Organ Systems

The Organ System

Serves a particular purpose within the organism (living thing) in which they exist

• they serve a variety of different particular purposes within the human body, but many of these organ systems also exist in a variety of other organisms

The Circulatory System

Responsible for pumping blood to all the tissues of the body

The Heart (diagram is usually drawn in reverse)

• Oblique positioned diagonally

• Heart divided into two parts by a cellular wall (Spetum) and has four chambers

The Upper Cavities

Right Atrium and Left Atrium

Starts in the left ventricle where the deoxygenated blood and nutrients enter the heart

Starts at the Largest most Powerful Chamber of the Heart

The Left Ventricle.

• It pushes blood out to the body

• Pushes it out through the biggest artery; the Aorta

• The aorta then branches out into smaller arteries

  • Arties take blood out

  • Veins bring blood back in

• These arteries branch out to large arteries like the femoral artery (runs down the leg) then branches into smaller and smaller arteries until branches into capillaries

Aorta

Biggest artery in the heart

• Then branches out into smaller arteries

Arteries

take blood out

Veins

bring blood back in

Capillaries

Very small, tiny even blood vessels connected to the arteries with veins and cells

Part 2

The capillaries weave throughout the tissues and allows cells to absorb the oxygen and the food that the red blood cells are carrying

• Then waste product is picked up by other capillaries and is fed back into the veins

  • These veins pass by organs such as the kidneys that can filter out toxins and eventually, the blood is brought back to the right atria

Part 3

So the blood depleted of oxygen comes back to the right atria and is pushed through a Valve

• The valve one directional so the blood cannot go back through the other way. It gets pushed into the right ventricle

The right ventricle then pushes the blood out again to the lungs to be reoxygenated

• The lungs alveoli are where capillaries that weave through lungs can be absorbed

Valve

“doors”

Alveoli

• are where capillaries that weave through lungs can be absorbed

Part 4

• The re-oxygenated blood comes backup and goes into the left atrium

• It gets pushed through another one directional valve and into the left ventricle

• Now we have oxygenated blood that can go back out into the body again and this circles around in this cycle

White Blood Cells

used to fight disease, sort of the protectors of the body.

• Think of them as defenders

  • e.g. cops on a highway

Red Blood Cells

Transports Hemoglobin, oxygen food supply

• Think of them like truckers on highway

  • police protect them

Where are White and Red Blood Cells Produced?

Both in the BONE MARROW

The Nervous System

Central Nervous System: the brain and spinal cord

Peripheral Nervous System: all other components of the nervous system such as nerves throughout the body

The Brain

Cerebral Cortex: wrinkly outter layer made up of 4 lobes. It’s responsible for a variety of different higher functioning behaviors like spatial awareness, conscious thought and reasoning, language and vision

Dendrites and Axon

Nerve cells that make up the nervous system that look like brooms

• Dendrites catch messages from other neurons and bring them to the main part of the cell. They help neurons talk to each other!

• Axons are like long wires that send messages away from the neuron to other neurons, muscles, or body parts. They help messages travel far and fast!

The axon is wrapped in a myelin sheath

Myelin Sheath to Synaptic Gap

Holds in energy

It’s a special coating that wraps around nerve cells (neurons) to help messages travel quickly and smoothly

• that energy gets transmitted through the axon up to the next nerve cell across a gap called the SYNAPSE/SYNAPTIC GAP

Then, the next set of dendrites receives that message and relays it again

We see this occur in the brain, nerves of the spinal cord, and nerve cells that go out to your fingers

When you feel something

Something presses on that nerve and it relays it through millions of nerve cells back to your brain

which itself is made of the same types of nerve cells

The Cerebral Cortex

The wrinkly outer layer (what we picture when we think of a brain)

• Made up of 4 lobes

• Responsible for a variety of different higher-functioning behaviors like

  • Spatial awareness

  • conscious thought,

  • reasoning,

  • language ability,

  • vision

Within the CC, there are Inner Cortical structures (hippocampus, thalamus, hypothalamus) things that process our

• satiation,

• feeling full,

• fear responses, and memory

The Cerebellum

Responsible for the timing of motor movements

• It sits at the back of your brain, right under the big part of your brain (the cerebrum).

