Human Body SystemsChapters 35-40

Themes

How do systems work together to achieve a shared function?

How do systems maintain homeostasis?

What’s the relationship between a system’s structure and function?

Objectives – SWBAT:

Know that complex organisms are comprised of organ systems, which are comprised of organs, which are comprised of tissues, which are comprised of cells.

Describe how feedback control can act to maintain homeostasis.

Feedback Control Homeostasis is often

maintained through the use of Feedback systems (or loops).

A feedback system uses the consequences of the process (too much or too little produced) to regulate the rate at which the process occurs Consists of a sensor, a

control center, and an effector pathway

Maintaining homeostasis

high

low

hormone 1

lowersbody condition

hormone 2

gland

specific body condition

raisesbody condition

gland

Feedback

liver

pancreas

liver

Regulation of Blood Sugar

blood sugar level(90mg/100ml)

insulin

body cells takeup sugar

from blood

liver storessugar

reducesappetite

glucagon

pancreas

liver releases

sugartriggershunger

high

low

FeedbackEndocrine System Control

Organization in Multi-cellular Organisms

1. Cell –smallest functional unit of life

2. Tissue – group of similar cells that perform a specific function

3. Organ – group of tissues that perform a general function

4. Organ System – group of organs that achieve a major bodily function

5. Organism

Tissue Types

Four major types of tissues:• Muscle: controls the internal movement of materials

in the body and external movements of body parts• Nervous: receives and transmits messages• Epithelial: covers internal and external organ

surfaces • Connective: holds organs in place and binds body

parts together

Body Cavities The organs and systems are housed in

compartments called body cavities to protect them and allow them to contract or expand as needed

Four major human body cavities Cranial: holds the brain Spinal: holds the spine and spinal cord Thoracic: Upper compartment in trunk of body—holds

the heart, esophagus, and respiratory system Abdominal: Lower compartment in trunk of body—

holds the digestive, reproductive, and excretory systems

Thoracic and abdominal cavities are separated by the diaphragm muscle

11 Organ Systems

Objectives – SWBAT:

Identify the functions of 11 major human organ systems (nervous, endocrine, digestive, excretory/urinary, cardiovascular/circulatory, respiratory, muscular, skeletal, reproductive, lymphatic, integumentary).

Distinguish between the mechanical and chemical digestion of foodIdentify the organs of the digestive system, in the order that food passes through them, and their roles in processing food.

Explain the functions of the accessory organs of the

digestive system.

Digestive System

Structures: mouth, pharynx, esophagus, stomach, small intestine, large intestine

Accessory Structures (help digestion, but no food enters them): salivary glands, pancreas, liver, gallbladder

Functions: Acquiring nutrients

Converts food into simpler molecules that can be transported to body cells

Absorbs food molecules into bloodstream

Processes Ingestion

taking in food Digestion

mechanical digestion breaking up food into smaller pieces

chemical digestion breaking down food into molecules small

enough to be absorbed into cells Accomplished by enzymes

Absorption absorb nutrients across cell membranes

diffusion active transport

Elimination/Excretion undigested material passes out of body

intracellulardigestion

extracellulardigestion

Human digestive system

Mouth

Functions mechanical digestion (teeth) chemical digestion (saliva from salivary

glands) amylase enzyme

digests the polysaccharide starch

mucus protects soft lining of digestive system lubricates food for easier swallowing

buffers neutralize acid to prevent tooth decay

Swallowing (& not choking)

Pharynx Uppermost part of throat Epiglottis

flap of tissue in pharynx, closes pathway to respiratory or digestive system to ensure proper pathway for food

Esophagus Peristalsis

involuntary muscle contractions push food to stomach

StomachFunctions

disinfect foodhydrochloric acid = pH 2

kills bacteria

food storagecan stretch to fit ~2L food

digests proteinpepsin enzyme

But the stomach is made out of protein!What stops the stomach from digesting itself?

mucus secreted by stomach cells protects stomach lining

Small intestine Functions: Digestion

Liver and pancreas secrete enzymes into small intestine

digest carbohydrates Enzymes from pancreas

digest proteins Enzymes from pancreas

digest lipids (fats) Bile from liver & enzymes from pancreas

Absorption Absorbs all three nutrient groups into bloodstream Nutrients move into body cells by:

