Transcript Unit 10 - OpenWetWare

Structure/Function of Circulatory
System
Structure
•Heart
•Blood Vessels
•Blood
Function
•Transport nutrients and oxygen
•Remove waste and carbon dioxide
Heart Structure
Structure
1. Chambers
a. Right and left atria
b. Right and left ventricles
2. Arteries
a. Pulmonary artery
b. Aorta
3. Veins
a. Pulmonary vein
b. Vena cava
(superior/inferior
4.
Four valves
5.
Heart Muscle called
myocardium
Blood Flow through Heart
Blood Flow
1. Superior/inferior vena cava
returns deoxygenated blood
from body to right atrium.
2. Blood moves from right atrium
right ventricle
pulmonary artery
lungs (oxygenated)
pulmonary vein
left atrium 
left ventricle 
aorta
3. Aorta brings oxygenated blood to
body
Circulation Types
• Heart is two separate
pumps.
• Right side of heart
pumps blood to lungs –
pulmonary circulation.
• Left side of heart
pumps blood to bodysystemic circulation.
Heartbeat
• Electrical Stimulation –Cardiac Action
Potential
1. Heart muscles contract due to neural
impulse (action potential).
2. SA (sinoatrial) Node=Pacemaker
3. Electrical impulse generated by SA
Node; moves through atria; atria
contract.
4. Electrical impulse moves to AV
(atrioventricular) Node; impulse
spreads through ventricles.
5. Ventricles contract.
6. Pacemaker is the origin of the electrical
impulse; brain does not control
whether or not heart beats; brains
controls how fast/slow heart beats.
Checkpoint
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1. Chamber pumping blood to aorta?
2. Vessel bringing blood to lungs?
3. Vessel bringing blood from body to heart?
4. Chamber pumping blood to pulmonary artery?
5. Type of circulation pumping blood to lungs.
6. Type of circulation pumping blood to body.
7. Name of the pacemaker.
8. Role of the pacemaker
9. Spreads cardiac neural impulse to ventricles.
10. Type of vessel which brings blood away from heart.
Blood Vessels
Three types
• Arteries – carry blood away from heart
• Veins – carry blood to heart
• Capillaries – connect arteries & veins.
Artery
Artery
1. Made of muscle and thick
elastic wall.
2. Systole(ventricle contracts);
artery stretches from the
pressure of blood.
3. Diastole (ventricle relaxes);
artery snaps back.
Capillary
• Capillary
1. One cell thick.
2. Allows for transfer of gases,
nutrients, wastes between
capillary and cell by
diffusion.
3. Every cell bordered by at
least one capillary
Vein
• Vein
1. Thin walls of muscle and
elastic tissue.
2. Valves to prevent
backflow of blood.
3. Skeletal muscle
movement aids in return
of blood from veins to
heart.
Blood Pressure
• Blood Pressure
1. Blood pressure= pressure of blood against artery walls.
2. Pressure due to heart contraction and resistance of artery wall to blood flow.
3. Normal BP 120/80
4. Upper number = systole=pressure when ventricles contract.
5. Lower number = diastole= pressure when ventricles relax.
6. Blood highest in arteries and lowest in veins.
Objectives
• Compare and contrast the structure and function
of arteries, capillaries, and veins.
• Describe the causes and consequences of high
blood pressure and atherosclerosis.
• List some ways to prevent cardiovascular
diseases.
• Describe the blood plasma fluids and proteins
(give examples).
• Compare and contrast the role of red and white
blood cells in the body.
Blood
Blood is made of
1. Plasma – liquid portion
2. Cells
a. Red blood cells
b. White blood cells
c. Platelets
Plasma
Plasma
a. Straw colored liquid
portion of blood in which
cells are suspended.
b. Primarily water
c. Contains proteins, amino
acids, glucose, fats, carbon
dioxide, ions (electrolytes),
hormones, vitamins,
nitrogenous waste.
Red Blood Cells
1. Red Blood Cells
(Erythrocytes)
a. Non-nucleated biconcave
discs.
b. 4-6 million in body; lifespan
120 days
c. Made in bone marrow.
d. Function: Carry oxygen via
hemoglobin molecule;
concave in center for easy
diffusion of gases.
White Blood Cells
6. White Blood Cells
(Leukocytes)
a. 5 types; lifespan few hours to
few days.
b. Make about 100 billion/day;
lower numbers than RBC;
made in bone marrow.
c. Function in body defense;
some ingest bacteria and other
pathogens, some produce
antibody.
Platelets
7. Platelets
(Thrombocytes)
a. Small nonucleated
cell fragments;
lifespan 8-12 days;
made in bone marrow
b. Function in blood
clotting.
Blood Clotting
• Blood Clotting (Hemostasis)
1. In broken blood vessel,
vessel contracts to inhibit
blood loss.
