Week 1: Intro

Question 1

Define the anatomical position (1 point)

Answer 1

• The scientifically agreed upon reference position for the description of the human body and the relation of its parts to one another

Question 2

Describe the appearance of the anatomical position (5 points)

Answer 2

• Body in standing position
• Face and feet facing forward always
• Palms facing forward - thumbs point away from body
• Feet slightly apart
• ‘Right’ and ‘Left’ refer to the sides of the body of the actual subject being viewed - not those of the observer

Question 3

List and define directional terms (13 points)

Answer 3

1. Superior (cranial)=above; toward the head end or upper part of a structure or the body
2. Inferior (caudal)=below; away from the head end or toward the lower part of a structure or the body
3. Ventral/Anterior=towards the front or at the front of the body; in front of
4. Dorsal/Posterior=towards the back or at the back of the body; behind
5. Medial=towards the middle or at the midline; on the inner side of
6. Lateral=away from the midline of the body; on the outer side of
7. Intermediate= between; between a more medial and a more lateral structure; example: the collarbone is intermediate between the breastbone and shoulder
8. Proximal= toward the point of attachment to the trunk; closer to the origin of the body part or the point of attachment of a limb to the body trunk; example: the elbow if proximal to the wrist
9. Distal = away from the point of attachment to the trunk; farther from the origin of a body part or the point of attachment of a limb to the body trunk: example: the knee is distal to the thigh
10. Superficial=external; toward or at the surface of the body
11. Deep=internal; toward the interior of the body and away from the body surface
12. Supine = upwards
13. Prone = downwards

Question 4

List and define movement terms that apply to multiple joints (8 points)

Answer 4

1. flexion = decreasing the angle of the joint, bending the joint
2. extension = increasing the angle of the joint, straightening the joint
3. hyper extension = straightening of a joint beyond its natural range of motion
4. abduction = moving the limb away from the center line (medial line) of the body
5. adduction = moving the limb towards the center line (medial line) of the body
6. circumduction = a circular movement of a limb
7. lateral rotation = rotating a limb away from the center line (medial line) of the body
8. medial rotation = rotating a limb towards the center line (medial line) of the body

Question 5

Describe the movement terms that apply to a specific few joints (13 points)

Answer 5

1. plantarflexion = increasing the angle of the ankle joint
2. dorsiflexion = decreasing the angle of the ankle joint
3. eversion = rotating the ankle so that the sole of the foot points away from the other
4. inversion = rotating the ankle so that the sole of the foot points towards the other
5. protraction = anterior movement (towards the front of the body) of the arm at the shoulder
6. rectraction = posterior movement (towards the back of the body) of the arm at the shoulder
7. depression = moving a body part in an inferior direction
8. elevation = moving a body part in a superior direction
9. opposition = tip of the thumb comes to meet (and oppose) the tip of another finger from the same hand
10. reposition = the thumb and finger move away from each other and return to their original position.
11. supination = rotating the forearm so that the palm faces up if the forearm is flexed
12. pronation = rotating the forearm so that the palm faces down if the forearm is flexed
13. Lateral flexion = bending the spine to the side, away from the center line (medial line) of the body

Question 6

List and define the common regional terms (11 points)

Answer 6

1. Cephalic= of or relating to the head
2. Cervical= relating to the neck
3. Thoracic = relating to the thorax, commonly known as the chest
4. Abdominal= relating to abdomen, commonly known as the belly
5. Pelvic = relating to the pelvis, the area of the body below the abdomen and between the hip bones
6. Pubic = relating to the genitalia
7. Upper limb = consists of the upper arm, forearm and hand
8. Manus = the terminal segment of a forelimb/upper limb, corresponding to the hand and wrist
9. Lower limb = consists of the thigh, leg and foot
10. Pedal = the terminal segment of a lower limb, corresponding to the foot and ankle
11. Dorsal = encompassing the back

Question 7

List and define the less common regional terms (15 points)

