the human body an overview

7/28/2019 The Human Body an Overview

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The Human Body:

An Overview



How do Humans and other complex mammals

maintain homeostasis? They must carry out all

needed life functions in a coordinated way.What does our species need to accomplish?

Growth Repair of injuries

Get energy Get building materials

Get rid of waste

Keep away disease

Respond to changing environment

Reproduce



Eleven Body Systems work together to

maintain homeostasis and carry out these

tasks:

1. Nervous System 2. Endocrine System

3. Lymphatic System 4. Circulatory System

5. Respiratory System 6. Digestive System

7. Excretory System 8. Skeletal System 9. Muscular System 10. Integumentary System

11. Reproductive System



1. Nervous System:

Structures: Brain, SpinalCord, Peripheral Nerves,

Neurons (Cells of nervous

system)

Functions: Coordinates

the body’s response tochanges to internal and

external environment



2. Endocrine System – Hormone System

Structures: Glands -Hypothalmus, pituitary, thyroid,

parathyroids, adrenals,

pancreas, ovaries (in females),testes (in males)

Functions: Produce Hormones.Controls growth, development,

metabolism, and reproduction



3. Lymphatic System – Immune System

Structures: White blood

cells, thymus, spleen,lymph nodes, lymph

vessels

Function: Helps protect

the body from disease;

collects fluid lost from

blood vessels; returns the

fluid to the circulatory

system



4. Circulatory System

Structures: Heart,Blood vessels, blood

Functions: Brings

oxygen, nutrients, andhormones to cells;

fights infection;

regulates body

temperature



5. Respiratory System

Structures: Nose, pharynx, larynx, trachea,

bronchi, bronchioles, lungs

Functions: Provides

oxygen needed for cellular

respiration and removescarbon dioxide from body



6. Digestive System

Structures: Mouth,

pharynx, larynx,esophagus, stomach,

liver, pancreas, small

and large intestines,Function: Breaks down

foods into simple

molecules that can beused by the body for

respiration and building

cells



7. Excretory System

Structures: Skin, lungs,kidneys (nephrons),

ureters, urinary bladder,

urethra

Functions: Removes

waste products of metabolism from the

body



8. Skeletal System

Structures: Bones,cartilage, ligaments,

tendons

Functions: Supports the

body; protects internal

organs; allows movement;

stores mineral reserves;

provides a site for blood

formation



9. Muscular System

Structures: Skeletalmuscle, smooth muscle,

cardiac muscle

Function: Works with

skeletal system to produce

voluntary movement; helpscirculate blood and move

food through the digestive

system



10. Integumentary System (Skin)

Structures: Skin, Hair, Nails, Sweatand Oil Glands

Functions: Serves as a barrier against

infection and injury; Helps to regulate

temperature; Protects against UV light



Structures:

Female- Uterus, Fallopiantubes, ovary, cervical canal,

cervix, vagina

Male – Penis, Vas Deferens,

Prostate, Epididymis, Testes,

Scrotal Sac, Seminal Vesicle

Function: Produces

reproductive cells; in females

nurtures and protects

developing embryo

11. Reproductive System



Support and Motion

Functions of the SKELETAL ANDMUSCULAR SYSTEM

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How does the human body

move from place to place and

have the ability to run, blink or build things?

These things are all made

possible by the skeletal and

muscular systems.

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Skull

Sternum

Ribs

Vertebral

column

Metatarsals

Metacarpals

Phalanges

Clavicle

ScapulaHumerus

RadiusPelvisUlnaCarpals

Femur

Patella

Fibula

Tibia

Tarsals

Phalanges

A. Skeletal

System

There are 206bones in the adult

human body.

These bonesprovide a system

of supports and

levers on whichmuscles can

produce

movement



Figure 36-3 The Structure of BoneBones are a solid network of living cells and

protein fibers that are surrounded by calcium

deposits. Bones contain blood vessels and cavities

containing marrow. Red marrow produces red

blood cells, white blood cells and platelets

Bone

Marrow



Ball-and-Socket Joint

Hinge

Joint

Pivot Joint

Saddle Joint

Clavicle

Figure 36-4 Freely Movable Joints and Their Movements

Section 36-1

Joints are places where one bone attaches to another.