2. Platelets are sticky. Stick to
each other and to blood
vessel to form platelet
plug; controls blood loss
3. Coagulation is forming a
clot; i.e. formation of fibrin
threads which entangle
RBC and platelets creating
blood clot.
Respiratory System
• Cellular Respiration – Breakdown of glucose
to create ATP in presence of oxygen.
• Respiration – Gas exchange; intake of oxygen
and release of carbon dioxide.
Respiratory System
Function
Exchange oxygen &
carbon dioxide
between the
blood, air, &
tissues
Respiratory System- Structure
• Use the picture
in your text on
page 957.
• Label the parts of
the respiratory
system.
• Describe the
function of each.
Gas Exchange
• 150 Million alveoli/lung
• Oxygen diffused from
inside alveolus to red
blood cell.
• Oxygen binds to
hemoglobin in RBC and
is carried to cells in
body.
• Carbon dioxide diffuses
from the blood into the
alveolus and is released
from the lungs.
Breathing
• Inhalation• Air enters lungs;air
pressure inflates lungs.
• Muscles attached to rib
cage pull ribs to
expand.(contract)
• Diaphragm moves down
(contracts).
• Exhalation –
• Air is released from lungs;
lungs deflate.
• Muscles attached to ribs
relax.
• Diaphragm relaxes (moves
up.)
Checkpoint
• Explain how the structure of the alveoli is
related to its function
• Explain how the respiratory system and the
circulatory system work together to respond
to your body’s needs during vigorous exercise.
objectives
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Nervous System (35-2, 35-3)
Explain the function of the nervous system.
Describe, draw and label, the structure of a neuron.
Relate the functions of the three different types of neurons.
Describe the role of the myelin sheath.
Explain how a nerve impulse is transmitted using the following
terms: resting potential, action potential, threshold, synapse, and
neurotransmitter.
• Discuss the overall function of the central nervous system.
• Discuss the functions of the two divisions of the central nervous
system.
• Compare the central nervous system to the central processing unit
of a computer.
Nervous System
• Structure:
1. Central Nervous System
a. Brain
b. Spinal Cord
2. Peripheral Nervous System
a. Somatic Nervous System
b. Autonomic Nervous System
• Function
1. Control/coordinate function
throughout the body.
2. Respond to external/internal
stimuli.
Neuron
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Neural signals are transmitted by nerve cells called neurons.
Three types of neurons
1. Sensory – Impulse from sense organ to brain.
2. Motor – Impulse from the brain and spinal cord to muscles & glands.
3. Interneuron – connect sensory and motor neurons.
How are the functions of the three neuron types related?
Neuron
Draw and label
the neuron and
describe the
function of each
of the labeled
structures.
Nerve Impulse
• Nerve impulse similar to electrical current through a metal wire.
• Resting Neuron
• At rest, outside of neuron has net + charge; inside neuron has net –
charge.
• Difference of electrical charge across the membrane called resting
potential.
Resting Potential
• Resting potential maintained by
sodium/potassium pump (active transport).
• Na+/K+ pump is a channel in cell membrane.
• Uses ATP to pump 3 Na+ to outside of
membrane and 2 K+ to inside of membrane.
Action Potential
• Impulse begins when neuron is
stimulated by another neuron.
• Causes reversal of membrane potential.
• Gated channels allow Na+ to flood into
neuron; inside of cell has + charge.
• Reversal of charge called action
potential.
• Gated channels then allow K+ to flow to
outside of cell; re-establishes + charge
outside and – charge inside.
• Action potential is self propagating;
impulse at any point on membrane
causes impulse at next point on
membrane.
Threshold
• Minimum level of nerve impulse (stimulus)
required to activate a neuron = threshold.
• Stimulus stronger than threshold produces
action potential.
• Stimulus weaker than threshold doesn’t
produce action potential.
• All or none principle.
Model Resting Action Potential
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Materials – Red and white beans, tooth picks.
Create the nerve membrane with tooth picks.
Na+ = red beans, K+ = white beans
Create the resting potential by placing Na+/K+
on correct side of membrane.
• Demonstrate by moving the beans across the
membrane how an action potential moves
down the axon.
Synapse
• End of neuron impulse reaches axon
terminal.
• Neuron passes impulse to second
neuron.
• Synapse – location of impulse
transfer.
• Neurotransmitters (chemicals) used
to transfer impulse.
• Impulse arrives at synapse;
neurotransmitters released across
synaptic cleft.
• Neurotransmitters attach to receptor
sites on second neuron; stimulates
action potential in second neuron.
Divisions of Nervous System
• Two major divisions:
1. Central Nervous
System- Relays messages,
processes & analyzes
information.
2. Peripheral Nervous
System – Receives
information from
environment & relays
commands from CNS to
organs & glands.