Diffusion, active transport

Absorption in Small Intestines Absorption through villi & microvilli

finger-like projections of intestine wall, full of capillaries (blood vessels)

increases surface area for absorption

SMALL INTESTINES6 meters long,but can stretch

to cover a tennis court

Liver & Gall Bladder Liver produces bile, gallbladder only stores

it Bile digests lipids Liver also functions to filter toxins, drugs, and

dead blood cells from bloodstream

Function Re-absorbs water

You use ~9 liters of water per day in digestive juices if you don’t reabsorb water, death by

dehydration

> 90% of water re-absorbed If not enough water re-absorbed

Diarrhea (can be fatal) If too much water re-absorbed

constipation

Large intestines (colon)

You’ve got company! Living in the large intestine is a

community of mutualistic bacteria E. coli

digest cellulose in fruits & vegetables

produce vitamins vitamin K & B vitamins

but generate gases byproducts of bacterial metabolism

stomachkills germs break up fooddigest proteinsstore food

mouthbreak up fooddigest starchmoisten food

small intestinesbreakdown food

- proteins- starch- fats

absorb nutrients

pancreasproduces enzymes to digest proteins & carbs

liverproduces bile

- stored in gall bladderbreak up fats

large intestinesabsorb water

Rectum

Last section of large intestines eliminate feces

undigested materials mainly cellulose from plants, called

roughage or fiber masses of bacteria dead intestinal cells

Objectives – SWBAT:

Identify the functions of 11 major human organ systems (nervous, endocrine, digestive, excretory/urinary, cardiovascular/circulatory, respiratory, muscular, skeletal, reproductive, lymphatic, integumentary).

Identify the organs of the respiratory system in the order that air passes through them.

Explain how the respiratory system conducts gas exchange.Identify the main components of the cardiovascular system (heart chambers, vessels) in the order that blood passes through them.

Distinguish between the pathways of oxygenated and deoxygenated blood.

Give examples of things the cardiovascular system transports. Explain the parts of blood and their functions, including the roles of

hemoglobin and bone marrow.

Respiratory System

Structures: nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs (alveoli)

Functions: Gas exchange

Provides oxygen (cellular respiration reactant)

Removes excess carbon dioxide (cellular respiration waste product)

Negative pressure breathing Diaphragm moves down & expands chest

cavity, pulls air into lungs

inhale exhale

Structures

alveoli

Air passes through, in order:

nose/mouth pharynx larynx trachea bronchi bronchioles alveoli

capillaries(circulatory system)

Lungsspongy texture

high surface area for more absorption of O2

cilia move mucus and trapped particles

upward to clear out lungs

line most of respiratory tract from nose to bronchioles

Respiratory Surface Lung interior made of small air sacs called alveoli

– the site of gas exchange Each bronchiole ends in a cluster of them

Thin—for simple diffusion Moist—allow for gases to dissolve for diffusion Surrounded by tiny blood vessels (capillaries)

Moving gases into bloodstream Inhale

Bring air in, O2

diffuses from alveoli to blood

Exhale CO2 diffuses from

blood to alveoli, air pushed out

capillaries(circulatory system)

Breathing and Homeostasis

Homeostasis need to balance O2 in and CO2 out

For cellular respiration Exercise

breathe faster need more ATP, muscles conducting more

respiration

= bring in more O2 & remove more CO2

Disease poor lung or heart function = breathe faster

need to work harder to bring in enough O2 & remove CO2

O2

ATP

CO2

Circulatory System

Structures: heart, blood vessels, blood

Functions: Transport

Brings oxygen, nutrients, and hormones to cells

Carries waste away from cells Helps fight infection

Regulation of body temperature

Blood & blood cells Blood is a tissue of fluid & cells

plasma liquid part of blood dissolved macromolecule monomers (sugars,

amino acids), salts, and more cells

red blood cells (RBC) white blood cells (WBC)

defense & immunity

platelets blood clotting

Red blood cells Small round cells

produced in bone marrow full of hemoglobin, an iron-containing protein

which carries oxygen 5-6 million RBC in drop of human blood

last 3-4 months (120 days) Dead cells filtered out by liver

~3 million RBC destroyed each second

O2O2

O2O2

Blood vesselsarteries

arterioles

capillaries

venules

veins

artery

arteriolesvenules

veins

Arteries: Built for their job Arteries

Carry blood away from heart

thicker walls Can resist the high

pressure of pumped of blood

Veins: Built for their job Veins

carry blood back to heart thinner-walled

blood travels back to heart at low speed & pressure

valves in large veins in larger veins one-way valves

allow blood to flow only toward heart

Open valve

Blood flowstoward heart

Closed valve

Structure-function relationship Capillaries

very thin vessels with very thin walls

allows diffusion of materials across capillary O2, food diffuse out of

capillary blood and to nearby body cell

CO2, waste diffuse from body cell into capillary

body cell

O2

food

waste

CO2

Blood In describing circulation, blood is either:

Oxygenated (oxygen is bound to hemoglobin, not much CO2)

Deoxygenated (little oxygen, lots of CO2) (Deoxygenated blood is not blue!)

