Homeostasis (Unit 4) chapter 10/11 Flashcards
The ______ system is a system of small organs that involve the release of extracellular signalling molecules known as
hormones.
endocrine
_______ are chemical regulators
produced by cells in one part of the body that affect cells in another part of the body.
Hormones
Chemicals produced in glands and secreted
directly into the bloodstream are referred
to as:
ENDOCRINE HORMONES
Hormones are classified according to their:
activation site
_________ HORMONES – Stimulate
various parts of the body
NON-TARGET
______ regulates blood sugar by increasing
permeability to glucose
Insulin
_________ HORMONES – Stimulate specific
sites of the body
TARGET
NON-TARGET Examples:
______ Hormone stimulates the development of long bones
Growth
______ (A.K.A Adrenaline) is produced in times of stress
Epinephrine
TARGET Examples
______ hormone regulates calcium levels in the body
Parathyroid
______ stimulates cells of the stomach to produce digestive enzymes
Gastrin
Chemical Control Systems:
The ______ system enables the body to quickly adjust to environmental changes.
nervous
The ______ system is designed to
maintain the body over longer periods of
time.
endocrine
T/F? all cells have the receptors for all hormones
FALSE
Not all cells have the receptors for all hormones and
some cells have more receptors than others for a
given hormone.
For example ______ and ______ hormones regulate and sustain the body for many years.
growth hormone and various sex hormones
Chemical Signals: _____ and _____ Hormones
Steroid and Protein Hormones
Hormones can affect cells when they combine with
__________.
cell receptors
_______ Hormones = made from cholesterol (Lipid
compound) and includes male and female sex
hormones and cortisol (stimulates the conversion
of amino acids to glucose by the liver)
Steroid
Steroid hormones are fat or water soluble
FAT SOLUBLE
______ Hormones = obviously made from
proteins (Chains of amino acids). Includes insulin
and growth hormone.
Protein
Protein hormones are fat or water soluble
WATER SOLUBLE
Steroid Hormones
4.
- Diffuses through the cell membrane
- Attaches to a target receptor molecule
- The hormone-receptor complex moves
into nucleus and attaches to DNA - This activates a gene that sends a
message to the ribosomes in the
cytoplasm to create specific proteins.
Protein Hormone
4.
- Hormone released from cell
- Hormone attaches to receptor site on cell
(Doesn’t diffuse across the membrane) - Hormone-receptor turns ATP into cyclic
AMP (Adenosine monophosphate) - Cyclic AMP acts as a messenger which
activates enzymes/directs protein
synthesis
The ______ gland exercises control over other
endocrine glands and so may be considered the
KING (or queen) of the GLANDS!
pituitary
The pituitary gland is made up of two lobes:
Posterior Lobe & Anterior Lobe
This lobe is responsible for:
Storing and releasing hormones produced by
the hypothalamus such as ADH and OXYTOCIN
Posterior Lobe
The pituitary is connected to the __________.
hypothalamus
The hypothalamus sends ______ _______ to the pituitary which stores and releases hormones.
nerve signals
This lobe is responsible for:
Producing hormones and releasing them
when stimulated by the hypothalamus
Anterior Lobe
The______ is a
butterfly-shaped
gland located in front
of the throat in all
vertebrates.