Each type of joint is designed to allow movement

without damaging the other bones. Joints in the skull

allow no movement, joints in the spine allow a small

amount of movement and those shown below allow

movement in one or more directions.

Knee

Elbow



Muscle

Tendon

Femur

Patella

BursaLigament

Cartilage

Fat

Fibula

Tibia

KneeJointSection 36-1

Ligaments are atough connective

tissue that attach

bones to bones

Tendons are

connective tissue

which attach bonesand muscles to

allow bones to move



B. The Muscular System

More than 40% of the average human is muscle.

Muscles are involved in both voluntary actions andinvoluntary actions. Three types of muscles cells are:

•Skeletal – Attached to bones for voluntary actions

and controlled by the central nervous system

•Smooth – Found in the digestive tract and the blood

vessels to move food and blood. Control involuntary

actions (you do not decide for them to work)

•Cardiac – Heart muscle cells are involuntary.



Figure 36-7 Skeletal Muscle Structure

Section 36-2Skeletal muscles are made up of clusters of

filaments of proteins known as actin and myosin

which control muscle contraction and relaxation



Figure 36-8 Muscle Contraction

During Muscle

contraction Actin

filaments slide over myosin filaments

shrinking the

muscle



Energy for muscle contraction is supplied by

ATP



Nervous system cells known as motor neurons

are attached to skeletal muscle cells to control

the voluntary movement.

Threadlike Nerveor neuron

Axon or junction



Movement

Movement

Biceps

(relaxed)

Triceps

(contracted)

Biceps

(contracted)

Triceps

(relaxed)

Figure 36-11 Opposing Muscle Pairs

Section 36-2Skeletal muscles work in opposing pairs.

When one muscle contracts, the other relaxes.

N i i d W R l



How does the human body take in required

nutrients and get rid of wastes?

The Digestive and Excretory Systems are

responsible for bringing in food and getting rid of

the leftovers.

Nutrition and Waste Removal

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Food supplies the raw materials for

building molecules your body needs, such

as:

• enzymes

• Lipids in cell membranes

• DNA

Food contains 45 substances your

body needs but cannot manufacture.

Overview of Nutrients



The nutrients your body needs are water,

carbohydrates, fats, proteins, vitamins and

minerals.

WATER – Most of the bodies reactions take place in

water. Humans need an average of 1 liter of water a

day. Dehydration causes many problems throughout

the body.

CARBOHYDRATES – Sugars and starches are used by the

body to provide the simple sugars needed for Respiration

(energy)



FATS- Deposits of fats protect body organs, insulate

the body and store energy, make up cell membranes and

coat the nervous system cells

PROTEINS – Supply the raw materials for

growth and repair in the form of enzymes

VITAMINS – Organic molecules that work with

enzymes to control body processes.

MINERALS – Inorganic nutrients that areneeded in small amounts. Calcium is needed to

build bones, Iron is needed for red blood cells.



Fats

Sugars

Food Guide PyramidA Balanced Diet



C. The Digestive System

Pharynx

Esophagus

Liver

Gallbladder

Rectum

Mouth

Salivary

Glands

Stomach

Pancreas behind stomach

Large Intestine

Small Intestine

The Process of Digestion: The path of food



The Process of Digestion: The path of food

Each organ of the digestive system helps convert

foods into simpler molecules that can be absorbed andused by the cells of the body.

Teeth – Cut, Crush and tear food

Salivary glands – Moisten food to make it easier to chew and pass through the system, enzymes break down starches

Esophagus – Tube from mouth to stomach connected by

Pharynx. Works by contraction of the smooth musclesknown as peristalsis.

Stomach – Muscular sac that churns and mixes food with acid

As food lea es the stomach it tra els into the small



Section 38-2

As food leaves the stomach it travels into the small

intestine through the doudenum, and it mixes with

with enzymes and digestive fluids from the liver,

gallbladder and pancreas.

Liver

Gallbladder

Doudenum

Bile Duct

Pancreas

Ch i l f th b kd



.Chemicals from the pancreas breakdown

carbohydrates, proteins, lipids and nucleic

acids. In addition chemicals from the pancreasproduce substances which neutralize stomach

acid. If the acid travels too far without being

neutralized it will change the shape of

enzymes and cause problems in the body.