2 part system Circulation to lungs

blood gets O2, drops off CO2

brings oxygenated blood from lungs to heart

Circulation to body pumps oxygenated blood to

body picks up nutrients from

digestive system collects CO2 & cell wastes

Circulation of Blood

heart

lungs

body

Circulationto lungs

Circulationto body

Stops along the way…

Lungs gas exchange

Small Intestines pick up nutrients from digested food

Large Intestines pick up water from

digested food Liver

clean out toxins and deteriorated blood cells

More stops along the way… Kidneys

filters out cell wastes (urea) and extra water

Bone pick up new red

blood cells Spleen

pick up new white blood cells

Vertebrate Heart

Made of muscle, pumps blood

4 chambers 2 atria (atrium)

Small, thin-walled chambers that receive blood

2 ventricles Large, thick-walled

chambers that pump blood out

rightatrium

leftatrium

rightventricle

leftventricle

Circulatory System: Heart FLOW:

Right side: Deoxygenated blood Right Atrium: Blood comes in from the

body Right Ventricle: Pumps blood to lungs

Left side: Oxygenated blood Left Atrium: Blood returns from lungs Left Ventricle: Pumps blood out to

body

Pacemaker: bundle of tissue, coordinates contraction

AV

SL

AV

Lub-dub, lub-dub 4 valves in the heart

flaps of tissue prevent backflow of blood

Heart sounds caused by closing of valves

Heart murmur = leaking valve, causes a hissing sound

waste

food

Circulatory System & Homeostasis Homeostasis

need to balance food & O2 in, CO2 & waste out

Exercise heart beat faster

In response to muscles’ need for more cellular respiration for more ATP

Disease poor lung or heart function =

heart beat faster need to work harder to bring in O2 &

food & remove wastes Temperature

Blood is hot. More blood in surface capillaries = more body heat lost.

O2

ATP

CO2

Objectives – SWBAT:

Identify the functions of 11 major human organ systems (nervous, endocrine, digestive, excretory/urinary, cardiovascular/circulatory, respiratory, muscular, skeletal, reproductive, lymphatic, integumentary).

Diagram the basic anatomy of a neuron and how neurons communicate.

Distinguish between the central and peripheral nervous system, and sensory vs motor neurons.

Explain the locations and functions of the three types of muscle. Differentiate between connective tissues: cartilage, tendon, and

ligament

Nervous System

Structures: brain, spinal cord, peripheral nerves (sensory and motor)

Function: Communication and

control Coordinates functions

throughout the body in response to internal and external stimuli

Nervous system cells

dendrites

cell body

axon

synapse

Neuron = basic cell of nervous system

signal direction

signaldirection

Action potentials, electrical “messages,” travel down each neuron in one direction.

Neurons consist of 3 parts:• Dendrites – receive messages from other cells• Cell body – contains the nucleus and performs normal

cell metabolism to support cell• Axon – sends messages to other cells

Synapse

synapse

Synapse = junction between nerve cells 1st cell releases chemical

(neurotransmitter) to trigger action potential in the next cell

(FYI: psychoactive drugs affect nervous system by affecting neurotransmission at synapse)

Nervous System

Central nervous system brain & spinal chord “decision making”

Peripheral nervous system body nerves “detecting and action-taking”

cerebrum

cerebellum

spinal cord cervicalnerves

thoracicnerves

lumbarnerves

femoral nerve

sciatic nerve

tibialnerve

Sending and Receiving Messages

Information Collection Sensory neurons– gather information about

what is happening in and around your body and send this information to the CNS for processing. Receptors detect changes inside and outside the body

example, receptors in your eyes detect light.

