Download File

Muscles
So exciting
Muscle Control
• Involuntary Muscle: not under conscious
control
• Ex: heartbeat, digestion
• Voluntary Muscle: Under your control
• Ex: walking, jumping, dancing…
Types of Muscles
Smooth
Locations:
Walls of hollow organs (Stomach, lungs etc.)
Blood vessels
Eyes
Skin
Glands
Not striated
Uses:
Food movement through digestive tract
Regulation of blood vessel diameter
Pupil dilation
Emptying of bladder
Cardiac
Location:
Heart
Striated
Involuntary
Uses:
Pumps blood
Major source that moves blood throughout
the body
Skeletal
Location:
Attached to bones
Striated
Uses:
Voluntary and involuntary movements
Types of Muscles
Take NOTES!!
• http://www.youtube.com/watch?v=bwOE1ME
ginA
Anatomy of a Muscle Cell
• Take notes!!!
• http://www.youtube.com/watch?v=uY2ZOsCn
XIA
Skeletal Muscle Contraction
Acetylcholine reaches the muscle cell

Na+ gates on muscle open

Muscle fires

Ca2+ enters the muscle cell cytoplasm

Ca2+ binds to troponin and tropomyosin

Troponin moves away from the actin

Myosin cross-bridges attach to actin

Cross-bridges pull the actin

Actin filaments slide past myosin

ATP attaches to myosin cross-bridges

Cross-bridges release

Cross-bridges reattach
Let’s see it in Action!
Take notes.
• http://www.youtube.com/watch?v=e3NqP1ww5E
• http://www.youtube.com/watch?v=hqynCsign
8E
The Heart <3
BLOOD AND THE HEART FUN FACTS
♦ An average adult human contains
about 5 liters (5.3qt) of blood.
♦ The blood makes up about onethirteenth
of the body’s weight.
♦ The adult heart weighs about 280 grams (10 oz.)
♦ At rest, the heart pumps out about 80 millimeters
(2.6 oz) of blood with each beat.
♦ The heart beats, on average, 70 times each
minute at rest.
♦ This means all the blood is circulated (goes
round the body once) in about one minute.
♦ During strenuous exercise the heart can pump
six to eight times the amount of blood that it
pumps at rest.
Superior vena cava and
inferior vena cava – bring
deoxygenated blood to
right atrium
Pulmonary artery – takes
blood away from right
ventricle to the lungs for
O2
Pulmonary veins – bring oxygenated blood
from lungs to left atrium
Aorta – takes blood away from left ventricle to
rest of the body
Chambers and Valves
• SEPTUM divides into R and L halves
• Upper chambers – RIGHT ATRIUM
and LEFT ATRIUM
• Lower chambers – RIGHT
VENTRICLE and LEFT VENTRICLE
• Four heart valves permit flow of
blood in one direction
TRICUSPID VALVE – between right atrium and
right ventricle
BICUSPID (MITRAL) VALVE – between left atrium
and left ventricle
Semilunar valves are located where blood leaves
the heart - PULMONARY SEMILUNAR VALVE
and AORTIC SEMILUNAR VALVE
The heart=a muscular double pump with 2 functions
Overview
• The right side receives
oxygen-poor blood from the
body and tissues and then
pumps it to the lungs to pick
up oxygen and dispel carbon
dioxide
• Its left side receives
oxygenated blood returning
from the lungs and pumps
this blood throughout the
body to supply oxygen and
nutrients to the body tissues
16
• Two circulations
– Systemic circuit: blood vessels that transport
blood to and from all the body tissues
– Pulmonary circuit: blood vessels that carry blood
to and from the lungs
17
Chambers of the heart
sides are labeled in reference to the patient facing you
• Two atria
– Right atrium
– Left atrium
--------------------------------------------------------------------------------
• Two ventricles
– Right ventricle
– Left ventricle
18
Valves
three: tricuspid
one: bicuspid
(cusp means flap)
• “Tricuspid” valve
– RA to RV
• Pulmonary valve
