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TRANSCRIPT
Chapter 11
Human Organization
Structure fits Function
Palm
Finger 2
Finger 3
Shaft
Barb
Barbule
Hook
Feather structure
Wrist
Forearm
Finger 1
Internal bone structure
Shaft
Figure 20.1
Animal structure has a hierarchy
• Structure in the living world
– Is organized in a series of hierarchical levels
Muscle cell A Cellular level
B Tissue level Muscle tissue
C Organ level Heart
E Organism level Many organ systems functioning together
D Organ system level
Circulatory system
Tissues are groups of cells with a common structure and function
• Tissues are groups of many similar cells
– That perform a specific function
Four Types of Tissues in the Human Body
• Epithelial: covers body surfaces and lines cavities
• Connective: supports and binds body parts
• Muscular: moves the body and its parts
• Nervous: receives stimuli, processes that information, and conducts impulses
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
cilia
Pseudostratified, ciliated columnar • lining of trachea
• sweeps impurities toward throat
basement membrane
Simple cuboidal • lining of kidney tubules, various glands
• absorbs molecules
basement membrane basement
membrane
goblet cell secretes
mucus
Simple columnar • lining of small intestine, oviducts
• absorbs nutrients
basement membrane
goblet cell secretes
mucus
basement membrane
Simple squamous • lining of lungs, blood vessels
• protects
Stratified squamous • skin (epidermis)
• lining of nose, mouth, esophagus, anal canal, vagina
• protects
Functions in protection, secretion, and exchange
Epithelial Tissue Connective tissue binds and supports other tissues
• The various types of connective tissue
– Are characterized by sparse cells in an extracellular gel matrix
Cartilage- forming cells Matrix
D Cartilage (at the end of a bone)
Central canal
Matrix Bone- forming cells
E Bone
F Blood A Loose connective tissue (under the skin)
Elastic fibers
Collagen fiber
Cell
Collagen fibers
Cell nucleus
B Fibrous connective tissue (forming a tendon) White blood
cells
Red blood cell
Plasma
C Adipose tissue
Fat droplets
– Binds and supports other tissues
Connective Tissue Muscle tissue functions in movement
• Skeletal muscle is responsible for voluntary body movements
• Cardiac muscle pumps blood
• Smooth muscle moves the walls of internal organs such as the stomach
• The three types of muscle tissue
Unit of muscle contraction
Muscle fiber
Nucleus
A Skeletal muscle
Nucleus
Muscle fiber Junction between
two cells
Muscle fiber Nucleus
C Smooth muscle
B Cardiac muscle
Muscle Tissue
Cell body
Nucleus
Cell extensions
LM 3
30×
• forms a communication network
• The branching neurons of nervous tissue
– Transmit nerve signals that help control body activities
Nervous Tissue
Artificial tissues have medical uses
• Artificial tissues
– Can assist in the healing of several injuries
CONNECTION Several tissues are organized to form an organ
• Each organ is made of several tissues
– That collectively perform specific functions
Small intestine (cut open)
Lumen
Epithelial tissue (columnar epithelium)
Connective tissue
Smooth muscle tissue (2 layers)
Connective tissue
Epithelial tissue
Lumen
Organ systems work together to perform life functions
• Each organ system
– Has one or more functions
• The digestive and respiratory systems
– Gather food and oxygen
A Digestive system
Mouth
Esophagus Liver
Stomach
Small intestine
Large intestine
Anus
B Respiratory system
Nasal cavity Larynx
Trachea
Bronchus
Lung
• The circulatory system, aided by the lymphatic system
– Transports the food and oxygen
• The immune system
– Protects the body from infection and cancer
C Circulatory system
Heart
Blood vessels
E Lymphatic system
D Immune system
Bone marrow
Thymus
Spleen Lymph nodes
Lymph vessels
• The excretory system
– Disposes of certain wastes
• The endocrine and nervous systems
– Control body functions
F Excretory system
Kidney
Ureter
Urinary bladder
Urethra
Pituitary gland
Thymus
Thyroid gland
Testis (male)
Adrenal gland
Pancreas
G Endocrine system
Ovary (female)
• The integumentary system
– Covers and protects the body
• Skeletal and muscular systems
– Support and move the body
I Integumentary system
Hair
Skin
Nails
K Muscular system
Skeletal muscles
Cartilage
Bones
J Skeletal system
• The reproductive system
– Perpetuates the species
Female
Vas deferens
Penis
Urethra
Testis
Prostate gland
Male
Oviduct
Ovary
Uterus
Vagina
L Reproductive systems
EXCHANGES WITH THE EXTERNAL ENVIRONMENT
Structural adaptations enhance exchange between animals and their environment
• An animal must exchange materials
– With its environment
• Small animals with simple body construction
– Have enough surface area to meet their cells’ needs
Diffusion
Two cell layers Diffusion
Mouth
Gastrovascular cavity
• Larger, complex animals
– Have specialized structures that increase surface area
• Exchange of materials between blood and body cells
– Takes place through the interstitial fluid
Respiratory system
Excretory system
Digestive system
Circulatory system
External environment
Food Mouth
Animal
Body cells
Interstitial fluid
Anus
Unabsorbed matter (feces)
Metabolic waste products (urine)
Intestine
Nutrients
CO2 O2
• The respiratory system
– Has an enormous internal surface area
Animals regulate their internal environment • In response to changes in external conditions
– Animals regulate their internal environment to achieve homeostasis, an internal steady state
Homeostatic mechanisms
External environment
Internal environment
Small fluctuations
Large fluctuations
Homeostasis depends on negative feedback
• Negative feedback mechanisms
– Keep internal variables fairly constant, with small fluctuations around set points
Homeostasis: Internal body temperature of approximately 36–38οC
Temperature rises above normal
Temperature falls below normal
Temperature decreases
Temperature increases
Thermostat shuts off warming mechanisms
Blood vessels in skin constrict, minimizing heat loss
Thermostat in brain activates warming mechanisms
Skeletal muscles rapidly contract, causing shivering, which generates heat
Thermostat in brain activates cooling mechanisms
Sweat glands secrete sweat that evaporates, cooling body
Blood vessels in skin dilate and heat escapes
Thermostat shuts off cooling mechanisms