Biomedicine workbook Flashcards
1
Q
Define the term homeostasis.
A
Homeostasis is the dynamic maintenance of the body’s internal physiological environment within narrow limits that ensure the individual’s well-being.
2
Q
What are our internal and external environments?
A
The changing physical, chemical and biological conditions outside of an individual make up that individual’s external environment. The internal environment consists of the interstitial fluid surrounding all cells.
3
Q
Name some of the physiological variables that are controlled by homeostasis.
A
- Core temperature
- Water and electrolyte concentrations
- PH of body fluids
- Blood glucose levels
- Blood and tissue oxygen and carbon dioxide levels
- Blood pressure
4
Q
Give two examples of variables that are controlled by positive feedback and two that are controlled by negative feedback.
A
Positive feedback: * Uterine contractions during childbirth
* Blood clotting
Negative feedback: * Body temperature
* Blood glucose levels
5
Q
Which feedback mechanism is the most common?
A
Negative feedback
6
Q
What are the three key differences between these two mechanisms?
A
- Negative feedback mechanisms reverse changes, whereas positive feedback mechanisms increase the change.
- Negative feedback mechanisms maintain balance, whereas positive feedback mechanisms amplify change.
- Negative feedback mechanisms involve inhibitory signals, while positive feedback mechanisms involve stimulatory signals.
7
Q
What are the three basic components of a feedback mechanism?
A
- Sensor
- Control centre
- Effector
8
Q
Is the system described in figure 1 an example of a positive or negative feedback mechanism?
A
Negative feedback mechanism
9
Q
Explain one reason why the wall of the left ventricle is thicker than that of the right.
A
Pumping blood into the systemic circulatory system requires the left ventricular wall to be thicker to create higher pressure.
10
Q
Fill in the gaps: Blood from the left atrium is pumped through the _______ valve into the left _______.
A
[left atrioventricular] valve into the left [ventricle]
11
Q
Which blood vessel contains blood with the highest concentration of oxygen?
A
The pulmonary veins
12
Q
Which blood vessel contains blood with the lowest concentration of oxygen?
A
The pulmonary arteries
13
Q
Most veins return deoxygenated blood to the heart, with which exception?
A
The pulmonary veins
14
Q
Give two reasons why standing still for long periods can cause fainting due to pooling of blood in the lower legs.
A
- Veins rely on one-way valves to prevent backflow of blood.
- Veins have thinner walls and rely on muscle contractions to push blood back to the heart.
15
Q
Why do the ventricles contract from the base upwards?
A
To ensure optimal blood pumping efficiency out of the heart.
16
Q
How is the structure of an erythrocyte suited to its function?
A
- Biconcave shape
- Lack of nucleus and organelles
- Flexible membrane
17
Q
Fill in the gaps: Erythrocytes are produced in the red bone marrow. In an adult, this is present in the _______ of long bones.
A
[epiphyses]
18
Q
List 3 main sites for haemolysis.
A
- Spleen
- Liver
- Bone marrow
19
Q
Complete the equation: Haemoglobin + _______ <-> Oxyhaemoglobin.
A
[Oxygen]
20
Q
What are the 2 main types of leukocytes?
A
- Granulocytes
- Agranulocytes
21
Q
What are the 2 types of lymphocytes?
A
- T-lymphocytes
- B-lymphocytes
22
Q
Describe the 4 stages of haemostasis.
A
- Vasoconstriction
- Platelet plug formation
- Coagulation
- Thrombolysis
23
Q
What is the function of lymph?
A
- Tissue drainage
- Absorption in the gastrointestinal tract
- Immunity
24
Q
Which types of tissue are found in lymph nodes?
A
- Fibrous
- Reticular
- Lymphoid tissue
25
The nervous system can be divided into two parts, the _______ nervous system and the _______ nervous system.
[central] nervous system and the [peripheral] nervous system
26
List four types of sensory nerve ending found in the skin.
* Merkel cell
* Meissner’s corpuscle
* Pacinian corpuscle
* Free nerve ending
27
Motor neurons controlling voluntary activity are called _______.
[somatic]
28
Fill in the blanks: Structure / Organ: Heart - Effect due to Sympathetic Nervous System: _______.
[Rate and force of contraction increased]
29
Name five neurotransmitters found in the brain and spinal cord (CNS).
* Dopamine
* Acetylcholine
* Serotonin
* GABA
* Noradrenaline/norepinephrine
30
What happens when blood vessels constrict?
Blood supply is reduced.
31
What happens when blood vessels dilate?
Blood supply is increased.
32
Name five neurotransmitters found in the brain and spinal cord (CNS).
