division of the nervous system and is responsible for transmitting motor and sensory information to and from the central nervous system, it also controls the skeletal muscles
what is the Autonomic nervous system and its function
The Autonomic nervous system is the involuntary division of the nervous system. It controls the body’s unconscious functions, also known as the parasympathetic(rest and digest) and sympathetic(fight or flight) responses. The Parasympathetic response relaxes the body and slows activity, whereas the sympathetic response prepares the body for intense physical activity
What are dendrites and their functions?
They are extensions of the cell body that contain the receptors which receive the chemical stimulus, initiating the transfer of information(receives stimulus)
What is the cell body and its function
Contains the organelles responsible for powering and nourishing the neuron. Dendrites extend from the cell body
What is the axon and its function
A long narrow section of the neuron that carries the electrical impulse away
What is the myelin sheath and its function
Insluates the axon and accelearates the impluse speed
What are Schwann cells and their function
Makes the myelin that insulates the axon
What is neurilemma and its function
Only found in the PNS, used to regenarate the neuron after damage
What are the nodes of Ranvier
Gaps in the myelin sheath that speed up the impulse transmission by allowing it to hop(making it clap)
What are the synaptic knobs and their function
Found at the end part of the axon, transmits information to the dendrites of other neurons
What are the parts of the neuron
Dendrites, cell body, axon, myline sheath, schwann cells, neureliema, nodes of ranvier, synaptic knobs(axon terminal)
What is white and grey matter? What’s the difference?
White matter: Parts of the nerve cells of the CNS that have myeilnated fibers (appeared white)
Grey matter: Parts of the nerve cells In the CNA that have no myline(appear darker)
What are the steps of the neural transmission pathway?
- sensory receptors: Highly modified dendrites of a sensory neuron that are activated by environmental stimulus
- sensory neuron: Carries impulses to CNS
- Interneuron: A neuron of the CNS that connects with sensory, motor and other interneurons to integrate sensory input with motor output
- Motor neuron: Carries impulses from the CNS to an effector
- Effector: A cell or organ that produces a physiological response when stimulated by a nerve impulse
What are oligodendrocytes and their function?
Specialized glial cells that produce myelin in the CNS
What are glial cells?
Cells that nourish the neurons, remove their waste and defend against infection. myelin is produced by specialized glial cells called oligodendrocytes found in the CNS and Schwann cells found in the PNS
What is the reflex arc and what are the steps of it?
The reflex arc is the simplest nerve pathway. There is no coordination by the brain, instead the information is read by the spinal cord. Therefore a much quicker response is generated
1. sensory receptors are activated by enviornmental stimulus
2. sensory neurons carry the information to the spinal cord
3. the neurons in the spinal cord respond to the information
4. motor neuron carries the information from the spinal cord to the effector
5. effector responds to the information before it gets prossed in the brain
What is the Patellar reflex
“the knee-jerk response” Tapping the ligament under the knee cap causes the lower leg to raise in response
What is the pupillary reflex?
pupils restrict in response to light, more light=pupils restrict and become smaller. less light=pupils dilate to become smaller
What are the steps of a nerve impulse/action potential
- resting potential
- depolarization
- action potential
- repolarization
- hyperpolarization
- refractory period
What is the first step of a nerve impulse
Resting potential: -70mV(inside of the cell) higher concentration of k+ ions inside the cell and a higher concentration of Na+ outside the cell. Sodium/potassium pump working to maintain a resting state (3Na+ out, 2K+ in).
What is the second step of a nerve impulse
Depolarisation: Na+ channels open. Enough depolarization needs to happen to meet the threshold of -55mv.
