Transcript One main transport system

Animal Systems
1.
Describe how nutrients and oxygen are moved to the body cells.
.1
Review the principles of diffusion and active transport.
1.2 Contrast passive transport systems with active transport
systems.
1.3
Compare open circulation systems with closed systems of vertebrates.
1
1.4
1.5
Compare the efficiencies of hearts with one, two, three, and four chambers.
Describe the blood circulation pattern and vessels in the mammalian systems.
To begin...
What is the definition of each of the terms listed below and what
does each have to do with transport?
Diffusion:
the movement of molecules from an area of high concentration to an area of lower
concentration
Passive transport (osmosis):
the movement of molecules, across a cell membrane, by their own energy
Active transport (exocytosis, endocytosis):
the movement of a substance through a cell membrane, requiring the use of
ENERGY!
One main transport system--the circulatory system...
Your body is made up of billions of cells. Each cell is like a tiny factory because it
must be supplied with certain chemicals and it must be "relieved of" certain waste
products.
The 3 methods of transport mentioned earlier all work together to deliver these
needed chemicals to each cell (such as oxygen and food) and to pick-up/remove the
waste products (e.g. carbon dioxide gas).
Also, these 3 methods of transport are, more importantly, a part of one main system
known as the CIRCULATORY SYSTEM. Although, when discussing the movement
of oxygen and nutrients in simple organisms, we usually just talk about a "transport
system" as there is no blood involved...only in more complex animals do we begin to
see blood, hearts, vessels, etc.
In various organisms, the type of transport system used will vary...
1. In some multicellular organisms, such as a sponge,
almost every cell has part of its surface exposed
to the environment. Each cell can obtain its
own oxygen and get rid of its own wastes.
In these cases, diffusion and active transport are
sufficient for moving substance into cells.
2. In roundworms, there is a fluid-filled body cavity surrounding the digestive tube. As the
roundworm wiggles, the fluid is squeezed about from one place to another. In this way,
substances dissolved in the fluid are carried to and from body cells.
Comparison of the transport systems, continued...
3. In arthropods (crayfish, lobsters, insects), the blood is pumped through blood
vessels that empty into body spaces. Through these spaces, the blood moves about
sluggishly, in contact with tissues. Eventually it gets back into another set of vessels. These
carry it back to the pumping point. This type of incomplete vascular system is called an
open circulatory system.
4. Annelids (earthworms) have a closed
circulatory system. In this system, blood flows
within vessels all the time. An earthworm has
five hearts and a complicated set of finely
branched vessels. In this way, all body cells
are located relatively close to a blood vessel so that they can obtain food and exchange
wastes. They do this through diffusion and active transport.
5. In vertebrates, circulation also occurs in a closed system. A single, muscular heart with
two or more chambers pumps blood through the system.
Review...
1. What type of transport system is the most developed? Why?
1.
1.1
1.2
Describe how nutrients and oxygen are moved to the body cells.
Review the principles of diffusion and active transport.
Contrast passive transport systems with active transport systems.
.3
Compare open circulation systems with closed systems
of vertebrates.
1.4 Compare the efficiencies of hearts with one, two, three,
and four chambers.
1.5
Describe the blood circulation pattern and vessels in the mammalian systems.
1
Two Important Definitions...
Atrium: chambers on the upper side of the heart that receive blood
from the veins and in turn force it into the ventricles
Ventricle: chambers on the lower side of the heart that receive
blood from the atria and in turn force it into the arteries (vessels
that carry blood away from the heart and around to the rest of the
body)
Different types of hearts exist in vertebrates...which one is best??
