Transcript Humamn Systems PP

Human Anatomy and Body Systems
Levels of Organization
Remember, the human body is organized in several levels,
from the simplest to the most complex. . .
Cells – the basic unit of life
Tissues – clusters of cells performing a similar function
Organs – made of tissues that perform one specific
function
Organ Systems – groups of organs that perform a
specific purpose in the human body
The purpose of the 10 organ systems is for the human body to
maintain homeostasis
The 10 Human Body Systems
1) nervous system
2) respiratory system
3) excretory system
4) muscular system
5) endocrine system
6) immune system
7) digestive system
8) skeletal system
9) circulatory system
10) reproductive system
The Digestive System
Purpose: to convert food particles
into simpler molecules that can
be absorbed into the
bloodstream and used by the
body
2 kinds of digestion:
1) mechanical – physically
breaking down food
2) chemical – using ENZYMES to
chemically hydrolyze food
• Major Organs and their Functions:
• Mouth:
1) mechanical - chew and grind up food
2) chemical - saliva (from salivary glands) has
amylase enzyme (ptyalin) that breaks down
starch ---- sugar.
• Esophagus – tube that connects mouth to
stomach.
• Peristalsis (wavelike muscular contractions that
move food) begins here. Produces mucus. Food
passes thru cardiac sphincter.
Stomach – has gastric glands
1)mechanical – muscular
organ – churns food
2) chemical - secretes an
strong acid (HCl) that is
necessary for enzyme
PEPSIN to work. Pepsin
starts protein digestion.
Once the food is broken down
in the stomach and mixed
with digestive juices, it
becomes a liquid called
chyme. Chyme passes into
SI through pyloric sphinctor.
• Small Intestine – the chyme enters the small
intestine where:
• 1) digestion is completed w/ the help of intestinal
ENZYMES (amylases, proteases & lipases) and
secretions from accessory organs (pancreas &
liver).
• 2) absorption - end products of digestion (simple
sugars, amino acids, etc.) are absorbed into the
bloodstream through folded surfaces called villi
(increase the surface area).
• Large Intestine – reabsorbs of water from the
chyme back into the bloodstream and gets the
waste ready for excretion (forms feces) with help
of bacteria.
Accessory Organs:
Pancreas – produces: a) digestive enzymes (amylases,
proteases & lipases) that are sent to small intestine
b) Produces the hormone insulin that regulates blood sugar
levels
c) Diabetes can be a result of the pancreas not making enough
of these enzymes.
Liver – produces bile, which EMULSIFIES (physically breaks
down) fats in foods
• Gallbladder – pouch-like
organ that stores bile
temporarily
• 3 processes:
• Ingestion – taking in of food
• Digestion – break down of
food
• Egestion – removal of
undigested, nonusable food
material
Image of the Digestive System
The Excretory System
Purpose: to rid the body of cellular wastes, including
excess water, salts and urea (nitrogenous waste
resulting from breakdown of proteins/amino acids)
Major Organs and Their Functions
Kidneys – the main organs of the excretory system
blood enters the kidney and the kidney filters out
urea, excess water and other waste products
eventually travel out of the kidney as urine.
Kidneys are made up of millions of nephrons (mini
filters)
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Functional unit of
kidney – nephron;
carries out 2
processes:
Filtration – all
dissolved substances
(harmful & harmless)
are filtered out of
blood. BOWMANS
CAPSULE
Reabsorption –
harmless (useful)
materials are put
back into blood.
LOOP OF HENLE
Skin – sweat glands remove excess water and salts from the
body. Sweat actually cools body down & maintains
homeostasis
Lungs – expel the waste gas carbon dioxide upon exhalation
Image of the Excretory System
Carry urine into
bladder
Temorarily
stores urine
Releases urine from body
The Respiratory System
Purpose: to provide the body
with a fresh supply of oxygen for
cellular respiration and remove
the waste product carbon
dioxide
Major Organs and Their
Functions
Nose – entry and exit point for
air; ciliated & produces mucus
Pharynx – serves as a passage
way for both air and food at the
back of the throat
• Larynx – your “voicebox”, as
air passes over your vocal
chords, vibrations cause
sound
• Trachea – the “windpipe”, or
what connects your pharynx
to your lungs; supported by
rings of cartilage
•
-- a piece of skin, called
the epiglottis, covers the
trachea when you swallow,
preventing food from
entering
Bronchi – two passageways that
lead from the trachea to your lungs
(one for each lung)
-- the bronchi are further
subdivided into bronchioles
-- eventually, the further
subdivisions lead to tiny air sacs
called alveoli (RESPIRATORY
SURFACE)
-- alveoli are in clusters, like
grapes
-- capillaries surrounding each
alveolus is where the exchange of
gases with the blood occurs
• The diaphragm is the
muscle that causes you to
breath
• Moves down to bring
about inhalation
• Moves up to bring about
exhalation
• -- hiccups are involuntary
contractions of the
diaphragm
Image of the Respiratory System
The Circulatory System
Purpose: to deliver oxygenated blood to the various cells and
organ systems in your body so they can undergo cellular
respiration
Major Organs and Their Functions
Heart – the major muscle of the circulatory system
-- pumps blood through its four chambers (two
ventricles and two atria)
-- pumps deoxygenated blood into the lungs, where it
gets oxygenated, returned to the heart, and then
pumped out through the aorta to the rest of the body
-- valves regulate the flow of blood between the
chambers
Pathway of Blood Through the
Heart
Arteries – carry oxygenated
blood away from the heart
and to the major organs of
the body. PULSE is felt in
arteries ONLY!
