A receptor detects a change in the internal or external environment. This triggers a response by the control center to return conditions back to normal.
3. Tissue
A collection of cells of the same type
that perform a common function
There are 4 major tissue types in the
body:
1. Connective
2. Muscular
3. Nervous
4. Epithelial
4. Connective Tissue
Binds and supports parts of the body
All have specialized cells, ground
substance and protein fibers
There are three main types of connective
tissue: A. fibrous , B. supportive and C.
fluid
6. Ground Substance
Ground substance is noncellular and
ranges from solid to fluid
The ground substance and protein fibers
together make up the matrix of the tissue
7. Fibres
Collagen: white, gives flexibility and
strength
Reticular: thin collagen, branched,
support network
Elastic: yellow, elastin, very flexible
protein, not as strong as collagen
10. Fibrous Connective Tissue
There are two types: dense or loose, but
both contain fibroblast cells with a matrix
of collagen and elastic fibers
Loose fibrous tissue is found supporting
epithelium and many internal organs
Adipose tissue is a special loose fibrous
tissue where fat is stored
11. Fibrous Connective Tissue
Loose Fibrous (areolar tissue) Dense Fibrous
1. Supports epithelium and internal organs Many tightly packed collagen fibres
2.Allows for expansion of organs ie
bladder, lungs
Tendons (connect muscle to bone)
3.Protective covering for
internal organs ie muscle, nerves,
blood vessels
Ligaments (connects bone to other bones
at joints)
Adipose tissue special type,
enlarged cells to store fat
Fat used for energy, insulation and
protection under skin, around organs
and on surface of heart
Matrix for both has collagen and elastin fibres
Ground substance is gel-like
13. Supportive Connective
Tissue
Cartilage:
Cells are in chambers called lacunae
Ground substance (matrix) is solid but
flexible
No direct blood supply
3 types are distinguished by types of fibers
14. Types of Cartilage
Hyaline cartilage – most common type,
fine collagen fibers
Location: Nose, ends of long bones and fetal
skeleton
Elastic cartilage – more elastic fibers than
cartilage fibers, more flexible
Location: Outer ear, epiglottis
Fibrocartilage – strong collagen fibers,
withstand tension and pressure
Location: Disks between vertebrae, knee
15. Supportive Connective
Tissue
Bone:
Cells are in chambers called lacunae
Matrix is solid and rigid that is made of
collagen and calcium salts
Most rigid connective tissue
Has nerve cells and blood supply
2 types are distinguished by types of fibers
16. Types of Bone
Compact: Location: Shafts of long bone
Spongy: Location: Ends of long bones
Composition of bone will be studied in more depth
with Skeletal System
17. Fluid Connective Tissue
Blood:
Often not considered connective tissue, but
vascular tissue
Made of a fluid matrix called plasma and
cellular components that are called formed
elements
Formed elements: red and white blood cells
and platelets
18. Blood: Formed Elements
3 formed elements:
Red blood cells:
cells that carry
oxygen
White blood cells:
cells that fight
infection
Platelets: pieces of
cells that clot blood
19. Fluid Connective Tissue
Lymph:
Clear, watery, yellowish fluid (lymph) made by
lymphatic tissue
White blood cells congregate in this tissue
Absorb excess tissue fluids and transport
dissolved solutes and fat molecules
Lymph nodes clean lymph
Help fight infection
20. Muscle Tissue
Allows for movement in the body
Made of muscle fibers/cells and protein
fibers called actin and myosin
There are 3 types of muscle tissue in
humans:
A. Skeletal
B. Smooth
C. Cardiac
21. Muscle Tissue: Skeletal
Appearance: long,
cylindrical cells, multiple
nuclei, striated fibers (light
and dark bands of actin
and myosin)
Location: attached to
bone for movement
Nature: voluntary
movement
22. Muscle Tissue: Smooth
Appearance: spindle-
shaped cell with one
nucleus, lack striations
Location: walls of hollow
organs (eg. Intestine,
bladder, etc) and blood
vessels
Nature: involuntary
movement
23. Muscle Tissue: Cardiac
Appearance: branched
cells with a single nucleus,
striated
Location: heart
Nature: involuntary
movement
24. Nervous Tissue
Allows for communication between cells
through sensory input, integration of data
and motor output
Made of 2 major cell types:
A. Neurons
B. Neuroglia
25. Neurons
Made of dendrites, a
cell body and an axon
Dendrites carry
information toward the
cell body
Axons carry information
towards a cell body
26. Neuroglia
A collection of cells that
support and nourish
neurons
Outnumber neurons 9:1
Examples are
oligodendrocytes,
astrocytes and microglia
27. Epithelial Tissue
A groups of cells that form a tight, continuous
network – have a basement membrane
Lines body cavities, covers body surfaces and found
in glands
protective covering, secretion, absorption, excretion,
filtration
Types: simple, stratified
Basement Membrane:
Thin layer of carbohydrates and proteins used to anchor epithelial
tissue to underlying connective tissue
28. Simple Epithelia
Number of cell layers:
Simple: one layer of cells
Stratified: more than one layer of cells
Pseudostratified: appears to have layers but
only has one layer
Shape of cell:
Cuboidal: cube-shaped
Columnar: column-shaped
Squamous: flattened
29.