1. Fish: a 2-chambered heart
- single loop of blood, closed system
1. loop begins in the atrium (chamber #1), which acts as a chamber to receive the deoxygenated blood that has been circulated around the body
2. from the atrium, blood is passed to the ventricle (chamber #2) which pushes
deoxygenated blood to the gills
3. gills remove CO2 and replace it with O2, oxygenated blood is circulated around the
fish and the body of fish uses up O2, leaving de- oxygenated blood
4. de-oxygenated blood is carried back to the atrium
atrium
ventricle
gills
body
Pros: no mixing of oxygenated and de-oxygenated blood
Cons: heart must pump blood through gills and body in 1 circuit
2. Amphibian: 3-chambered heart
1. the loop begins simultaneously in the right atrium (chamber #1), this chamber collects
de-oxygenated blood from body, and the left atrium (chamber #2), this chamber collects
oxygenated blood from the lungs
2. the heart contracts and drains both atriums into the ventricle (chamber # 3) at the same
time (ventricle receive a mixture of oxygenated and de- oxygenated blood)
3. ventricle contracts and forces mixed blood to the lungs and to the body
body
right atrium
ventricle
lungs
left atrium
Pros: ridges in walls of blood vessels reduces mixing of both kinds of blood
Cons: body receives a mixture of oxygenated and de-oxygenated blood
3. Birds and Mammals: 4-chambered heart
- most efficient circulatory system, double loop, blood doesn't mix
3. First Loop:
a) Pulmonary Circulatory System:
- right atrium collects de-oxygenated blood from the body and it drains
through the right
tricuspid valve into the right ventricle
- this blood is pumped into the lungs to pick up O2, it then goes to the
left atrium
Second Loop:
b) Systemic Circulatory System:
- left atrium receives oxygenated blood from the lungs, which drains
through the left
bicuspid valve into the left ventricle
- this blood is pushed to the whole body
Important Notes:
- although there are two separate loops for the blood to follow, both occur simultaneously
- This means that blood is pumped through the right side of the heart to the lungs at the
same time that blood is received from the lungs and pumped throught the left side of the
heart to the rest of the body
Diagram of the Flow of Blood in a Mammalian Heart
body
right atrium
tricuspid valve
right ventricle
lungs
left atrium
bicupsid valve
left ventricle
Pros: heart is a double pump
no mixing of oxygenated and de-oxygenated
blood
HOW BLOOD TRAVELS THROUGH THE BODY
Review...
1. What type of heart is most efficient? Why?
1.
1.1
1.2
1.3
1.4
Describe how nutrients and oxygen are moved to the body cells.
Review the principles of diffusion and active transport.
Contrast passive transport systems with active transport systems.
Compare open circulation systems with closed systems of vertebrates.
Compare the efficiencies of hearts with one, two, three, and four chambers.
.5
Describe the blood circulation pattern and vessels in the
mammalian systems.
1
There are three specific types of blood vessels that are used in moving blood through
our circulatory system, based on size, which ones carry blood to the heart and which
ones carry blood away form the heart?
What do capillaries do?
VESSELS THAT MAKE UP THE CIRCULATORY SYSTEM
Arteries: carry oxygenated blood away from the heart.
Veins: carry deoxygenated blood to the heart.
Capillary Beds: diffusion of oxygen into cells and carbon dioxide out of cells; plus food and
wastes.
Structure of the Heart and Names of Blood Vessels:
1. Atria: thin-walled chamber of the heart
a) left atrium: receives oxygenated blood from the lungs via the pulmonary veins
b) right atrium: receives de-oxygenated blood from the body via the vena cava
2. Atrioventricular (A.V.) valves:
- located between each atrium and ventricle,
- prevent backflow of blood from ventricle to atrium
a) bicuspid valve: between left atrium and ventricle
b) tricuspid valve: between right atrium and ventricle
3. Ventricles: muscular chamber responsible for pumping blood
a) left ventricle: pumps oxygenated blood to body via aorta
b) right ventricle: pumps de-oxygenated blood to lungs via pulmonary ateries
Structure of the Heart and Names of Blood Vessels Continued...
4. Septum: wall of muscle separating the 2 ventricles
5. Pulmonary Arteries (left and right): carry de-oxygenated blood from heart (r.v.) to lungs
***only arteries that carry de-oxygenated blood***
6. Pulmonary Veins (left and right): carry oxygenated blood from lungs to heart (l.a.) ***only
veins that carry oxygenated blood***
7. Aorta: the largest artery in the body, carries oxygenated blood from the heart (l.v.) to body
8. Vena Cava: carries de-oxygenated blood back to heart (r.a.)
a) superior vena cava, comes from head
b) inferior vena cava, comes from the rest of the body
9. Semilunar Valves: found where blood vessels attach to the heart in each ventricle, preven
back flow of blood into ventricles from veins
Blood From the Body Flows:
1. to the Superior and Inferior Vena Cava,
2. then to the Right Atrium
3. through the Tricuspid Valve
4. to the Right Ventricle
5. to the Pulmonary Artery
6. to the Lungs
The Blood Picks up Oxygen in the Lungs, and then Flows
from the Lungs:
1. to the Pulmonary Veins
2. to the Left Atrium
3. through the bicuspid valve
4. to the Left Ventricle
5. through the Aortic Valve
6. to the Aorta
7. to the body
HEART
(to body arteries)
(to lungs)
(from lungs)
(body vein from body)
Review...
