By: Christina, Sunny, & Ann

1
Skeletal, Muscular, Nervous, and Integumentary
Systems

• By Christina, Sunny, Ann

2
The Skeletal System
3
Animal skeletons function in support, protection,
and movement

• Most land animals would sag from their own weight
  if they had no skeleton to support them. Even an
  animal that lives in water would become a
  formless mass with no framework/skeleton to
  support and maintain its shape.
• In many animals, a hard skeleton provides
  protection for soft tissues. For example, the
  vertebrate skull protects the brain, and the ribs
  of terrestrial vertebrates form a cage around the
  heart, lungs, and other internal organs.
• Skeletons also aid in the movement by giving
  muscles something firm to work against.

4
Skeletons

• There are three main types of skeletons
• Hydrostatic skeletons
• Exoskeletons
• Endoskeletons

5
Hydrostatic Skeletons

• S

6
A Hydrostatic skeleton consists of fluid held
under pressure in a closed body compartment.

• This is the main type of skeleton in most
  cnidarians , flatworms, nematodes, and annelids.
  These animals control their form and movement by
  using muscles to change the shape of fluid filled
  compartments.
• Among cnidarians, a hydra can elongate by closing
  its mouth and using contractile cells in the body
  wall to constrict the central gastrovascular
  cavity.
• In planarians, the interstitial fluid is kept
  under pressure and functions as the main
  hydrostatic skeleton. The planarian movement
  results mainly from muscles in the body wall
  exerting localized forces against the hydrostatic
  skeleton.
• Nematodes hold fluid in their body cavity, which
  is a pseudocoelom.
• In annelids and earthworms, the coelomic fluid
  functions as a hydrostatic skeleton. The coelomic
  cavity is divided by septa between the segments
  in many annelids, allowing the animal to change
  the shape of each segment individually, using
  both circular and longitudinal muscles. These
  annelids use their hydrostatic skeleton for
  peristalsis.

7
Exoskeletons

• E

8
An exoskeleton is a hard encasement
deposited on the surface of an animal

• As an animal grows, it enlarges the shell by
  adding to its outer edge.
• Clams close their hinged shell using muscles
  attached to the inside of this exoskeleton.
• The jointed exoskeleton of arthropods is a
  cuticle, a non-living coat secreted by the
  epidermis. Muscles are attached to knobs and
  plates of the cuticle that extend into the
  interior of the body.
• About thirty to fifty percent of the cuticle
  consist of chitin, a polysaccharide similar to
  cellulose. Fibrils of chitin are embedded in a
  protein matrix, forming a composite material that
  combines strength and flexibility. Where
  protection is the most important, the cuticle is
  hardened with organic compounds that cross link
  the proteins of the exoskeleton.
• Some crustaceans, such as lobsters, harden
  portions of their exoskeleton even more by adding
  calcium salts.

9
Endoskeleton
10
An endoskeleton consists of hard supporting
elements, such as bones, buried within the soft
tissue of the animal.

• Endoskeletons of various complexity are found
  chordates, and echinoderms.
• An endoskeleton allows the body to move and gives
  the body structure and shape.
• A true endoskeleton is derived from
  mesodermal tissue. Such a skeleton is present in
  echinoderms and chordates.
• Echinoderms have an endoskeleton of hard plates
  called ossicles beneath the skin.
• Chordates have an endoskeleton consisting of
  cartilage, bone, or some combination of these
  materials.
• The mammalian skeleton is built from more than
  200 bones, some fused together and others
  connected at jointsby liagments that allow
  freedom of movement.
• Vertebrates have a distinctive endoskeleton made
  up of an axial and appendicular skeleton.

11
Joints

• Joints provide flexibility for body movements.
• Some examples of joints are
• Ball and socket joints
• - Hinge joints
• - Pivot joints

12
Label the skeleton1 172
18 3 194 205
21 6 227
238 249 2510
26111213141516
13
Some Helpful Sites on the Skeletal System

• http//www.mnsu.edu/emuseum/biology/humananatomy/s
  keletal/skeletalsystem.html
• http//yucky.discovery.com/flash/body/pg000124.htm
  l
• http//hes.ucfsd.org/gclaypo/skelweb/skel01.html

14
The Integumentary System
15
Definition

• Integumentary system is the outer covering of a
  mammals body, including the skin, hair, and nails

16
Functions

• Protects the body's internal living tissues and
  organs
• Protects against invasion by infectious organisms
• Protects the body from dehydration
• Protects the body against abrupt changes in
  temperature

17
Functions (continued)

• Helps dispose of waste materials
• Acts as a receptor for touch, pressure, pain,
  heat and cold
• Stores water, fat, and vitamin D.