Answer 7

1. Axillary = relating to the armpit
2. Brachial = relating to the arm
3. Carpal = relating to the wrist
4. Costal= relating to the ribs
5. Coxal = relating to the hip
6. Crural = relating to the lower leg
7. Femoral = relating to the thighs
8. Orbital = relating to the eyes
9. Plantar = relating to the sole of the foot
10. Popliteal = relating to the back of the knee
11. Sacral = relating to the sacrum
12. Sternal = relating to the sternum
13. Sural = relating to the calf
14. Tarsal = = relating to the ankle

Question 8

Label the marked areas in the image (55 points)

Answer 8

Question 9

List and define the body planes and sections (5 points)

Answer 9

1. sagittal plane= a vertical plane that divides the body into right and left parts.
   
   1. A sagittal plane that lies exactly in the midline is the median or midsagittal plane.
   2. Sagittal planes that are offset from he midline are parasagittal planes (para = near)
2. frontal= also known as a coronal plane, a vertical plane that divides the body into anterior and posterior parts
3. transverse planes= also known as a horizontal plane, divides the body into superior and inferior parts

Question 10

List the levels of human structure from the simplest to the most complex (6 points)

Answer 10

1. Chemical level
2. Cellular level
3. Tissue level
4. Organ level
5. System level
6. Organism (whole body)

Question 11

Describe the chemical level (3 points)

Answer 11

• Atoms are the building blocks of matter
• Atoms combine to form molecules with three-dimensional structures
• Molecules combine to formmacromolecules

Question 12

Describe the Cellular level (12 points)

Answer 12

• Molecules and macromolecules combine to form the components of cells such as the fluid and organelles
• Cell components such as organelles combine to formcells
• Cells are special units that carry out particular functions, including essential life functions
• There are 8 life functions that cells perform. These include:
  1. Maintaining boundaries
  2. Movement
  3. Responsiveness
  4. Digestion
  5. Metabolism
  6. Excretion
  7. Reproduction
  8. Growth

Question 13

Briefly describe maintaining boundaries (2 points)

Answer 13

• Every living organism must maintain its boundaries so that its internal environment remains distinct from the external environment
• Examples: cell membrane and integumentary system

Question 14

Briefly describe movement (3 points)

Answer 14

• includes the activities promoted by the muscular system, such as propelling ourselves from one place to another, and manipulating the external environment
• also occurs when substances such as blood, foodstuffs, and urine are propelled through internal organs
• On the cellular level, the muscle cell’s ability to move by shortening is more precisely called contractility

Question 15

Briefly describe responsiveness (2 points)

Answer 15

• the ability to sense changes in the environment, both internal and external, and then respond to them
• the nervous system is most involved with responsiveness. However, all body cells are excitable to some extent.

Question 16

Briefly describe digestion (4 points)

Answer 16

• the breaking down of ingested foodstuffs to simple molecules that can be absorbed.
• In a simple, one-celled organism such as an amoeba, the cell itself is the “digestion factory,”
• but in the multicellular human body, the digestive system performs this function for the entire body, which is then absorbed into the blood.
• The nutrient-rich blood is then distributed to all body cells by the cardiovascular system.

Question 17

Briefly describe metabolism (4 points)

Answer 17

• Sum total of the chemical reactions occurring in the living organism
• includes:
  1. breaking down substances into simpler building blocks (the process of catabolism)
  2. synthesizing more complex substances from simpler building blocks (anabolism),
  3. using nutrients and oxygen to produce (via cellular respiration) ATP, the energy-rich molecules that power cellular activities.

Question 18

Briefly describe excretion (2 points)

Answer 18

• Elimination of waste products
• examples: (1) the digestive system rids the body of indigestible food residues in feces, (2) the urinary system disposes of nitrogen-containing metabolic wastes, such as urea, in urine, and (3) Carbon dioxide, a by-product of cellular respiration, is carried in the blood to the lungs, where it leaves the body in exhaled air

Question 19

Briefly describe reproduction (3 points)

Answer 19

• the production of offspring
• In cellular reproduction, the original cell divides, producing two identical daughter cells that may then be used for body growth or repair.
• In human reproduction, a sperm unites with an egg, a fertilized egg forms and develops into a baby within the mother’s body until birth.