thyroid gland
________
have a wide range of
effects
Thyroid hormones
Primary thyroid hormone is ______ (T4)
thyroxine
T4 is a ____ soluble hormone
lipid
______ is necessary to produce
hormone; not enough results in overstimulated thyroid gland (goiter)
Dietary Iodine
Thyroid hormones stimulate ____, _____, ____, and _____ in all vertebrates
growth, development, maturation and metabolism
Increase sensitivity of body cells to the effects of _____ and ______
epinephrine and norepinephrine
Increased _______ increases metamorphosis of tadpoles, and seasonal moulting in some birds and mammals
thyroid hormones
Thyroid secretes _____, which lowers the level of Ca2+ in the blood (prevents release from bones)
calcitonin
Calcitonin is secreted when blood ____ rises above
normal range
calcium
Inhibited when blood calcium falls ____ normal range
below
Hormone can also be synthesized in the _____ and _____
lungs and intestines
Secreted when blood calcium levels fall
Parathyroid Hormone (PTH)
PTH Stimulates_____ to dissolve tissue, releasing calcium and phosphate levels
bone cells
______ is used in the body for enzyme activation, nerve impulses, muscle contractions, blood clotting, and other uses
Calcium
DIAGRAM for calcium levels
________ are located above each
kidney
The adrenal gland
Each gland is made up of:
two glands encased
in one shell
Adrenal Medulla
Produces two hormones:
Epinephrine (Adrenaline)
Norepinephrine (Noradrenalin)
The inner gland, the ______ _______ is
surrounded by an outer casing called the
_______ _________
ADRENAL MEDULLA
ADRENAL CORTEX
Accelerates heart rate and body reactions
Epinephrine (Adrenaline)
Increased heart rate and blood sugar
Norepinephrine (Noradrenalin)
Adrenal Cortex
Produces Three different types of Hormones:
GLUCOCORTICOIDS
MINERALOCORTICOIDS
SEX HORMONES
Stimulated by ______ to secrete hormones in times of stress
NERVES
helps the body meet the demands
of continued stress
(Ex. CORTISOL = increases amino acids in the bloodstream
to be converted to sugar)
GLUCOCORTICOIDS
Regulates salt/water balance
(Increases blood volume/pressure)
(Ex. ALDOSTERONE = helps increase water reabsorption by
increasing Na+ retention)
MINERALOCORTICOIDS
Helps to regulate sex organs
SEX HORMONES
short stress response vs long diagram
________ (located in the brain)
regulates several biological rhythms
Pineal gland
pineal gland Secretes _____, which maintains biorhythms
melatonin
More than 2000 tiny islets, each containing thousands of
cells, are scattered throughout the ______
pancreas
The pancreas contains two types
of cells: One type produces
________ while the
other type produces
_______
digestive enzymes
HORMONES
The islets contain ____ and ____ cells which produce
hormones which control blood glucose levels
beta and alpha
Light inhibits melatonin secretion; ________ activates melatonin secretion
darkness
Alpha Cells – Produce ______
GLUCAGON
The hormone producing cells are located in structures
called the _____ of Langerhans, named after German
Scientist Paul Langerhans.
islets
Beta Cells – Produce _______
INSULIN
After a meal blood sugar levels ____ and insulin is released
rise
Insulin is released when blood sugar levels ________
INCREASE
The insulin causes cells of the muscles, liver and other organs to become permeable to ______
glucose
This returns blood glucose levels to _______
NORMAL
The cells can then absorb the glucose from the bloodstream while the liver
converts glucose to ________ (The primary storage molecule of glucose)
GLYCOGEN
Glucagon is released when blood glucose levels ________
DECREASE
After fasting blood sugar levels ______ and Glucagon is released
decrease
homeostasis (blood glucose level diagram)
This promotes the conversion of GLYCOGEN to _______ in the liver
which is then released into the bloodstream
GLUCOSE
Refers to a class of lipids that includes cholesterol and its
derivatives
Steroids
Recall that steroid hormones _______ through cell membrane and
attach to _______ molecules inside of the cell
pass
receptor
This receptor-hormone complex diffuses into the nucleus and binds to a _________ ________ adjacent to the gene whose
expression is controlled by the hormone
regulatory sequence
The binding activates ________
transcription
Natural Steroids
_______- steroid that increases muscle mass
________ – produced in the adrenal glands during times of
stress
______ – produced by adrenal gland and raises blood glucose
levels
_______ and _______ – in females – trigger female sexual
development and control reproductive cycle
Testosterone
Aldosterone
Cortisol
Estrogens and Progestins
Chemicals that have been designed to mimic the actions of
natural hormones.
