Animal Bio exam 3 chapters 10, 11, 12, 14 & 16

What is the function of the respiratory system?

Gas exchange: to bring oxygen into the body and remove carbon dioxide from the body.

What is the reason that we breathe in oxygen and breathe out carbon dioxide, i.e., which cellular process requires oxygen and produces carbon dioxide as a waste gas?

The reason we breathe is for aerobic cellular respiration, which is the process that produces energy for the body in the form of the molecule ATP. Our body can't directly use the energy stored in food molecules. It can only use energy stored in ATP. Aerobic cellular respiration transfers energy from food to ATP. Aerobic cellular respiration requires oxygen and produces carbon dioxide as a waste gas.

Alveoli

Site of exchange of oxygen and carbon dioxide between air and blood (external respiration)

Bronchi

Conducts air from the trachea to the bronchioles

Bronchioles

Conducts air from the bronchi to the alveoli

Diaphragm

This is a muscle involved in breathing

Larynx

Conducts air from the pharynx to the trachea. Contains the vocal cords

Lungs

Contain bronchi, bronchioles, and alveoli. Manage the overall process of breathing

Nasal Cavity

Especially adapted to filter, warm, and humidify the incoming air

Pharynx

Conducts air from the nasal cavity to the larynx.

Trachea

Conducts air from the larynx to the bronchi. Wall is reinforced with C-shaped cartilage.

What are cilia?

Small hair-like structures

What is the function of cilia and mucus?

Mucus traps debris and cilia beat to move the mucus to the throat to be swallowed

In which direction do oxygen and carbon dioxide move during external respiration, i.e., Does oxygenmove from air in alveoli into blood in capillaries or vice versa? Does carbon dioxide move from air inalveoli into blood in capillaries or vice versa? (Remember, body cells need oxygen, and they producecarbon dioxide as a waste gas)

In external respiration, oxygen moves from the air in alveoli into the blood (body cells need oxygen) and carbon dioxide moves from the blood into alveoli to be breathed out (carbon dioxide is a waste gas that needs to be removed from the body)

In which direction do oxygen and carbon dioxide move during internal respiration, i.e., Does oxygenmove from blood in capillaries into cells or vice versa? Does carbon dioxide move from blood incapillaries into cells or vice versa. (Remember, body cells need oxygen, and they produce carbondioxide as a waste gas).

In internal respiration, oxygen moves from blood into cells (cells need oxygen) and carbon dioxide moves from cells into blood (carbon dioxide is a waste gas, so it needs to be transported to the lungs to be breathed out).

During normal breathing, which muscles contract to increase the volume of the thoracic/chest cavityduring inspiration (i.e., breathing in)?

The diaphragm and the external intercostal muscles (in between ribs)

Bronchitis

Inflammation of the trachea and bronchi due to an infection (if acute) or an irritant (if chronic). Usuallycauses coughing with mucus.

Asthma

Inflammation and constriction of the airways due to an immune response to an allergen (i.e., it is a type ofallergic response).

Emphysema

Alveoli burst and fuse, which decreases surface area for gas exchange and causes difficulty breathing.Smoking is the most common cause.

Pulmonary Tuberculosis

Caused by an infection of the lungs by the bacterium Mycobacterium tuberculosis

Pulmonary Fibrosis

A serious, chronic, lung disease that causes scarring, thickening, and loss of elasticity of lung tissue.

Pneumonia

Caused by an infection of the lungs (can be bacterial, viral, or less commonly fungal)

kidneys

Filter blood and produce urine in a 3-stage process

ureters

Transports urine between kidneys and bladder

urinary bladder

Stores urine

urethra

Transports urine from bladder out of the body

Name the functional units inside kidneys that filter blood and produce urine.

Nephrons

What is the glomerulus?

A ball of blood vessels in a nephron that have pores to filter blood

During which stage of urine production does the glomerulus function, and what does it do?

It functions during stage 1 and filters the blood. Anything large enough to pass through the pores is filtered out of the blood and into the filtrate (which will form urine)

Where are the internal and external urethral sphincters located and what is the function of the twosphincter muscles?

The internal urethral sphincter is located at the internal opening of the urethra from the bladder. Theexternal urethral sphincter is located at the external opening of the urethra to the outside. Sphincters aremuscles and they function to keep passageways (like the urethra) closed.

Is each sphincter skeletal muscle (and therefore under voluntary control) or smooth muscle (andtherefore under involuntary control)?

The internal urethral sphincter is smooth muscle (under involuntary control), and the external urethralsphincter is skeletal muscle (under voluntary control)

Put the following steps in order from first to last to describe how urine is stored in the bladder andeliminated through the urethra

1. The bladder fills with urine coming in from the ureters. The internal and external sphincters are contracted and closed.

