Science - Body | Test #4 Flashcards
In Ancient Egypt, how was the Brain removed from bodies before they were mummified?
The preparers would use an iron hook to scramble and pull the Brain out through the nostrils
The Brain was not considered to be a vital organ, and was usually disposed of instead of being placed in Canopic Jars
3 main regions of the brain
The Hindbrain controls breathing and heart rate
The Midbrain controls reflexes and voluntary movements
The Forebrain is the largest and most developed region, and separates humans from other species
(The Cerebellum controls coordination and movement)
The Cerebrum
The Cerebrum controls intellectual activities such as memory, organization, imagination, and computation
The Cerebrum is made of two hemispheres
The Left Hemisphere controls the right-side of the body, and the Right Hemisphere controls the left-side of the body
The Glands of the Brain
The Brain contains 3 main glands:
The Hypothalamus, the Pituitary Gland, and the Pineal Gland
The Hypothalamus controls many metabolic functions such as body temperature, hunger, and sleep
The Pituitary Gland mainly controls the growth of the body by excreting growth hormones
The Pineal Gland mainly produces Melatonin which helps with the regulation of sleep and the body’s circadian rhythms
Brain Issues
Headaches are the most common Brain Issue affecting almost everyone within their lifetime
Headaches are often caused by signals between the Brain, and surrounding blood vessels and nerves, which then creates pressure of the nerves that send pain signals to the Brain
There are two classifications of Headaches
Primary Headaches such as Migraines are not caused by another medical condition
Secondary Headaches are caused by another medical condition such as a Tumour or a Sinus Infection
The Neuron
The Neuron is a basic cell within the body’s Nervous System that helps transmit information between nerves and within the Brain
There are 3 main components of Neurons
Cell Body: Contains the nucleus and genetic material for the neuron
Axon: A long, protected section of the neuron that allows for impulses to be transmitted
Dendrites: They pick up impulses from other nerves
Synapses
The points of connection between neurons
The two types of Synapses
Chemical Synapses:
The gap between two neurons allows for chemicals called neurotransmitters to be sent to other neurons
The majority of neuron transmissions occurs through chemical synapses
Electrical Synapse:
The gap between two neurons is very small, and allows for electrical signals to be transmitted across the gap
Electrical synapses are mainly found where quick reflexes are needed
The Nervous System
The Nervous System allows for two-way transmission of electrical impulses between the Body and the Brain
The Body sends signals to the Brain through nerves in order for the Brain to process and understand, and the Brain is able to send signals to the Body through the nerves to respond to stimuli
The Body and the Brain will use the Spinal Cord as the main juncture point for communications
Sympathetic vs. Parasympathetic Nervous Systems
The Sympathetic Nervous System is responsible for the “Fight, Flight, or Freeze” response to a stimuli
This can include increased heart rate, breathing, dilated pupils, and the release of adrenaline
The Parasympathetic Nervous System is responsible for keeping the body calm and regulated
This can include slowing the heart rate, encouraging digestion, and promoting rest
The three types of teeth in a Human mouth
Incisors, used for biting food
Canines, used for tearing food
Molars, used for crushing food
The Mouth
The main function of the mouth in digestion is to chew food in order to make it soft enough to swallow
There are enzymes in your saliva that help to soften the food while you chew
The Esophagus
The Esophagus helps connect the mouth with the stomach
The esophagus uses muscle contractions called Peristalsis to force food to travel down the esophagus
The Stomach
The main purpose of the Stomach is to further soften foods before they enter into the Small Intestines
Gastric Acid, which is mainly Hydrochloric Acid, helps break down Proteins within the Stomach
To help prevent the Stomach from being consumed by its own Gastric Acid, it has a lining of mucus protecting the Stomach
For some animals called Ruminants, they will have several stomachs in order to assist with the breaking down of foods
The Intestines
The Small Intestines is responsible for most of the digestion in the Digestive System
Enzymes in the Small Intestines help break down food to the point of having it enter into the bloodstream
About 95% of nutrients are absorbed through the Small Intestines
The main purpose of the Large Intestines is to absorb water and minerals from the food, and to ferment the food into waste
Humans have an average of 6 metres of Small Intestines and 2 metres of Large Intestines
The 4 main Blood Types
A, B, AB, and O ( -/+ )
4 main components of Blood
One component is Red Blood Cells, which are created in Bone Marrow
Red Blood Cells don’t have a Nucleus
Hemoglobin allows the Red Blood Cells to bind with Oxygen and Carbon Dioxide
White Blood Cells, who’s main function is to protect the body from infections
White Blood Cells have a Nucleus and have the ability to move independently from the blood flow to attack invaders
Platelets, who’s main function is to assist in clotting blood
Platelets bind together to create barriers to stop blood flow
Plasma, who’s main function is to carry nutrients and waste to and from cells
Heart Chambers
All mammals and birds have a 4-chambered heart
Reptiles and Amphibians have a 3-chambered Heart, and Fish have a 2-chambered Heart
Atrium and Ventricle
The Right Atrium and Right Ventricle collects de-oxygenated blood from the body through the Vena Cava or the main veins to the Heart
Then is pushed to the Lungs through the Pulmonary Artery from the Right Ventricle
Oxygenated blood returns to the Heart and enters into the Left Atrium and Left Ventricle before being pushed towards the rest of the body through the Aorta
Heart Valves
Help control the flow of blood, Prevent backflow of blood within the Heart
Complications of the Heart often stem from the Valves (not being able to close properly, or not being able to open properly)
Lungs
The main purpose of Lungs is to allow for Gas Exchange
Air is breathed into the left and right lungs, and continues through the network of Bronchioles until the air reaches the Alveoli, there are several blood vessels that are connected to each Alveoli
The barrier between the Alveoli and blood vessels is so thin that Oxygen can be absorbed into the blood vessels through Diffusion
ATP
The main purpose for the inhaling of Oxygen is to allow for the release of ATP from energy sources like glucose
The byproduct of the ATP release is Carbon Dioxide, which needs to be filtered out of the body through the blood
Lactic Acid
Not enough Oxygen provided to the body (especially the muscles), the buildup of Lactic Acid occurs when sugars are processed
The buildup of Lactic Acid is what causes muscles to fatigue