Synthetic Steroids
Ex – _______ steroids mimic muscle building characteristics
of testosterone
anabolic
Many synthetic steroids are produced for legitimate ________
purposes
medical
Ex – of medical use of synthetic steroids
transplant patients to suppress the immune system to
reduce organ rejection; reduce inflammation in patients
afflicted with arthritis, asthma, and lupus
Medical Synthetic Steroids:
Drug: ________
Use: Lupus and organ transplantation
prednisone
Medical Synthetic Steroids:
Drug: ________
Use: asthma
beclomethasone
Medical Synthetic Steroids:
Drug: ________
Use: Rheumatoid arthritis
dexamethasone
Medical Synthetic Steroids:
Drug: ________
Use: Inflammatory skin disorders
hydrocortisone
Performance Enhancement
in Sports: ____ percentage of athletes willing to risk health to gain
competitive advantage
Small
Most common way is by using anabolic steroids to increases
__________
muscle mass
_______ is a protein hormone that can stimulate
red blood cell production (increases oxygen uptake by cells
thereby increasing endurance and energy)
Erythropoietin (EPO)
Adverse Effects of Steroids
_______ – acne, bad breath, high bp, liver disease,
and cancer
Anabolic steroids
For men additionally –
reduce size of testes, and enlarge
breasts
For women –
irregular menstrual cycles and growth of facial
hair
Some steroids alter ____,“roid rage”, anxiety, depression,
paranoia, or addiction
mood
Banned Drugs:
-Anabolic Steroids
-Peptide Hormones
-Masking Agents
The ____ are the sex glands in males
(testes) and females (ovaries)
gonads
These glands produce ______,
______ and _______
androgens, estrogens and progestins
These hormones regulate the development of male and female ______ systems, ____ characteristics, and ______ behaviour
reproductive
sex
mating
The Male Reproductive System:
Male sex hormones, ________ and _______, are produced in the interstitial cells of the testes
ANDROSTERONE
TESTOSTERONE
Testosterone Stimulates:
____________ or the development of Sperm
Spermatogenesis
Also promotes the development of secondary male sexual characteristics such as;
(Deepening Voice, Facial Hair etc.)
Negative Feedback: The ________ and ______ gland control the production of sperm and male sex hormones
hypothalamus
pituitary
At puberty the hypothalamus secretes
__________________ which activates
the pituitary gland to secrete __________ and __________
gonadotropin-releasing hormone (GnRH)
follicle-stimulating hormone
(FSH) and lutenizing hormone (LH).
_____ acts directly on sperm producing cells stimulating sperm production
FSH
_____ stimulates the production of TESTOSTERONE which
then increases sperm production
LH
The Female
Reproductive System:
The female reproductive system is far more complicated than that of the male (T/F)
TRUE
While males produce sperm cells at a
relatively constant rate, females follow a
complicated sexual cycle in which one egg matures _______
every month
Eggs develop in the ovary in a collection of cells called ______
follicles
Follicles are made up of the primary ______ (the egg) and cells called ______ which nourish the developing egg
oocyte
granulosa
Approximately ____ eggs will mature in the lifetime of a female (That’s a lot of eggs!)
400
Ovulation:
The developing follicle eventually releases the egg
into the _________; this process is called ovulation
fallopian tube
The remaining follicle cells form the _____________ which begins to secrete hormones essential for pregnancy
CORPUS LUTEUM
If pregnancy does not occur the corpus luteum _______ and the cycle begins again
degenerates
Menstrual Cycle
Takes an average of __ days
28
_____ – Shedding of the endometrium
_______ – Follicles develop within the ovary. Estrogen is
secreted.
________ – Egg bursts from the ovary and travels into the
uterus
______ – Corpus Luteum develops. Estrogen and Progesterone
are secreted.
FLOW
FOLLICULAR
OVULATORY
LUTEAL
Menstrual cycle has Four Distinct Phases:
FLOW
FOLLICULAR
OVULATORY
LUTEAL
________ – stimulates the endometrium and prepares uterus for embryo. Also inhibits further ovulation and prevents uterine contractions.