2. When the bladder is half-full, sensory neurons in the bladder wall sense stretching and send signals tothe brain. We then become aware of the sensation that the bladder is full.

3. We voluntarily relax the external sphincter.

4. The brain sends automatic signals to relax the smooth muscle of the internal sphincter and contract the smooth muscle in the bladder wall.

5. Urine is expelled into out through the urethra

What proportion of the US population has chronic kidney disease (a progressive loss of kidney functionwith 5 stages)?

It is estimated 15% of the US population, which includes stages 1 - 5.

What are the top two causes of chronic kidney disease?

Diabetes and hypertension.

When is dialysis necessary, and what does dialysis do?

Dialysis is a treatment for stage 5 chronic kidney disease, also called kidney failure (approximately 2% or1 in 50 with chronic kidney failure will advance to stage 5). Dialysis performs the blood filtering function of the kidneys, so it filters the patient's blood to remove cellular waste molecules. It also has some ability to remove excess fluid and adjust blood composition.

What are the 5 functions of the skeletal system?

1. It gives the body shape and support (just like the beams of a house give it shape and mechanical support). 2. It protects internal organs.

3. Together with the muscular system, it facilitates movement (i.e., muscles pull on bons to bring about movement).

4. Storage of fat (in yellow bone marrow), calcium, and phosphorus.

5. Production of blood cells (blood cells are produced by hematopoietic stem cells located in the red bone marrow).

Name the two types of bone tissue.

Compact bone and spongy bone

Where is red bone marrow located and what is its function?

It is located in the spaces between trabeculae in spongy bone. It contains hematopoietic stem cells thatproduce all of our blood cells.

Where is yellow bone marrow located and what is its function?

It is located in the medullary cavity of long bones (i.e., the cavity in the diaphysis) and it contains mostly fat, so it serves as a fat reserve.

Define joint

A place where two bones meet.

These cells produce the bone matrix and become trapped in the matrix they just produced.

Osteoblasts

These cells reabsorb bone tissue.

Osteoclasts

These cells reside in the bone matrix in chambers called lacunae. They oversee/coordinate the activitiesof the other two cell types during bone remodeling.

Osteocytes

The matrix of bone is hard and flexible. Which substance gives bone its hardness? Which substance gives bone its flexibility?

Calcium and phosphate minerals are incorporated into the bone matrix (and some others, but these two are the main ones). The minerals crystallize and give bone its hardness. Bone matrix also contains protein fibers (notably collagen), and the protein fibers give bone flexibility. Bone is therefore hard and flexible (not brittle)

During the development of most bones, a model of the bones is first produced. What tissue type producesthe initial model of bones?

A cartilage model of bones is initially produced during fetal development

What type of tissue is present in the epiphyseal plate of long bones? What is the function of the epiphysealplate?

Cartilage remains at the epiphyseal plate of long bones throughout childhood and adolescence (and even into early adulthood for many males). The epiphyseal plate enables continued growth of the long bones throughout childhood and adolescence. The cartilage cells proliferate to produce more cartilage, and the cartilage is converted to bone tissue. The production of new bone tissue at the epiphyseal plate continuously elongates the long bones.

Explain the meaning of bone remodeling

Existing bone tissue is continuously being absorbed (by osteoclasts) and new bone tissue is beingproduced (by osteoblasts).

When does bone remodeling occur, or does it occur throughout life?

Bone remodeling occurs throughout life. In a young adult, ~10% of the adult skeleton is remodeled (i.e.,absorbed and replaced) each year. The activity of osteoblasts producing new bone tissue decreases with age beginning at about age 40; therefore, bone mass gradually decreases after that age as bone remodeling continues but at a lower rate

What is the purpose of bone remodeling?

Bone remodeling serves 3 purposes, 1) to repair flaws in bone (such as micro fractures), 2) to thicken and strengthen bone in areas that are subjected to stress (some stressors stay constant, e.g., the stress places on bones from walking, while others stressors change throughout life, e.g., if someone starts playing more tennis or doing more swimming, then bone remodeling will thicken bones in areas that are subjected to the new areas of stress from those sports), and 3) to absorb or release mineral ions that are incorporated into bone tissue (e.g., calcium and phosphorus are needed for other purposes in the body, too). As we age, regular exercise is important to maintain stress on bones, which maintains bone mass (bones weaken and lose mass if they are not subjected to stress).

What causes osteoporosis?