What is the third step of a nerve impulse
Action potential: Once inside becomes positive(+40mv) Na+ channels close and charge is restored. (impulse is created)
What is the fourth step of a nerve impulse
Repolarization: K+ channels open and K+ rushes out of the cell. this restores the original polarity
What is the fifth step of a nerve impulse
Hyperpolarization: K+ channels close slowly and the inside of the cell becomes more negative than a resting state(below -70mV)
what is the sixth step of a nerve impulse
Refractory period: Time taken to restore the membrane to the resting potential, NA+/K+ pump is working to restore the resting state
What are the steps of a synaptic transmission
- Impluse/action potential
- Ca2+ channels open causing the movement of vesicles to the membrane to release NTs
- Diffusion of NTs across synaptic cleft
- Reception(NTs attach to receptor sites)
- Impluse is created
- cholinesterase pulls NTs off the receptor site and the reuptake begins(recycling of NTs)
What are the different kinds of neurotransmitters and their functions
Excitatory neurotransmittors: Opens sodium channels on the postsynaptic neuron causing the inside to become more positive
Inhibitory neurotransmittors: Opens channels such as potassium or anions(negative ions) channels which make the cell more negative
What is a threshold level?
The minimum voltaic charge that a neuron must have in order to fire an action potential (-55mv in humans)
What is the skull
The bone that surrounds the brain
What are the meninges
protective layer that surrounds the spinal cord and brain
What is cerebrospinal fluid
cushioning fluid that circulates between the innermost and the middle layer of the brain and spinal cord
What is the spinal cord
The part of the CNS that transports signals from the brain to the body and emerges from the skull through an opening called the foreman magnum
What is the cerebrum
The uppermost part of the brain that contains the major lobes of the brain, these lobes are the Frontal lobe, Parietal lobe, Occipital lobe, and Temporal lobe.
what is the forebrain
The frontmost part of the brain contains the cereberum, the corpus callosum, the hypothalamus, and the thalamus
what is the hindbrain?
The back part of the brain containing the cerebellum, and the brain stem( medulla oblongata and the pons)
What is the frontal lobe
The frontmost part of the brain responsible for voluntary muscle movement, intellectual activities, personality, speach and creativity
What is the pituitary gland
A small bean-shaped gland responsibal for hormone production
What is the temporal lobe
Part of the brain responsible for hearing and memory
What is the pons
relay station which sends messages between the cerebellum and the medulla
What is the medulla oblongata
Part of the brainstem that joins the cerebellum to the spinal cord and is responsible for coordinating heart rate and breathing rate
What is the parietal lobe
Part of the brain responsible for touch and temperature awareness, emotions and speech interpretation
What is the corpus callosum
Joins the two hemispheres together(helps with communication)
what is the occipital lobe
Part of the brain responsible for vision and interpreting visual information
What is the cerebellum
Part of the brain responsible for limb movement, muscle tone and balance
What is a sensory receptor
Highly modified ends of sensory neurons that are found in specialized sensory organs like the eyes.
What is sensory adaptation
When a receptor becomes conditioned to a stimulus. neuron no longer fires an action potential when stimulus is present
What are the parts of the eye?
lid/lashes, extrinsic muscles, sclera, Choroid layer, Retina, Fovea, Blind spot, optic nerve, cornea, aqueous humor, iris, pupil, lens, vitreous humor
What is the function of the eyelids/lashes
protection of the eyes and elimination of florigen particles
What is the function of the extrinsic muscles
Controls the movement of the eye in the optic cavity
What is the sclera and its function
This is the white outer layer of the eye that gives the eyeball its shape and is the attachment site for the extrinsic muscles
What is the choroid layer and its function
The layer inside the sclera that contains the blood vessels which supply the eye with oxygen and nutrients. It also contains a dark pigment making the inside of the eye appear black
What is the retina and its function
Location at the back of the eye containing the photoreceptors rods and cones. Rods are responsible for vision in dim light and allows us to discriminate between shades of grey. Cones are activated by bright light and used for color vision and sharp detail, cones are less numerous than rods
What is the fovea
Location with the highest concentration of cones, making this the spot with the sharpest vision
What is the blind spot
The site on the retina where the optic nerve attaches, resulting in no rods or cones being present.
What is the function of the optic nerve
Transmission of visual sensory information to the occipital lobe of the brain.
