BIOL-21 Midterm: Heart & Blood Flow

• The BIOL-21 Midterm #2 exam is on Apr 14, 2025, at 9:00 AM PDT.
• The exam location is Morris Dailey Auditorium (MD).
• Students should bring their SJSU Tower Card or ID and a #2 pencil with an eraser.

Heart Structure and Blood Flow

• The heart has four chambers.
• Left atrium receives oxygen-rich blood from the lungs.
• Left ventricle pumps oxygen-rich blood to the body via the aorta.
• Right atrium receives deoxygenated blood from the body.
• Right ventricle pumps deoxygenated blood to the lungs via the pulmonary arteries.
• Oxygen-rich blood flows from the left atrium to the left ventricle and then to the aorta.
• Deoxygenated blood flows from the right atrium to the right ventricle and then to the pulmonary arteries.

Blood Circulation

• Aorta is the largest artery, carrying oxygen-rich blood from the left ventricle to the systemic circuit.
• In the systemic circuit, blood delivers O2 and picks up CO2, returning to the heart through the superior and inferior vena cava.
• The systemic circuit includes all of the body except for the lungs.
• The pulmonary circuit involves the lungs, where blood picks up oxygen and releases CO2.
• Pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs.
• In the lungs, blood passes through pulmonary capillaries for gas exchange.
• Superior & Inferior Vena Cava returns deoxygenated venous blood to the right atrium

Heart Cycle

• Deoxygenated venous blood returns to the heart via the superior and inferior vena cava.
• Blood enters the right atrium.
• Blood passes through the right atrioventricular valve (AV) into the right ventricle.
• The right ventricle pumps blood into the right semilunar valve and into the pulmonary trunk.
• The pulmonary trunk divides into the left and right pulmonary arteries.
• Blood enters the left and right lungs and gives up CO2 and receives O2, becoming oxygenated.
• Oxygen-rich blood flows into the left and right pulmonary veins.
• Blood flows into the left atrium.
• Blood passes through the left AV valve into the left ventricle.
• The left ventricle pumps blood into the left semilunar valve and into the aorta.
• Blood travels through the systemic circuit, providing tissues with O2 and receiving CO2, then returns through the superior and inferior vena cava.

Blood Vessels

• Arteries carry oxygen-rich blood away from the heart; the pulmonary arteries are an exception.
• Capillaries are tiny vessels that connect arteries and veins, facilitating gas, nutrient, and waste exchange.
• Veins carry deoxygenated blood back to the heart; the pulmonary veins are an exception.

Capillary Beds and Venous Valves

• Capillary beds are small blood vessels that connect arteries to veins, facilitating gas and nutrient exchange.
• Venous valves within veins ensure blood flows in one direction toward the heart.

Plasma

• Plasma makes up 55% of blood and contains nutrients, hormones, waste (CO2), and proteins like albumin, fibrinogen and immunoglobulins.

Formed Elements in Blood

• Red Blood Cells (Erythrocytes) - RBC
• White Blood Cells (Leukocytes) - WBC
• Platelets (Thrombocytes)

Stem Cells

• Blood stem cells (hematopoietic stem cells) are located in the bone marrow.
• They differentiate into RBCs, WBCs, or platelets.
• The body continually produces new blood cells due to their short lifespans.

White Blood Cells

• Neutrophils are the most abundant WBCs and fight bacterial and fungal infections.
• Basophils, the rarest WBCs, secrete histamine during allergic reactions.
• Eosinophils defend against parasites and release chemicals to reduce allergic reactions.
• Lymphocytes work in the lymphatic system.
• Monocytes, the biggest WBCs, become macrophages to destroy pathogens and stimulate other WBCs.

Red Blood Cells

• Red blood cells carry oxygen in the lungs using hemoglobin, an iron-rich protein.
• Hemoglobin delivers oxygen and picks up carbon dioxide in oxygen-poor tissues.

Platelets

• Platelets detect damage, stick together to form a plug, and release clotting factors

Blood Diseases

• Anemia: Low red blood cells, results in insufficient oxygen.
• Hemophilia: Improper blood clotting due to missing proteins.
• Thrombocytopenia: Low platelet count, leads to improper clotting.
• Sickle Cell Disease: Misshapen red blood cells that cause blockages.

Blood Pressure

• Systolic: Pressure when the heart pumps.
• Diastolic: Pressure when the heart relaxes.
• Blood pressure measures the force of blood against artery walls.
• Normal blood pressure is around 120/80, where 120 is systolic and 80 is diastolic.