1. What is the main difference between the right and left
atrium?
2. What structures are used to allow oxygen to diffuse into our
body cells and carbon dioxide to diffuse out of our body cells?
2.
Explain the functioning of the human circulation system.
.1
Describe the functions of the heart, lungs, kidneys, and liver
in the circulation system.
2
2
.2
2.3
2.4
2.5
Describe the ABO and Rh typing systems for human blood.
Consider the role of the blood in the immune system and the effect of the human.
Research the use of artificial hearts, heart transplants, and circulation machines used during open-heart surgery.
Discuss respiration by relating the activity to the physical structure like the lungs and blood and the cells fed by the blood.
BLOOD COMPONENTS
Blood is composed of cells and other substances suspended in plasma.
Plasma: a clear, straw-colored liquid that is 90% water and 10% dissolved substances
that include vitamins, enzymes, hormones, food, and respiratory gases.
3 types of cells: red, white, and platelets (all made
in the bone marrow)
Red Blood Cells:
specialized for the transport of O2
have no nucleus or other organelles and are filled with hemoglobin
hemoglobin: contains iron and has a red pigment; picks up oxygen in the lungs to deliver to
body cells to help with respiration
only survive 110-120 days because they experience alot of wear and tear
after this time, they are removed from circulation and destroyed in the liver and spleen.
the liver salvages iron ions from these cells and then cells in the bone marrow use this iron to
make new red cells
White Blood Cells:
have a nucleus
they have no hemoglobin and are therfore colorless
they are larger than red blood cells, there are less of them in the blood
only survive about 10 days
they can differ in size and function, but their main function is to destroy pathogens (e.g.
bacteria) that invade your body.
some aid in the repair of wounds
Platelets:
they are only fragments of cells
they are colorless and disk-shaped, and do not have nuclei
have a lifespan of about four days
their function is to aid in blood clotting
BLOOD CLOTTING PROCESS
Platelets in bone marrow are released to blood
cells. They stick to broken vessels, then stick to
each other. The cells get trapped in the fibrin
threads, thus building up a clot.
Review...
1. What is the most important component of blood?
Why?
2. What would happen if a person lacked platelets in their
blood? Does anyone know what word is used to describe this
condition?
2.
2.1
2.2
Explain the functioning of the human circulation system.
Describe the functions of the heart, lungs, kidneys, and liver in the circulation system.
Describe the ABO and Rh typing systems for human blood.
.3
Consider the role of the blood in the immune system and th
effect of the human.
2
2
.4
2.5
Research the use of artificial hearts, heart transplants, and circulation machines used during open-heart surgery.
Discuss respiration by relating the activity to the physical structure like the lungs and blood and the cells fed by the blood.
First, what is immunity??
Any ideas what a definition of immunity would be?
How might our blood help our body with immunity?
Immunity: the capacity of the human body to resist most
pathogens that might damage tissues or organs
The Body has Two Types of Immunity...
1. Nonspecific Protection and Inflammatory Process:
this type involves intact skin and mucous membranes
the layers of skin covering the body and the layers of mucous membranes lining the
digestive and respiratory tracts provide a protective barrier against invasion
if the barrier is broken, substances in the circulating blood initiate an inflammatory
response
this means that injured cells release a chemical called histamine
this chemical causes nearby capillaries to swell and become "leaky"
then, various types of white blood cells pass through the capillary walls and gather at the
site of the injury
Two New Words...
antigens: any foreign substance (e.g. bacteria, virus, fungus) that
can stimulate the production of antibodies and that can combine
specifically with them
antibodies: a protein molecule produce by the immune system
that is capable of binding with antigens in order to "disable" them
and provide immunity
2. Specific Immune Response:
carried out by small, white blood cells called lymphocytes
they are specialized so that they recognize foreign substances (antigens)
Three types of lymphocytes:
a) B cells
- found in the bone marrow
- their function is to produce antibodies to act against
antigens in our body
- memory B cells and antibodies also exist to recognize antigens that
have previously
infected the body
b) T cells
- found in the thymus gland
- four types of T cells
i) killer T cells: attack infected cells
ii) helper T cells: help B cells make antibodies
iii) memory T cells: help remember antigens that have previously
infect the body
iv) suppressor T cells: used to release a chemical when an infection
is over so that B and T cells stop being produced
c) Macrophage
- it engulfs pathogens, via phagocytosis, and disassembles them
How do all 3 of these cells work together in an "attack?"