What is the cornea and its function
The transparent part of the sclera that rounds out the outer segment of the eye, responsible for refracting entering light towards the pupil
What is the aqueous humor and its function
Watery liquid that protects the lens of the eye and supplies the cornea with nutrients
What is the iris and its function
A pigmented ring around the pupil that acts as a “shutter” contracting/dilating to control the amount of light entering the eye
What is the pupil and its function
Opening in the center of the iris that allows light to enter the inner eye
What is the function of the lens
Focuses the incoming image on the retina
What is the vitreous humor and its function
A cloudy, jelly like material that fills the eyeball to maintain its shape
How do we see in dim light
The retina contains photoreceptors called rods which contain a chemical called rhodopsin. When light hits the rhodopsin its molecular structure changes causing an action potential. This impulse travels through the optic nerve to the occipital lobe
How do we see in bright light
Rods have a limited amount of rhodopsin so it must be regenerated. In bright light rhodopsin does not regenerate fast enough so other photoreceptors called cones are needed to compensate. The photoreceptors pick up red blue and green light allowing us to see in colour
What are the different types of eye dysfunction and their corrections?
Nearsightedness(myopia): Image focuses in front of the retina, correction is a concave lens
astigmatism: Lense or retina are irregular, correction is an astigmatic lens
Farsightedness(hyperopia): Image focuses behind the retina, correction is a biconvex lense
What are the eye reflexes and their functions?
-Light reflex: Reflex that controls the diameter of the pupil in response to the intensity of light
-Accommodation reflex: A reflex action of the eye in response to focusing on a near object and then looking at a distant object
-Adaptation reflex: Change over time in the responsiveness of the sensory system to a constant stimulus
What are the three divisions of the ear
Outter, Middler and inner ear
What are the parts of the outer ear and their functions
-Pinna(ear part): Directs sound into the ear and funnels it towards the tympanic membrane
-Auditory canal(the part you clean): Sound travels through this part to reach the tympanic membrane
What are the parts of the Inner ear and their functions
-Vestibule: Small fluid-filled sac that plays a role in maintaining balance
-Semicircular canals: Similar to the vestibules, these fluid-filled structures also play a role in maintaining balance
-Cochlea: Shell-like structure that is filled with fluid. Inside the cochlea is the basilar membrane of the organ of Corti, which is lined with tiny hairs. When the cochlea vibrates, the fluid causes the organ of corti to move, and thus the tiny hairs move triggering an action potential
-Auditory nerve: Carries stimulus information to the temporal lobe of the brain.
What are the parts of the middle ear and their functions?
-Tympanic membrane(ear drum): Vibrates when hit by sound waves
- Ossicles(hammer, anvil, stirrup): Three tiny bones that amplify the vibrations made by the tympanum
-Oval window: Pushes inward when it receives amplified vibrations from the ossicles
-eustachian tube: Connects the ear with the throat; responsible for maintaining the correct pressure
What are the steps involved in hearing
- sound waves enter the outer ear and are funneled to the middle ear by the pinna
- Sound waves cause the tympanum(eardrum) to vibrate
- Vibrations are amplified by the ossicles(hammer, anvi, stirrup)
- amplified vibrations push on the oval window, which is the gateway to the cochlea
- Cochlea contains the basilar membrane of the organ of Corti as well as fluid, this membrane is lined with microscopic hairs.
