The Human Body Part II

1
The Human Body Part II

• Chapters 37-39

2
The Respiratory SystemCh. 37-3

• Respiration is the process by which oxygen
  carbon dioxide are exchanged between cells, the
  blood, and air in the lungs
• The Human Respiratory System
• Exchanges oxygen and CO2 between the blood, air,
  and tissues

3
The Respiratory SystemCh. 37-3

• The Respiratory System Consists of
• Nose, Pharynx ,Trachea, Bronchi, Lungs
• How it works
• Air moves from the pharynx into the trachea
• Air passes from the trachea into two large
  passageways called the bronchi (singular
  bronchus)
• Each bronchus leads into one of the lungs
• Within each lung, the bronchus subdivides into
  smaller passageways called the bronchioles
• Bronchioles continue to subdivide until they
  reach tiny air sacs called alveoli
• Oxygen crossed over from the alveolus into thin
  capillaries and the blood stream
• CO2 crosses over from the blood back into the
  alveolis to be disposed of as waste

4
The Respiratory SystemCh. 37-3

• Generally speaking, the brain controls breathing
• The diaphragm, located at the bottom of the chest
  cavity, contracts and allows air to rush into the
  lungs
• When the diaphragm relaxes, air is forced back
  out of the lungs
• The rate of breathing is controlled by the level
  of CO2 in the blood
• The level of CO2 is measured by the medulla
  oblongata in the brain
• As CO2 levels rise the medulla oblongata sends
  nerve impulses to the diaphragm resulting in the
  contractions that make us breath in and out.

5
The Respiratory SystemCh. 37-3

• Tobacco smoke harms the respiratory system
• Tobacco smoke contains nicotine, tar, and carbon
  monoxide
• Nicotine is a stimulant that increased the heart
  rate and blood pressure
• Tar contains substances that cause cancer
• Carbon monoxide is a poisonous gas that blocks
  the transport of oxygen
• Smoking can also cause Emphysema

6
Food and NutritionCh. 38-1

• The energy to perform actions, as well as the
  materials from which body cells and tissues are
  made comes from food
• The energy available in foods can be measured by
  calories
• The of calories you need each day depends on
  your size level of activity
• Nutrients are substances in food that supply
  energy and raw materials the body uses for
  growth, repair, and maintenance

7
Food and NutritionCh. 38-1

• Carbohydrates are the main source of energy for
  the body they include
• Sugars, starches, and fiber
• Fatty acids form fat which is needed to make cell
  membranes and certain hormones
• Proteins are formed by amino acids and are needed
  for growth and repair of the body
• Many proteins are also hormones

8
Food and NutritionCh. 38-1

• Vitamins are organic molecules that help regulate
  the body
• Minerals are inorganic molecules that perform
  vital functions in the body
• EX Calcium iron

9
Food and NutritionCh. 38-1

• The Food Guide Pyramid can help people select a
  balanced diet
• Classifies food into 6 groups
• Foods at base of pyramid should make up major
  portion of your diet
• Foods at top of pyramid should be consumed in
  small amounts

10
The Process of Digestion Ch. 38-2

• The function of the digestive system is to break
  down food into simpler molecules that can be
  absorbed used by the cell
• Human digestive system includes
• Mouth, pharynx, esophagus, stomach, small
  intestine, large intestine, salivary glands,
  pancreas, and liver
• Digestions starts in the mouth

11
Food and NutritionCh. 38-1

• The teeth tear crush food
• Salivary glands secrete saliva
• Amalyse is enzyme found in saliva that breaks
  chemical bonds between the sugar monomers in
  starches
• This begins process of chemical digestion
• From the mouth, food passes through the pharynx
  into the esophagus (passage that carreies food
  between the pharynx and the stomach)

12
Food and NutritionCh. 38-1

• Food from the esophagus empties into the stomach
• Glands in the stomach produce an acid and the
  enzyme pepcin
• Stomach churning, along with the acid and enzyme
  breaks down food into a soft partially digested
  mixture called chyme
• Chyme passes into the small intestine (where most
  chemical digestion and absorption of food occurs)

13
Food and NutritionCh. 38-1

• Enzymes from the pancreas help digest starch,
  protein and fat
• A liquid called bile from the liver helps break
  up fat droplets
• Nutrients are absorbed through the lining of the
  small intestines
• Villi (small fingerlike projections) found in the
  small intestines increase the surface are of the
  small intestines and aide in absorbtion

14
Food and NutritionCh. 38-1

• Chyme next enters the large intestine where water
  is removed from digested material
• After most of the water has been removed,
  remaining waste is passed out of the body
• Digestive Disorders include
• Peptic ulcers caused by bacteria
• Diarrhea when too little water is removed
• Constipation when too much water is removed

15
The Excretory SystemCh. 38-3

• The function of the excretory system is to help
  maintain homeostasis by removing wastes
• Wastes like CO2 and urea are produced during
  normal metabolism
• The main organs of excretory system are the
  kidneys
• They remove waste products from blood, maintain
  blood pH, and control water content of blood