Veins – carry deoxygenated
blood back to the heart away
from the major organs of the
body. Veins have valves!
Capillaries – thin-walled blood
vessels; gas exchange
occurs through these walls
(oxygen & carbon dioxide are
exchanged)
•
Blood – the liquid tissue that flow through
the circulatory system. 4 components:
1. red blood cells - contain hemoglobin, an
iron-containing pigment that carries
oxygen. Most numerous blood cells.
2. white blood cells - function in the immune
system. Numerous kinds: phagocytes
(macrophages) lymphocyte, B cells/ T
cells
3. Platelets – initiate the blood clotting
process
4. Plasma – clear, yellowish liquid portion –
carries nutrients & wastes
Comparison of Blood Vessels
Blood Components
Image of the Circulatory System
AIDS
• Acquired immune deficiency disorder
• Caused by an RNA (retro) virus
• The virus attacks the t helper cells that are
necessary for the body to defend itself
• Spread by bodily fluids (blood &
reproductive secretions)
• Death usually results from infection due to
weakened immune system
• Associated with risky behaviors , such as
IV drug use & unprotected sex
The Nervous System
Purpose: to coordinate the body’s response to changes in its
internal and external environment.
Major Organs and Their Functions
Brain – control center of the body, where all processes are
relayed through & information is interpreted
3 parts:
1) cerebrum - controls thought, senses, learning
2)cerebellum - coordinates motor functions, balance
3) medulla – controls involuntary functions (breathing,
heartbeat, digestion, reflexes such as blinking & sneezing
• Spinal Cord – sends
instructions from the
brain to the rest of the
body and vice versa
•
Nerves – conduct
impulses between
brain and muscles
and/or gland & sense
organs (sensory &
motor)
Major Parts of the Brain
Diagram of a Nerve Cell (Neuron)
Motor Neuron – carries impulses
from brain to muscles
Sensory Neuron carries impulses
from sense
organs to brain
Reflexes
• Reflexes are involuntary, quick responses to
stimulus that are controlled by the spinal cord (of
evolutionary significance).
The Endocrine System
Purpose: to control growth, development, metabolism and
reproduction through the production and secretion of
hormones (chemical messengers – travel in bloodstream)
Major Organs
Location
-- hypothalamus
brain
-- pituitary gland
brain
-- thyroid
on trachea (throat)
-- parathyroid
on thyroid
-- adrenal glands
on top of kidney
-- pancreas
next to stomach
-- testes
outside lower ab
-- ovaries
inside lower ab
Endocrine Glands
Hormones
Hypothalamus
Releasing factors
Pituitary Gland
Thyroid
Growth hormone, ACTH,
FSH, TSH
thyroxine
Parathyroid
parathormone
Adrenal Glands
Adrenaline, steroid
hormones (cortisol)
Insulin & glucagon
Pancreas (Islets of
Langerhans)
Gonads (testes/ovaries)
testosterone (M)
estrogen & progesterone(F)
How endocrine glands work
• Endocrine gland produce hormones which
are carried by the bloodstream to a target
tissue where it has an affect:
Feedback (know for regent’s)
• Mechanism by which hormone levels in
the body are regulated.
The Skeletal System
Purpose: to provide structure
and support to the body, point
of attachment for muscles,
protects organs, stores
minerals & produce blood
cells
Bones are where new blood
cells are generated (in the
marrow), and require the
mineral calcium for strength
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Major Bones of the Human Body
-- femur (thigh bone)
-- humerus (upper arm)
-- radius and ulna (lower arm) -- cranium (skull)
-- sternum (breastbone)
-- clavicle (shoulder
blade)
• -- fibula and tibia (calf)
-- vertebrae (back)
• -- scapula (shoulder)
-- pelvic bone
• -- coccyx (tail bone)
-- phalanges
(fingers/toes)
The Muscular System
Purpose: works with the skeletal and nervous system to
produce movement, also helps to circulate blood through the
human body
-- muscle cells are fibrous and slide on top of each other
Name
3 types of muscles
Voluntary or
Location
Involuntary
Appearanc
e
Skeletal
Attached to bones
Voluntary
striated
Smooth or
visceral
Organs, in blood
vessels
Involuntary
smooth
Cardiac
Heart
Involuntary
striated
3 lines of Defense
1. Skin – also called the integumentary
system, the skin is the body’s first line of
defense; preventing entry of pathogens
into the body.
2. Phagocytes are the white blood cell
type that actually eats and destroys
these antigens (pathogens)
3. White Blood Cells – recognize
pathogenic agents (antigens) and create
antibodies to tag and remove these
antigens
The Immune System
Purpose: to prevent the entry & spread of pathogens in the
human body – MAINTAINS HOMEOSTASIS
Vocabulary:
1. Pathogen – any organism that can cause sickness and/or
disease (usually bacteria or virus)
2. Antigen – any foreign protein that brings about an immune
response
Antibody – a protein produced by an organism in response to
a foreign antigen (to destroy it).
Immune response – production of antibodies in response to
foreign antigens
• Endocytosis is a process where cells
absorb material (molecules such as
proteins) from the outside by engulfing it
with their cell membrane
• Phagocytosis (literally, cell-eating) is the
process by which cells ingest large objects,
such as bacteria, or viruses.
• Pinocytosis (literally, cell-drinking). This
process is concerned with the uptake of
solutes and proteins
Lymphatic System
• Lymph Vessels – help restore fluid lost by
the blood and return it to the circulatory
system
• Lymph Nodes – filter bacteria or cancer
cells from lymph fluid