Osteoporosis is characterized by bones that have lost mass and weakened to the extent that it interferes with age appropriate physical activity and health because the bones are more prone to fractures.Some factors that may decrease risk of osteoporosis include regular exercise, eating a balanced diet with adequate protein and calories, getting enough vitamin D and calcium, and not smoking.

What causes osteoarthritis?

Osteoarthritis is caused by age-related breakdown/wear and tear of cartilage and bone tissue at joints.Break down of cartilage causes bone on bone at the joints, which leads to pain, stiffness and decreasedmobility.

What is a common function of the nervous and endocrine systems?

The systems both regulate and coordinate the body's functions. They send messages to communicate outcomes to target organs. (The nervous system is also responsible for our conscious thoughts, feelings and personality).

What type of signals does the nervous system use to send messages?

Electrical signals called action potentials.

What type of signals does the endocrine system use to send messages?

Chemical signals called hormones.

What are the two major sub-divisions of the nervous system?

Central nervous system and peripheral nervous system

What are the two organs of the central nervous system, and what do they do?

The brain receives sensory input, integrates the sensory input and makes sense of it, and formulates output

signals.

Within the peripheral nervous system, what does the sensory division do?

It receives sensory information from the environment (e.g., vision, hearing, touch, temperature, etc.) andtransmits the information to the brain via electrical signals

Within the peripheral nervous system, what does the motor division do? What are the target organs ofthe motor division?

It sends output commands to target organs via electrical signals. The target organs are muscles orglands.

Name the cells of the nervous system that transmit the electrical signals (action potentials)

Neurons

What are nerves?

Nerves contain bundles of axons of neurons in the peripheral nervous system (those axons are sending sensory signals to the brain and transmitting output signals to target organs). Collections of cell bodies of neurons in the peripheral nervous system are called ganglia

Define hormones. (i.e., what are hormones?)

They are chemical messengers produced by glands of the endocrine system. Hormones are released into the bloodstream and act on target organs that have a receptor for the hormone.

Gonads

Includes ovaries in females and testes in males, Produce the hormones estrogen (females) and testosterone (males), Regulate gamete production, secondary sex characteristics, and pregnancy (females only)

Hypothalamus

Control center for the endocrine system. Receives information from the nervous system and controls theactivity of the pituitary gland.

Pancreas

Produces the hormones insulin and glucagon, Regulates blood sugar level

Pituitary Gland

Regulates a variety of body processes (including growth, labor, lactation) and controls the activity of thethyroid, gonads, and adrenal glands.

Thyroid

Regulates the way that cells use energy (i.e., regulates metabolic activity of cells)

Given that release of thyroid hormone stimulates metabolic activity of cells, which scenario would you expect, A or B, if the thyroid gland is overactive (hyperthyroidism)?

Scenario B: Metabolic activity of cells increases (i.e., use energy more rapidly)- increased appetite and weight loss, heat sensitivity, increased heart rate, diarrhea, irritability

Given that release of thyroid hormone stimulates metabolic activity of cells, which scenario would you expect, A or B, if the thyroid gland is under active (hypothyroidism)?

Scenario A: Metabolic activity of cells decreases (i.e., use energy less rapidly)- decreased appetite and weight gain, cold sensitivity, decreased heart rate, constipation, fatigue

What effect does insulin have on blood sugar?

Decreases blood sugar (acts on liver cells and muscle cells and causes the cells to take up glucose andstore it as glycogen).

What effect does glucagon have on blood sugar?

ncreases blood sugar. It acts on liver cells to break down glycogen and release glucose into the blood.

Define diabetes.

The body cannot produce enough insulin or cannot use insulin, which results in high blood glucose.

What causes type I diabetes? What proportion of patients with diabetes have type I?

Type I diabetes is an autoimmune disease; this means the immune system produces an immune response to a molecule in the body, which causes destruction/damage to that part of the body. In type I, the immune system attacks the insulin producing cells of the pancreas causing destruction of those cells. After the cells are destroyed, the individual can no longer produce insulin.Approximately 5% of diabetes patients have type I.

What causes type II diabetes? What proportion of patients with diabetes have type II?

Type II diabetes is not an autoimmune disease. There is no destruction of cells in the pancreas. It occurs when the pancreas stops producing sufficient insulin (despite no damage) or when the target cells become resistant/desensitized to insulin. Approximately 95% of diabetes patients have type II.

Most cases of type II diabetes (though not all) are linked to lifestyle factors. What are the lifestyle factorsthat are significant risk factors for developing type II diabetes (and are often interconnected)?

Obesity, inactivity (sedentary lifestyle), and a diet high in added sugars and refined carbohydrates and

low in fiber.