16
The Excretory SystemCh. 38-3

• 2 kidneys are located in the lower back
• Blood containing waste enters kidneys
• Both useful substances and wastes are removed
  from the blood by filtration
• Some of the substances are later returned to the
  blood
• Wastes are excreted
• The purified blood leaves the kidneys and returns
  to circulation
• The fluid that remains is called urine which
  contains urea, excess salts other substances

17
The Excretory SystemCh. 38-3

• A tube called the ureter leaves each kidney and
  carries urine to the bladder (a saclike organ
  that stores urine)
• Urine passes from the body through a tube called
  the urethra.
• Kidneys are controlled by hormones and
  concentration of the blood
• A person can survive with one kidney
• If both kidneys fail, a person must undergo
  dialysis to survive
• Dialysis purifies blood by passing it through a
  filtering machine

18
The Endocrine SystemCh. 39-1

• The endocrine system consists of gland that
  release hormones into the bloodstream
• Hormones are chemicals released from one area of
  the body that travel throughout the body to
  affect cells elsewhere
• Hormones bind to chemical receptors on cells
  called target receptors
• The endocrine system is made up of glands
• A gland is an organ that releases a secretion or
  hormone
• There are endocrine and exocrine glands
• Exocrine glands release secretions directly into
  tissues and organs
• EX Sweat glands

19
The Endocrine SystemCh. 39-1

• There are two types of hormones
• Steroid hormones can cross cell membranes, enter
  the nucleus and turn cells on and off
• Nonsteroid hormones cannot cross cell membranes
• All cells also produce hormonelike substances
  called prosaglandins that affect only NEARBY
  cells

20
The Endocrine SystemCh. 39-1

• The endocrine system is regulated by feedback
  mechanisms that help maintain homeostasis
• Complementary Hormone Action 2 hormones with
  opposite effects may work together to maintain
  homoestasis
• EX thyroid hormone and thyroid stimulating
  hormone

21
Human Endocrine GlandsCh. 39-2

• Human endocrine glands include
• Pituitary Gland controls actions of other
  endocrine glands
• Hpothalamus Controls pituitary gland
• Thyroid Gland Regulates metabolism
• Parathyroid Glands Regulates calcium levels in
  blood
• Adrenal Glands Produce hormones to help deal
  with stress
• Pancreas Produces insulin to keep blood sugar
  stable
• Reproductive Glands Produce gametes (egg sperm)

22
The Reproductive SystemCh. 39-3

• Sex hormones are produces by gonads of an embryo
  cause embryo to become either male or female
• Sex hormones cause puberty to occur between ages
  9 15
• At end of puberty reproductive organs are fully
  developed and able to function

23
The Reproductive SystemCh. 39-3

• The male reproductive system produces and
  delivers sperm
• Main organs of male reproductive system are
• Testes produce sperm in tiny tubes called
  seminiferous tubulues
• Scrotum hold testes
• Vas Deferens first tube sperm travel through
• UrethraFinal tube that allows sperm to exit the
  body from the penis

24
The Reproductive SystemCh. 39-3

• The main function of the female reproductive
  system is to produce eggs and prepare the female
  body to nourish an embryo
• Main organs of the female reproductive system
  are
• Ovaries Produce eggs
• Follicles cluster of cells found in ovaries that
  surround egg and help it mature
• Fallopian Tube Egg travels through here where it
  can be fertilized if sperm are present
• Uterus Final resting place of egg
• Vagina Connects uterus to the outside of the body

25
The Reproductive SystemCh. 39-3

• One egg develops each months during the menstrual
  cycle that is controlled by hormones
• There are 4 phases to the menstrual cycle
• Follicular Phase egg matures in the follicle and
  the uterus is prepared to receive a fertilized
  egg
• Luteal Phase Follicle turns into structure
  called corpus luteum
• Fertilization results in implantation in the
  uterus
• No fertilization results in menstration
• Menstration the lining of the uterus falls away
  and exits the body through the vagina
• Will not occur if the egg has been fertilized

26
Fertilization and DevelopmentCh. 39-4

• Fertilization is the process of a sperm joining
  an egg
• A fertilized egg is called a zygote
• A week after fertilization, a blastocyst (hollow
  ball the zygote becomes) implants itself in the
  lining of the uterus
• The blastocyst differentiates and becomes an
  embryo
• As the embryo develops, membranes also form to
  protect and nourish it and help remove waste
• EX Placenta forms and provides nutrients to the
  fetus from the mother

27
Fertilization and DevelopmentCh. 39-4

• After 8 weeks of development the embryo is called
  a fetus
• By the end of 3 months, most of the major organs
  are formed
• The last 6 months are used for growth and
  maturation of fetal organs
• Childbirth results when hormones cause the
  mothers uterus to contract
• Contractions push the baby from the mothers
  uterus and out through the vagina

28
Fertilization and DevelopmentCh. 39-4

• Twins are born if more than one egg was
  fertilized (fraternal twins), or if the zygote
  splits into two embryos during early development
  (identical twins)
• Growth and development continue throughout
  infancy and childhood
• Adolescence begins with puberty and ends with
  adulthood
• The first signs of aging usually appear in the
  30s