Cardiovascular Disease Risk Factors

• High Blood Pressure (Hypertension) puts extra strain on the heart and arteries.
• High Cholesterol can clog arteries.
• Smoking harms blood vessels and reduces oxygen.
• Obesity increases heart strain and raises blood pressure/cholesterol.
• Diabetes damages blood vessels over time.
• Unhealthy Diet raises CVD risk.
• Lack of Exercise weakens the heart.
• Excessive Alcohol raises blood pressure & cholesterol.
• Chronic Stress leads to high blood pressure and unhealthy habits.

Central Nervous System Structures

• The brain and spinal cord.

Functions of the Nervous System

• Sensory Function: Detects stimuli through sensory receptors like touch, temperature, pain, and pressure.
• Integrative Function: Processes sensory input to make decisions.
• Motor Function: Sends signals to muscles and glands to elicit a response.
• Homeostasis Regulation: Maintains stable internal conditions like temperature and hormone release.
• Reflex Actions: Enables quick responses without conscious thought.
• Cognitive and Emotional Processing: Supports thinking, learning, memory, emotions, and decision-making.

Peripheral Nervous System Divisions

• The central nervous system consists of the brain and spinal cord.
• The peripheral nervous system relays information between the CNS and the body.
• Sensory (afferent) neurons transmit info from the body to the CNS.
• Motor (efferent) neurons carry signals away from the CNS to muscles and glands.
• The Somatic nervous system primarily controls the voluntary movements via skeletal muscles and processes reflexes.
• The autonomic nervous system performs involuntary processes.
• The sympathetic nervous system prepares for action.
• The parasympathetic nervous system calms the body.

Neuron Structure

• Dendrite takes in information.
• Axon transmits information away.
• Myelin Sheath insulates and speeds up signal transmission.
• Axon Terminal releases neurotransmitters.
• Synapse is where neurons communicate.
• Neuroglia supports, protects neurons, maintains homeostasis, and forms myelin.

Action Potential

• It's an electrical signal that moves along the axon.

Synapse

• The action potential arrives at the axon terminal and depolarizes the membrane.
• Voltage-gated Ca²+ channels open.
• Ca²+ enters the cell and signals to vesicles.
• Vesicles dock to synapse and release neurotransmitters.
• Neurotransmitters diffuse into the synaptic cleft and bind to receptors.

Neuron Types

• Sensory neurons carry information to the CNS from sensory receptors.
• Motor neurons carry information from the CNS to effectors (muscles, glands).
• Interneurons are located between sensory and motor neurons, acting as the middleman.

Nervous System Disorders

• Multiple sclerosis is an autoimmune disease damaging the myelin sheath in the CNS and slows down action potentials.

Brain Structure

• Frontal lobe: initiates motor activity.
• Parietal lobe: interprets senses.
• Temporal lobe: interprets auditory information.
• Occipital lobe: processes visuals.
• Limbic system manages emotions and memory.
• Thalamus relays sensory information in the brain.
• Hypothalamus regulates hormones and behaviors.
• Hippocampus retains memory.
• Amygdala processes fear and motivation.
• Cerebrum receives and combines emotions and conscious thoughts.
• Spinal cord acts as the highway and manages reflexes.
• Brain functions as the control center for complex processing.

Reflex Pathway

• Stimulus: Sensory receptor detects a change
• Sensory Neuron (Afferent Pathway) carries the signal to the spinal cord.
• Integration Center (Spinal Cord) processes the signal through a synapse.
• Motor Neuron (Efferent Pathway) transmits the response to the effector.
• Effector carries out the response.

Special Senses

• Vision (Sight): Processes light through the optic nerve
• Hearing (Audition): Converts sound vibrations into electrical signals.
• Equilibrium (Balance): Detects head position to maintain coordination.
• Olfaction (Smell): Detects air molecules.
• Gustation (Taste): Detects chemical molecules for basic tastes.

Ear Anatomy

• Outer ear collects sound waves with the pinna.
• Middle ear amplifies vibrations and equalizes pressure through the Eustachian tube.
• Inner ear converts vibrations to electrical signals in the cochlea, and the semicircular canals manage balance.

Reducing Hearing Loss

• Install acoustic treatments.
• Use directional speakers.
• Use "quiet zones”.
• Set volume limits on speakers
• Provide "high-fidelity” earplugs.

Balance

• Spinning causes fluid in semicircular canals to continue moving, causing dizziness.
• The vestibular system in the inner ear provides information about motion and orientation, and spatial orientation.

Eye Anatomy

• Sclera: The gives the eye shape and protection.
• Cornea: Bends light.
• Iris: Controls Pupil size.
• Pupil: Center that lets light enter.
• Lens: Tunes focus with shape.
• Retina: Lining with photoreceptors.
• Rods: Low light.
• Cones: Detect color.
• Macula: Central vision.
• Fovea: The sharpest vision.

Pupillary Reflex

• Automatic response to light changes pupil size.