– RV to pulmonary trunk (branches R and L)
• Bicuspid valve (the bicuspid one)
– LA to LV
• Aortic valve
– LV to aorta
19
Function of AV valves
20
Function of semilunar valves
(Aortic and pulmonic valves)
21
Meet the Heart
• http://www.youtube.com/watch?v=Vi1JK6IYV
t8
Pattern of flow
(simple to more detailed)
•
•
•
•
•
•
•
Body
RA
RV
Lungs
LA
LV
Boby
Body to right heart to lungs to
left heart to body
Body, then via vena cavas to
RA, to RV via tricuspid valve,
then to lungs through
pulmonary semilunar valve and
via pulmonary arteries, then to
LA via pulmonary veins, to LV
via bicuspid, then to body via
aortic semilunar valve and the
aorta
LEARN THIS
23
Cardiac Cycle
Blood enters the atria through the vena cava (R) and the
Pulmonary vein (L)
↓
Atria will contract
↓
Blood is pushed through the AV valves into the ventricles
↓
Ventricles contract and AV valves close
↓
Blood is pushed though the pulmonary and aortic semilunar
valves into the pulmonary trunk and the aorta
↓
Ventricles relax and valves close
Cardiac Cycle Tutorial
• http://faculty.alverno.edu/bowneps/cardiaccy
cle/cardiaccycle1map.htm
PHYSIOLOGY OF THE HEART
The heart is a double pump. When the heart
beats…
Right Heart
Deoxygenated blood flows into heart from vena
Cava ---right atrium ---tricuspid valve--- right
ventricle --pulmonary semilunar valve--pulmonary artery ---lungs (for oxygen)
Left Heart
Oxygenated blood flows from lungs via pulmonary
Veins--- left atrium--- bicuspid valve--- left
ventricle--- aortic semilunar valve--- aorta --general circulation (to deliver oxygen)
Electrical conduction system:
specialized cardiac muscle cells that carry
impulses throughout the heart musculature,
signaling the chambers to contract in the
proper sequence
(Explanation in next slides)
27
Control of Heart Contractions
SA (sinoatrial) NODE = PACEMAKER
• Located in right atrium
• SA node sends out electrical impulse
• Impulse spreads over atria, making them
contract
• Travels to AV Node
AV (atrioventricular) NODE
• Conducting cell group between atria and
ventricle
• Carries impulse to bundle of His
BUNDLE OF HIS
• Conducting fibers in septum
• Divides into R and L branches to network of
branches in ventricles (Purkinje fibers)
PURKINJE FIBERS
• Impulse shoots along Purkinje fibers causing
ventricles to contract
Flow Through the Heart
• http://www.youtube.com/watch?v=7XaftdE_h
60
Heart Contraction
SA Node
Sinalarterial node
“Pacemaker”
AV Node
Atrioventricular node
Allows impulse to cross
into ventricles
Bundle of His
Bundle Branches
Purkinje Fibers
Conduction system
• SA node (sinoatrial)
– In wall of RA
– Sets basic rate: 70-80
– Is the normal pacemaker
• Impulse from SA to atria
• Impulse also to AV node via internodal
pathway
• AV node
– In interatrial septum
31
Conduction continued
• SA node through AV bundle (bundle of His)
– Into interventricular septum
– Divides
R and L bundle branches
become subendocardial
branches (“Purkinje
fibers”)
• Contraction begins
at apex
32
Heart Contraction Flow Chart
SA Node fires
↓
Impulse spreads across atria
↓
Atria contract (lub)
↓
Blood is pumped to the ventricles
↓
AV Node receives impulse from SA Node
↓
Impulse passes through bundle of His
↓
Impulse passes through Purkinje fibers
↓
Ventricles contract (dub)
↓
Blood is pumped into the lungs and out to the body
• Watch- Electrical Changes in the Heart
35
EKG→ measures heart electricity
P Wave→ Atria contract & Depolarize
PQ Interval→ Impulse is passing through the
bundle of His to the Purkinje fibers
QRS Wave→ Ventricles depolarize and
contract
T Wave→ Ventricles repolarize