The Liver makes bile which acts like a

detergent to break down fat. The gall

bladder is a storage area for the bile

The small intestine absorbs nutrients from the



SmallIntestine

Villus

Section 38-2

The small intestine absorbs nutrients from the

digestive systems and transfers many of the nutrients

to the circulatory system. The small intestine is lined

with small fingerlike projections known as villi whichdesigned to have a large surface area for this task.

Large intestine (Colon)



Large intestine (Colon)

Food that enters the large intestine is nutrient-free.

Usable nutrients have been absorbed leaving water and undigestible substances. The large intestine

removes water from the waste. Once water is

eliminated the solid waste passes out of the body

through the rectum.

The appendix is located just below the entry

to the large intestine. In many animals ithelps digest difficult materials such as cellulose.

In humans the appendix is not used for any purpose

in digestion. When it gets infected it is

removed.



D. Excretory System:

In the process of obtaining nutrients and

carrying out chemical reactions the human body

produces wastes (CO2, Urea, Salts). If some of

these wastes are not removed they couldthreaten homeostasis. Excess chemicals that

are not toxic also need to be removed.

The skin, lungs and kidneys all function to

get rid of excess or harmful products

produced in the body.



Kidney Nephron

Section 38-3

Kidneys contain millions of small filters called

nephrons, which filter your entire blood supply

every 45 minutes. Filtration takes place because

blood pressure forces water, salt, glucose, amino acids

and urea into structures known as Bowman’s capsules.

(Protein and Blood are too large to enter)

Bowman’s

Capsule

Processes of osmosis and active transport filter the



Processes of osmosis and active transport filter the

useful materials from the waste (urine). Substances

your body needs to keep are returned to the blood

stream. Substances your body needs to get rid of arepassed from the renal tubes to the urinary bladder.

Kidney

Urinary Bladder

Ureter

Urethra

Vein Artery

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Other important parts of the bodies

excretory system

•The skin excretes excess water and

salts

•The lungs excrete carbon dioxide produced from respiration

Both of these body organs serves multiple functions

in the human body.

The Respiratory System links to the

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Section 37-3

Figure 37-13 The Respiratory System

Bronchi branch to air sacs

known as aveoli where

gas exchange occurs

The Respiratory System links to the

Circulatory System to provide cells with

oxygen and remove carbon dioxide

G E h i



Alveoli

Bronchiole

Capillary

Section 37-3

Gas Exchange in

the lungs occurs

through the

process of

DIFFUSION

High concentration of oxygen (O2) moves out

of lungs into blood to

balance concentration.CO2 does the opposite

(moves from blood to

lungs)

Fi 37 15 Th M h i f B thiThe Lungs are only air sacs In order for them to



Air

inhaled

Diaphragm

Rib cage

rises

Air

exhaled

Diaphragm

Rib

cage

lowers

Inhalation

Exhalation

Section 37-3

Figure 37-15 The Mechanics of BreathingThe Lungs are only air sacs. In order for them to

move they must work together with a muscle

known as the Diaphragm

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Breathing is not an entirely

voluntary process. While

you have control of breathing so that you can

briefly hold your breath or

blow up a balloon, your body will not allow you not

to breathe. The brain has

control over the diaphragmif the level of carbon dioxide

in the blood rises to high.

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The circulatory system works together

with several other body systems to bring

needed supplies to cells which cannot move.

The circulatory system is a delivery system

that consists of the following:• The Heart

• Blood Vessels• Blood

The Heart:



The Heart:

The heart is about the size of a clenched fist. On

average the heart contracts about 72 times aminute, pumping about 70 milliliters of blood with

each contraction.

The entire circulatory systemincluding Heart has structures

which prevent oxygen rich blood

and oxygen poor blood frommixing. All blood is really red

but oxygen poor blood is shown

as blue in pictures for ease.

The heart has four main chambers with valves



The heart has four main chambers with valves

that separate each to prevent backflow

Left Ventricle

Left Atrium

Pulmonary Artery

Oxygen poor

blood to lungs



The heart acts as two pumps. One for sending

oxygen poor blood to the lungs and the other

for sending oxygen rich blood to the body.