30.
31. Glands
epithelial tissue that secrete substances are
termed glandular epithelial.
may be single cells (sweat and mucous glands)
or multiple (endocrine glands eg.pancreas)
32. Cell Junctions
Epithelial cells cover the surface of
organs and line body cavities.
Depending on their location, their
function at that site dictates the manner
in which they are connected to each
other and to nerves and muscles.
33. Cell Junctions
If the epithelial layer must be impermeable,
proteins will join each cell forming a tight
junction. This occurs in stomach, intestines
and kidneys.
Tissue that is exposed to mechanical stress is
joined by adhesion junctions. Proteins
again join the epithelial cell, but allow some
stretching of the cells by creating a small
space between the cell membranes. These
junctions are found in skin.
34. Cell Junctions
If some communication must occur
throughout a tissue, the junction must
allow for some ions and molecules to
pass from one cell to another.
The gap junction makes up part of the
cardiac muscle, allowing electrical
impulses to coordinate one heart beat.
36. The integumentary system
Includes the skin and accessory organs such as
hair, nails and glands
The skin has two main regions called the
epidermis and the dermis
Under the skin there is a subcutaneous layer
between the dermis and internal structures
where fat is stored
Is important for maintaining homeostasis
37. Function
1. Protects the body from physical trauma,
invasion by pathogens and water loss
2. Helps regulate body temperature
3. Allows us to be aware of our surroundings
through sensory receptors
4. Synthesizes chemicals such as melanin
and vitamin D
39. Epidermis
The thin, outermost layer of the skin
Made of epithelial tissue
Cells in the uppermost cells are dead
and become filled with keratin thus
acting as a waterproof barrier
40. Epidermis continued
new cells constantly being produced at
innermost layer by stem cells
Langerhans cells are a type of white blood
cell that help fight pathogens
Melanocytes produce melanin that lend to
skin color and protection for UV light
Some cells convert cholesterol to vitamin D
41.
42. Dermis
The thick, inner layer of the skin
Made of dense fibrous connective tissue
Contains elastic and collagen fibers
Contains blood vessels, many sensory
receptors and glands
43. Dermis
sebaceous (oil) glands secrete sebum.
The oil moves to epidermis layer to act
as protectant, lubricant and waterproof
sweat glands for body temperature
control and also anti-bacterial
44. Subcutaneous Layer
Located below the dermis, this layer is
the site of “subcutaneous” injections. It is
made up of adipose and loose
connective tissue.
The subcutaneous layer is NOT part of
the skin. Its function is protection and an
energy source.
45. Accessory Organs
originate in the epidermal layer
Includes nails, hair and glands
Nails
nail roots begin in epithelial layer
cuticle protects root
lunula (half-moon) is thick cell layer
nail made up of keratin (protein)
46. Accessory Organs
Hair
follicles start as bulb in dermis and grow to
outside epidermis
colour dictated by melanin (and iron and
sulfur content in the pigment)
muscles cause hair to become erect
Sweat Glands
present in all regions of skin
begins in dermis
opens to epidermis or hair follicle
help to control body temperature
47.
48. Moving from tissue to
organs and organ systems
An organ is 2 or more tissue types
working towards a particular function
An organ system is a combination of
organs that work together to carry out a
particular function
52. Membranes
Mucous membranes – lining of the digestive, respiratory,
urinary and reproductive systems
Serous membranes – line lungs, heart, abdominal cavity
and cover the internal organs; named after their location
• Pleura: lungs
• Peritoneum: abdominal cavity and organs
• Pericardium: heart
Synovial membrane – lines the cavities of freely movable
joints
Meninges – cover the brain and spinal cord
53. Homeostasis
Maintaining relative constancy within an environment.
Warm blooded animals maintain a constant internal
environment by communication between organ systems
If constancy is not maintained, illness results
The endocrine and nervous system play a major role in
maintaining homeostasis
Regulation is monitored and controlled by feedback
mechanisms
54. Negative Feedback
The primary mechanism
for maintaining
homeostasis
Has two components:
• sensor
• control center
The output of the system
dampens the original
stimulus
56. Positive Feedback
A mechanism for increasing the change
of the internal environment in one
direction
An example is the secretion of oxytocin
during birth to continually increase
uterine contractions
Can be harmful such as when a fever is
too high and continues to rise
57. Explain how the following are
examples of negative feedback:
body temperature regulation
glucose regulation
58. Explain how the following are
examples of positive feedback:
nursing
childbirth