Progesterone
______ – Stimulates the development of female secondary sex characteristics (Pubic hair, breasts) also causes thickening of the endometrium
Estrogen
The ______-______ complex regulates the
production of estrogen and progesterone
(produced in the ovary)
hypothalamus-pituitary
___ and ____ (from the pituitary) regulate the control of these hormones
FSH and LH
However all four of these hormones are involved in
a ______ feedback system
negative
If fertilization does not occur the decrease in
progesterone causes ___________
to help shed the endometrium
weak uterine contractions
GnRH is released from the _________
Hypothalamus
Follicle development initiates _____ secretion which eventually
turns off FSH secretion
Estrogen
___ promotes ovulation and the formation of the Corpus Luteum
LH
____ stimulates follicle development in ovaries
FSH
_____ stimulates the pituitary to release LH and FSH
GnRH
After Ovulation LH turns the follicle cells into the _______
which secretes estrogen and progesterone to ready the
endometrium
Corpus Luteum
Post-Ovulation:
Estrogen and Progesterone continue to _______
increase
This inhibits LH and FSH secretion which
eventually causes the Corpus Luteum to
deteriorate and stop producing ______ and ______
Estrogen and
Progesterone
The drop in these hormones signals the beginning of _______
menstruation
If males and female both secrete the same hormones then why do we have different sexual characteristics?
The answer lies in the amount of hormone produced
Males are manly because they produce more male sex
hormones (ANDROGENS) than female sex hormones
Males also excrete (get rid of) female sex hormones faster
to ensure they don’t build up in the system (This explains why stallions may have high levels of estrogen
in their urine)
Females are feminine because they produce more female
sex hormones than male sex hormones
Your nervous system is active when?
all the time
nervous system gets information about the depth of your:
breathing, pressure on your skin, temperature,
light, odours
nervous controls _____ movements such as blinking,
scratching your nose. Memory, language are all
functions of the _____ system.
muscle
nervous
degenerative disorder of the central nervous system that often impairs the sufferer’s motor skills and speech.
Parkinson’s disease
chronic, inflammatory, demyelinating disease
that affects the central nervous system (CNS). Among the
symptoms are changes in sensation, visual impairment, muscle weakness, depression, difficulties with coordination and speech, cognitive dysfunction, problems with balance, urinary difficulties, constipation, sexual dysfunction, spasticity and pain.
Multiple sclerosis
_____ was a young girl who was locked in a small
closet-like room at the age of 18 months.
Genie
Genie was finally freed
from the closet. She was 13 years old. Although Genie is now an
adult, her language development is quite ______.
immature
The nervous system (NS) has two main divisions:
Central Nervous System (CNS) and Peripheral
Nervous System (PNS)
The CNS consists of the ____ and _______ and acts as a coordinating centre for incoming and outgoing information.
brain and the spinal cord
The ____ consists of nerves that carry information between the organs of the body and the CNS.
PNS
PNS is further subdivided into _____ nervous system and _____ nervous system.
somatic
autonomic
Somatic ___ controls the skeletal muscle, bones and skin.
NS
Somatic nerves can be either _____ nerves (relay info) or _____ nerves (generate response).
sensory
motor
The Autonomic NS controls the internal organs of the body. The two divisions of ANS are :
Sympathetic nervous system (fight or flight) and Parasympathetic nervous system (rest and digest)
Two different types of cells are found in the nervous system:
Glial cells and neurons.
____ cells are non conducting cells that are for structural support and metabolism of neurons.
Glial
_____ are the functional units of the nervous system.
Neurons
Parts of a Neuron
_____: projection of cytoplasm, carries impulses towards the cell
body.
Dendrite
____: extension of the cytoplasm that carries nerve impulses away
from the cell body.
Axon
_______: insulated covering over the axon.
Myelin Sheath
_______: contains synapses, specialized structures where
neurotransmitter chemicals are released in order to communicate
with target neurons.
Axon Terminal
Types of Neurons
3 groups:
- ______ neurons (aka afferent neurons): relay info from the environment to CNS.
Sensory
- ______: link neurons, located in the brain
and spinal cord usually; short length
Interneurons
- _____ neurons (aka efferent neurons): relay
information to the effectors which produce
responses.
Motor
A type of glial cell (support
cell) is called the _____
cells.
Schwann
_____ cells form the
myelin sheath which wrap
around axons.