Question 20

Briefly describe growth (3 points)

Answer 20

• an increase in size of a body part or the organism as a whole.
• It is usually accomplished by increasing the number of cells. However, individual cells also increase in size when not dividing.
• For true growth to occur, constructive activities must occur at a faster rate than destructive ones.

Question 21

Describe the Tissue level (6 points)

Answer 21

• Cells that carry out similar functions are grouped together to formtissues.
• The four main types are:
  1. Epithelial tissue
  2. Connective tissue
  3. Muscle tissue
  4. Nervous tissue

Question 22

Describe the Organ level (3 points)

Answer 22

• Two or more different tissues are grouped to form organs
• The liver, the brain, and a blood vessel are very different from the stomach, but each is an organ.
• Each organ of the body is a specialized functional center responsible for a necessary activity that no other organ can perform.

Question 23

Describe the System level (13 points)

Answer 23

• Two or more organs work closely together to perform the vital functions of a body system
• There are 11 organ systems:
  1. Cardiovascular system
  2. the integumentary system
  3. skeletal system
  4. muscular system
  5. nervous system
  6. endocrine system
  7. lymphatic system (Note that the immune system is closely associated with the lymphatic system.)
  8. respiratory system
  9. digestive system
  10. urinary system
  11. reproductive system

Question 24

Briefly describe the cardiovascular system (3 points)

Answer 24

• consists of heart and blood vessels
• heart pumps blood
• blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes etc

Question 25

Briefly describe the integumentary system (3 points)

Answer 25

- consists of skin, hair and nails - forms the external body covering and protects deeper tissues from injury - synthesizes vitamin D and houses cutaneous receptors (pain, pressure, etc.) and sweat/oil glands

Question 26

Briefly describe the skeletal system (3 points)

Answer 26

- consists of bones and joints - protects and supports body organs and provides a framework the muscles use to cause movement - blood cells are formed within bones; bones store minerals

Question 27

Briefly describe the muscular system (3 points)

Answer 27

- consists of skeletal muscles - allows manipulation of the environment, locomotion and facial expression - maintains posture and produces heat

Question 28

Briefly describe the nervous system (3 points)

Answer 28

- consists of brain, spinal cord and nerves - the fast-acting control system of the body - responds to internal and external changes by activating appropriate muscles and glands

Question 29

Briefly describe the endocrine system (9 points)

Answer 29

- consists of 5 glands and 2 organs: 1. Pineal gland 2. Pituitary gland 3. thyroid gland 4. thymus 5. adrenal gland 6. pancreas 7. gonads (ovaries and testis) - glands secrete hormones that regulate processes such as growth, reproduction and nutrient use (metabolism) by body cells

Question 30

Briefly describe the lymphatic system (10 points)

Answer 30

1. Red bone marrow 2. Thymus 3. Lymphatic vessels 4. Thoracic duct 5. Spleen 6. Lymph nodes - picks up fluid leaked from blood vessels and returns it to blood - disposes of debris in the lymphatic stream - houses lymphocytes (white blood cells) involved in immunity - immune system response mounts the attack against foreign substances within the body

Question 31

Briefly describe the respiratory system (3 points)

Answer 31

1. Nasal cavity 2. Pharynx 3. Larynx 4. Trachea 5. Bronchus 6. Lungs - keeps blood constantly suppled with oxygen and removes carbon dioxide - these exchanges occur through the walls of the air sacs of the lungs

Question 32

Briefly describe the digestive system (10 points)

Answer 32

1. Oral cavity 2. esophagus 3. liver 4. stomach 5. small intestine 6. large intestine 7. rectum 8. anus - breaks down food into absorbable units that enter the blood for distribution to body cells - indigestible foodstuffs are eliminated as feces

Question 33

Briefly describe the urinary system (3 points)

Answer 33

- consists of kidney, ureter, urinary bladder and urethra - eliminates nitrogenous wastes from the body - regulates water, electrolyte and acid-base balance of the blood

