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)