Download Chapter 11 Structure fits Function

Structure fits Function
Forearm
Chapter 11
Wrist
Finger 1
Palm
Shaft
Finger 2
Human Organization
Internal bone structure
Finger 3
Shaft
Feather
structure
Barb
Barbule
Hook
Figure 20.1
Animal structure has a hierarchy
•  Structure in the living world
–  Is organized in a series of hierarchical levels
Tissues are groups of cells with a common structure
and function
•  Tissues are groups of many similar cells
–  That perform a specific function
A Cellular level
Muscle cell
B Tissue level
Muscle tissue
C Organ level
Heart
D Organ system level
Circulatory system
E Organism level
Many organ systems
functioning together
Four Types of Tissues in the
Human Body
•  Epithelial: covers body surfaces and lines
cavities
•  Connective: supports and binds body parts
Epithelial tissue covers the body and lines its organs
and cavities
•  Epithelial tissue occurs as sheets of closely
packed cells
–  That cover surfaces and line the cavities and
tubes of internal organs
•  Muscular: moves the body and its parts
•  Nervous: receives stimuli, processes that
information, and conducts impulses
Epithelial Tissue
Pseudostratified, ciliated columnar
• lining of trachea
• sweeps impurities toward throat
Connective tissue binds and supports other tissues
Stratified squamous
• skin (epidermis)
• lining of nose, mouth, esophagus,
anal canal, vagina
• protects
Simple squamous
• lining of lungs, blood vessels
• protects
Functions in
protection,
secretion, and
exchange
cilia
goblet cell
secretes
mucus
–  Are characterized by sparse cells in an
extracellular gel matrix
basement
membrane
basement membrane
basement membrane
Simple cuboidal
• lining of kidney tubules, various glands
• absorbs molecules
Simple columnar
• lining of small intestine, oviducts
• absorbs nutrients
goblet cell
secretes
mucus
basement
membrane
•  The various types of connective tissue
basement
membrane
Connective Tissue
Muscle tissue functions in movement
–  Binds and supports other tissues
•  Skeletal muscle is responsible for voluntary
body movements
Fat
droplets
Cartilageforming
cells
C Adipose tissue
Cell
nucleus
Matrix
D Cartilage
(at the end of a bone)
•  Cardiac muscle pumps blood
•  Smooth muscle moves the walls of internal
organs such as the stomach
Collagen
fibers
Central
canal
B Fibrous connective tissue
(forming a tendon)
Cell
White blood
cells
Collagen
fiber
Matrix
Boneforming
cells
Red blood
cell
Elastic
fibers
E Bone
Plasma
A Loose connective tissue
(under the skin)
F Blood
Muscle Tissue
Nervous Tissue
•  The three types of muscle tissue
Unit of
muscle
contraction
Muscle
fiber
Muscle
fiber
•  forms a communication network
Junction between
two cells
Nucleus
•  The branching neurons of nervous tissue
–  Transmit nerve signals that help control
body activities
Nucleus
Muscle fiber
Nucleus
B Cardiac muscle
A Skeletal muscle
Cell body
Nucleus
C Smooth muscle
LM 330×
Cell extensions
CONNECTION
Artificial tissues have medical uses
•  Artificial tissues
–  Can assist in the healing of several injuries
Several tissues are organized to form an organ
•  Each organ is made of several tissues
–  That collectively perform specific functions
Lumen
Small intestine
(cut open)
Lumen
Epithelial tissue
(columnar epithelium)
Connective tissue
Smooth muscle
tissue (2 layers)
Connective tissue
Epithelial tissue
Organ systems work together to perform life
functions
•  The digestive and respiratory systems
–  Gather food and oxygen
•  Each organ system
Mouth
–  Has one or more functions
Esophagus
Liver
Nasal cavity
Larynx
Trachea
Bronchus
Stomach
Small
intestine
Lung
Large
intestine
Anus
A Digestive system
B Respiratory system
•  The circulatory system, aided by the lymphatic system
–  Transports the food and oxygen
•  The excretory system
–  Disposes of certain wastes
•  The immune system
–  Protects the body from infection and cancer
•  The endocrine and nervous systems
–  Control body functions
Bone
marrow
Heart
D Immune system
Pituitary gland
Thymus
Spleen
E Lymphatic system Lymph
nodes
Blood
vessels
Lymph
vessels
F Excretory system
Thyroid gland
Kidney
Thymus
Adrenal gland
Ureter
Pancreas
Urinary
bladder
Testis
(male)
Urethra
Ovary
(female)
C Circulatory system
G Endocrine system
•  The integumentary system
•  The reproductive system
–  Covers and protects the body
–  Perpetuates the species
•  Skeletal and muscular systems
Male
Female
–  Support and move the body
Hair
Prostate
gland
Cartilage
Skin
Skeletal
muscles
Vas
deferens
Urethra
Nails
Bones
Penis
Oviduct
Ovary
Uterus
Vagina
Testis
I Integumentary system
J Skeletal system
K Muscular system
L Reproductive systems
EXCHANGES WITH THE EXTERNAL ENVIRONMENT
Structural adaptations enhance exchange
between animals and their environment
•  An animal must exchange materials
•  Small animals with simple body construction
–  Have enough surface area to meet their
cells’ needs
Mouth
–  With its environment
Diffusion
Diffusion
Gastrovascular
cavity
•  Larger, complex animals
•  The respiratory system
–  Have specialized structures that increase
surface area
•  Exchange of materials between blood and body cells
–  Takes place through the interstitial fluid
External environment
CO2 O2
Mouth Food
Animal
Respiratory
system
Digestive
system
Interstitial
fluid
Nutrients
Circulatory
system
Body
cells
Excretory
system
Intestine
Anus
Unabsorbed
matter (feces)
Metabolic waste
products (urine)
–  Has an enormous internal surface area
Two
cell
layers
Animals regulate their internal environment
•  In response to changes in external conditions
–  Animals regulate their internal environment to
achieve homeostasis, an internal steady state
Homeostasis depends on negative feedback
•  Negative feedback mechanisms
–  Keep internal variables fairly constant, with
small fluctuations around set points
Sweat glands secrete sweat
that evaporates, cooling body
Thermostat in brain
activates cooling
mechanisms
Blood vessels in
skin dilate and
heat escapes
External
environment
Temperature rises
above normal
Homeostatic
mechanisms
Large
fluctuations
Thermostat shuts off
cooling mechanisms
Internal
environment
Small
fluctuations
Temperature
decreases
Homeostasis:
Internal body temperature
of approximately 36–38οC
Temperature
increases
Thermostat shuts off
warming mechanisms
Temperature falls
below normal
Blood vessels in skin
constrict, minimizing
heat loss
Thermostat in
brain activates
warming
mechanisms
Skeletal muscles rapidly
contract, causing shivering,
which generates heat