Question 34

Briefly describe the reproductive system system (6 points)

Answer 34

- male reproduction system consists of prostate, penis, testis, scrotum and ductus deferens - female reproduction system consists of mammary glands in breasts, ovary, uterus, uterine tube and vagina - overall function is production of offspring - testes produce sperm and male sex hormone. ovaries produce eggs and female sex hormones - male ducts and glands aid in delivery of sperm to the female reproductive tract. the female tract serve as sites for fertilization and development of the fetus - mammary glands of female breast produce milk to nourish the newborn

Question 35

Describe the Organism (3 points)


Answer 35

- The highest level of organization is the organism, the living human being. - The organismal level represents the sum total of all structural levels working together to keep us alive. - Many organs systems work harmoniously together to perform the functions of an independent organism

Question 36

Describe the body cavities (11 points)

Answer 36

- The human body has two main internal cavities: 1. Dorsal (posterior) cavity: *  which protects the organs of the nervous system * Its subdivisions are: 1. Cranial cavity which encases the brain 2. Vertebral (or spinal) cavity which surrounds the spinal cord 2. Ventral (anterior) cavity: * which houses a number of internal organs termed viscera (viscus = an organ in a body cavity) * Its subdivisions are: 1. Thoracic cavity 2. Abdominopelvic cavity, consisting of abdominal cavity and pelvic cavity

Question 37

Describe the ventral cavity (9 points)

Answer 37

- Divided into two subdivisions, which is seperated by the diaphragm (the dome-shaped breathing muscle). They are: 1. The thoracic cavity. It contains: - the pleural cavities = lateral cavities which enclose the lungs - mediastinum = medial cavity which encloses the heart, esophagus, trachea and other thoracic organs, cab be further divided into two sections - Superior mediastinum which envelopes esophagus, trachea and other thoracic organs - Mediastinum also contains pericardial cavity which surrounds the heart 2. The abdominopelvic cavity. It contains: - the abdominal cavity, which contains the stomach, intestines, spleen, liver and other organs - the pelvic cavity, which contains the urinary bladder, some reproductive organs and the rectum

Question 38

Describe serous membranes (11 points)

Answer 38

- Also known as the serosa - Serous (or fluid secreting) membranes are two layered membranes with fluid in between. - These two layers are called: 1. parietal membrane lining the cavity wall (outer layer) 2. visceral membrane covering the organ in the cavity (inner layer) - Serous fluid is thin, lubricating fluid produced by both serous membranes - separates the parietal and visceral membrane layers - Function: - Wall off organ from surrounding infection - Protect from trauma - Decrease friction between moving organs

Question 39

List and describe other body cavities (5 points)

Answer 39

1. Oral & digestive cavity: Cavity starts from the mouth, extends into the cavity of the digestive tract & finally opens to the exterior at the anus. 2. Nasal cavity: Located within and posterior to the external nose 3. Orbital cavities: House the eyes 4. Middle ear cavities: Carved into the temporal bone and consist of tiny bones to transmit sound vibration to the inner ears. 5. Synovial cavities: Joint cavities

Question 40

Describe abdominopelvic quadrants and regions (7 points)

Answer 40

- Because the abdominopelvic cavity is large and contains several organs, it helps to further divide it into quadrants to identify exact locations. - The quadrant divisions are: 1. Right upper quadrant (RUQ) 2. Left upper quadrant (LUQ) 3. Right lower quadrant (RLQ) 4. Left lower quadrant (LLQ) - Transverse and median planes for quadrants pass through umbilicus

Question 41

Describe abdominopelvic regions (14 points)

Answer 41

- Primarily used by anatomists to separate the abdominopelvic cavity into smaller sections (called regions) - The anatomical divisions of the abodominopelvis can be split into nine regions: 1. Right hypochondriac region 2. Epigastric region 3. Left hypochondriac region 4. Right lumbar region 5. Umbilical region 6. Left lumbar region 7. Right lilac (inguinal) region 8. Hypogastric (pubic) region 9. Left lilac (inguinal) region - Superior tranverse plane is just inferior to the ribs - Inferior tranverse plane is just superior to hip bones - Parasagittal planes are just medial to the nipples