1. Identification of the Antigen = helper T cells (building the army):
- have special receptors that can detect when a B cell has started
producing
antibodies
- this leads to a chemical being released that causes production of
more
macrophages, killer and suppressor T cells being produced
2. Attack from the B cells and macrophage:
- antibodies of B cells attach to antigens (using the lock and key
method)
- after attachment, the antibodies begin to multiply, and make
clusters of antibodies and antigens
- macrophage can then engulf and destroy cluster of antigens
3. Attack from killer T cells:
- infected body cells displays an antigen that the killer T cell
recognizes
- bores holes into the infected cell membrane (cell bursts)
4. Suppressor T cells
- after an attack is over, suppressor T cells release chemical to shut off B and T cell
production
5. Memory B and T cells
- memory B and T cells are formed during the battle that contain a
specific antibody that
is then stored in the spleen, if body is exposed a second time to the same antigen,
memory B cells release many
antibodies so that the pathogen is killed before symptoms
occur
Flow chart of a Specific Immune Response...
1. Detection and production
2. Attack from B cells
3. Attack from T cells
4. Suppressor T cells
5. Memory B and T cells
Review...
1. What are the three types of lymphocytes and what are their
main function?
2. What is the main connection between blood and our immune
system?
2.
2.1
Explain the functioning of the human circulation system.
Describe the functions of the heart, lungs, kidneys, and liver in the circulation system.
.2
2
Describe the ABO and Rh typing systems for human blood.
2.4
2.5
Research the use of artificial hearts, heart transplants, and circulation machines used during open-heart surgery.
Discuss respiration by relating the activity to the physical structure like the lungs and blood and the cells fed by the blood.
2
.3
Consider the role of the blood in the immune system and the effect of the human.
http://www.youtube.com/watch?v=U2h0ECyMWhE
Problems with the Immune Response:
1. Human Immunodeficiency Virus (HIV):
- HIV primarily infects the T cells of the immune system.
- the virus attaches itself to a host, T cell
- inside the host cell, the viral RNA is copied and becomes a part of a cell's DNA
- each infected cell then becomes a factory for the production of HIV
- when the host cell ruptures, hundreds of viruses are released
- reproduction of HIV in T cells leads to a gradual decline in the
number of T cells, weakened function of the immune system, and
increased susceptibility to infections and cancers.
2. Organ transplant rejections:
- rejection occurs by T cells
- these cells identify the planted organs as foreign and invade the tissue
- to prevent this from happening, drugs are used to suppress the immune system, but
this leaves the patient vulnerable to other infections
ABO Blood Typing and its Effect on the Immune System
some of the blood group systems can cause problem under certain
circumstances
the blood types that arise from the ABO blood group are not always compatible
this incompatibility comes about because antibodies in the plasma of one blood type (type
A) react with antigens on the red blood cells of another blood type (type B)
this reactions causes clumping
therefore, transfusing blood of one type into blood of another type can be fatal
ABO blood groups and Rh antigens
Rh antigens:
In some humans, there are what are called Rh antigens found on the surface of red blood
cells.
An Rh positive individual HAS these Rh antigens on their red blood cells, and an Rh
negative person DOES NOT.
Usually, antibodies to these Rh antigens are not present in the blood plasma. However,
antibodies will develop if Rh positive blood is transfused in an Rh negative individual or if
an Rh negative woman delivers an Rh positive baby.
When either of the conditions mentioned above occurs, antibodies to these Rh antigens
develop, and the result is that red blood cells are destroyed
In the case of the Rh negative woman, there is no danger in the first pregnancy, but in the
2nd pregnancy, some of the Rh antibodies could transfer into the fetal blood and cause the
red blood cells to be destroyed.
In-Class Assignment...
- Once you have finished answering the questions on your sheet, please
read pages 171? and find out what problems occur in a person's immune system in order to develop
allergies or autoimmune disorders.
- Please write a 3-4 sentence paragraph explaining each problem
Review...
1. What are two potential problems people could have with
their immune systems?
2.
2.1
2.2
2.3
2.4
Explain the functioning of the human circulation system.
Describe the functions of the heart, lungs, kidneys, and liver in the circulation system.
Describe the ABO and Rh typing systems for human blood.
Consider the role of the blood in the immune system and the effect of the human.
Research the use of artificial hearts, heart transplants, and circulation machines used during open-heart surgery.