• Even though it’s small, it works without you even thinking about it, ensuring your body moves just right.

• There’s specific nerve fibers: Purkinje fibers are the internal timing mechanisms

  • Balance

  • Smooth movement

  • Coordination

e.g. think rah rah robot

The Brain Stem

Responsible for base life-support functions

• Respiration

• Heart Rate

• Helps w/ digestion

The Digestive System

Responsible for breaking down and absorbing food

Salivary Glands and Esophagus

First, eat food and chew it with your teeth causing it to break down the cell walls (plants) you’re coating the food w/saliva from the salivary glands. It also makes it easier for the food to go down your esophagus to the stomach. This is the beginning process of digestion

Stomach and Pancreas

Once the small pieces of food enter the stomach, the stomach has a mucous lining that protects it from digesting itself.

Then the sphincters at both ends that close the stomach off

It then secretes digestive acids produced by organs such as the pancreas.

Those digestive acids further break down the food

Heartburn

When sphincters fail to close off, the stomach acid can come into the esophagus and starts to digest the esophagus itself

Small Intestine

After break down in the stomach, the food gets passed into the small intense, a long winding tract of intestines

This is where we absorb the nutrition

We absorb the nutrition in the small intense

Large Intestine and Colon

After gliding through the tract of the small intense

the depleted food (after nutrition is absorbed) gets passed into the large intestines 3 different parts

• ascending

• transverse

• and the descending parts (the colon)

Rectum

This is where the depleted good passes through before it’s excreted through the rectum

The reproductive system

Most animals → repo sexually

sperm created in the testes

eggs created in ovaries (ova)

When sperm fertilizes an egg, the two haploid cells combine to form a diploid cell

(two haploid cells, only 1 chromosome each combine to form a fertilized cell that has a pair of chromosomes aka diploid cells)

Key Advantage of Sexual Reproduction

Greater Genetic Variation

• because you’re sharing genetic information between two parents

  • so you get a variety of traits from each

Greater variation can be an advantage in terms of Evolution because

• traits that can be MORE or LESS useful in a given environment and t- that extra variation makes organism more chance of having a trait maybe useful

Key Disadvantages of Sexual Reproduction vs Asexual Reproduction

Reproduction requires a mate and fertilization

• you have no choice after reproduction has taken place

BUT

An organism that reproduces asexually can choose when it wants to produce offspring.

• It can wait for right amount of food, right temperature, and right conditions and then reproduce using its own genetic material

Asexual Reproduction Advantages

Aphids

Aphids can use asexual repo in the summertime when they get a lot of food to reproduce thousands and thousands of offspring

Asexual Reproduction Disadvantages

Aphid doesn’t get to combine DNA with another partner to create variation so flawed gene or other disadvantage, trait, will continue to propagate

Types of Reproduction in Plants

Can occur sexually and asexually

• Algae

• Fungi

• Angiosperms

• Gymnosperms

Algae

One of the oldest organisms on Earth

Green, photosynthetic plant and it reproduces asexually

Fungi

Only one in the list in terms plant type that’s not photosynthetic

• depends on decaying biological material to feed

  e.g. can grow on food in your fridge. It doesn’t need light; think closed fridge door

ASEXUAL REPRODUCER

Ferns

BOTH ASEXUAL AND SEXUAL REPOS

• The reason they’ve survived so long

You can see two different plants that look entirely different and they’re the same plant in 2 different phases of its life cycle

• one in a sexual phase

• one in an asexual phase

Ferns enjoy advantages and variation from sexual repo, but also enjoy ability to repo when needed to when conditions are “just right”

Angiosperms

Flowering plants and have sex organs within the flower so its a

• SEXUAL REPRODUCER

Sex organs: PISTOL and the STAMEN

Pistol: Female sex organ

Stamen: Male sex organ

Gymnosperm

SEXUAL REPRODUCERS

• They’re “Cone bearing plants”

  • e.g. Pine trees

In those cones it’s producing a seed that’s being fertilized and after fertilization, it grows into an adult version of that plant