Delivering Orders Motor neurons– send impulses from the brain

and spinal cord to other systems. When muscles get impulses from motor neurons,

they respond by contracting example, motor neurons signal muscles around your eyes to

contract

Types of neuronssensory neuron(from senses)

interneuron(brain & spinal chord)

motor neuron(to muscle)

Simplest Nerve Circuit Reflex, or automatic response

signal only goes to spinal cord no higher level

processing = rapid response

advantage Fast, don’t need to

think or make decisions about blinking balance pupil dilation startle

Muscular System

Structures: Skeletal muscle, smooth muscle, cardiac muscle

Functions: Movement

Works with skeletal system to produce voluntary movement

Helps circulate blood and move food through the digestive system

Three Types of Muscle: Skeletal: attached to bones by tendons;

responsible for voluntary bodily movement Smooth: controls digestion, breathing,

capillary width; involuntary Cardiac: heart muscle; involuntary

Muscles movement Muscles do work by

contracting contracting = shortening

move skeletal parts involves active transport, so

it requires ATP

tendons tough connective tissue,

connects bone to muscle

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.

Voluntary Muscle Contractions

Skeletal SystemThe adult human body has approx. 206 bones organized into an internal framework called the skeleton

Structures: bones, cartilage, ligaments, tendons

Functions: Structural support

Supports the body Protects internal organs

Allows movementStores mineral reserves (calcium)Provides a site for blood cell formation

Bone Structure

Bone = a solid network of cells and protein fibers that are supported by deposits of calcium. Compact bone forms the outside of bones. Dense,

calcium-rich, lined with canals carrying nerves & blood vessels.

Spongy bone forms the inside of bones. Less calcium, less dense.

Cavities within bones contain bone marrow produces red blood cells,

some white blood cells, and blood platelets.

FYI, teeth are not bones! Their anatomy is completely different.

Joints

Joints are where bones are joined together. Bones in immovable joints are

fused (ex: skull) Bones in moveable joints are

held together by ligaments. Unlike tendons, which connect

muscle to bone.

Cartilage covers the area of the bones that rub together when joints move, prevent bones from grinding.

Objectives – SWBAT:

Identify the functions of 11 major human organ systems (nervous, endocrine, digestive, excretory/urinary, cardiovascular/circulatory, respiratory, muscular, skeletal, reproductive, lymphatic, integumentary).

Identify the organs involved in removing non-gaseous waste from the bloodstream.

Recognize that the kidneys remove nitrogenous waste and excess water, and the liver filters toxic compounds from the bloodstream.

Know what lymph is. Explain the three lines of defense against pathogens, distinguishing between

specific and non-specific defenses. Explain what a hormone is and how one can act to maintain homeostasis. Give examples of different functions that hormones can regulate. Identify the pathways to fertilization taken by male and female gametes, in the

order that they pass through each structure. Compare and contrast the functions of the male and female reproductive

systems.

Integumentary System

Structures: skin, hair, nails, sweat glands, oil glands

Functions: Serves as a barrier against infection

and injury Provides protection against ultraviolet

radiation from the sun Helps to regulate body temperature Helps remove some waste

Close-up of Integumentary System

Body temperature regulation = sweat evaporation cools skin

Waste function = sweat contains excess salt, water

Excretory System

Structures: kidneys, ureters, urinary bladder, urethra

Functions: Eliminates waste products of

metabolism from the body Maintains homeostasis by

regulating the water content of the blood which controls blood volume, blood pH, and waste

What liquid waste do we make?

Digesting protein makes ammonia nitrogen waste = ammonia = poison

H

CO2 + H2O

NH2 = ammonia

H

HN C—OH

|| O

H|

—C—|

Waste-laden blood enters the kidneys through the renal artery.

Urea, excess water, and other wastes are filtered out of the blood by the kidney and collected as urine.

Urine travels down the ureters, is stored in the bladder, and then is expelled from the body through the urethra.

How do the kidneys work?

Lymphatic SystemStructures: white blood cells, thymus,

spleen, lymph nodes, lymph vessels

Functions: Immune defense and fluid balance

Helps protect the body from disease Collects fluid lost from blood vessels

(lymph), cleans it, and returns it to the circulatory system

Lymph

Lymph = excess tissue fluid pale white, similar to blood

plasma, but with more fats and immune cells

seeps between cells, accumulating “junk” like bacteria, cell debris

Lymph vessel = carries lymph, like blood vessel

Lymph node = filters the “junk” from lymph

Why an immune system? Attack from the outside & inside

lots of organisms want you for lunch! we are a tasty vitamin-packed meal

cells are packages of proteins, carbohydrates & fats no cell wall

animals must defend themselves against invaders… viruses

HIV, flu, cold, measles, chicken pox, SARS bacteria

pneumonia, meningitis, tuberculosis fungi

yeast protists

amoeba, Lyme disease, malaria cancer cells

…but, must do so as efficiently as possible!