.5
Discuss respiration by relating the activity to the physical
structure like the lungs and blood and the cells fed by the blood.
2
Respiratory System
Definition: responsible for exchange of O2 and CO2 in the human body
Respiration is divided into 2 steps:
1. Breathing:
- external respiration
- the exchange of gases between the atmosphere and the body (?)
2. Respiration:
- internal respiration
- the exchange of gases between the blood and the body's cells
themselves
The PHARYNX (throat) collects incoming air from the nose and mouth and passes it
downward to the trachea (windpipe).
Parts of the Respiratory System:
a) Nose and Nasal Passages:
The NOSE is the preferred entrance for outside air into the respiratory system. The hairs that line the
wall are part of the air-cleaning system,
they helps to screen out dirt and foreign particles. Nose also moistens and warms the air.
Air also enters through the MOUTH.
Parts of the Respiratory System
b) The TRACHEA (windpipe) is the nasal passage leading to the lungs via the pharynx and larynx.
Lined with cilia and mucus to remove dirt and foreign particles.
The EPIGLOTTIS is a flap of tissue that guards the entrance to the trachea, closing when
anything is swallowed that should go into the esophagus and stomach.
c) Bronchi, Bronchioles, Alveoli
The trachea divides into two branches called BRONCHI, which extend into each lung.
Each bronchus subdivides into many smaller tubes called BRONCHIOLES which end in cluster
of air sacks
called ALVEOLI.
Alveoli exchange gases between the air and the blood.
Each alveolus is surrounded by capillaries and is only 1 cell thick to promote diffusion. While in
the capillaries, the blood gives off carbon dioxide through the capillary wall into the alveoli and
takes up oxygen from the air in the alveoli.
Alveoli make of most of the sponge-like lung tissue.
d) Lungs
Composed of the bronchi, bronchioles, and alveoli.
Together with the heart, the lung occupies the thoracic cavity.
The lung and heart are covered by a membrane which secretes a mucous coating to
lubricate the lungs.
e) Diaphragm
The DIAPHRAGM is the strong wall of muscle that separates the chest cavity from the abdominal
cavity. By moving downward, it creates suction in the chest to draw in air and expand the lungs.
3.
3.1
3.2
Describe the functions and functioning of nervous systems.
Describe the structure of a neuron.
Explain how neurons transmit impulses within and between themselves.
.3
Compare the complexity of nervous systems in the
planaria, earthworm, and human.
3.4 Contrast the functions of the central nervous system and
the peripheral nervous system in humans.
3.5
Compare the structure of the brains of reptiles and humans.
3
Types of Nervous Systems...
All animals have a nervous system.
Its degree of complexity depends
upon the complexity of the animal.
Flatworms:
- have a fairly complex system for a worm
- there nervous system is made up of
2 nerve cords (called transverse and
longitudinal nerves) that extend
along the length of its body.
- at the anterior end, there is a mass of nerve tissue called a ganglion (similar
to a brain, a center where nerve impulses are exchanged)
Types of Nervous Systems...
Earthworms:
- have well developed nervous systems
- a main nerve cord extends along the ventral (bottom) side of the body
- many ganglia occur along the nerve cord
- a large ganglion (brain) is found at the anterior end of the body
Types of Nervous Systems...
Humans:
- chordates (that's us!) have a dorsally (top) located nerve cord
- this cord is surround by bone (vertebrae) and the anterior end of the nerve cord is
enlarged (brain) and is the dominant controller of the whole nervous system
Organization of the Nervous System
In vertebrates, the nervous system is quite complex. Therefore, it is divided into 2 parts that
differ in their functions.
1. Central Nervous System (CNS)
Brain and spinal cord
Acts as a coordinating center for all incoming and outgoing information
Connected to the rest of the body by nerves that make up the peripheral
nervous system
Speaking and walking are controlled by the CNS
Peripheral Nervous System
Composed of sensory neurons and motor neurons
I. Sensory Neurons
Carry nerve impulses from sense organs and
receptors to CNS
II. Motor Neurons
Carry nerve impulses from CNS to muscles and glands
Further subdivided into:
- Somatic nervous system:
contains sensory and motor nerves of skin, skeletal, muscle,
and bone = voluntary
- Autonomic nervous system:
motor nerves which control internal organs = involuntary (e.g. controls the
heart, smooth muscles)
divided into the sympathetic (prepares the body for emergencies) and
parasympathetic
(counteracts the sympathetic nervous system; slows the
heartbeat down) nervous systems
3.