* Dopamine
* Acetylcholine
* Serotonin
* Gamma-aminobutyric acid (GABA)
* Noradrenaline/norepinephrine
33
Name two neurotransmitters found in the peripheral nervous system.
* Acetylcholine
* Noradrenaline/norepinephrine
34
Label the following neuron diagram: A.
Cell body
35
Label the following neuron diagram: B.
Nucleus
36
Label the following neuron diagram: C.
Myelin sheath
37
Label the following neuron diagram: D.
Terminal boutons/synaptic knobs
38
Describe the anatomical location of the pituitary gland.
In the brain in the hypophyseal fossa of the sphenoid bone below the hypothalamus.
39
Give three main differences between the anterior pituitary and the posterior pituitary.
* Anterior pituitary is glandular tissue; posterior pituitary is nervous tissue.
* Anterior pituitary is an upgrowth from pharynx; posterior pituitary is a downgrowth from brain.
* Anterior pituitary secretion is stimulated by hormones; posterior pituitary secretion is stimulated by nerve tissues.
40
What is the abbreviation for Growth Hormone?
GH
41
What is the function of Thyroid Stimulating Hormone (TSH)?
Stimulates growth and activity of the thyroid gland and secretion of T3 and T4.
42
What does Adrenocorticotrophic Hormone (ACTH) stimulate?
Stimulates the adrenal cortex to secrete glucocorticoids.
43
What is the function of Prolactin (PRL)?
Stimulates growth of breast tissue and milk production.
44
What does Follicle Stimulating Hormone (FSH) stimulate in males?
Stimulates production of sperm in the testes.
45
What does Follicle Stimulating Hormone (FSH) stimulate in females?
Stimulates secretion of oestrogen by the ovaries, maturation of ovarian follicles, and ovulation.
46
What does Luteinizing Hormone (LH) stimulate in males?
Secretion of testosterone by the testes.
47
What does Luteinizing Hormone (LH) stimulate in females?
Stimulates secretion of progesterone by the corpus luteum.
48
What is the most abundant hormone secreted by the anterior pituitary?
Growth hormone
49
What is the rhythm maintained throughout life for ACTH secretion called?
Circadian rhythm
50
What is T3 also known as?
Tri-iodothyronine
51
Which pituitary hormone is controlled by a positive feedback mechanism?
Oxytocin
52
Describe the anatomical location of the thyroid gland.
In the neck, in front of the larynx and trachea at the levels of the 5th, 6th, and 7th cervical and first thoracic vertebrae.
53
Describe the anatomical location of the parathyroid glands.
Embedded in the posterior surface of each lobe of the thyroid gland.
54
Name two main actions exerted by thyroid hormones on the body.
* Increasing metabolic rates
* Regulating metabolism of carbohydrates, proteins, and fats
55
How does exercise influence the hypothalamus?
Modulates/stimulates the secretion of thyrotrophin-releasing hormone (TRH) via a negative feedback loop.
56
What are the effects of hypersecretion of T3/T4 on metabolic rate?
Increased
57
What are the effects of hyposecretion of T3/T4 on weight?
Gain
58
What is the adrenal gland composed of?
Adrenal medulla and adrenal cortex
59
What hormones are produced by the adrenal medulla?
* Adrenaline (epinephrine)
* Noradrenaline (norepinephrine)
60
What group of hormones secreted by the adrenal cortex suppresses immune response?
Glucocorticoids
61
Renin is secreted by which organ?
Kidney
62
Angiotensinogen is produced by which organ?
Liver
63
Angiotensin converting enzyme (ACE) is produced in small quantities by which organs?
* Lung
* Kidney
* Heart endothelial cells
64
Aldosterone acts on which organ?
Kidneys
65
What hormones are secreted by pancreatic alpha cells?
Glucagon
66
What hormones are secreted by pancreatic beta cells?
Insulin
67
What hormones are secreted by pancreatic delta cells?
Somatostatin (GHRIH)
68
What group of lipid substances is involved in inflammatory response?
Prostaglandins
69
What is the function of the greater omentum?
Protective role, assisting with immunity, stores fat, helps with insulation.
70
What is the largest serous membrane of the body?
Peritoneum
71
What are the two layers of the peritoneum called?
* Parietal peritoneum
* Visceral peritoneum
72
What is the myenteric plexus responsible for?
Stimulating peristalsis
73
What is the submucosal plexus responsible for?
Stimulation of glandular secretions
74
How many deciduous teeth do children have?
20
75
How many permanent teeth do adults have?
32
76
What specific extra teeth do adults have?
* Premolars
* Extra set of molars (wisdom teeth)
77
What supplies teeth in the upper jaw?