Eye Disorders

• Myopia (Nearsightedness): blurred distance due to light focusing in front of the retina, correct with concave lenses.
• Hyperopia (Farsightedness): blurred close-up vision due to light focusing behind the retina. corrected with convex lenses.
• Astigmatism: blurred vision due to irregular cornea/lens shape; corrected with cylindrical lenses.

Respiratory System

• Delivers oxygen and removes carbon dioxide.
• Oxygen enters the blood, and carbon dioxide exits.
• Nose/nasal cavity warms and filters air.
• Pharynx (throat) provides passageway.
• Larynx (voice box) helps talking.
• Trachea (windpipe) is the main airway.
• Bronchi split to each lung.
• Bronchioles are small branches.
• Alveoli are sacs where gas exchange happens.
• Conducting Zone brings air in w/ upper & lower respiratory.
• Respiratory Zone is where gas exchange happens with the alveoli.
• Anatomy consists of the lower respiratory tract.
• Alveoli thin walls w/ capillaries, the moist surface makes gas exchange work well.
• Inhalation: contracts and moves down, chest expands, rib muscles pull chest with low pressure.
• Exhalation: diaphragm relaxes, chest reduces and increases pressure.

Breath Rate

• Mostly is handled by the medulla oblongata; is part of the ANS.
• Monitors the amount of CO2, raises if needed.
• Can be changed by control choices.

Lung Volumes

• Tidal Volume (TV): Normal air.
• Inspiratory Reserve Volume (IRV): Extra air after a normal breath.
• Expiratory Reserve Volume (ERV): Forces air after a norm.
• Residual Volume (RV): Air unable to be released.
• Vital Capacity (VC): Range during max inhalation, and exhalation.

Respiration Types

• Internal Respiration is Gs exchange between tissues.
• External Respiration is Gas exchange between lungs and blood.
• Blood is a capillary relationship.
• Oxygen diffuses with aid from a membrane of the alveolar.
• Higher temps, more speed.
• Lower temps, more slow.

Cell Membranes

• They are selectively permeable let substances pass, are are secure.
• They nutrients, take waste, prevent harmful compounds.
• Solutes move 3 ways.
• 1. Diffusion: Is made of small particles.
• 2. Facilitated diffusion: It is uses proteins to move compounds.
• 3. Active transport: Moves solutes against flow, and needs energy.
• 4. Osmosis moves solvents.

Hemoglobin

• Carries oxygen, and transports CO2.

Respiratory Disease

• They are hard to inhale; or make sure to expand lungs all the way.
• Some indications involve, short, breaths, a lowered volume for the lungs.
• Some include Pneumonia.
• Diseases that prevent exhaling can be long, and/or wheezy.
• Asthma contracts bronci muscles and produce mucus.
• Can destroy areas (like alveoli) and reduce gas exchange.
• COPD is often long term and tough to exhale.

COPDs

• COPD differs because it is a long term disease and hard to improve.
• They may also be lower diseases, like Asthma.

Lifesyle

• Factors increasing risk include smoking being a big one or pollution.
• Being around smoke or little exercise, or diet can also contribute.

E-Cigarettes

• They contain damage products and don't benefit lung inflammation.

Urinary System

• The function is to regulate water and blood pressure, and manages waste.
• Nephrons are located in the center.
• Ureters are tubes in the kidneys.
• Bladders store, while Urethra releases.
• Function is to reabsorb water, and the system is made for filtration of blood.
• waste products are released.
• ADH retains the water.
• Aldosterone adjusts sodium.
• The system uses kidneys to manage and get rid what the PH balance.
• Routine urinalysis examines hydration, leukocytes, protein, and blood.

Diabetes

• Type 1 is an auto immune with little insulin made.
• Under 40s cases, with high glucose.
• Type 2 is a insulin, the cells are hard.
• Symptoms cause excess thirst, often over for a decade.
• The pancreas releases to move around.
• Cells can be protected due to fat build up.
• Extra causes the liver to push for glucose, and up insulin.
• Extra causes the liver to push for glucose, and up insulin.

Feedback Loops

• Negative brings the body state back.
• Positive amplifies the response, and moves the body away from a target point.

Endocrine System

The function is to use hormones to control growth, metabolism, sugar, reproduction, and mood.

• Steriod hormones work, made of cholesterol and membrane. They have slow effects.
• Non-Steriod works fast, is made of amino acids and has water.
• When high levels come the, it slows down release speed.
• The glands consist of outer and inner like Inflammatory.
• Pancreas lowers sugar, sends to the cells.
• They also raise or have sexual characteristics like melatonin.

Key Glands

• Anterior pituitary manages, as well as the posterior.
• Thyroid is about regulating as well.
• If sugar runs too high, insulin will release to lower.
• Disruptors causes disruptions, there are also disruptors that can mimic hormones for thyroid, puberty, and fertility.
• Diets contain, hydration, that help support.