Describe the functions and functioning of nervous systems.
.1
Describe the structure of a neuron.
3.2 Explain how neurons transmit impulses within and
between themselves.
3.3
Compare the complexity of nervous systems in the planaria, earthworm, and human.
3
3.4
3.5
Contrast the functions of the central nervous system and the peripheral nervous system in humans.
Compare the structure of the brains of reptiles and humans.
Nervous System
3 Elements of the Nervous System:
1. Receptors: any organ that picks up stimulus (i.e. eyes, noes,
skin, ears)
2. Effectors: any organ that reacts to a stimulus (i.e. muscle,
gland)
3. Conductors: transmit information about stimuli between the
receptor and an effector (i.e. neurons, including the brain and
spinal cord)
What are Neurons?
- are the building blocks of all nervous systems, most nerves are composed of many neurons
- transmit impulses. These nerve impulses are actually
small electrical currents passing from neuron to neuron,
sending messages to and from the brain and body
Made up of several parts:
1. Dendrite: connects nerve to nerve, carries nerve
impulses towards the cell body, made up of cytoplasm
2. Cell Body: area of the nerve containing the nucleus
3. Myelin Sheath: is the fatty covering over the axon
of a nerve cell, to speed the rate of impulse.
Acts as insulators for the neurons.
4. Axon: area of the cytoplasm that carries nerve impulses away from the cell body to other
nerves or effectors
5. Synapse: the region over which an impulse passe
How the Nervous System Works:
Neurons do not touch one another, there is a space (SYNAPSE)
between neurons
Synapses contain a chemical (neurotransmitter: acetylcholine) that passes the impulse from neuron
to neuron
synapses are capable of transmitting impulses in one direction only
the process then of transmitting impulses is like a chain reaction, made possible by sodium and
potassium ions
How the Nervous System Works
Process of transmitting impulses:
In a resting nerve cell, there is normally more potassium ions inside of the cell and more sodium
ions outside of the cell (due to the protein pump); however, when an impulse is received by the
dendrite of a nerve cell:
1. part of the cell membrane becomes more permeable to sodium ions.
2. As a result, sodium ions rush into the neuron, causing the electrical charge of the neuron to
suddenly change and, forcing potassium ions to diffuse out of the nerve cell.
3. This movement of sodium into the cell and potassium out of the cell, causes a chain reaction,
which moves the impulse along the entire length of the neuron.
5. Once the impulse reaches the end of the neuron, the neurotransmitter then carries the
impulse to the next neuron.
6. This continues until the message reaches the desired effector.
Movement of an impulse down a nerve cell...
3 Types of Neurons
1. Sensory Neurons: receive information from the internal and
external environment;
transmit impulses towards the brain or spinal cord
2. Interneurons: transmit impulses from one neuron to another
3. Motor Neurons: transmit impulses from brain or spinal cord to an effector--a muscle of
a gland
These 3 neurons, combined with the receptor, which detects impulses, and the effector,
which acts upon the impulse makes up the REFLEX ARC.
Reflex Arc
1. Sensory neurons (receptor) in the ear
hear the ringing of the phone.
2. Sensory neurons transmit this message
to interneurons (how??) and then to motor
neurons.
3. Motor neurons cause muscles in your
hand to contract and
pick up the phone.
4. Some neurons may
synapse to your brain
(making it aware that the ring of the phone
is loud) and may result in a secondary
response of plugging your ears because
that is a loud ring!
Review...
3.
3.1
3.2
3.3
Describe the functions and functioning of nervous systems.
Describe the structure of a neuron.
Explain how neurons transmit impulses within and between themselves.
Compare the complexity of nervous systems in the planaria, earthworm, and human.
.4
Contrast the functions of the central nervous system and
the peripheral nervous system in humans.
3.5 Compare the structure of the brains of reptiles and
humans.
3
The Brain, a Part of the Central Nervous System
- is the control center of an animal's body; is found at the anterior end of the body, at the
end of the nerve cord
- is made up of a large cluster of neurons, which, together, make up an organ capable of
thinking, reacting, and running a body
- endorphins (natural painkillers produced by the brain) block the pain receptor sites in
the brain, reducing the intensity of the pain
- the brain is divided into 2 hemispheres (halves)
a) right hemisphere, controls the left side of the body
b) left hemisphere, controls the right side of the body
The Brain has Four Lobes...
