Anatomy and psychology

1. Ministry of Higher Education
and Scientific Research
Almaarif University college
Medical
Instrumentation
Technical Engineering
‫وزارة‬
‫التعليم‬
‫العالي‬
‫والبحث‬
‫العلمي‬
‫كلية‬
‫الجامعة‬ ‫المعارف‬
‫قسم‬
‫هندسة‬
‫تقنيات‬
‫األجهزة‬
‫الطبية‬
The muscular system (6) lecture
Master Surgery : Natheer Ahmad Hameed
2023-2024

2. Characteristics of all muscle tissues:
1. Specialized cells: elongated, high density of
myofilaments“cytoplasmic filaments of actin and myosin”.
2. Excitability/irritability: receive and respond to stimulus.
3. Contractility:shorten and produce force upon stimulation.
4. Extensibility: can be stretched.
5. Elasticity: can be recoil after stretch.

3. TYPES OF MUSCLES
 SKELETAL MUSCLE
 CARDIAC MUSCLE
 SMOOTH MUSCLE

4. 1. SKELETAL MUSCLE
 Characteristics of skeletal muscles
 Cells are multinucleate
 Nuclei are just beneath the
sarcolemma (cell membrane)
 Voluntary .
 Are attached to the skeleton.
 They are striated in appearance
 and under voluntary control

5. Connective T covering of
Skeletal Muscle
 Fascia – on the outside
of the epimysium
 Each muscle is wrapped in
a sheath of connective
tissue called the
Epimysium.
 Endomysium – around
single muscle fiber
 Perimysium – around a
fascicle (bundle) of
fibers
Figure 6.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 6.4a

6. Microscopic Anatomy of Skeletal
Muscle
 Sarcomere
Contractile unit of a muscle fiber
Figure 6.3b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide

7. Figure 6.3c
Microscopic Anatomy of Skeletal
Muscle
 Organization of the
sarcomere
 Thin filaments = actin
filaments
 Composed of the
protein actin
 Organization of the
sarcomere
 Thick filaments = myosin
filaments
 Composed of the protein
myosin
 Has ATPase enzymes
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide

8. Microscopic Anatomy of Skeletal Muscle
 Myosin filaments have heads
(extensions, or cross bridges)
 Myosin and
actin overlap
somewhat
Figure 6.3d
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide

9. Functions
 Functions
 1) Provides Structural Support
 2) Movement
 3) Important In Respiration
 4) Maintaining Body Temperature

10. Cardiac Muscle
Cardiac Muscle Characteristics
 Heart wall divided into 3
layers.
I. Endocardium
II. Myocardium ( muscle
layer)
III. Epicardium
 Has striations
 Usually has a single
nucleus
 Joined to another muscle
cell at an intercalated disc
 Involuntary
 Found only in the heart
 Steady pace!
Function
 Pumping blood to the whole
Co p yrb
i g h
o
t ©
d2
y
003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 6.2b
Slide 6.7

11. Characteristics
Smooth Muscle
 Smooth muscle cells
known as myocytes,
 Has no striations
 Spindle-shaped cells
 Single nucleus which
centrally located
 Involuntary – no
conscious control
 Found mainly in the
walls of hollow organs
 Slow, sustained and
tireless
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 6.2a
Slide 6.6

12. Types of smooth muscles
 1.Single-unit smooth muscle,
or visceral smooth muscle
 found in the uterus, gastro-
intestinal tract, and the
bladder’. muscle cells
contract synchronously.
Contain abundant gap
junction
 2. multi-unit smooth muscle
 is found in airways to the
lungs and large arteries
 each cell contracts and
relaxes on its own . has
fewer gap junction

13. Functions of smooth muscle
 Smooth muscle determines the flow of blood in the
arteries.
 Smooth muscles move food through the digestive tract.
 Folds in the stomach and small intestine, which are made
of smooth muscle, help the body better absorb nutrients.
 Smooth muscle composes all sphincters in the digestive
system.
 In the bladder, smooth muscle helps to push out urine

15. Muscle atrophy :
Is a reduction in muscle size , tone , and power .
Ex: if stimulation reduced , (nerves : leading to loses
both mass and tone)
Muscular hypertrophy :
Increase in muscle fiber size .
( hyperplasia : means increase in number )