Regents Biology Major Parts of the Human Brain

Regents Biology Major Parts of the Human Brain 1. Cerebrum- (4 lobes) Frontal lobe Parietal lobe Occipital lobe Temporal lobe 2. Cerebellum 3. Brain stem – (3 sections) medulla oblongata pons midbrain (not on EOC)

Regents Biology Lobes of the Cerebrum

Regents Biology Cerebrum  Cerebrum – Makes up the majority of the brain (85%)  Divided into 4 sections called lobes. They are: frontal lobe, temporal lobe, occipital lobe & the parietal lobe

Regents Biology Cerebrum

Regents Biology Cerebellum

Regents Biology Crerebellum  Cerebellum- located at the back of the brain under the occipital and temporal lobes

Regents Biology Cerebellum

Regents Biology Brain Stem

Regents Biology Brain Stem  Brain Stem- sits beneath the cerebrum & in front of the cerebellum- it connects the brain to the spinal cord  It consists of three main parts, midbrain, pons, & the medulla oblongata

Regents Biology Brainstem

Regents Biology Three major Parts of the Brain

Regents Biology Brain Parts

Regents Biology Blood Flow  5 Factors Affecting Blood Flow through the Cardiovascular system 1. Blood pressure 2. Blood volume 3. Resistance 4. Disease 5. Exercise

AP Biology The Human Heart

Regents Biology What is Blood Flow?  Blood flow is the volume of blood flowing through a vessel, organ, or the entire circulation in a given period and may be expressed as ml/min (blood flow of the entire circulation is equal to cardiac output).

Regents Biology What is blood pressure?  Blood pressure is the force per unit area exerted by the blood against a vessel wall and is expressed in millimeters of mercury (mm Hg).

Regents Biology What is resistance?  Resistance is a measure of the friction between blood and the vessel wall, and arises from three sources:  1. blood viscosity  2. blood vessel length  3. blood vessel diameter

Regents Biology Blood Flow through Vessels is effected by Pressure and Resistance  The flow of blood through the vessels of the circulatory system is a function of the pressure in the system and the resistance to flow caused by the blood vessels.

Regents Biology  Blood flow is directly proportional to pressure and inversely proportional to resistance.

Regents Biology Which means!!!!  If the pressure in a vessel increases then the blood flow will increase.  However, if the resistance in a vessel increases then the blood flow will decrease.

Regents Biology Resistance in the blood vessels is effected by three parameters  Length of the vessel. The longer the vessel the greater the resistance.  Viscosity of the blood. The greater the viscosity the greater the resistance.  Radius of the vessel. The smaller the radius the greater the resistance.

Regents Biology  The pumping action of the heart generates blood flow; pressure results when blood flow is opposed by resistance.

Regents Biology Blood volume  The volume of blood in the body also affects blood pressure. (Due to obesity)  A higher volume of blood in the body raises blood pressure by increasing the amount of blood pumped by each heartbeat which in turn increases blood flow!!!!

Regents Biology Low blood volume  If blood volume decreases, blood pressure decreases resulting in a decrease in blood flow!  (fluid loss i.e. dehydration)

Regents Biology Resistance  If the resistance increases, blood flow decreases  If the resistance decreases, blood flow increases

Regents Biology Viscosity of blood (thickness)  If the viscosity increases, resistance increases-decreasing blood flow

Regents Biology Diseases affect on Blood flow  Atherosclerosis-is a disease in which plaque builds up inside your arteries.  Arteries are blood vessels that carry oxygen-rich blood to your heart and other parts of your body.  Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body.

Regents Biology Normal vs Narrow Artery

Regents Biology Coronary Heart disease  Coronary heart disease (CHD), also called coronary artery disease, occurs when plaque builds up in the coronary arteries. These arteries supply oxygen-rich blood to your heart. Coronary heart disease  Plaque narrows the coronary arteries and reduces blood flow to your heart muscle. Plaque buildup also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow.  If blood flow to your heart muscle is reduced or blocked, you may have angina (chest pain or discomfort) or a heart attack.angina

Regents Biology Exercise  Causes the heart to beat faster, stronger, and increases the blood flow to provide more oxygen to the working muscles to the body.

Regents Biology % Blood Flow During Exercise