- When the vibrations hit the cochlea, the fluid moves, which causes the hairs on the organ of corti to also move. The movement of these hairs triggers an action potential
- Action potential travels along the auditory nerve to the temporal lobe for interpretation
What is ACTH(adrenocrototropic hormone) , its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target or non-tatget: Target (Adrenal cortex)
-Function: Stimulates the adrenal cortex to release aldosterone, cortisol, and sex hormones before puberty
-Hypo: Low levels of adrenal cortex hormones
-Hyper: High levels of adrenal cortex hormones
-tropic or non-tropic: tropic
What is FSH(follicle stimulating hormone) , its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target or non-target: Target (ovaries and testes)
-Function: Stimulates the development of follicle into a mature egg/ova(females). Stimulates sperm production(spermatogenesis) in males
-Hypo: No eggs/sperm produced
-Hyper: Multiple follicles developed (females), High sperm count(males)
-tropic or non-tropic: Tropic
What is LH(luteinizing hormone), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target: Target(ovaries and testes)
-Function: In males stimulates the interstitial cells of the testes to produce testosterone. In females Stimulates ovulation and develops the remaining follicle into the corpus luteum after ovulation, this produces progesterone
-Hypo: No ovulation, and thus low progesterone(female), low testosterone(male)
-Hyper: generally no effect
-tropic or non-tropic: Tropic
What is HGH(human growth hormone), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target: Non-target (all cells)
-Function: cell division, bone/muscle growth, metabolic breakdown of fat
-Hypo: Dwarfism
-Hyper: In Children’s Giantism, in adults(Acromegaly) does not increase height but widens the face, hands and ribcage
-tropic or non-tropic: non-tropic
What is Prolactin(PRL), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target or non-target: Target (mammary glands)
-Function: stimulates the production of breast milk
-Hypo: little or no milk produced
-Hyper: excessive milk production
-tropic or non-tropic: non-tropic
What is TSH(Thyroid-stimulating hormone) , its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target or non-target: Target(thyroid gland)
-Function: Stimulates the thyroid gland to produce thyroxine
-Hypo: low thyroxine
-Hyper: High thyroxine
-tropic or non-tropic: Tropic
What is ADH(antidiuretic hormone), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target or non-target: Target(kidneys)
-Function: Manages water balance in the body, released during times of dehydration. Causes the kidneys to increase water reabsorption from urine to blood
-Hypo: Diabetes Insipidus(inadequate water retention resulting in excess urine output)
-Hyper: Excessive water retention resulting in bloating and little urine output
-tropic or non-tropic: Non-tropic
What is Oxytocin, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pituitary
-Target or non-target: Target(mammary glands and uterus)
-Function: Stimulates the contraction of uterine muscles during labour. stimulates the RELEASE of milk from the mammary glands
-Hypo: delayed/difficult labour. Difficulty nursing
-Hyper: Excessive milk release
-tropic or non-tropic:
What is Calcitonin, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Thyroid gland
-Target or non-target: Target(blood and bones)
-Function: Lowers blood calcium levels by increasing the movement of calcium from the blood to the bones
-Hypo: High blood calcium levels
-Hyper: Low blood calcium levels
-tropic or non-tropic: non-tropic
What is Thyroxin, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Thyroid gland
-Target or non-target: Non-target(most cells)
-Function: Manages the body’s metabolism by, increasing the rate at which the body metabolites fats, proteins and carbs by speeding up cellular respiration. And by glucose usage and oxygen consumption
-Hypo: Kids—Cretenism; causes mental delays, shortness and stockiness. Adults—myxedema; causes tiredness, puffy skin, weight gain, hair loss
-Hyper: Grave disease; causes anxiety, insomnia, irregular heartbeat, and protruding eyes
-tropic or non-tropic: non-tropic
What is Parathyroid hormone(PTH), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Parathyroid gland
-Target or non-target: Target(blood, bones, kidneys, small intestine)
-Function: Increases blood calcium by increasing the release of calcium from the bones into the blood and by increasing the absorption of calcium by the kidneys and small intestine
-Hypo: Low blood calcium
-Hyper: High blood calcium
-tropic or non-tropic: Non-tropic
What is Aldosterone, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Adrenal cortex
-Target or non-target: Target(kidneys)
-Function: raises blood pressure by increasing the absorption of NA+ from urine to blood. Because NA+ is dissolved in water, the increase in NA+ results in increased water retention, thus raising blood volume(and therefore pressure)
-Hypo: Low Na+ levels, Low blood pressure
-Hyper: High Na+ levels, High blood pressure
-tropic or non-tropic: Non-tropic
What is cortisol, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Adrenal cortex
-Target or non-target: Non-target(most cells)
-Function: Long-term stress hormone that manages stress by increasing blood glucose levels. This increase in blood glucose provides more fuel for cellular respiration to meet the demands of the increased stress.
