1. Human Body Systems

2. Organization in Multi-cellular Organisms
the smallest functional unit of life
Tissue
a group of similar cells that perform a particular function
Organ
many groups of tissues that work together
Organ System
groups of organs that work together to perform a specific function
Organism
consists of several organ systems that function together

3. Tissue Types Muscle Nervous Epithelial Connective
Controls the internal movement of materials in the body and external movements of body parts
Nervous
Receives and transmits messages
Epithelial
Covers the surface of the body and lines internal organs
Connective
Holds organs in place and binds body parts together

4. 11 organ systems

5. Digestive System Structures Accessory Structures Functions
mouth, pharynx, esophagus, stomach, small intestine, large intestine
Accessory Structures
salivary glands, pancreas, liver, gallbladder
Functions
Breaks down food into smaller pieces
Absorbs nutrients into blood stream
Eliminates indigestible food waste

6. Pathway of Food Chewing (mastication) physically breaks down food
Mouth:
Chewing (mastication) physically breaks down food
Salivary Glands:
Saliva contains the enzyme amylase which begins the chemical digestion of carbs and lubricates food so it’s easier to swallow
Pharynx:
Beginning of throat
Epiglottis or a flap of tissue that covers the trachea (windpipe) to prevent food from entering the lungs while swallowing

7. Pathway of Food Esophagus: Stomach:
Waves of muscle contractions (peristalsis) push food down toward the stomach
Stomach:
Muscular contractions continue the mechanical digestion of food
Secretes acid which kills bacteria in food and activates enzymes
Secretes the enzyme, pepsin, which begins the chemical digestion of proteins
Secretes mucus which protects the stomach from acid and enzymes

8. Small Intestine: Pathway of Food
Chemical digestion of carbs, proteins, and fat finishes and nutrients are absorbed
Very long and lined with villi or projections that increase surface area for more absorption of nutrients
Peristalsis moves food through small intestine
Liver, gallbladder, and pancreas secrete chemicals into the small intestine to aid in digestion

9. Accessory Organs: Food never enters these organs
Pancreas:
Secretes enzymes into small intestine to break down fats, carbohydrates, and proteins
Liver:
Stores extra glucose as glycogen
Makes vitamin A and bile (which breaks down fats) and neutralizes food coming from the stomach
Breaks down alcohol, drugs, bacteria, old blood cells
Gallbladder:
Stores bile made by the liver and secretes it into the small intestine

10. Large Intestine (including rectum and anus):
Pathway of Food
Large Intestine (including rectum and anus):
Absorbs water from waste and then eliminates indigestible food waste (fiber)

11. Summary of Food Breakdown

12. Respiratory System Structures Functions: nose pharynx larynx trachea
bronchi
bronchioles
lungs
Functions:
Provides oxygen needed for cellular respiration
Removes excess carbon dioxide from the body
Filters debris from air being inhaled

13. Breathing Inhalation Exhalation
diaphragm contracts expanding the volume of the chest cavity causing air to rush into the lungs
Exhalation
diaphragm relaxes decreasing the volume of the chest cavity causing air to be forced out of the lungs

14. GAS EXCHANGE IN THE LUNGS
Air enters the nose and passes through the pharynx, larynx, trachea, bronchi, and bronchioles.
Clusters of tiny air sacs called alveoli are at the end of each bronchiole.
Alveoli are surrounded by capillaries allowing for gas exchange between blood and lungs.

15. Circulatory System Structures Functions: heart blood vessels blood
Transports oxygen, nutrients, hormones, and wastes around body
Helps fight infection
Regulates body temperature

16. Circulatory System: Blood Vessels
Arteries
Carry blood away from heart
Surrounded by muscles to move blood
Capillaries
Tiny vessels (only one cell layer thick) that allow diffusion of materials between blood and cells
Where arteries and veins meet
Veins
Carry blood back to heart
Have valves to prevent backflow

17. Blood Contents Plasma Erythrocytes (red blood cells)
fluid part of blood that carries nutrients, enzymes, hormones, and wastes
Erythrocytes (red blood cells)
contain hemoglobin which carries oxygen
Leukocytes (white blood cells)
attack foreign substances by engulfing them or producing antibodies to destroy them
Platelets
cell fragments that help blood clot when needed

18. Oxygenated blood flows back to the heart.
De-oxygenated blood is pumped from the heart to the lungs where it picks up oxygen.
Oxygenated blood flows back to the heart.
Oxygenated blood is then pumped out to body cells to deliver oxygen and pick up carbon dioxide.
De-oxygenated blood flows back to the heart and the cycle starts again.

