Body SystemsBody Systems• Our bodies are made up Our bodies are made up

of several systems of several systems that that work togetherwork together to perform to perform certain functions and certain functions and tasks in order to tasks in order to maintain maintain homeostasishomeostasis. Although . Although each system has its own each system has its own task or task to task or task to accomplish, all systems accomplish, all systems employ other systems. employ other systems.

• Example: the muscular Example: the muscular system, nervous system system, nervous system and the skeletal system and the skeletal system work together during work together during movement.movement.

Levels of organizationLevels of organization

• CellsCells• TissueTissue• OrgansOrgans• Organ systemsOrgan systems• OrganismOrganism

Digestive SystemDigestive System

– – the function of the the function of the digestive system is digestive system is to to convert food convert food into simple into simple molecules that can molecules that can be absorbed and be absorbed and used by cells in the used by cells in the body.body.

1. Path of food through the 1. Path of food through the digestive tractdigestive tract

a. a. Mouth – Mouth – mechanical breakdown of mechanical breakdown of food with teeth and chemical food with teeth and chemical breakdown of food via salivabreakdown of food via saliva. Food is . Food is broken down into a pasty substance broken down into a pasty substance called bolus.called bolus.

b. b. Esophagus – bolus is transported Esophagus – bolus is transported form the mouth to the stomach via form the mouth to the stomach via the esophagus. To get the food to the the esophagus. To get the food to the stomach, the esophagus contracts stomach, the esophagus contracts rhythmically. (peristalsis)rhythmically. (peristalsis)

c. c. Stomach – Stomach – combination of combination of mechanical digestion by grinding, mechanical digestion by grinding, and chemical digestion.and chemical digestion. The stomach The stomach has a ribbed lining to grind food, and has a ribbed lining to grind food, and secretes hydrochloric acid to break secretes hydrochloric acid to break down food.down food.

d.d. Small intestine – Small intestine – most digestion and most digestion and nutrient absorption occurs here.nutrient absorption occurs here. Nutrients are absorbed and Nutrients are absorbed and delivered to the blood streamdelivered to the blood stream

e. e. Large intestine – removes water Large intestine – removes water from undigested materialfrom undigested material

f. f. Pancreas – produces digestive Pancreas – produces digestive enzymesenzymes

g. g. Liver – produces bile to break down Liver – produces bile to break down fatfat

h. h. Gall bladder – stores excess bileGall bladder – stores excess bile

The Excretory SystemThe Excretory System

The function of the The function of the excretory system is excretory system is to to maintain maintain homeostasishomeostasis..

Excretory OrgansExcretory Organs– Lungs – excrete Lungs – excrete carbon carbon

dioxidedioxide– Skin – excretes excess Skin – excretes excess

water and saltwater and salt– Liver – converts nitrogen Liver – converts nitrogen

wastes into ureawastes into urea– Kidneys – Kidneys – main excretory main excretory

organorgan of the excretory of the excretory systemsystem• Remove waste products Remove waste products

from the bloodfrom the blood• Maintain blood pHMaintain blood pH• Regulate Regulate water contentwater content of of

bloodblood• Filtered waste travels Filtered waste travels

through the uretersthrough the ureters• Waste is stored in the Waste is stored in the

urinary bladderurinary bladder

The Circulatory SystemThe Circulatory System

means of means of communication communication and transportand transport throughout the throughout the bodybody

a.a. Heart – Heart – pumps bloodpumps bloodb.b. Arteries – carry Arteries – carry oxygen oxygen

rich bloodrich blood away from the away from the heart, heart, to organsto organs. Lined . Lined with smooth muscle to with smooth muscle to aid the heartaid the heart

c.c. Capillaries – smallest Capillaries – smallest vessels that are one cell vessels that are one cell thick. thick. Allow nutrients to Allow nutrients to diffuse from blood to the diffuse from blood to the tissuetissue. Carries away . Carries away waste products to the waste products to the excretory organsexcretory organs

d.d. Veins – carry Veins – carry deoxygenated blooddeoxygenated blood from from the capillaries the capillaries to the to the heartheart

