MODULE 03 Morphological Characterization
PUMP IT UP! Muscle can be categorized morphologically as either
MUSCLE BASICS striated or smooth.
• Striated
SECTION 01: TYPES OF MUSCLE - Striated muscle is marked by both light and dark
bands (striations).
THE MUSCULAR SYSTEM - Striated muscle can be found in the heart and
skeletal muscles.
Muscles are contractile organs. Through muscle - Striated muscle is characterized by long muscle
contraction, these organs can perform a number of fibres (cells) with multiple nuclei which are located
important functions such as movement - from the gross peripherally for skeletal muscle or centrally for
physical movements of our skeleton (walking) to the more cardiac muscle. Cardiac muscle also features
finely tuned intricate movements such as beating of the intercalated discs.
heart, breathing, digestion, and constriction of blood
vessels, all of which serve to move substances throughout
the body.
TYPES OF MUSCLE
There are three types of muscle.
Skeletal muscles help the human body move. Most skeletal
muscle is attached to bones via tendons.
Cardiac muscle is found in the heart. It contracts
rhythmically, and is modulated by neural activity and
hormones. • Smooth
– Smooth muscle is found in blood vessels, the
Smooth muscle is controlled by the nervous system or digestive system, and other viscera.
hormones. It may be either generally inactive and then – Unlike striated muscle, each smooth muscle fibre
respond to stimulation, or it may be rhythmic. (cell) contains a single centrally located nucleus.
Note: smooth muscle has fusiform-shaped cells
without striations.
CHARACTERIZATION OF MUSCLE
Muscles can be characterized based on their morphology
(form) or how they function. Learn about the two types of
muscle characterization.
, Functional Characterization HOW DO MUSCLES FUNCTION?
Muscle can be categorized functionally as voluntary or Muscle has two basic properties: excitability and
involuntary. contractility.
• Voluntary Excitability
– Voluntary muscle is muscle that is consciously The ability of muscle tissue
controlled in order to perform a specific function, to receive and respond to
such as the muscles that move the skeleton for electrical signals from
walking, reaching, talking, etc. nerves or stimulation from
– The type of muscle that is voluntarily controlled is hormones
skeletal muscle, for example, muscles of the upper
limb. Contractility
When a muscle cell is
excited by a nerve or
hormone, this causes the
muscle to shorten, resulting
in contraction
ACTIVITY: TYPES OF MUSCLE
Select the correct characteristics that best describe each
• Involuntary
muscle type
– Involuntary muscle is not consciously controlled.
Involuntary muscle consists of smooth muscle and
cardiac muscle.
– Example of involuntary muscles are the muscles of
the intestines (smooth) and the heart (cardiac).
SECTION 02: SKELETAL MUSCLE
INTRODUCTION TO SKELETAL MUSCLE
Skeletal muscle is the only voluntary muscle tissue in the
human body, meaning that it is controlled consciously.
Every physical action that a person consciously performs,
such as speaking, walking, or writing, requires skeletal
muscle.
VIDEOS: MUSCLE CELL TYPES – take notes
Attached to the bones of the skeletal system are about 700
named muscles that account for roughly half of a person’s
body weight. Each of these muscles is a discrete organ
composed of skeletal muscle tissue, epithelial, connective,
and nervous tissue.
PUMP IT UP! Muscle can be categorized morphologically as either
MUSCLE BASICS striated or smooth.
• Striated
SECTION 01: TYPES OF MUSCLE - Striated muscle is marked by both light and dark
bands (striations).
THE MUSCULAR SYSTEM - Striated muscle can be found in the heart and
skeletal muscles.
Muscles are contractile organs. Through muscle - Striated muscle is characterized by long muscle
contraction, these organs can perform a number of fibres (cells) with multiple nuclei which are located
important functions such as movement - from the gross peripherally for skeletal muscle or centrally for
physical movements of our skeleton (walking) to the more cardiac muscle. Cardiac muscle also features
finely tuned intricate movements such as beating of the intercalated discs.
heart, breathing, digestion, and constriction of blood
vessels, all of which serve to move substances throughout
the body.
TYPES OF MUSCLE
There are three types of muscle.
Skeletal muscles help the human body move. Most skeletal
muscle is attached to bones via tendons.
Cardiac muscle is found in the heart. It contracts
rhythmically, and is modulated by neural activity and
hormones. • Smooth
– Smooth muscle is found in blood vessels, the
Smooth muscle is controlled by the nervous system or digestive system, and other viscera.
hormones. It may be either generally inactive and then – Unlike striated muscle, each smooth muscle fibre
respond to stimulation, or it may be rhythmic. (cell) contains a single centrally located nucleus.
Note: smooth muscle has fusiform-shaped cells
without striations.
CHARACTERIZATION OF MUSCLE
Muscles can be characterized based on their morphology
(form) or how they function. Learn about the two types of
muscle characterization.
, Functional Characterization HOW DO MUSCLES FUNCTION?
Muscle can be categorized functionally as voluntary or Muscle has two basic properties: excitability and
involuntary. contractility.
• Voluntary Excitability
– Voluntary muscle is muscle that is consciously The ability of muscle tissue
controlled in order to perform a specific function, to receive and respond to
such as the muscles that move the skeleton for electrical signals from
walking, reaching, talking, etc. nerves or stimulation from
– The type of muscle that is voluntarily controlled is hormones
skeletal muscle, for example, muscles of the upper
limb. Contractility
When a muscle cell is
excited by a nerve or
hormone, this causes the
muscle to shorten, resulting
in contraction
ACTIVITY: TYPES OF MUSCLE
Select the correct characteristics that best describe each
• Involuntary
muscle type
– Involuntary muscle is not consciously controlled.
Involuntary muscle consists of smooth muscle and
cardiac muscle.
– Example of involuntary muscles are the muscles of
the intestines (smooth) and the heart (cardiac).
SECTION 02: SKELETAL MUSCLE
INTRODUCTION TO SKELETAL MUSCLE
Skeletal muscle is the only voluntary muscle tissue in the
human body, meaning that it is controlled consciously.
Every physical action that a person consciously performs,
such as speaking, walking, or writing, requires skeletal
muscle.
VIDEOS: MUSCLE CELL TYPES – take notes
Attached to the bones of the skeletal system are about 700
named muscles that account for roughly half of a person’s
body weight. Each of these muscles is a discrete organ
composed of skeletal muscle tissue, epithelial, connective,
and nervous tissue.