The heart’s contractions are controlled by a small

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The heart s contractions are controlled by a small

group of cardiac muscle cells known as the

sinoatrial node. These are the pacemakers of the

heart. These cells send an electrical message from

the atrium to the ventricles to contract

Sinoatrial

Node

Atrioventricular

node

Conducting

Fibers

Blood mo es thro gh 3 different t pes of essels:



Blood moves through 3 different types of vessels:

Arteries – Carry oxygen rich blood away from the heart

Capillaries – Tiny vessels only one cell thick. Bring oxygenand nutrients to the cells. Remove waste products.

Veins – Carry blood back to the heart with wastes

ARTERYVEIN

CAPILLARIES

Blood Pressure:



Blood Pressure:

When the heart contracts it produces

pressure in the arteries. The force of the blood on the arteries is known as

blood pressure. Blood pressure

decreases when the heart relaxes but it

does not disappear. The difference

between the two pressures is what is

measured when you go to the doctor

and have your blood pressure checked.

The average adult’s blood pressure is

120/80.



Blood

The Human body contains 4 to 6 liters of blood, which

is about 8% of the total body mass. Blood is made upof a number of types of cells and substances:

55% Plasma – mostly water with dissolved

gases, salts, nutrients, enzymes, hormones, waste

products and plasma proteins.

45% Cells – Red Blood cells, White BloodCells, and platelets.



Whole

Blood

Sample

Plasma

Sample Placed inCentrifuge

Blood Sample

That Has Been

Centrifuged

Cells

Red blood cells transport oxygen on an iron



Red blood cells transport oxygen on an iron

containing protein called hemoglobin. They are

shaped like flat disks so that they have maximum

surface area and don’t get caught in the blood vessels.

Your body produces red blood cells in bone marrow

and each one circulates for about 120 days. RBC’s

are destroyed by the liver and the spleen.

Mature red

blood cells donot have a

nucleus.

Platelets and plasma proteins work together to



p p g

make sure that too much blood is not lost.

1. Injured blood

vessel

2. Platelets

clump at site andrelease Thrombin

3. Fibrin forms

fromThrombin and

clot stops

blood loss

White Blood cells (also known as Leukocytes) are



( y )

also produced in the bone marrow but do not have

hemoglobin for carrying oxygen. They contain

nuclei and live anywhere from a few days to a fewmonths. They carry out an entirely different function

than the Red Blood Cells.

White blood cells are the army of the

circulatory system. They attack

foreign substances or organisms.

Normally the body contains 700 times more red



y y

blood cells than white blood cells.

The body can increase the number of white blood

cells on demand if the body is threatened by aforeign invader. Doctors often test for increased

White Blood Cell levels to check your health

F. The Lymphatic



Thymus

Thoracic

DuctSpleen

Heart

Superior Vena

Cava

Lymph

Nodes

Lymph

Vessels

F. The Lymphatic

system collects

fluid that leaks

into body tissues

and returns it to

the circulatorysystem.

Lymph nodes are

also filters thatcollect invaders that

cause disease.

G Th Integumentary system Skin i th b di



G. The Integumentary system or Skin is the bodies

largest organ. It serves many purposes and overlaps

with many of the body systems.• Serves as a barrier against infection and injury

• Helps regulate body temperature

• removes excess salts and water

• Protects internal cells from UV radiation

• Serves as one link between the nervous system and

the environment (receives information on pressure,

temperature, pain)

The skin is made of 2 main layers



The skin is made of 2 main layers

1. Epidermis – Outer layer of skin which comes in

contact with environment.

•The outermost layer is coated in dead cells.

•The inner epidermis rapidly divides to produce a

constant supply of new cells, constantly pushing

old cells to the top.

• As skin cells are forced upward they flatten andorganelles disappear and they form a layer of

waterproof covering

2. Dermis – Inner layer of the skin containing blood



y g

vessels, nerve endings, sweat glands, oil glands, sense

organs, hair follicles.

Epidermis

Dermis

Hair and Nails are made up of a



p

substance known as keratin. They are

both used to protect the skin from

damage:

• Fingernails and toe nails protect the

tips of your toes and fingers

•Hair on your head protects from UV

rays

•Eyelashes, Nose Hair and Ear Hair prevent dirt and other particles from

entering the body.



