Final Exam Flashcards
Homeostasis
3 components of homeostatic system
Ability of an organism to maintain a consistent internal environment in response to changing factors
Receptor: detects a stimulus (change in a variable) eg. sensory receptors in skin
Control center: integrates feedback from receptors, initiates change through effectors eg. hypothalamus
Effector: Brings about change eg. blood vessels and skeletal muscles
Negative versus positive feedback
Negative: Control mechanism where resulting action is the opposite direction of stimulus
Eg. INCREASE blood glucose after a meal-> insulin->DECREASE blood sugar
Positive feedback: outcome reinforces stimulus eg. breastfeeding (suckling triggers breast milk ejection which triggers more suckling)
dissociate, anion, cation, solvent, solute, solution, acid,
and base
Dissociate: dissolve
Anion: atom w/ negative electrical charge eg. chloride
Cation: atom w/ positive charge eg. sodium
Solute: dissolved in liquid
Solvent: dissolves solute
Solution: mixture of 2+ substances
Acid: dissolves in water to produce anion and H+, proton donator, increases H+ concentration
Base: Accepts H+, decreases H+ concentration
Define pH and explain the relative pH values of both acids and bases
Stands for potential of hydrogen
Measure of relative H+ concentration
Low pH (less than 7) is more acidic=higher concentration of H+
High pH (higher than 7) is more basic=lower H+ concentration
Pure water= 7
Stomach acid= 2-3
Blood= 7.35-7.45
List five important molecules within the body that function primarily in chemical energy exchange and how long that energy source can sustain exercise
- ATP: (ADP+Pi) ~2 seconds
- Phosphocreatine (PCr) ~10 seconds
Produces ATP when phosphate is added to ADP using creatine kinase - Glycogen: ~1-2 hours
Can be broken down into glucose, stored as glycogen in liver+SKM - Lipids (triglyceride most common) ~3-7 days, stored around organs under skin and in SKM
- Proteins: long duration, intense exercise can use up to 10-15% of energy as protein
Explain how the H+gradient is used to produce ATP and what is the name of the specific enzyme?
Electron transport system
Electrons from NADH and FADH2 transfer to electron carriers
Energy from electrons “falling” is used by hydrogen pumps to move H+ up its concentration gradient from matrix to outer compartment
H+ travels down concentration gradient back into matrix through ATP synthase
ATP synthase harnesses energy from H+ “falling” to bond ADP and Pi to create ATP
Describe passive transport and distinguish between simple and facilitated diffusion
Requires no external energy (ATP)
Substances move down their concentration gradient from high->low
Simple: small, nonpolar molecules (CO2, O2) move down concentration gradient
Facilitated: channel or carrier-mediated transports polar (charged) molecules (Na+, K+)
Channel ex. sodium, potassium
Carrier ex. glucose
Describe active transport and distinguish between primary and secondary active transport
Requires cellular energy (ATP) to move a substance against its concentration gradient
Primary: ion pumps use energy from ATP breakdown to move ions across cell membrane
Secondary: kinetic energy of one substance moving down concentration gradient provides power to pump another substance against concentration gradient
Describe how keratinocytes change as they mature
How long does it take?