Schwann
The gaps between Schwann
cells are called ______ (electrical impulses can jump between nodes faster)
Nodes of Ranvier
Neural circuit through the _____ _____ that provides a framework for a reflex action.
spinal cord
It begins with a _____ that relays the stimuli to spinal cord.
receptor
_____ in the spinal cord receive information and relay it
to motor neurons which activate the effector organs causing a response.
Interneurons
Sequence of Events
- stimulus causes action potentials
in sensory receptors - message travels along sensory
axon - message travels along the
dendrites - message reaches interneuronal
dendrites - Message goes to brain
- Message traveling in the motor
neuron axon - message causes muscle to
contract
_______ are electrochemical signals created by movement of ions through the nerve cell membrane.
Nerve impulses
When nerves are ___ (in reaction to a pinprick or sight of someone’s face), a rapid
change in _______ (commonly called just potential) is detected.
excited
electrical potential difference
A _____ is a site where a neuron makes a connection with another neuron or effector
synapse
Depending on the kind of neuron
communication may occur _____ or _______
chemically or electrically
In a chemical synapse a chemical
transmitter called a _______ is released
neurotransmitter
The plasma membranes of presynaptic and postsynaptic cells are separated by a narrow gap called the ______ cleft
synaptic
The membranes of the ______ and ______ membranes are in direct contact
presynaptic and postsynaptic
______ flows in gap junctions between the cells
Current
Allow for rapid _______ transmissions
synchronous
All animal cells have a separation of positive and negative charges across the plasma membrane (______ potential)
Membrane
Membrane potential is caused by uneven distribution of ___ and ____ inside and outside the cell
Na+ and K+
Plasma membranes are selectively permeable – must travel through ____ channels
ion
A special ion channel, the Na+/K+ pump uses energy to pump 3Na+ out of the cell for every ____ K+ in, creating a net _____ extracellular environment
two
positive
Resting Potential of a neuron is – ___ mV
70
The concentration of _____ within the cell
results in the inside being ______ charged
and outside being _____ charged
anions
negatively
positively
When a nerve becomes excited it
conducts an ______
impulse
There is a quick temporary change in membrane potential called an _____ potential.
action
An action potential begins as a stimulus that causes positive charges from outside the neuron to flow _____
inward
Phases of Action Potential:
Phase 1 –
Incoming positive ion raise membrane potential, this is called depolarization
______ will continue when the membrane potential reaches its threshold potential, about -50 to -55mv and Na+
channels open
Depolarization
Phase 2-
Na+ channels continue to open,
sodium rushes in along concentration
gradient
Phase 3 -
Membrane becomes very
positive reaching a peak +30mV or more
Phases 4 –
Na+ channels close and K+
channels open allowing potassium to exit
Membrane potential falls again, called _______
repolarization
Phase 5-
Potassium gates close slowly,
membrane dips below resting
(hyperpolarized)
Phase 6 –
membrane re-established
resting membrane potential
Stages 4-6 are considered the _____ period, the threshold that is required to
generate another AP is much higher than
normal (allows for one way
communication)
refractory
The period of ______ must be completed and the nerve cell
must repolarize before the next AP is completed.
depolarization
This “waiting
period” is referred to as the _______ period, which lasts about 10
ms.
refractory
The wave of depolarization is followed by a wave of _______
repolarization
___ occur either maximally or they do not occur at all.
APs
The intensity of the nerve impulse and speed of transmission remain the ____.
same
Occurs in myelinated gaps called the _______
Nodes of Ranvier
Conduction is much more rapid, about _____ vs_____ in unmyelinated nerve cells
130 m/s vs 1m/s
Small spaces between neurons or neuron and effectors are known as _____.
synapses
At the end of axons, small vesicles are present that contain _______.
neurotransmitters
As impulse moves down the axon, neurotransmitters are released from ________ and diffuse along the synaptic cleft creating a depolarization of dendrites of the _________
pre synaptic neuron
post synaptic neuron.
________ is an example of a NT found in pre synaptic neurons. It acts as a excitatory NT on post synaptic neurons by opening up Na+ ion channels.
Acetylcholine
________ from the postsynaptic
membrane destroys acetylcholine so that the AP does not continue.
Cholinesterase
_____ is the effect produced by the accumulation of NTs from two or more neurons.
Summation