18
Epidermis
The outermost layer of skin and is composed
mostly of dead epithelial cells that continually
flake and fall off. New cells pushing up from
lower layers replace the cells that are lost.
19
Dermis
Supports the epidermis and contains hair
follicles, oil and sweat glands, muscles, nerves,
and blood vessels
20
Activity True or False

• 1. Skin is the largest organ.
• 2. The integumentary system only consist of skin.
• 3. Part of the integumentary system job is to
  protect the body from dehyrdration.
• 4. The skin consists of five layers of skin.

21
Answer to Activity

• True
• 2. False, the Integumentary system consists of
  the outer covering of a mammals body, including
  the skin, hair, and nails
• 3. True
• 4. False, the skin consist of two layers, the
  epidermis and dermis

22
To learn more about the integumentary system you
can look under

• AP Biology Textbook by Campbell Reece
• Websites such as
• http//www.cancerindex.org/medterm/medtm5.htm
• And even videos ttp//video.google.com/videoplay?
  docid-5613693526435958138

23
Muscular System
24
Overview

• The main job of the muscular system is to provide
  movement for the body.
• There are just over 650 skeletal muscles in the
  whole human body.
• The muscular system consist of three different
  types of muscle tissues skeletal, cardiac,
  smooth, all of which have the ability to
  contract, allowing the body movements and
  functions.

25
Major muscles of the body
26
Cardiac Muscle

• Cardiac muscle, called the myocardium, is found
  only in the heart.
• It is involuntary, controlled by the autonomic
  nervous system.
• The myocardium is composed of thick bundles of
  muscle, forming the walls of the chambers of the
  heart and contracts to pump blood throughout the
  body.
• Its cells are joined by intercalated disks that
  relay each heartbeat.

27
Smooth Muscle

• Smooth muscles are involuntary muscles found in
  the stomach and intestinal walls, in artery and
  vein walls, and in various hollow organs.
• In a vessel or organ, smooth muscles are arranged
  in sheets or layers.

28
Skeletal Muscle

• Stabilize joints, help maintain posture, and give
  the body its general shape.
• In men, they make up about 40 percent of the
  body's mass or weight and in women, about 23
  percent.
• Are generally responsible for the voluntary
  movements of the body.

29
Structure of Muscle Cells

• Within the cells are myofibrils myofibrils
  contain sarcomeres, which are composed of actin
  and myosin.
• Individual muscle fibers are surrounded by
  endomysium.
• Muscle fibers are bound together by perimysium
  into bundles called fascicles the bundles are
  then grouped together to form muscle, which is
  enclosed in a sheath of epimysium.
• Muscle spindles are distributed throughout the
  muscles and provide sensory feedback information
  to the central nervous system.

30
Muscle Cell in Detail
31
Movement and muscle arrangement

• In skeletal muscle, contraction is stimulated by
  electrical impulses transmitted by the nerves,
  the motor nerves and motorneurons in particular.
• Cardiac and smooth muscle contractions are
  stimulated by internal pacemaker cells which
  regularly contract, and propagate contractions to
  other muscle cells they are in contact with.
• Muscular activity accounts for much of the body's
  energy consumption. All muscle cells produce
  adenosine triphosphate (ATP) molecules which are
  used to power the movement of the myosin heads.
• Muscles also conserve energy in the form of
  creatine phosphate which is generated from ATP
  and can regenerate ATP when needed with creatine
  kinase.
• They keep a storage form of glucose in the form
  of glycogen. Glycogen can be rapidly converted to
  glucose when energy is required for sustained,
  powerful contractions.

32
Activity

• What are muscles made of?
• What are the 3 types of muscles?
• What are smooth muscles and what do they do and
  where are they found?
• What are cardiac muscles, where are they and what
  do they do?
• What are skeletal muscles what do they do?
• Whats the difference between voluntary and
  involuntary muscles?
• Where do facial muscles attach?
• What do facial muscles do?
• Name the muscle thats attached only at one end?
• List the 6 major types of muscles

33
Nervous System
34
Overview

• All animals except the sponges have some type of
  nervous system.
• Nervous systems consist of circuits of neurons
  and supporting cells.
• The human brain contains an estimated 100 billion
  nerve cells or neurons.
• Invertebrate nervous systems range in complexity
  from simple nerve nets to highly centralized
  nervous systems having complicated brains and
  ventral nerve cords.

