Blood Composition and Functions Quiz

Questions and Answers

What is the natural anticoagulant found in the body?

Heparin (correct)

Warfarin

Aspirin

Clopidogrel

What is the primary benefit of the biconcave shape of erythrocytes?

Ability to produce hemoglobin

Increased surface area to volume ratio (correct)

Increased lifespan in circulation

Optimized oxygen storage capability

What causes anemia in the human body?

High levels of white blood cells

Increased red blood cell production

Blood loss or reduced hemoglobin levels (correct)

Excessive oxygen transport

Which of the following leukocytes are involved in combating parasites?

Eosinophils Signup and view all the answers

What is the main function of hemoglobin in the blood?

Loading and unloading oxygen and carbon dioxide Signup and view all the answers

What is the term for the process of producing red blood cells?

Erythropoiesis Signup and view all the answers

Why is a differential WBC count more informative than a total WBC count?

It measures the percentage of each type of WBC present. Signup and view all the answers

What type of cell is referred to as a 'committed cell'?

A precursor whose specialization path is determined Signup and view all the answers

What is saltatory conduction?

The process of conduction leaping along myelinated neurons Signup and view all the answers

Which of the following is NOT directly involved in the production of a typical spinal reflex?

Brain Signup and view all the answers

Which division of the nervous system controls smooth muscle and internal organs?

Autonomic division Signup and view all the answers

Which division of the nervous system controls both voluntary and involuntary skeletal muscle movement?

Somatic division Signup and view all the answers

Which division of the nervous system predominates during the relaxed state?

Parasympathetic division Signup and view all the answers

What effect does the sympathetic nervous system facilitate?

Increased blood pressure Signup and view all the answers

What are the membranes that enclose the central nervous system called?

Dura mater, arachnoid, and pia mater Signup and view all the answers

Which region of the brain coordinates antagonistic muscle movements?

Cerebellum Signup and view all the answers

Which of the following statements about muscle contraction is true?

All muscles shorten when they contract Signup and view all the answers

What initiates the contraction of a skeletal muscle cell?

Release of acetylcholine by a neuron Signup and view all the answers

Which statement is NOT necessary for muscle contraction to occur?

The troponin and tropomyosin must slide relative to each other Signup and view all the answers

Once ATP is depleted in a muscle cell, what will it use next for energy?

Creatine phosphate Signup and view all the answers

What is the primary energy source used by muscle cells to generate ATP?

Glycogen Signup and view all the answers

What happens when an electrical impulse reaches a neuromuscular junction?

There is an increase in secretion of acetylcholine Signup and view all the answers

Which of the following is NOT a function of bone?

Serving as an endocrine organ Signup and view all the answers

Where is compact bone primarily located in long bones?

Covers the ends and forms the shaft Signup and view all the answers

What is the primary function of erythrocytes?

Gas transport, specifically O2 and CO2 Signup and view all the answers

Which component of blood plasma is involved in the regulation of osmotic pressure?

Albumin Signup and view all the answers

What occurs during the platelet phase of haemostasis?

Platelets aggregate to form a plug Signup and view all the answers

How many oxygen molecules can a single hemoglobin molecule transport?

Four Signup and view all the answers

Which type of leukocyte is primarily responsible for an immune response through antibody production?

Lymphocytes Signup and view all the answers

What is a primary component of plasma that helps in the clotting process?

Fibrinogen Signup and view all the answers

Which of the following statements about leukocytes is correct?

They play a crucial role in defending against disease Signup and view all the answers

What vital factor is necessary for erythropoiesis to proceed effectively?

Vitamin B12 Signup and view all the answers

Which phase of haemostasis involves the transformation of prothrombin to thrombin?

Coagulation phase Signup and view all the answers

What type of blood cell is characterized by a lack of granules and plays a role in phagocytosis?

Monocytes Signup and view all the answers

What is the role of erythropoietin in erythrocyte production?

Stimulates the production of red blood cells Signup and view all the answers

Which protein helps to maintain blood clotting by converting fibrinogen to fibrin?

Thrombin Signup and view all the answers

During which phase of erythropoiesis is hemoglobin and iron accumulated?

Normoblast phase Signup and view all the answers

Which type of leukocyte is primarily involved in fighting parasitic infections?

Eosinophils Signup and view all the answers

What is the primary role of tendinous muscle attachments compared to direct attachments to bone?

They conserve space and can span bony prominences. Signup and view all the answers

Which type of joint is characterized by being immovable?

Synarthroses Signup and view all the answers

What is a defining characteristic of rheumatoid arthritis?

Causes inflammation to the synovial membrane. Signup and view all the answers

Which of the following best describes the function of the fixator muscle?

Immobilizes bones and/or origins. Signup and view all the answers

In the sliding filament model of muscle contraction, what role does calcium play?

It facilitates the exposure of actin binding sites. Signup and view all the answers

What type of muscle fiber arrangement is classified as short and containing many fibers per unit area?

Pennate Signup and view all the answers

Which joint type allows for the greatest range of motion?

Ball-and-socket Signup and view all the answers

What is an example of a first-class lever in the human body?

Nodding the head. Signup and view all the answers

Which connective tissue layer surrounds the entire muscle?

Epimysium Signup and view all the answers

What is the main role of the sarcoplasmic reticulum?

It stores Ca2+ ions necessary for contraction. Signup and view all the answers

Which type of muscle interaction opposes the movement initiated by the prime mover?

Antagonist Signup and view all the answers

What happens to tropomyosin when calcium levels increase in muscle tissue?

It moves away from the binding sites on actin. Signup and view all the answers

What is the primary function of muscle tissue regarding heat?