Question 42

Label the marked areas in the image (14 points)

Answer 42

Question 43

Label the marked areas in the image (22 points)

Answer 43

Question 44

Describe ECF (5 points)

Answer 44

- The internal environment of the body consists of extracellular fluid (ECF) bathing the body cells.  - The body is like a bag of skin, containing fluid in which cells can be found – the fluid is called extracellular because it is on the outside of the cells. - The extracellular fluid (ECF), located in the extracellular fluid compartment, is made up of: - interstitial fluid (the fluid in the tissues around the cells) - plasma (the fluid part of the blood)

Question 45

Describe homeostasis (14 points)

Answer 45

- The processes that lead to the maintenance of relatively stable conditions in the ECF is called homeostasis.  - Homeostasis is a state of dynamic equilibrium or stable internal environment of the body. - Various factors in the ECF are kept within a narrow range of defined limits that are essential for life. Some of these are: 1. Gases and nutrients 2. Water volume and pressure 3. Salt concentration 4. pH and temperature 5. Waste products - For example: - Water moves freely between the plasma, interstitial fluid and the intracellular fluid – evenly distributed between the fluid compartments - Sodium moves freely out of the plasma but its entry into and out of cells is regulated or controlled - The levels of potassium inside the cell are carefully controlled - Proteins cannot leave the plasma or cells except through special transport processes which will be covered in the module on cells - The conditions of the extracellular fluid – which includes the plasma and the interstitial fluid, are carefully controlled so that cells are able to function most efficiently – and if cells function efficiently, then so do the tissues, organs and organ systems they make up, and the whole organism functions properly.

Question 46

Describe the relationship between homeostasis and health (13 points)

Answer 46

- Health can be viewed as the ability to maintain homeostasis in the face of change. - Body processes maintain a dynamic stable state in the internal environment, making appropriate corrections for changes - “Dynamic stable state” means internal conditions vary within narrow limits - An internal change outside the normal limits act as a stimulus which causes an appropriate corrective response - Even though the term homeostasis means “to stay the same’ it really refers to maintaining a balance in the internal environment of the body – so internal conditions can vary but they do so within fairly narrow limits - All homeostatic control mechanisms are processes that involve three components that work together to maintain balance, these include: 1. Receptor= a sensor that monitors the environment and responds to changes (or stimuli) by sending information (input) along an afferent pathway to the second component 2. Control centre= which determines the normal range of a particular condition (e.g. temperature), analyses the input from the receptor, compares this with the normal range and then determines the appropriate response – information then flows from the control centre, along an efferent pathway to the third component, the 3. Effector= which brings about the response – the results of the response then feedback to the control centre via the receptor/afferent pathway and the control centre then either shuts off or enhances the response to restore and maintain internal conditions - Temperature control is an easy example to explain the idea of a homeostatic control mechanism, here the three components include: 1. Receptor = thermoreceptors in the skin and brain 2. Control centre = thermoregulatory centre in the brain (hypothalamus) 3. Effector = either sweat glands or muscles (shivering) – depending on the response required

Question 47

Describe feedback mechanisms (6 points)

Answer 47

- Homeostatic control mechanisms use feedback to maintain balance in the internal environment - Feedback mechanisms operate in a closed loop arrangement where the response alters the initial stimulus - Feedback automatically returns the body to homeostatic balance. - There are two types of feedback: 1. Negative feedback – the response shuts off the original effect of the stimulus or reduces its intensity (= decreases); most of the body's feedback systems are negative; an example of negative feedback is Temperature. 2. Positive feedback – the result or response enhances the original stimulus (accelerates the response); , only a few of the body's feedback systems are positive; an example of positive feedback is Uterine contractions

Question 48

Describe the relationship between body systems and homeostasis (10 points)