35
The Brain

• The brain is composed of three parts the
  cerebrum, the cerebellum, and the medulla
  oblongata.
• The medulla oblongata is closest to the spinal
  cord, and is involved with the regulation of
  heartbeat, breathing, vasoconstriction (blood
  pressure), and reflex centers for vomiting,
  coughing, sneezing, swallowing, and hiccuping.
• The hypothalamus regulates homeostasis. It has
  regulatory areas for thirst, hunger, body
  temperature, water balance, and blood pressure,
  and links the Nervous System to the Endocrine
  System.
• The midbrain and pons are also part of the
  unconscious brain. The thalamus serves as a
  central relay point for incoming nervous
  messages.
• The cerebellum is the second largest part of the
  brain, after the cerebrum. It functions for
  muscle coordination and maintains normal muscle
  tone and posture. The cerebellum coordinates
  balance.

36
Central nervous system consists of the brain and
the spinal cord

• In invertebrates, the central nervous system
  consists of the brain and the spinal cord, which
  is located dorsally.
• Nervous systems process information in three
  stages sensory input, integration, and motor
  output to effector cells.
• The three stages are illustrated by the knee jerk
  reflex.
• The CNS integrates information, while the nerves
  of the peripheral nervous system transmit sensory
  and motor signals between the CNS and the rest of
  the body.
• Sensory neurons transmit information from sensors
  that detect external stimuli and internal
  conditions.
• Most neurons have highly branched dendrites that
  receive signals from other neurons.
• They also typically have a single axon that
  transmits signals to other cells at synapses.

37
Nerve Cell

• A basic nerve cell consists of a cell body, an
  axon, and many dendrites.
• Dendrites are thread-like branches that increase
  the surface area of a cell making it possible for
  the receiving many connections with other nerve
  cells.
• Signals picked up by the dendrites travel through
  the cell and continue along the axon where they
  are transmitted to the next cell.
• Synaptic bulbs on the ends of the axons make
  connections with other nerve cells, via synapses.

38
All cells have an electrical potential difference
across their plasma membrane called the membrane
potential

• Ions pumps and ion channels maintain the resting
  potential of a neuron.
• In neurons, the membrane potential is typically
  between -60 and -80 mV when the cell is not
  transmitting signals.
• The inside of the cell is negative related to the
  outside.
• The membrane potential depends on ionic gradients
  across its plasma membrane the concentration of
  Na is higher in the extracellular fluid than in
  the cytosol, while the reverse is true for K.
• A neuron that is not transmitting signals
  contains many open K channels and fewer open Na
  channels in its plasma membrane.
• The diffusion of K and Na through these
  channels leads to separation of charges across
  the membrane, producing the resting potential.
• Gated ion channels open or close in response to
  membrane stretch, the binding of a specific
  ligand, or a change in the membrane potential.
• Stretch gated ion channels are found in cells
  that sense stretch and open when the membrane is
  mechanically deformed.

39
Somatic Nervous System

• Includes all nerves controlling the muscular
  system and external sensory receptors.
• External sense organs are the receptors.
• Muscle fibers and gland cells are effectors. The
  reflex arc is an automatic, involuntary reaction
  to a stimulus.
• A reaction to the stimulus is involuntary, with
  the CNS being informed but not consciously
  controlling the response.
• Sensory input from the PNS is processed by the
  CNS and responses are sent by the PNS from the
  CNS to the organs of the body.
• Motor neurons of the somatic system are distinct
  from those of the autonomic system.
• Inhibitory signals, cannot be sent through the
  motor neurons of the somatic system.

40
Autonomic Nervous System

• Part of PNS consisting of motor neurons that
  control internal organs. It has two subsystems.
• The autonomic system controls muscles in the
  heart, the smooth muscle in internal organs such
  as the intestine, bladder, and uterus. The
  Sympathetic Nervous System is involved in the
  fight or flight response.
• The Parasympathetic Nervous System is involved in
  relaxation.
• Each of these subsystems operates in the reverse
  of the other (antagonism). Motor neurons in this
  system do not reach their targets directly (as do
  those in the somatic system) but instead they
  just connect to a secondary motor neuron which
  innervates the target organ.

41
Crossword Activity
1. System of the nervous system that contains the
brain and spinal cord 2. The sensory and motor
neurons that connect to the central nervous
system 3. Receive and communicate information
from the sensory environment 4. Makes synaptic
connections with other neurons a. one of many
short, branched processes of a neuron that help
bring the nerve impulses toward the cell body b.
A system of the nervous system that can be broken
down into a sensory and a motor division c. Takes
the command of the CNS and put them into action
as motor outputs d. one of three divisions of the
autonomic nervous system generally enhances body
activities that gain and conserve energy, such as
digestion and reduced heart rate e. one of three
divisions of the autonomic nervous system
generally increases energy expenditure and
prepares the body for action f. Longer extensions
that leave from a neuron and carry impulse away
from the cell body to toward target cells g. main
body of the neuron
42
Answer to Activity