Maxillary nerves
78
What supplies teeth in the lower jaw?
Branches of the mandibular nerves
79
What beneficial substances are found in saliva?
* Antimicrobial substances
* Immunoglobulins (antibodies)
* Lysozyme
80
What is the function of chief cells?
Secrete pepsinogens (inactive enzyme precursors)
81
What is the order of the three sections of the small intestine?
* Duodenum
* Jejunum
* Ileum
82
What food group is absorbed by the lacteals?
Fats (and fat-soluble vitamins)
83
What is the enzyme that converts inactive enzyme precursors in pancreatic juice to active enzymes?
Enterokinase
84
What vital substances are synthesized in the large intestine?
* Vitamin K
* Folic acid
* B vitamins
85
List eight functions of the liver.
* Carbohydrate and fat metabolism
* Storage of glycogen, fat-soluble vitamins, iron, copper, some water-soluble vitamins
* Protein metabolism
* Breakdown of erythrocytes
* Detoxification of drugs
* Inactivation of hormones
* Production of heat
* Secretion of bile
86
What are essential amino acids?
Amino acids that cannot be synthesized in the body.
87
What are endogenous amino acids?
Amino acids released from the breakdown of existing body proteins.
88
Why is the right kidney usually slightly lower than the left one?
Due to the space taken up by the liver.
89
Where are the kidneys located?
Behind the peritoneum and below the diaphragm.
90
What vertebrae do the kidneys extend between?
12th thoracic and 3rd lumbar vertebrae.
91
What surrounds the kidneys?
A layer of fat and a fibroelastic sheath called the renal fasciae.
92
What is the structure of the adrenal cortex?
Composed of three groups of steroid hormones.
93
What are the kidneys embedded in?
A layer of fat
## Footnote
This layer is surrounded by a fibroelastic sheath called the renal fasciae.
94
What is the renal fasciae?
A fibroelastic sheath surrounding the kidneys.
95
What structures are involved in the formation of urine?
* Filtration
* Selective reabsorption
* Secretion
96
Which substances are reabsorbed into the system from glomerular filtrate via active transport?
* Potassium
* Sodium
* Chloride
* Calcium
97
What is the function of the afferent arteriole?
Enters nephron from branch of renal artery
98
What is the function of the efferent arteriole?
Leaves glomerulus and forms secondary capillary network which surrounds nephron
99
What does the glomerulus lie within?
Bowman's capsule
100
What surrounds the glomerulus?
Bowman's capsule
101
What are the main areas where selective reabsorption takes place within the nephron?
* Proximal convoluted tubule
* Loop of Henle
* Distal convoluted tubule
102
What is the function of the collecting duct?
Collects fluid from distal convoluted tubules and transports it to renal pelvis
103
How much fluid does a normal bladder contain before awareness of the need to pass urine occurs?
600ml
104
What is an immune complex?
An antigen and antibody bound together
105
Which statement about 'complement' is false?
Activated by lysozyme
106
List the five cardinal signs of inflammation.
* Redness
* Heat
* Swelling
* Pain
* Loss of function
107
What is the purpose of increased blood flow in inflammation?
More oxygen and nutrients for raised cellular activity of inflammation
108
What causes increased tissue fluid during inflammation?
Raised capillary permeability, caused by inflammatory mediators, and raised pressure in capillaries due to raised blood flow
109
What is phagocytosis?
The process of removing debris from the system
110
What are the two types of lymphocytes produced by bone marrow involved in immunity?
* T cell
* B cell
111
What is active, naturally acquired immunity?
Immunity to an infection that develops following natural exposure during day-to-day life
112
What is passive, artificially acquired immunity?
Gained by transferring antibodies from an external source
113
What type of tissue are bones classified as?
Connective tissue
114
What is the process by which bones are hardened?
Ossification
115
What connects the patella to the bones of the lower leg?
Ligament
116
What connects the pectoral muscle to the humerus?
Tendon
117
What is the average length of the menstrual cycle?
28 days (26-30 days)
118
Name the three phases of the menstrual cycle.
* Menstrual phase – around 4 days
* Proliferative phase – approximately 10 days
* Secretory phase – about 14 days
119
At what age does menopause usually occur?
Between the ages of 45 and 55
120
What is aetiology?
The cause of a disease
121
What does pathogenesis refer to?
The nature of a disease and the biological mechanism through which it develops
122
What is prognosis?
The predicted course or outcome of a disease
123
What are idiopathic diseases?
Diseases that arise spontaneously without a known cause
124
What does iatrogenic mean?
Adverse effects experienced due to medical intervention
125
What are congenital disorders?
Disorders present from birth