Keratin cells divide and produce new cells, pushing older cells up
More mature cells synthesize more keratin, accumulation=cell death through death of nucleus and organelles
20-40 days
Explain what causes differences in skin color
Hemoglobin, melanin, and carotene
Define a motor unit and describe the differences between small and large motor units and the muscles they innervate
Alpha motor neuron and the muscle fibers it innervates
Large: thousands of muscle fibers, lots of force but little precision eg. thighs
Small: less than 5 MUs, lots of precision, little force eg. eyes
Describe the different types of muscle contractions (2)
Concentric vs. eccentric
Isometric: tension generated is less than resistance-no muscle movement
Isotonic: tension results in concentric (shortening) or eccentric (lengthening) movement
Describe the different skeletal muscle fiber types
- Slow oxidative (Type I)
Slow contraction, long duration, small diameter-endurance
High O2 capacity - Fast glycolytic (Type IIx)
Fast, powerful contraction, short duration-high glycogen, low O2 - Fast oxidative (Type IIa)
Moderate
Identify the three functional categories of neurons and where they are primarily located
SAME DAVE
- Sensory (afferent)
Conduct sensory input to CNS (spinal cord)
Dorsal - Interneurons
Facilitate communications between motor and sensory
Completely within spinal cord - Motor (efferent)
Conduct motor output away from CNS spinal cord
Ventral
Briefly describe the physiological events that occur at the different segments of the neuron
RICT
Receptive: binding of neurotransmitters, ion channel opens, production of graded potentials
Initial: summation of graded potentials, initiation of AP
Conductive: propagation of AP
Transmissive: AP causes NT release
Partial pressure of oxygen and CO2
Inspired air: 159 mmHg, 0.3 mmHg
Mixed with residual air, water vapor, and O2 dissolves out of blood into alveoli and CO2 dissolves in
Alveolar: 104 mmHg, 40 mmHg
Blood from cardiac and lung tissue dilutes
Arterial blood: 100 mmHg, 45 mmHg
Systemic cells: 40, 45
Which accurately reflects the PO2 mmHg in the alveoli, systemic arteries, systemic veins and right atrium?
A. 104, 40, 40, 40
B. 104, 104, 40, 40
C. 104, 100, 40, 40
D. 100, 100, 40, 40
C. 104, 100, 40, 40
True or False: A small drop in the blood PO2 will stimulate an increase in ventilation.
A. True
B. False
B. False
Hypoventilation versus hyperventilation
Hypoventilation: breathing is too shallow/slow to meet metabolic needs, decrease in O2
Hyperventilation: breathing is too deep and rapid, leads to decrease in CO2
Functions of kidneys/urinary system
Filter blood and regulate blood volume
1. Eliminates metabolic waste (urea, uric acid, creatine)
2. Regulation of ion levels (Na+, K+)
3. Regulation of acid-base balance (H+, bicarbonate)
4. Regulation of blood pressure (fluid excretion)
5. Elimination of biologically active molecules (eg. hormones, drugs)
General structures of urinary system
Renal artery brings blood to kidneys (20-25%)
Renal vein carries blood away
Kidneys (renal cortex and renal medulla)
Minor renal calyces->major renal calyx->ureter->urinary bladder->urethra
Innervation of the kidneys
SNS innervates kidneys
Increased SNS->vasoconstriction->decreased urine output
Somatic NS innervates external urethral sphincter, PsNS innervates bladder and internal US
After entering the ureter where does urine go next?
A. Renal pelvis
B. Renal calyx
C. Urethra
D. Urinary bladder
D. Urinary bladder
Minor calyx->major calyx->renal pelvis->ureter->urinary bladder->urethra
What is the name of the most superficial region of the kidney?
A. Renaliss Superficialous
B. Renal medulla
C. Renal cortex
D. Renal pelvis
C. Renal cortex
The kidney is innervated by what branch(s) of the autonomic
nervous system?
A. Sympathetic Nervous System
B. Parasympathetic Nervous System
C. Enteric Nervous System
D. Both A and B
A. Sympathetic
Anatomy of a nephron (filter)
A) Renal corpuscle
1a. Bowman’s capsule
2a. Glomerulus- bundle of capillaries, 1st filter
3a. Capsular space- receives filtrate
B) Renal tubule
1a. Proximal convoluted tubule
1b. Descending + ascending nephron loop
1c. Distal convoluted tubule
Afferent versus efferent arteriole
Afferent arteriole brings blood into glomerulus
Efferent arteriole takes blood away
Collecting tubule and collecting duct pathway to calyx
Several nephrons->collecting tubule->several tubules->collecting duct->papillary duct->minor calyx
3 transport processes in the nephron
- Glomerular filtration
Water and dissolved substances pass through glomerulus into capsular space (filtrate), formed elements, proteins, platelets sent back out through efferent arteriole - Tubular reabsorption
Movement of substances from tubular fluid back into blood - Tubular secretion
Results in excretion
Substances move out of blood into tubules for excretion
Filtration membrane of glomerulus
3 layers
What does each block?