1. Frontal lobe: controls voluntary muscle movement
and intellectual activities
2. Temporal lobe: vision, hearing, memory, and
interpretation
Parietal
Frontal
3. Parietal lobe: touch temperature, emotions, and
speech interpretation
4. Occipital lobe: vision and the interpretation of
visual information
Temporal
Occipital
All brains have a common set of parts:
1. Olfactory bulbs:
interprets and registers smell
2. Cerebrum:
thinking and interpreting part of the brain
3. Cerebellum:
essential for coordination of movement
4. Optic Lobe:
interprets and registers sight
5. Pituitary:
controls hormone functions
6. Medulla Oblongata:
hind brain; transmits impulses
7. Thalamus
interprets sensory information
8. Corpus Callosum
allows communication between the two
hemispheres of the brain
9. Pons
Relays information between the peripheral
and central nervous systems
10. Hypothalamus:
link to the endocrine system; controls the
pituitary gland
Parts of the Brain, Excluding the Olfactory Bulb and the
Optic Lobe
Comparison of Vertebrate Brains...
- If you were to examine other vertebrate brains (besides the human
one we have just
learned about) you would identify many of the same structures just discussed; however,
some of these structures would be reduced or enlarged in size depending on the specific
function the vertebrate needs their brain to carry out.
- For example, in fish, amphibians, reptiles, and birds, the optic lobes (vision center) are
large because these animal require keen eyesight. Although vision is important in
mammals, the optic lobes are not as large.
- There are other adaptations, too. We are going to read and answer questions about
these adaptations in order to compare several different vertebrate brains.
4.
Explain how the human endocrine system influences body development and maintenance.
.1
4
Describe the general structure of hormones.
4.3
4.4
Discuss the relationship between insulin and the body’s control of blood sugar levels in the two forms of diabetes.
Outline the functions of hormones produced by several other glands.
4
.2
Describe the influence of the pituitary gland on body processes and on other glands.
Endocrine System
The endocrine system is a series of glands that secrete hormones which:
- regulate all the body's functions. It controls the rate of growth, feelings
temperature, how much fluid we have in our bodies and much more.
- regulate physical and mental development
- control chemical reactions
- affect maturity and reproduction
of hunger, body
Definition of a Hormone: is an informational molecule that is synthesized by cells called
endocrine cells.
Two Types of Hormones...
Steroid Hormones:
include both male and female sex hormones
made of complex rings of C, H and O molecules
are fat soluble molecules
these molecules move directly into the fluid between cells, then into cells
once inside of a cell, they combine with receptor molecules in the cytoplasm and then move in to the
nucleus
in the nucleus, the molecules match with a like strand of a chromatid and a message is sent to the RNA to
begin the production of specific protein (control protein synthesis)
Protein Based Hormones:
include insulin, growth hormone, epinephrine
are made of long chains of amino acids and are soluble in water
Hypothalamus and the Pituitary Gland--Important Endocrine Glands...
One of the most important endocrine glands is the pituitary, which secretes hormones that control the rate
at which several other endocrine glands (including the thyroid and adrenal glands) function.
The pituitary gland consists of 2 parts (the anterior and the posterior pituitary glands) which lie at the base of
the brain
The posterior pituitary is connected by means of a stalk to the hypothalamus. The hypothalamus controls the
pituitary through a negative-feedback system:
- change is detected by receptors
- receptors trigger release of a certain hormone to target specific cells of pituitary
gland to release certain
hormones
- when balance is reached, receptors trigger release of a different hormone to inhibit
the original hormone
released
Posterior Pituitary: releases 2 main hormones
a) antidiuretic hormone (ADH): it promotes the reabsorption of water in the kidneys. When it is
detected that the blood lack water, ADH is produced. When the water level returns to normal,
ADH production ceases.
b) oxytocin: causes the uterus to contract and can be used to artificially induce labor. It can also
be used to stimulate the release of milk from the breast when a baby is nursing.
Anterior Pituitary: it produces at least 6 different hormones, we'll discuss two of
them:
a) Growth hormone (GH): it determines the size of an individual. If a problem occurs, it results
in dwarfs or giants.
b) Lactogenic hormone (LTH): is produced in large amounts after childbirth. It causes the
mammary glands to develop and produce milk.
How does the Hypothalamus regulate growth in the body?
1. Receptors in the liver send a message to hypothalamus regarding the need for
growth
2. In response, the hypothalamus puts out growth hormones releasing factor
which affects the pituitary gland.
2. The pituitary releases the growth hormone into the blood
stream.