What’s forlunch?!

Immune System

Immune defenses may be non-specific or specific Non-specific = broad, defends against

many kinds of attackers Specific = targets one kind or a small

number of attackers

Three lines of defense…

1st line: Physical Barriers

Non-specific External barriers

skin & mucus membranes

excretions Sweat, stomach acid,

tears, mucus, saliva

Lining of trachea:

ciliated cells & mucus secreting cells

2nd line: Generalist responses Non-specific, internal defenses,

including: Patrolling white blood cells

attack invaders that get through the skin phagocyte cells

Macrophages “eat” invaders

Macrophage “eating” bacteria

histamines increases blood

flow =more WBC to

fight, RBC and platelets to repair

2nd line: Generalist responses

Bacteria

Blood vessel

Chemicalalarm

signals

Pin or splinter Blood clot

Phagocytes

Swelling

Inflammation injured cells release chemical signals

2nd line: Generalist responses Fever = elevated body temperature

slows growth of germs (enzyme denaturation) helps macrophages speeds up repair of tissues

3rd line: Lymphocytes Specific defense

responds to specific invaders recognizes specific

foreign antigens white blood cells

B cells T cells

antibodies

B cell

Lymphocytes

T cells Recognize invader, recruit other cells to come

fight B cells

Make antibodies Memory B cells

remembers invader can make antibodies quickly the next time

protects you from getting disease more than once

Proteins that tag invaders in the blood so macrophages can eat them tag says “this is an invader, sic ‘em!”

Antibodies

macrophageeating tagged invaders

invading germs tagged with antibodies Y

Y

YY

YY

Y

B cells releasing antibodies

Y

YY

Y

Y

Y

Y

Y Y

Y

Y

Y

Y

Y

Lines of defense 1st line:

broad, external defense “walls & moats”

skin & mucus membranes

2nd line: broad, internal defense

“patrolling soldiers” phagocyte (eating) WBCs

3rd line: specific, acquired immunity

“elite trained units” lymphocyte WBCs & antibodies

B & T cells

Barriers

Non-specific patrol

Immune system

Endocrine SystemStructures: glands: hypothalamus,

pituitary gland, pineal gland, thyroid gland, parathyroid glands, thymus gland, adrenal glands. Also pancreas, ovaries and testes

Function: Control

Secretes hormones = chemicals that cause changes in other parts of body

growth hormones sex hormones response hormones metabolism hormones and more….

Responding to hormones Lock and key system

hormone fits receptor on “target” cell

targetcell

non-targetcells

secretingcell

can’tread

signal

can’tread

signal

Glands Pineal

melatonin Pituitary

many hormones: master gland

Thyroid thyroxine

Adrenal adrenaline

Pancreas insulin, glucagon

Ovary estrogen

Testes testosterone

Reproductive SystemMale Structures: testes,

epididymis, vas deferens, urethra, penis

Female Structures: ovaries, Fallopian tubes, uterus, vagina

Functions: Reproduction

Produce gametes Males: deliver gametes to females Females: support developing

embryo

Structures Testes: Produce sperm and testosterone. Kept outside of body (in

scrotum) = permits temperature control. Epididymis: Stores sperm as they develop Vas Deferens: Tube from epididymis to urethra Urethra/Penis: Tube within the penis that leads sperm to outside of

body. Semen: Fluid containing hundreds of millions of sperm per ejaculation. Also

contains sugars (energy for sperm), bases (protect sperm from acidic environment of vagina), other chemicals to enhance sperm motility.

Testes produce hormones More testosterone than estrogen

Produces secondary sex characteristics (facial & body hair, increases body size/muscles, deepens voice)

Stimulates sperm production

Reproductive System: Male

Reproductive System: Female

Structures: Ovaries: Each ovary contains 400,000

primary follicles (single immature eggs). Once a month 1 follicle goes through meiosis and produces 1 mature egg (sometimes 2 or 3)Ovulation

Fallopian Tubes (oviduct): Carry eggs from ovary to uterus. Site of fertilization.

Uterus: Where a zygote will implant, develop into embryo, then fetus. Made of muscle for pushing in labor.

Cervix: opening of uterus into vagina. Vagina: Birth canal and entrance for sperm into reproductive tract.

Ovaries produce hormones More estrogen & progesterone than testosterone

Regulate menstrual cycle and pregnancy Produce secondary sex characteristics—breast formation, fat distribution,

wider pelvis (hips)