Podocytes
- Endothelium of glomerulus
Has holes to filter large particles like formed elements - Basement membrane
Blocks large proteins - Visceral layer
Composed of podocytes, filtration slits between extensions block small proteins
Freely filtered versus not filtered examples
Limited filtration
Not filtered (stopped at glomerular filtration): RBC, WBC, proteins, platelets
Filtered: water, glucose, amino acids, urea, some hormones, vitamins
Pass through filtration membrane
Limited: intermediate proteins-filtrate contains minimal protein
In what segment of the nephron does filtration occur?
A. Distal Convoluted Tubule
B. Descending loop
C. Glomerulus
D. Collecting Tubule
C. Glomerulus
Average urine and filtrate output and composition of urine
180 L/day filtrate
1-1.5 L/day urine
Events at the PCT, nephron loop, and DCT
Reabsorption and secretion
PCT: 100% of nutrients, 100% of proteins, majority of water and ions are re-absorbed (blood->PCT)
Nephron loop: 25% water 25% ions reabsorbed into blood
DCT, connecting tubule, and connecting duct: site of regulation, Na+, water, K+, Ca2+, pH
Antidiuretic hormone
Sleep, exercise, and alcohol
Increases water reabsorption, decreases urine production
Exercise and sleep increase ADH production=decreased urine
Alcohol blocks ADH release=increased urine
Atrial natriuretic peptide
Inhibits Na+ reabsorption and aldosterone release, reduces SNS activity
Increases urine production
Vasodilation->decreased blood pressure->increased blood flow to kidneys
Aldosterone
Triggered by low blood pressure
Decrease urine production by increasing sodium reabsorption
Erythropoiesis
RBC production
Stimulus: low oxygen in blood
Kidney, some liver, and some neurons release erythropoetin, stimulates red bone marrow to enhance erythropoeisis (RBC production)
What stimulates an increase in the release of atrial natriuretic peptide?
A. Decreased blood volume
B. Decreased osmolarity
C. Increased blood volume
D. Increased osmolarity
C. Increased blood volume
What impact would an increase in antidiuretic hormone in
the blood have on urine output/production?
A. Increased urine volume
B. Decreased urine volume
C. No change in urine volume
B. Decreased
Name the major gyri, sulci, and fissure of the brain
Central sulcus: divides brain anterior/posterior at the frontal and parietal lobe
Lateral sulcus: divides brain superior/inferior at frontal and temporal lobe
Longitudinal fissure: divides brain medially
Cerebral lateralization
Functional specialization of the left and right hemispheres of the brain
Left: categorical, analytical, sequential
Right: shapes and colors, representation, musical
Describe the general functions of the 5 lobes of the Cerebrum
- Frontal: decision making, planning, personality, verbal communication
- Parietal: general sensory input
- Occipital: Visual information and memories
- Temporal: hearing and smell
- Gustatory: taste
Describe the general structure and functions of parasympathetic and sympathetic divisions of the autonomic nervous system
Origin and functions
PsNS:
Preganglionic neurons originate in brainstem and S2-S4 (craniosacral) region of spinal cord
Brings body to homeostasis during rest/digst
SNS:
Preganglionic neurons originate in T1-L2 (thoraccolumbar) region of spinal cord
Brings body to homeostasis during fight/flight
Dual innervation
Antagonistic activity example
Innervation by both SNS and PsNS
Ex. heart
PsNS decreases HR and contractility
SNS increases HR and contractility
Describe the general function of sensory receptors as transducers