19. Circulatory System: Heart blood flow
Pacemaker
Bundle of nerves, tell heart to contract
Left Ventricle
Pumps blood to the body through aorta
Left Atrium
Receives blood returning from lungs
Right Ventricle
Pumps blood to lungs (waste is removed, oxygen added)
Right Atrium
Receives blood returning from the body through vena cava

20. Nervous System Structures Function: brain spinal cord
peripheral nerves
Function:
Contains receptors to perceive changes in environment
Integrates and processes information received from internal and external stimuli
Controls and coordinates functions throughout the body

21. Nervous System: Neurons
Messages travel down each neuron in electrical form.
Neurons consist of 3 parts:
Cell body
contains the nucleus and performs normal cell functions
Dendrites
receive messages from other cells
Axon
sends messages to other cells
Neurons transmit messages to other cells at the synapse using chemicals (neurotransmitters).
Neurotransmitters released at the axon of one cells transmit a message to the dendrites of another cell.

22. Receiving & Sending Messages
Sensory Neurons
gather information from in and around your body and send information to the brain and spinal cord for processing.
Brain integrates information to make decisions on what reaction should be.
Motor Neurons
send impulses from the brain and spinal cord to organs and/or muscles to produce a response.

23. Sensory & Motor neurons

24. Muscular System Structures Functions Skeletal Muscle Smooth Muscle
Cardiac Muscle
Functions
Works with skeletal system to produce voluntary movement
Helps circulate blood and move food through the digestive system
Helps produce heat for the body

25. Three Types of Muscle: Skeletal Smooth Cardiac
Attached to bones by tendons
Responsible for voluntary movement
Smooth
Controls digestion, breathing, circulation
Involuntary
Cardiac
heart muscle

26. Voluntary Muscle Contractions
Voluntary muscles work in opposing pairs so when one muscle contracts, the other one relaxes
Example:
When the bicep muscle (a flexor) contracts and the tricep muscle relaxes, the arm bends.
When the tricep muscle (an extensor) contracts and the bicep muscle relaxes, the arm straightens.

27. Skeletal System
An adult human body has approx. 206 bones organized into an internal framework called the skeleton
Structures:
Bones
Cartilage
Ligaments
Tendons
Functions:
Supports the body and protects internal organs
Allows movement
Stores mineral reserves
Provides a site for blood cell formation

28. Bone Structure Bones Compact bone Spongy bone
network of cells and protein fibers supported by deposits of calcium
Compact bone
forms outside of bones / very dense with canals running though for blood vessels and nerves
Spongy bone
forms inside of bones /less dense and resembles latticework
Cavities within bones contain bone marrow which produces red blood cells, some white blood cells, and blood platelets.

29. Joints Joints Tendons Ligaments Cartilage
where bones are joined together
Tendons
hold muscles to bone
Ligaments
hold bones to bones
Cartilage
protects the bone by covering parts that rub together when joints move

30. Integumentary System Structures: Functions: skin hair nails
sweat glands
oil glands
Functions:
Serves as a barrier against infection and injury
Helps to regulate body temperature
Provides protection against ultraviolet radiation from the sun

31. Close-up of Integumentary System

32. Excretory System Structures: Functions: kidneys ureters
urinary bladder
urethra
Functions:
Filters metabolic waste from the body
Maintains homeostasis by regulating the water content of the blood
Excretes urinary waste products

33. Waste-laden blood enters the kidneys through the renal artery.
How do the kidneys work?
Urine travels down the ureters, gets stored in the bladder, and is expelled from the body through the urethra.
Filtered blood is returned to the circulatory system through the renal vein.
Excess water and wastes are filtered out of the blood by the kidneys and collected as urine.
Waste-laden blood enters the kidneys through the renal artery.

34. Lymphatic System Structures: Functions: Spleen
thymus, spleen, lymph nodes, lymph vessels, white blood cells
Functions:
Helps protect the body from disease
Spleen
filters blood, destroying damaged red blood cells and platelets
Helps absorb fats and certain vitamins from intestines into blood

35. Endocrine System Structures: Function:
hypothalamus, pituitary gland, pineal gland, thyroid gland, parathyroid glands, thymus gland, adrenal glands, pancreas, ovaries (females), testes (males)
Function:
Secretes hormones that control growth, development, metabolism, and reproduction

36. Reproductive System Male Structures Functions Female Structures testes
epididymis
vas deferens
urethra
penis
Functions
Produces reproductive cells
Males deliver reproductive cells to females
Females nurture and protect developing embryo
Female Structures
ovaries
Fallopian tubes
uterus
vagina

37. Feedback Control
Consists of a sensor, a control center, and an effector pathway
A feedback system uses the consequences of the process (too much or too little produced) to regulate the rate at which the process occurs
Helps to maintain homeostasis
Feedback systems are used to control and regulate processes in the body.

38. Feedback Control Example: Body Temperature