Components of the Components of the Circulatory SystemCirculatory System

Functions of the circulatory Functions of the circulatory system :system :

a.a. Transport Transport oxygenoxygen to the to the organsorgans

i.i. Oxygen binds with Oxygen binds with hemoglobin on the red hemoglobin on the red blood cellblood cell

b.b. transport transport nutrients from nutrients from the digestive tractthe digestive tract to the to the cellscells

c.c. transport transport wastewaste from the from the cells cells to excretory organsto excretory organs

d.d. transport heat energytransport heat energy

e.e. transport transport hormoneshormones

f.f. transport transport white blood white blood cellscells

g.g. transport transport plateletsplatelets to to clot broken vesselsclot broken vessels

Blood is a mixtureBlood is a mixture

The Respiratory SystemThe Respiratory System

supplies oxygen to supplies oxygen to the blood stream the blood stream and takes away and takes away carbon dioxidecarbon dioxide

1. Path of an oxygen 1. Path of an oxygen molecule through the molecule through the

respiratory tractrespiratory tracta.a. Nasal cavity – warms and Nasal cavity – warms and

filters airfilters airb.b. Trachea – leads to the Trachea – leads to the

lungs. Held open with lungs. Held open with rings of cartilage. rings of cartilage. Also Also called windpipecalled windpipe

c.c. Bronchus – splits from Bronchus – splits from trachea to each lungtrachea to each lung

d.d. Lungs – filled with alveoliLungs – filled with alveoli• Expands and contracts Expands and contracts

with help of diaphragmwith help of diaphragm

d.d. alveoli – tiny air sacs alveoli – tiny air sacs surrounded by capillariessurrounded by capillaries• Oxygen diffuses into the Oxygen diffuses into the

capillaries to be taken to capillaries to be taken to the cells throughout the the cells throughout the body. Blood inflates body. Blood inflates alveoli with CO2 to be alveoli with CO2 to be exhaledexhaled

The Nervous SystemThe Nervous System

controls and controls and coordinates coordinates functions functions throughout the throughout the bodybody and responds and responds to external and to external and internal stimuli internal stimuli

The Nervous SystemThe Nervous System

1.1. Central Nervous Central Nervous SystemSystema.a. Brain – Brain – Receives Receives

processes and sends processes and sends information to information to different parts of the different parts of the body.body.

b.b. Spinal chord – Spinal chord – communications link communications link between the brain between the brain and the rest of the and the rest of the body. body. Processes Processes reflexesreflexes..

The Nervous SystemThe Nervous System

2. Peripheral Spinal 2. Peripheral Spinal Chord – Chord – transmits transmits impulses from the impulses from the sense organs to sense organs to the central the central nervous systemnervous system

The Endocrine SystemThe Endocrine System

System of glands System of glands that that deliver deliver messages messages throughout the throughout the body by means of body by means of hormoneshormones

Hormones work in Hormones work in antogonistic pairsantogonistic pairs

The Endocrine SystemThe Endocrine Systema.a. Pituitary glands – “Pituitary glands – “master master

glandgland” that secretes 9 ” that secretes 9 different hormones and different hormones and controls several other controls several other hormoneshormones

b.b. Hypothalamus – controls Hypothalamus – controls pituitary gland. pituitary gland. Link Link between the nervous and between the nervous and endocrine systemsendocrine systems

c.c. Thyroid – controls Thyroid – controls metabolismmetabolism

d.d. Adrenal glands – Adrenal glands – fight or fight or flight hormoneflight hormone

e.e. Islets of Langerhans – Islets of Langerhans – found in pancreas, found in pancreas, secretes secretes insulin and glucagonsinsulin and glucagons to to control sugar levels.control sugar levels.

.. Reproductive glands Reproductive glands • Ovaries – Ovaries – estrogenestrogen• Testes - Testes - testosteronetestosterone