Answer 48

- Body systems work together to maintain homeostasis in the internal environment. - Feedback systems work to restore balance. Stimulus-response mechanisms are the basis of the body's ability to make appropriate changes - Failure results in disease or maybe death - Humans are multi cellular organisms and our vital body functions are set out among different organs systems. The organ systems work together to ensure cell survival. - Cells require glucose and oxygen for survival- the two body systems that ensure these are taken in from the environment are: - Respiratory system- oxygen - Digestive system- glucose - Nutrients are then transported to cells by the Cardiovascular system - Cells use these nutrients and the resultant wastes are removed by the: - Urinary system- urea, uric acid - Respiratory system- carbon dioxide - Thus organ or body systems work together to promote the well-being of the entire body. Homeostatic adjustments are made to ensure cells receive sufficient nutrients and get rid of wastes.

Question 49

Describe the nervous system (7 points)

Answer 49

- A network of cells called nerves, or neurons, that send rapid, short-lived electrochemical messages around the body - The nervous system has two main structural divisions: 1. Central nervous system (or brain & spinal cord) is the control centre 2. Peripheral nervous system: - a peripheral nerve is a bundle of many nerve cells (fibres), e.g. the sciatic nerve - afferent nerves carry messages to the CNS from the receptor - efferent nerves carry messages from the CNS to the effector

Question 50

Describe the endocrine system (15 points)

Answer 50

- The endocrine system consists of a number of glands and functions to control metabolic activities that require duration through the action of hormones, a chemical message that is secreted by endocrine glands. - Hormones are: - chemicals (mainly protein or steroids) - produced by various endocrine glands - transported by blood to other parts of the body where they produce a response in target cells - tend to act slowly and are long lived compared to the nervous system - Hormones are released from the cells of the endocrine glands that produce them directly into the bloodstream. - Hormones control a wide variety of body functions: - Growth - Metabolic rate - Reproductive processes - Digestive processes - Blood pressure - Composition of blood plasma - Stress response

Question 51

List the organs of the endocrine system (8 points)

Answer 51

1. Pineal gland 2. Hypothalamus 3. Pituitary gland 4. Thyroid gland 5. Thymus 6. Pancreas 7. Adrenal glands 8. Testes or ovaries

Question 52

What are the similarities/differences between nerves and hormones? (9 points)

Answer 52

- Similarities: - both are a means of cellular communication - both involve stimulus-response mechanisms - Both are involved in homeostasis (regulation) - Differences: - nature of the message - speed and duration of the responses - target of the responses - Together, these two systems regulate and control body processes. 

Question 53

Describe blood (14 points)

Answer 53

- The liquid that is transported via the circulatory system. Body is suppose to possess 4.5 - 5.5 L - Blood is a fluid connective tissue composed of: 1. Plasma (makes up approximately 55% of blood) which is composed of: - 90% water - 70 different Proteins - mostly produced by the liver e.g. albumin (60% ) - Dissolved salts, hormones, metabolic wastes, CO2, nutrients and vitamins 2. Formed elements (makes up approximately 45% of blood) which are: - Erythrocytes (red blood cells, or RBC), which make up about that 95.1% - Leukocytes (white blood cells, or WBC), which make up less that 0.1% - Platelets, or cell fragments, which make up about 4.8% - Haematocrit = percent of blood volume that is Red Blood Cells (RBC) - Normal values are as follows: - 47% ± 5% for males - 42% ± 5% for females

Question 54

Describe function of blood (4 points)

Answer 54

- Has a number of functions such as: - Carrying gases, nutrients, hormones and wastes - Participates in immune system reactions - Helps maintain homeostasis

Question 55

Describe red blood cells (8 points)

Answer 55

- Red blood cells (erythrocytes) have a very interesting and unique shape. Their shape is termed a biconcave disc. - They possess four iron molecules - Red blood cells are: - Filled with haemoglobin (Hb), a protein that carries O2, which provides blood its red color. Each hemoglobin molecule has four iron atoms - Contain a plasma membrane protein which provides flexibility to allow changes of shape - Are the major factor contributing to blood viscosity or thickness - Their shape allows them to carry large amounts of oxygen, and stack and squeeze through capillaries.They pick up oxygen in the lungs and drop it off at the tissues. - The life span of RBC is about 100 - 120 days. Old RBC become fragile, and Hb begins to degenerate and white blood cells in the spleen engulf dying RBC.

