Transcript Human Anatomy CP1

College Biology
Human Body Systems
Chapters 35-40
Organization in Multi-cellular Organisms
1. Cell
2. Tissue – group of similar cells that
perform a particular function
3. Organ – group of tissues that work
together
4. Organ System – group of organs that
work together
5. Organism
11 Organ Systems
Feedback Control
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Feedback systems - control
& regulate body processes.
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Organ systems work together,
use feedback to maintain
homeostasis
Homeostasis = stable internal
conditions
Uses the consequences of
the process (too much or too
little produced) to control the
rate at which the process
occurs
Consists of a sensor, a
control center, and an
effector
Feedback Control
Example:
Body Temperature
Digestive System
Structures: mouth, pharynx,
esophagus, stomach, small intestine,
large intestine
Accessory Structures: salivary glands,
pancreas, liver, gallbladder
Functions:
 Acquiring nutrients: Breaks down
large food molecules into simpler
molecules that can be used by the
cells of the body
 Absorbs nutrients and eliminates
waste
Pathway of Food
Mouth:
 Chewing mechanically (physically) breaks down food
Salivary Glands:
 Saliva contains enzymes that break down starch
(carbohydrate)
Pharynx:
 Beginning of throat
 Connects mouth to esophagus
Esophagus:
 Muscle contractions
(peristalsis) push food
down toward the stomach
Stomach:
 Churns food (mechanical
digestion)
 Enzymes break down
proteins
 Does NOT absorb any
nutrients
 Secretes acid
Small Intestine:
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Chemical digestion of carbs, proteins, and lipids
finishes
Carbs, proteins, and lipids are absorbed into the blood
Liver, gallbladder, and pancreas secrete enzymes into
it for chemical digestion
Very long and lined with villi, “wrinkles” that increase
surface area for more absorption
Accessory Organs
Food never enters these organs!
Pancreas:
 Secretes enzymes into small intestine to break down
nutrients
Liver:
 Stores extra glucose as the polysaccharide glycogen
 Makes bile (which breaks down fats)
 Filters out toxins (alcohol, drugs, bacteria, old cells) from
blood
Gallbladder:
 Stores bile made by the liver
Close-up of the Digestive System
Summary of Food Breakdown
Respiratory System
Structures: nose, pharynx,
larynx, trachea, bronchi,
bronchioles, lungs
Functions:
 Gas exchange
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Provides oxygen needed for
cellular respiration
Removes excess carbon
dioxide from the bloodstream
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larynx, trachea, bronchi (lungs),
bronchioles (lungs).
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Tiny air sacs,
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Circulatory System: Structures

Heart - Made of muscle, pumps blood
through body

Arteries – carry blood away from heart to capillaries
Capillaries – tiny vessels that allow diffusion of
materials between blood and cells; where arteries
and veins meet
Veins – carry blood back to heart from capillaries
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Blood Flow
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De-oxygenated blood is
pumped from the heart to
the lungs where it picks up
oxygen.
Oxygenated blood flows
back to the heart.
Oxygenated blood
pumped out to body cells
to deliver oxygen and pick
up carbon dioxide.
De-oxygenated blood
flows back to the heart
and the cycle restarts.
Nervous System
Structures: brain, spinal
cord, peripheral nerves
(sensory and motor)
Function:
 Controls and coordinates
functions throughout the
body in response to
internal and external
stimuli
Neurons
 A message called an action potential is transmitted by
nervous cells (neurons).
 Action potentials are electrical signals.
 Neurons have 3 parts:
•
Dendrites – receive message (action potential)
•
Cell body – contains the nucleus and other normal
organelles
•
Axon – sends action potential message to another cell
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Synapse = the space between the end of one
neuron and the start of the next
Neurons transmit messages by sending
chemicals (neurotransmitters) across the
synapse.
Muscular System
Structures: Skeletal muscle,
smooth muscle, cardiac muscle
Functions:
 Movement
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Works with skeletal system to
produce voluntary movement
Helps circulate blood and move
food through the digestive system
Three Types of Muscle:
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Skeletal: attached to bones by tendons;
voluntary
Smooth: controls digestion, breathing,
circulation; involuntary
Cardiac: heart muscle; involuntary
Voluntary Muscle Contractions

Muscles cause movement by contracting (getting
shorter) or relaxing (getting longer)
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.
Skeletal System
 Internal
body framework = skeleton
Structures: bones, cartilage,
ligaments, tendons
Functions:
 Supports the body
 Protects internal organs
 Enables movement
 Stores calcium
 Makes blood cells
Bone Structure

Bones – cells and protein fibers supported by
hard calcium

Cavities within bones
contain soft bone
marrow, which
produces blood cells.
Joints
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Joints – where bones
are joined together
Tendons – connect
muscle to bone
Ligaments – connect
bone to bone
Cartilage – a protective
cushion or covering
Integumentary System
Structures: skin and its structures (hair,
nails, sweat glands, oil glands)
Functions:
 Serves as a barrier against infection,
injury, and UV radiation from the sun
 Helps to regulate body temperature
(by sweating or expanding blood
vessels)
 Removes waste (sweat)
Close-up of Integumentary System
Excretory System
Structures: kidneys, ureters, urinary
bladder, urethra (other: skin, lungs)
Functions:
 Eliminates waste, especially
byproducts of metabolism
 Regulates (controls) the amount of
water in blood, which determines
blood volume and pH
How do the kidneys work?
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Blood enters kidneys, full of excess
water and nitrogenous wastes.
Excess water & wastes filtered out by
the kidneys, collected as urine.
Urine travels down the ureters, gets
stored in the bladder, and is expelled
from the body through the urethra.
Remember: liver also filtered blood,
but it removed toxins, whereas the
kidneys remove wastes & water
Lymphatic System
Structures: white blood cells, thymus,
spleen, lymph nodes, lymph vessels
Functions:
 Helps protect the body from disease
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Maintains fluid balance in blood
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Spleen – filters old blood cells from
blood, stores extra blood
Immune System:
Non-specific Defenses
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Function: fights off invading
pathogens and prevents growth and
spread of cancer
Non-specific Defenses: protect
body from all pathogens.
 Skin: physical barrier
 Mucous membranes: protect
interior surfaces
 Cilia: line bronchi to “sweep”
mucus and pathogens out of lungs
Immune System:
Specific Responses
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Specific Responses: defend
against one certain invader
(pathogen)
 White blood cells recognize an
invader

Create antibodies, proteins
which bind to pathogens & mark
them for destruction
Endocrine System
Structures: ovaries (females),
testes (males), pancreas,
hypothalamus, glands (pituitary,
pineal, thyroid, parathyroid,
thymus, adrenal)
Function:
 Chemical communication &
control
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Hormones - chemicals that are
released into the blood and signal
cells to take action
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Actions include growth,
development, metabolism, and
reproduction
Reproductive System
Male Structures: testes,
epididymis, vas deferens,
urethra, penis
Female Structures: ovaries,
fallopian tubes, uterus, vagina
Functions:
 Produces reproductive cells
 Males: produce and deliver
gametes (sperm) to females
 Females: produce gametes
(eggs), maintain an
environment which can
support a developing embryo