3. The growth hormone target is in the liver, this is where the hormone travels to.
4. Once inside of the liver cells, the liver secretes hormones called somatomedins
which go to receptors on bones, muscles and connective tissue and cause an
increase of growth.
Review...
4.
4.1
Explain how the human endocrine system influences body development and maintenance.
Describe the general structure of hormones.
.2
Describe the influence of the pituitary gland on body
processes and on other glands.
4
.4
Outline the functions of hormones produced by several
other glands.
4
.3
4
Discuss the relationship between insulin and the body’s control of blood sugar levels in the two forms of diabetes.
Hormones Produced by Other Endocrine Glands...
Pineal Gland:
Location: in the brain (posterior to the pituitary and hypothalamus)
Hormone Produced: melatonin
Function: regulates circadian rhythms (day/night cycles)
Thyroid:
Location: base of the neck
Hormone Produced: thyroxine
Function: regulates the rate of cellular respiration in the body
Parathyroid:
Location: back of the thyroid gland
Hormone Produced: parathyroid hormone (PTH)
Function: controls the metabolism of calcium in the body necessary for healthy bones, teeth, and
tissues
Thymus:
Location: upper chest
Hormone Produced: thymosin
Function: controls the growth of certain white blood cells that help the body fight infection
Adrenal Glands:
Location: top of each kidney
Hormone Produced: epinephrine (adrenaline) and nor-epinephrine (nor- adrenaline)
Function: creates increased energy and aggressiveness in individuals
Pancreas:
Location: abdomen
Hormone Produced: insulin and glucagon
Function: controls blood glucose levels
Gonads:
Location: lower abdominal cavity or groin
Hormones Produced: males - testosterone
females - estrogen and progesterone
Function: testosterone: causes genitals to mature, sperm production,
deepening of the voice
estrogen: causes genitals to mature, breast and hip
beginning of menstrual cycle
progesterone: regulates pregnancy and child bearing
hair growth, and
development,
Review...
4.
4.1
4.2
Explain how the human endocrine system influences body development and maintenance.
Describe the general structure of hormones.
Describe the influence of the pituitary gland on body processes and on other glands.
.3
Discuss the relationship between insulin and the body’s
control of blood sugar levels in the two forms of diabetes.
4
4
.4
Outline the functions of hormones produced by several other glands.
Control of Blood Glucose (Sugar) Levels
**Remember: the pancreas produces two hormones: insulin and glucagon**
These two hormones are the primary regulators of blood glucose levels.
Scenario one: Low levels of blood glucose:
Low levels of blood glucose provide feedback to the pancreas, which causes its cells to
produce more glucagon. Glucagon then increases the conversion of glycogen to glucose in
the muscles and liver, thus increasing blood glucose levels.
Scenario two: High levels of blood glucose:
High levels of blood glucose provide feedback to the pancreas, which causes its cells to
produce more insulin. Insulin then causes the uptake of glucose, by muscle and liver cells,
thus decreasing blood glucose levels.
Insulin and Glucagon
have opposite effects on controlling the levels of glucose in the
blood
After a meal, glucose levels rise. As a result, insulin secretions increase and glucagon
secretions decrease.
On the other hand, during fasting, insulin secretions decrease and glucagon secretions
increase.
Maintaining an appropriate glucose level is crucial. If not, there are several problems that
can occur...one of these is diabetes.
Type 1 Diabetes
A genetic disorder associated with inadequate production of insulin. These individuals
are insulin-dependent.
Symptoms:
- blood sugar levels rise sharply following meals (known as
hyperglycemia)
- kidney is unable to reabsorb all the glucose that filters through it,
therefore large amounts of glucose appear in the urine
- excretion of glucose draws water out of body through osmosis,
therefore large amounts of urine are produced and individual is very
thirsty
- low energy levels (since there is no uptake of glucose, cells soon
become starved for glucose and must turn to other sources for
energy, such as fats and carbohydrates, which are not as energyrich as glucose)
Type II Diabetes
This form of diabetes occurs because the body becomes resistant to insulin. In these
cases, insulin is still produced, but the body does not respond to the effects of insulin as it
should. This is called insulin resistance.
90% of people who have diabetes have type II and this is partially due to the rise in obesity,
which is one factor that can contribute to the body becoming insulin-resistant.
Individuals with type II diabetes will experience the same symptoms as those with type I
diabetes, but many of their symptoms can be managed through proper diet and exercise,
and, in some cases, insulin shots may not be required at all.