Question 56

Describe white blood cells (17 points)

Answer 56

- White blood cells (WBC) otherwise known as leukocytes make up <1% of total blood volume. They are the only complete cells in the blood - Two types of leukocytes: granulocytes, which contain granules (small particles) with enzymes that are released during infections, allergic reaction and asthma, and agranulocytes, which do not possess granules - Primary function is defence against infection. Infection (bacterial/viral) stimulates the release of WBC from the bone marrow which leads to raised WBC numbers (Leukocytosis); WBC count over 11,000/μl - There are five main types of white blood cells. These include:  1. Neutrophils & monocytes - Able to leave the blood vessels and move into the tissues to sites of tissue damage, infection or invasion - Able to engulf (phagocytose) and destroy damaged and dead cells, and invaders e.g. bacteria 2. Eosinophils - attack large objects that are coated with antibodies, like parasites - sensitive to allergens and release enzymes to reduce inflammation 3. Basophils - Contain histamine that dilates blood vessels and heparin that prevents blood clotting 4. Lymphocytes - Have a large nucleus with a thin rim of cytoplasm - Found in the blood, but mostly in lymphoid tissue - Crucial to immunity - Neutrophils, eosinophil and basophils are granulocytes. Lymphocytes and monocytes are agranulocytes.

Question 57

Describe Haemostasis (6 points)

Answer 57

- Plasma proteins and platelets initiate clot formation to prevent blood loss (uses feedback). This process is otherwise known as Haemostasis or Hemostasis - In this process circulating platelets are normally kept inactive and mobile by chemicals produced by endothelial cells (form the walls of blood vessels). - Haemostasis is a fast series of reactions for the stoppage of bleeding. It occurs in 3 stages 1. Vascular spasm 2. Platelet plug formation 3. Coagulation (blood clotting)

Question 58

List the survival needs (5 points)

Answer 58

1. Nutrients 2. Oxygen 3. Water 4. Appropriate temperature 5. Appropriate atmospheric pressure

Question 59

Describe nutrients (7 points)

Answer 59

- contain the chemical substances used for energy and cell building. - Most plant-derived foods are rich in carbohydrates, vitamins, and minerals, whereas most animal foods are richer in proteins and fats. - Carbohydrates are the major energy fuel for body cells. - Proteins, and to a lesser extent fats, are essential for building cell structures. - Fats also provide a reserve of energy-rich fuel. - Selected minerals and vitamins are required for the chemical reactions that go on in cells and for oxygen transport in the blood. - The mineral calcium helps to make bones hard and is required for blood clotting.

Question 60

Describe oxygen (3 points)

Answer 60

- All the nutrients in the world are useless unless oxygen is also available. - Because the chemical reactions that release energy from foods are oxidative reactions that require oxygen, human cells can survive for only a few minutes without oxygen. - The cooperative efforts of the respiratory and cardiovascular systems make oxygen available to the blood and body cells.

Question 61

Describe water (3 points)

Answer 61

- accounts for 50–60% of our body weight and is the single most abundant chemical substance in the body. - It provides the watery environment necessary for chemical reactions and the fluid base for body secretions and excretions. - We obtain water from ingested foods and liquids. We lose it from the body by evaporation from the lungs and skin and in body excretions.

Question 62

Describe normal body temperature (3 points)

Answer 62

- If chemical reactions are to continue at life-sustaining rates, normal body temperature must be maintained. - As body temperature drops below 37°C (98.6°F), metabolic reactions become slower and slower, and finally stop. - When body temperature is too high, chemical reactions occur at a frantic pace and body systems stop functioning.

Question 63

Describe appropriate atmospheric temperature (3 points)

Answer 63

- the force that air exerts on the surface of the body. - Breathing and gas exchange in the lungs depend on appropriate atmospheric pressure. - At high altitudes, where atmospheric pressure is lower and the air is thin, gas exchange may be inadequate to support cellular metabolism.