Convert stimulus energy into electrical signal to open ion channels and change membrane potential
Adaptation
Tonic versus phasic
Decreased sensitivity to a continuous stimulus
Tonic receptors eg. pain receptors have limited adaptation, respond continuously
Phasic receptors eg. pressure receptors rapidly adapt, only respond to new stimuli
Identify the 5 major endocrine glands, the hormones they secrete, and the location of these glands in the body
- Pituitary gland, anterior base of the brain- releases GHRH, CRH, TSH, ACTH
- Pineal gland, posterior base of the brain, secretes melatonin
- Thyroid gland, anterior throat, secretes thyroid hormone, calcetonin
- Parathyroid gland, posterior TG, releases parathyroid hormone
- Adrenal gland, superior kidney, Adrenal cortex=cortisol
Adrenal medulla=epinephrine and norepinephrine
Explain the three reflex mechanisms for regulating the secretion of hormones and examples of each
- Hormonal-one hormone triggers another eg. TSH from anterior pituitary->TH from thyroid gland
- Humoral-blood levels trigger release eg. high glucose triggers insulin
- Nervous- eg. SNS stimulates adrenal medulla to release epinephrine and norepinephrine
Upregulation and down regulation
Up regulation increases sensitivity by increasing receptors
Ex. exercise increases insulin sensitivity
Down regulation decreases sensitivity by decreasing receptors
Ex. beta receptors on heart decrease with age
3 components of a centrifuged blood sample
- Plasma ~55%
92% water, 7% proteins eg. albumins, 1% electrolytes (Na+, K+), nutrients (glucose), respiratory gases, waste products - Buffy coat <1%
leukocytes, platelets - Erythrocytes (red blood cells) ~44%
Valves of the heart
Right side
Right AV valve/tricuspid
Separates right A/V
Pulmonary semilunar valve
Separates right ventricle from pulmonary trunk
Left:
Left AV valve/bicuspid
Separates left A/V
Aortic semilunar valve
Separates left ventricle/aorta
Great vessels of the heart
Right:
Superior vena cava (SVC) carries deoxygenated blood from upper body to RA
Inferior vena cava (IVC) carries low O2 blood from lower body to RA
Pulmonary trunk carries low O2 blood from RV to lungs
Left:
Pulmonary veins carry high O2 blood into LA
Aorta: carry blood from LV to systemic circulation
Describe the flow of blood through the heart
SVC+IVC carry low O2 blood to RA
Blood passes through right AV valve to RV, through pulmonary semilunar valve to pulmonary trunk to lungs (pick up 02, drop off CO2)
Pulmonary veins drain into LA, through bicuspid to LV through aortic semilunar to LV to aorta to body
Describe the components of the electrical conduction system of the heart
Where does it begin?
Begins in RA, spreads to LA, travels down septum
1. Sinoatrial (SA) node-pacemaker, 60-80 bpm
2. AV node, slows to 40-60 bpm
3. AV bundle/bundle of Hiss
4. L and R branches
5. Purkinje fibers 20-40 bpm
6. Cardiac tissue 15-30 bpm
Define the terms stroke volume, heart rate, and cardiac output and know the average resting values
SV: amount of blood pumped per beat ~70mL/beat
CO: amount of blood pumped by one ventricle in a minute ~5 L/min
HR: number of beats per minute ~60-80 bpm
Describe the cardiac cycle and define the two phases of the cardiac cycle, systoleand diastole
- Diastole- 3x longer
Isovolumetric relaxation (no blood flow, all valves closed)
Rapid filling, pressure difference between RA and RV opens tricuspid, blood flows from atria->ventricle
Atrial contraction, top off of 20-30% of blood - Systole
Isovolumetric contraction- AV valves close
Ejection, semilunar valve opens, blood ejected to pulmonary and peripheral systems