Generating heat through contraction. Signup and view all the answers

Study Notes

Blood Function and Composition

Blood is a specialized connective tissue with various critical functions:
- Distribution of oxygen (O2), waste products, hormones, and nutrients.
- Regulation of pH, temperature, and fluid levels.
- Protection through clotting processes and immune responses.
Composed of:
- Plasma: Non-living fluid matrix; approximately 90% water.
- Formed elements: Living blood cells including erythrocytes, leukocytes, and thrombocytes.
Plasma contains fibrous proteins visible during clotting.

Blood Plasma Components

Over 100 dissolved solutes found in plasma including:
- Proteins: Albumin, globulins (transport proteins and antibodies), clotting proteins (fibrinogen, prothrombin).
- Non-proteins: Urea, lactic acid, creatinine.
- Nutrients: Carbohydrates, amino acids, fatty acids, glycerol, vitamins.
- Electrolytes: Sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), bicarbonate (HCO3-).
- Gases: Respiratory gases O2 and CO2.
- Other: Enzymes, antigens, antibodies, hormones.

Formed Elements of Blood

Refers to cellular components of blood:
- Erythrocytes (red blood cells) which are incomplete cells.
- Leukocytes (white blood cells) which are complete cells functioning in immunity.
- Thrombocytes (platelets) are disc-shaped cellular fragments involved in clotting.
Formed elements originate from red bone marrow tissue.

Erythrocytes (Red Blood Cells)

Erythrocytes have a diameter of 7.5 μm and a biconcave shape for enhanced gas transport.
Mature erythrocytes are bound by a plasma membrane, lack a nucleus, and contain no organelles while being rich in hemoglobin (Hb).
Main function includes transporting CO2 (~20%) and O2 (~90+%).

Erythrocyte Formation

Erythrocytes are formed in red bone marrow under the control of erythropoietin.
The three main phases of formation include:
- Haemocytoblast (stem cell) to proerythroblast (committed cell) leading to developmental pathways involving ribosome synthesis, hemoglobin accumulation, and nucleus ejection.
Requires Vitamin B12 for stem cell division.

Hemoglobin Function

Hemoglobin binds reversibly with oxygen and consists of four polypeptide chains.
Each heme group contains an iron atom that binds one O2, allowing one Hb molecule to transport four O2.
Oxygen loading occurs in lungs forming oxyhemoglobin, while unloading in tissues produces deoxyhemoglobin; also participates in CO2 transport.

Leukocytes (White Blood Cells)

Leukocytes are spherical with sizes ranging from 10-24 μm.
Classified into granulocytes (with granules) and agranulocytes (without granules):
- Granulocytes: Neutrophils (bacteria), eosinophils (parasitic worms), basophils (inflammation mediators).
- Agranulocytes: Lymphocytes (immune function) and monocytes (migratory phagocytes).
Principal function: Defense against disease such as bacteria, viruses, and toxins.

Thrombocytes (Platelets)

Thrombocytes are cell fragments 2-4 μm in diameter, with a rough disc shape and lack a nucleus.
Mature platelets age rapidly, degenerating within 10 days if unused.
Rich in granules that aid in clotting processes, particularly serotonin.
Their chief function is to initiate blood clotting when injury occurs.

Hemostasis (Blood Clotting)

Defined as cessation of bleeding with a framework for tissue repair.
Occurs in response to damaged blood vessels through three phases:
- Vascular Phase: Contraction of the vessel wall (vasoconstriction).
- Platelet Phase: Platelet adhesion and aggregation forming a plug.
- Coagulation Phase: Fibrin formation leading to a stable clot.

Anticoagulants

Anticoagulants are substances that inhibit blood clotting.
Heparin is the body's natural anticoagulant, contrasting with Warfarin.

Muscle Structure and Function

Muscle tissue consists of over 600 muscles with four primary functions: movement, posture, stabilization of joints, and generation of heat.
Muscle characteristics include excitability, contractility, extensibility, and elasticity.
Muscles are classified by fiber arrangements: parallel, convergent, pennate, circular.

Muscle Interactions and Attachments

Muscles attach to bones via tendons, with each muscle having an origin (immovable) and an insertion (movable).
Interactions between muscles include prime movers (major force), synergists (assist in action), antagonists (oppose movement), and fixators (stabilize origin).
Muscles can only pull, never push.

Lever Systems in Muscle Mechanics

Levers consist of a fulcrum, effort, and load.
There are three types of bone-muscle levers:
- First Class: Effort and load are opposite.
- Second Class: Load is between effort and fulcrum.
- Third Class: Effort is between load and fulcrum.

Muscle Contraction Mechanism

At the neuromuscular junction, motor neuron impulses induce calcium influx and the release of acetylcholine (ACh), stimulating muscle contraction.
The sarcoplasmic reticulum releases calcium which binds to troponin, removing tropomyosin, thereby exposing actin binding sites for myosin binding.

Sliding Filament Model

Thick (myosin) and thin (actin) filaments interact to shorten the muscle during contraction.
Requires ATP for muscle contraction, with glycogen primarily serving as an energy source post-ATP depletion.

Importance of Blood Studies

Blood studies can reveal specific changes in formed elements or plasma constituents, signaling different disease states.

Differential WBC Count vs. Total WBC Count

A differential WBC count provides the percentage of each type of white blood cell, aiding in identifying specific pathologies.

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Description

Test your knowledge on the composition and functions of blood. This quiz covers essential aspects such as the role of plasma, the formed elements, and the various functions blood performs in the body, including distribution, regulation, and protection. Perfect for students in the School of Science at Edith Cowan University.