muscle types, blood vessels, &...
TRANSCRIPT
Muscle Types, Blood Vessels,
& Circulation
Muscle Types
Skeletal Muscle
In lab you will view skeletal muscle fibers, we
might have longitudinal and cross sections.
If you recall, a muscle fiber is simply a
muscle cell.
Working your way
from the outside, in:
The epimysium
separates m. from
surrounding
tissues.
The perimysium
surrounds each
muscle fiber
bundles
(fascicles).
And the
endomysium
surrounds each m.
fiber.
Working your way
from the outside, in:
The epimysium
separates m. from
surrounding
tissues.
The perimysium
surrounds each
muscle fiber
bundles
(fascicles).
And the
endomysium
surrounds each m.
fiber.
In a cross-
sectional
(transverse cut)
view, you will ID the
darkly stained nuclei
arranged around the
periphery of each m.
fiber.
You will ID the
endomysium that
surrounds each m.
fiber & the
perimysium that
surrounds each
bundle of m. fibers
In a longitudinal view, you will ID the striations as
alternating light & dark bands across the width of
each m. fiber, these are contractile protein filaments
called myofibrils.
The lighter I bands are thin filaments & the darker A
bands contain thick filaments.
Also note the nuclei.
Functions of skeletal m. is to produce
voluntary movement by acting on the skeleton
via the voluntary nervous system.
Each m. has its own n. and blood supply.
Smooth Muscle
Smooth m. forms around:
other tissues
Blood vessels
Reproductive & glandular systems
Digestive & urinary systems
And the integumentary system
Smooth m. is non-striated tissue (hence,
smooth m.) that is arranged into sheets
forming a circular layer.
Muscle tone is modified by n., hormones, or
chemical factors.
Contraction of opposing layers of muscle
leads to peristalsis, which propels
substances through the organs.
Cardiac Muscle
Functions of
cardiac tissue
are: Automatic
contraction
without nerve
(n.) stimulation &
Extended
contraction time.
Contraction is
controlled
without neural
stimulation but
by pacemaker
cells.
Intercalated
discs are
specialized
contact points
b/w heart cells.
They joint cells
mechanically,
chemically, &
electrically, thus
the heart
functions as a
single, fused cell.
Single Beating Heart Cell
http://www.dnatube.com/video/2375/Cells-of-a-
Beating-Heart
Blood Vessels In Detail
A circulating transport system known as the
circulatory system consists of: The heart acts as a pump
Blood vessels that takes blood away from the
heart, known as arteries. The
blood vessels that take blood back to the heart,
known as veins.
The blood vessels that are networks between
arteries and veins, known as capillaries. Exchange materials between blood and tissues
Materials include dissolved gases, nutrients, wastes
A conducting system of fluid known as blood
Capillaries are
networks that
exchange materials
between blood and
tissues
The Materials
include dissolved
gases, nutrients,
wastes
Figure 20–2c
The heart sits
between two pleural
cavities in the
mediastinum
The heart is located
on the left side
underneath rib #2 to
rib #5
There are great veins
and arteries located at
the base
Pointed tip is apex
The heart is
surrounded by the
pericardial sac
The Pulmonary Circuit Carries blood to and from
gas exchange surfaces of
lungs
The Systemic Circuit Carries blood to and from
the body
Blood alternates between
pulmonary circuit and
systemic circuit
Know the
highlighted
major
arteries:
Fibular artery
Know the
highlighted
major
veins:
Pulmonary Trunk
The blood vessels have different thickness due to the
differences in pressure.
Arteries have thick
walls due to the higher
pressure found in
them. The outer layer
is the tunica externa,
the middle layer is the
tunica media—is the
thickest layer & made
of smooth muscle and
elastic fibers, & the
innermost layer is the
tunica intima and
made of an elastic
tissue.
The area in the artery
where blood flows is
the lumen.
Veins are thinner
walled than arteries
and they do not have
the same elastic fibers
in the tunica media as
arteries.
The tunica interna of
veins is folded into
valves that allow for a
one-way flow of blood
through veins.
Capillaries are
different from both
arteries and veins in
that they are
composed of only
simple squamous
epithelium, called the
endothelium
The thin nature of
capillaries allows them
to exchange nutrients,
water, CO2 & O2 with
the cells.
Vein Valves
Circulation In Detail
Remember:
The Pulmonary Circuit Carries blood to and from
gas exchange surfaces of
lungs
The Systemic Circuit Carries blood to and from
the body
Blood alternates between
pulmonary circuit and
systemic circuit
The heart has 4
chambers, this
includes 2 superior
atria & 2 inferior
ventricles.
Right atrium Collects blood
from systemic
circuit
Right ventricle Pumps blood to
pulmonary circuit
Left atrium Collects blood
from pulmonary
circuit
Left ventricle Pumps blood to
systemic circuit
There are two major
circulations in the body, one
goes to the lungs and this
called pulmonary
circulation.
Deoxygenated blood leaves
the superior & inferior vena
cava into the right atrium,
then into the right ventricle,
then through the pulmonary
artery to the lungs where the
blood “gets” oxygenated
The other main circulation is
called the system
circulation.
Oxygenated blood leaves the
lungs by the pulmonary
veins into the left atrium,
then into the left ventricle and
finally out the aorta.
Color:
Pg 191: Overview of Cardiovascular System, Pg 193:
Circulation, Pg. 205: Vessels Overview, Pg. 201: Artery
Overview
Lab: Anatomy of the Blood Vessels Ex. 21
Pp 393-399 Activities 21.1-21.2
Lab: Dissection of Ventral Body Ex. 4
Pp 601-602 Activities P4.1 All & P4.2 #1-#2 only
Route blood, start @ the vena cava & ending @ the aorta
Lab: Dissection of Cardiovascular System
Pp 609-610 Act. P5.1 ID Heart & Great Vessels
Pp 612-613 Act. P5.3 ID Arteries (only those noted)
Pp 613-615 Act. P5.4 ID Arteries (only those noted)
Pp 615-617 Act. P5.5 ID Veins (only those noted)
Pp 617-619 Act. P5.6 ID Veins (only those noted)