REGULATION of the

HUMAN BODY

How does the Human Body Control (Regulate)



y ( g )

all these body systems and make them work

together?

Electrical Impulses from the

Nervous System

Chemical Hormones from the

Endocrine System

The Nervous System:



y

The nervous system is the number one

communication center of the body. The basic cell

type that carries the communications is a network

of neurons that transmit electrical impulses.

Axon terminals

Nodes

Myelin Sheath

Cell Body

Nucleus

Dendrites

NEURON CELL

Electrical Impulses depend on the movement of



Electrical Impulses depend on the movement of

negatively charged electrons compared with the

positively charged ions across a cell membrane

Once and impulse begins it



moves along the axon in the

direction of the impulse.

To pass between neuronsthe impulse must be sent

across a gap known as a

synapse which sends themessage from one neuron to

the other.

When the impulse reaches the end of the axon it

transfers its impulse to another cell by releasing

chemicals known as neurotransmitters which pass the

message across the synapse.

Synapse



The nervous system is divided into two

divisions:

• The Central Nervous System (CNS)–

Responsible for relaying messages, processing

and analyzing information.

• The Peripheral Nervous System – Receives

information from the environment and relays

commands from the CNS to the organs and glands

The brain is the main switching area of the central



nervous system.

Cerebrum – Responsible for voluntary activities of thebody (Intelligence, learning and judgement)

Cerebellum – Coordinates muscle movement

Brain Stem – Consists of the pons and the medulla

oblongata. Pass message between brain and body

Thalamus – Connects messages from the sense organsto the Cerebrum

Hypothalamus - Controll center for hunger, thirst,

anger and body temperature.

The Brain



Cerebrum

Thalamus

Hypothalamus

Pituitary Gland

Pineal

Gland

Cerebellum

Spinal Cord

Pons

Medulla oblongata

The Brain

The Endocrine System



Sends messages throughout the body by way of

chemicals known as hormones. Hormones travelthroughout the bloodstream to target cells which

contain matching receptors.

Hormone

Receptor

If a cell does not have a specific receptor the



If a cell does not have a specific receptor the

hormone will not affect the cell.

Responses to hormones take longer and lastlonger than nervous system messages.

Hormones can take minutes, hours or days

to influence cells.

Examples of functions controlled

by hormones:Growth, Metabolism, Sleep,

Reaction to stress, Reproduction.

The Endocrine System works through a FEEDBACK



system. Glands of the Endocrine system determine

the level of a hormone in the blood and then changes

the rate of hormone production or sends out theopposite hormone to counteract excess amounts of

hormone.

Examples of Feedback mechanisms:

Control of insulin/sugar levels in blood

Hypothalamus can measure water level in bloodand sends out hormones that tell the kidneys to

conserve water.

Thermostat sensesExample of



Room temperatureincreases

Thermostat senses

temperature change

and switches on

heating system

Thermostat senses

temperature change

and switches off

heating system

Room temperatudecreases

Section 35-1Feedback

Loop

Feedback Actions of Insulin and



Beta cells release

insulin into the blood

Body cells

absorb glucose

Blood glucose

level

decreases

Homeostasis: Normal

blood glucose level

Blood glucoselevel

decreases

Alpha cells release

glucagon into blood

Liver converts

glycogen to

glucose

Blood glucose

levelincreases

Blood glucose

level increases

Liver converts

glycogen to glucose

Glucagon

Important Glands and Hormones of the Human



Body

Gland Hormone Function

Pineal Melatonin Controls sleep and wakecycle

Thyroid Thyroxine Controls appetite and

metabolismAdrenal Adrenaline Deals with stressful

situations

Thymus Thymosin T-cell development (fight

diseases)

Ovary Estrogen Female reproduction

Testis Testosterone Male reproduction

Hypothalamus Pineal Gland



Pituitary

Parathyroids

Thymus

Adrenal

Glands

Thyroid

Pancreas

Ovary (female)

Testis

(male)

K The Reproductive System



K. The Reproductive System

Functions to make new individuals by

producing, storing and releasing specializedsex cells known as gametes.

Cells from the male reproductive system,

known as sperm, must fuse with cells of the

female reproductive system, known as eggs.

Reproduction in both males and females is

l d b h



regulated by hormones.