Central Nervous System
• Central Nervous
System –
1. Brain
2. Spinal Cord
Central Nervous System
• Skull protects brain.
• Vertebrae protect spinal
cord.
• Brain and spinal cord
wrapped in 3 layers of
connective tissue =
meninges.
• Cerebrospinal fluid bathes
brain and spinal cord; acts as
shock absorber & exchange
medium of nutrient/waste
between blood and nervous
tissue.
Central Nervous System - Brain
• Brain- place from which
impulses originate and flow;
contains 100 billion neurons.
• 3 major parts
1. Cerebrum –
voluntary/conscious
activities.
2. Cerebellum – Commands
muscle movement &
coordinates and balances
muscle actions.
3. Brain stem – Involuntary
actions; heart rate,
breathing, swallowing, blood
pressure
Cerebrum
• Cerebrum divided into left & right
hemispheres.
• Hemispheres connected by tissue
called corpus callosum.
• Each hemisphere deals with
sensations on opposite side of body.
• Some studies suggest right
hemisphere involved in creativity; left
hemisphere involved with analytical
functions
• Outside of cerebrum = cerebral cortex =
grey matter.
• Grey matter made of nerve cell bodies;
processes info from sense organs/controls
body movements.
• Inside of cerebrum = white matter
•White matter made of axon bundles &
myelin sheaths; connects grey matter to
brain stem.
Cerebrum
• Cerebrum contains 4 lobes
• Frontal lobe - higher level cognitive
functions - reasoning and judgment
(executive function) ; control of voluntary
muscle movement for the production of
speech and swallowing.
•Parietal lobe -sensation, sense of touch,
kinesthesia, perception of warmth & cold,
& vibration. Involved in writing & in some
aspects of reading.
•Temporal lobe - auditory processing &
olfaction. Involved in word meaning.
•Occipital lobe - primary visual area
Cerebellum
• Cerebellum involved in
coordination of
voluntary motor
movement, balance,
equilibrium &
muscle tone.
Brain Stem/Limbic System
Brain stem connects brain stem to
spinal cord.
• Responsible for basic life
functions: breathing, heart rate,
blood pressure.
• Three parts:
1. Midbrain
2. Pons
3. Medulla oblongata
Limbic System – Emotional brain
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Contains hypothalamus &
thalamus.
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Hypothalamus – hunger, thirst,
homeostasis, emotion,
circadian rhythms, controls
autonomic nervous system.
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Thalamus – receives all sensory
information/ relays to cerebral
cortex.
Spinal Cord
• Spinal cord – main
communication link between
brain and rest of body.
• 31 pairs of nerves branch from
spinal cord.
• 8 Cervical nerves –
head/neck/arms
• 12 Thoracic nerves –
chest/abdominal muscles
• 5 Lumbar nerves – legs
• 5 Sacral nerves –
bowel/bladder/sexual function
Peripheral Nervous System
• Nerves not part of brain
& spinal cord.
• Two major divisions:
1. Sensory – transmits
impulses from sensory
organs to CNS.
2. Motor – transmits
impulses from brain to
organs/glands.
Motor Nervous System
• 2 Divisions
1. Somatic – regulates primarily activities under
conscious control; wiggling toe, lifting fingers
etc. Also regulates involuntary reflexes.
2. Autonomic - regulates involuntary activities;
digesting food, heart rate, etc.
Somatic System – Reflex Arc
• To aid in survival, we have
evolved to react to some
stimuli automatically.
• Sensory information is not
sent to brain.
• Sensory receptor sends
impulse to spinal cord.
• Interneuron in spinal cord
activate motor neurons.
• Motor neurons activate an
effector (muscle).
Adult Reflex
• Some reflexes we know:
• Gag reflex
• Pupillary Light reflex
• Patellar (knee jerk) reflex
Newborn Reflexes
Sucking/ Rooting Reflex -Newborns turns head in
direction of stimulus, opens mouth, and begins
to suck when cheek, lip, or corner of mouth is
touched with finger or nipple.
Extrusion -Newborn pushes tongue outward
when tip of tongue is touched with finger or
nipple
Stepping -Newborn will step with one foot and
then the other in walking motion when one
foot is touched to flat surface.
Newborn Reflexes
Grasping - Newborn’s finger will curl around object and
hold on momentarily when finger is placed in palm of
newborn’s hand.
Startle - Newborn abducts and flexes all
extremities and may begin to cry when
exposed to sudden movement or loud noise.
Plantar Grasp -Newborn’s toes will curl
downward when a finger is placed against
the base of the toes.
Autonomic Nervous System
• Regulates activities that
are involuntary;
speed/slow heart rate;
increase/decrease blood
pressure; speed/slow
digestive muscles.
• Two parts of system
1. Sympathetic
2. Parasympathetic
• Sympathetic/
parasympathetic systems
have opposite effect on
an organ system.