-Hypo: low glucose levels
-Hyper: high glucose levels
-tropic or non-tropic: Non-tropic
What is epinephrine(adrenalin), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Adrenal medulla
-Target or non-target: Non-target (most cells)
-Function: Short-term stress hormone that prepares the body for flight or flight. Increases heart rate, blood volume, blood pressure, and glucose levels
-Hypo: inadequate response to stress
-Hyper: overreaction to stress
-tropic or non-tropic: Non-tropic
What is norepinephrine(Noradrenalin), its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Adrenal medulla
-Target: Non-target (most cells)
-Function: The same function as adrenalin, but seems to be released during stress like colds and infections. It is also released alongside adrenalin during the stress response
-Hypo: Inadequate response to stress
-Hyper: over-response to stress
-tropic or non-tropic: Non-tropic
What is Glucagon, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pancreas
-Target or non-target: target(liver and muscles)
-Function: increases blood glucose levels by stimulating the conversion of glycogen to glucose in the liver and muscles
-Hypo: low glucose levels
-Hyper: high glucose levels
-tropic or non-tropic: Non-tropic
What is Insulin, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Pancreas
-Target or non-target: Non-target(all or most cells)
-Function: decreases blood glucose levels by increasing the permeability of cells to glucose, increasing the conversion of glucose to glycogen, and increasing the cell metabolism of glucose
-Hypo: Diabetes mellitus (hyperglycemia) - high blood sugar
-Hyper: Low blood glucose
-tropic or non-tropic: Non-tropic
What is estrogen, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Ovaries (follicle)
-Target or non-target: Most cells
-Function: development of the secondary sex characteristics, stimulates the development of the endometrium lining, Provides positive feedback to the pituitary to LH, which triggers ovulation on the 14th day of ovulation
-Hypo: underdevelopment of the endometrium and female secondary sex characteristics.
-Hyper: generally no effect
-tropic or non-tropic: Non-tropic
What is Progesterone, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Ovaries (corpus luteum)
-Target: Most cells and endometrium
-Function: Maintains the endometrium by inhibiting uterine contractions, inhibits ovulation using negative feedback
-Hypo: early menstratuion
-Hyper: No menstratuion
-tropic or non-tropic: Non-tropic
What is testosterone, its function, where is it released, what does it target and what disorders hyper/hyposecretion can cause
-Released: Testes
-Target or non-target: Most cells
-Function: stimulates the development of the male secondary sex characteristics and increases sex drive
-Hypo: lack of secondary sex characteristics
-Hyper: increased sex drive
-tropic or non-tropic: Non-tropic
What is a target vs non-target hormone
A target hormone targets a specific part of the body, if a hormone affects most cells in the body its non-target
What is a tropic vs non-tropic hormone
A tropic hormone is a hormone that targets another endocrine gland, and a non-tropic hormone targets a part of the body that’s not an endocrine gland
What are endocrine glands
Pituitary gland, thyroid gland, parathyroid gland, adrenal cortex, adrenal medulla, pancreas, testes, ovaries
What are antagonistic hormones
Hormones that work against each other to maintain homeostasis Ex. insulin and glucagon, calcitonin and parathyroid hormone
What is a neuromuscular junction
The space between a neuron and muscle where information is transferred
What is the All or None affect
The threshold for an action potential is either reached and an impulse is triggered or it’s not reached and no impulse occurs. There is no in-between
How do we feel different intensities of our senses
If there are a larger amount of neurons being activated, or if a cell has a higher threshold the intensity of the impulse will be stronger than a normal one
What is summation
The additive effect of multiple electrical impulses on a neuromuscular junction, individually they can not generate an action potential but together they can. Summation is the effect produced by the accumulation of neurotransmitters from two or more neurons
What are the two kinds of diabetes and their causes
Diabetes mellitus: Hyposecretion of insulin resulting in Dangerous amounts of glucose
diabetes insipidus: Hyposecretion of ADH resulting in inadequate water retention
What is the difference between nervous and endocrine control
Nervous control: Enables the body to adjust quickly to changes in its environment
Endocrine control: Designed to maintain control over a much larger period of time
What is homeostasis and how does the endocrine system maintain it
Homeostasis is the desired resting state of an organism’s systems, maintained through a series of adjustments that require constant monitoring and feedback. The endocrine system helps maintain homeostasis by releasing chemical messengers called hormones into the blood.