•In males - Testosterone is produced by the testes.It is required for sperm production and

development of male physical characteristics.

•In females - Estrogen and progesterone arefemale hormones produced by the ovaries.

Estrogen is required for the development of eggs

and female physical characteristics.

Progesterone prepare the uterus for the arrival of

a developing embryo.

Neither males or females are capable of



Neither males or females are capable of

producing active reproductive cells until

puberty, which is a period of sexualmaturation.

Puberty begins when the hypothalmus signals the pituitary to produce increased

levels of hormones that affect the sex

organs (gonads). The hormones are folliclestimulating hormone (FSH) and luteinizing

hormone (LH).

In both the male and female reproductive



In both the male and female reproductive

system sex cells are produced by the process

of Meiosis.

Meiosis involves producing a cell with

only 1 copy of each chromosome (haploid

nuclei). When the egg and sperm fuse, a

cell with two copies of each chromosome is

created. Every cell in the new individualhas two copies of each chromosome

(diploid nuclei).

Th M l R d ti S t



The Male Reproductive System

UrinaryBladder

Vas deferens

Pubic Bone

Urethra

PenisEpididymis

Testis

Scrotum

SeminalVesicle

Prostate

Rectum

Bulbourethral

gland

Sperm development:



Sperm development:

1. Sperm are made from special cells in testes that

undergo the process of meiosis.

2. Once sperm mature they move through a tube

known as the vas deferens upward from the

scrotal sacs into the abdomen into the seminal

vesicle. The sperm mixes with seminal fluid to

form semen. Between 50 and 130 million

sperm are present in one milliliter of semen.The seminal vesicle merges with the urethra

(also connected to the urinary bladder)

3 During sexual excitement the nervous system



3. During sexual excitement the nervous system

of the male contracts the glands of the

reproductive tract. The release of semen iscontrolled by the autonomic nervous system

so it is not entirely voluntary. The male

reproductive system is designed to deliver

sperm into the female reproductive system.

The Female Reproductive System



The Female Reproductive SystemSection 39-3

Fallopian TubeOvary

Uterus

UrinaryBladder

Pubic Bone

Urethra

Cervix

Rectum

Vagina

1. The ovaries produce one mature ova or egg per

th F l b ith 400 000 i t



month. Females are born with 400,000 immature

eggs which are stored in follicles. The follicle

assist in the maturing process of an egg from eachovary once a month based on a signal from the FSH

hormone.

2. When the egg matures the follicle breaks openreleasing the egg into the fallopian tube. A process

known as ovulation. Fertilization occurs in the

fallopian tube if sperm is present.

3. The fallopian tube connects to the uterus which is a

cavity designed to protect and nourish a developing

embr o.

4. If fertilized egg enters the uterus it is implanted into

th li i f th t d th b d l If



the lining of the uterus and the embryo develops. If

fertilization does not occur the egg is discharged out

of the body along with the uterus lining through acanal known as the vagina. Known as

MENSTRUATION

5. The endocrine system controls the cycle of eventssurrounding ovulation through a feedback mechanism

that can signal the presence of a fertilized egg. While

the egg is maturing and preparing for release theuterus is preparing for a fertilized egg by building up

the lining of the uterus. A new lining must be created

each month to prepare for nourishing the embryo.

The Menstrual Cycle



Figure 11-15 Meiosis



Meiosis I

Section 11-4




Meiosis I

Section 11-4

Meiosis I




Section 11-4

Meiosis I




Section 11-4

Meiosis I

Figure 11-17 Meiosis II



Meiosis II

Meiosis I results in two

haploid (N) daughter cells,

each with half the number of

chromosomes as the original.

Prophase II Metaphase II Anaphase II Telophase IIThe chromosomes line up in a

similar way to the metaphase

stage of mitosis.

The sister chromatids

separate and move toward

opposite ends of the cell.

Meiosis II results in four

haploid (N) daughter cells.

Section 11-4




Meiosis II







stage of mitosis.






Section 11-4




Meiosis II

Prophase II Metaphase II Anaphase II Telophase II

Section 11-4



Meiosis produces specialized cells



p p

known as gametes

Each gamete must contain only half

the number of chromosomes that the

parent has. The gamete gets a mixture

of chromosomes from the parent cells.

the human body an overview

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