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Biology Flashcards

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1
Q

what is the purpose of chyme in the duodenum, and what is chyme

A

chyme is acidic, it made from HCl secretion from parietal cells, and contents within the stomach.
it activated release of enteropeptidase.
the presence of chyme would leads to release of brush border enzymes which would help digest some of the macromolecules contained within.

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2
Q

what hormone do the ovaries produce

A

estrogen

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3
Q

What is the relationship of ANP and blood pressure?

A

ANP decreases arterial blood pressure

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4
Q

outline the key concepts of the menstrual cycle

A
  • Follicles mature during follicular phase (FSH, LH)
  • LH surge at mid-cycle triggers ovulation
  • ruptured follice becomes corpus luteum, which secretes estrogen and progestrone to build up lining for implantation, FSH and LH are inhibited
  • if fertilization did not occuer CL dies, due to lack of LH, progesterone and estrogen levels decrease, LH and FSH begin to rise again
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5
Q

what is the function of efferent neurons ?

A
  • they send information from the CNS to the peripheral organs
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6
Q

How does a thyroid hormone complete its mechanism of action?

A

It binds to a nuclear receptor then modifies the protein, it is poorly water soluble

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7
Q

compare steroid hormones and thyroid hormones

A

thyroid hormone is amino acid derived hormone, but acts as a lipid based hormone, lipophilic. It has the same pathway of a steroid hormone.

  • steroid hormones can go into the cell by pass the plasma membrane, bind to receptors in the cytosol, and affect DNA transcription.
  • for thyroid hormones they enter the cell through a receptor, but don’t do a cascade they enter directly to the nucleus.
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8
Q

difference between lytic and lysogenic

A

Lyso- Long time, can remain dormant for years in the cycle

Lytic- short time, no regard for the host

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9
Q

which part of the sarcomere has organized bundles of myosin?

A

thick filaments are organized bundles of myosin
represented by the A band

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10
Q

how are single smooth muscle cells connected

A
  • via gap junctions, the greater the strength of these connections, the more calcium ions can be spread between cells, and the stronger the contraction
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11
Q

Do T-tubules exist is smooth muscle cells

A

No

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12
Q

What secretes TRH and where does the TRH act on?

A

The hypothalamus secreted thyroid releasing hormone (TRH) and it acts on the AP

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13
Q

what gland releases TSH

A

Anterior pituitary, and TSH (peptide hormone) that acts on the thyroid

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14
Q

if heart rate is faster, describe the effect on the cardiac cycle

A

The cardiac cycle will be shorter, leading to a shorter diastole, this means the ventricles have less time to fill, leading to a lower stroke volume and therefore lower cardiac output.

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15
Q

what layers of the skin are burned off in a second degree burn

A
  • dermis and epidermis
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16
Q

what are some structures and cell types located on the dermis

A
  • Sweat glands
  • Hair follicles
  • Blood vessels
  • afferent Nerve ending
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17
Q

what is keratin and where is it produced?

A
  • Produced by keratinocytes in the stratum basale of the epidermis, keratin is a tough fibrous protein that migrates superficially with keratinocytes to the stratum corneum.
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18
Q

Where is the pharynx located and its function?

A

-resides behind the nasal cavity and back of the mouth, it is a common pathway for air and destined for the lungs and food destined for the esophagus

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19
Q

what are the functional components of the testes ?

A

Seminiferous tubules- sperm is produced here, and nourished by the sertoli cells

Interstitial cells of leydig

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20
Q

when the sperm is formed where is it stored

A
  • it is stored in the epididymis, where flagella gain motility, and they are stored until ejaculation

-made in the testes

  • during ejaculation, sperm travels through the vas deferens and enters the ejaculatory duct
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21
Q

what system is the NK cells part of?

A
  • the innate immune system
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22
Q

Function of the lymphatic system

A
  • provides pathway for fats to enter circulation
  • return of fluids from tissues to circulatory system
  • in the lymphatic system, cells of the innate immune system, like macrophages and dendritic cells can communicate with cells of the adaptive immune system, like B cells
  • germinal center where B cells (not T cells) wait for their antigens, so then they build memory for reinfection
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23
Q

what type of cells are most effective in parasitic infections

A

-Eonsinophils, they release granules, that are effective against allergens and parasites

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24
Q

what is the subsection of the the nucleus that synthesizes ribosomal RNA

A

-Nucleolus

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25
Q

where are T cells produced?

A

They are produced by the thymus, not the thyroid

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26
Q

Describe the mechanism of autoimmunity? In relationship to Self-antigens

A

Self antigens are proteins and carbs present on the surface of every cell of the body.

  • Self antigens signal to immune cells that the cell is non threatening, and should not be attacked.
  • When the immune systems do not recognize between self and foreign, it may attack cells showing self- antigens that are not threatening.
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27
Q

what is hyperthyroidism?

A

Graves Disease

  • hyperthyroidism increase production of thyroid hormone due to excessive stimulation by an antibody that can activate the TSH receptor.
  • Normally TSH stimulates TSH receptors on the thyroid and lead to release of thyroid hormones
  • An Antibody (TSI) that is similar to TSH could bind to the TSH receptor and cause an increase in thyroid production as well.
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28
Q

what are macrophages and MHCs?

A

Macrophages are tissue specific populations of monocytes, they also secrete cytokines that signal other immune cells to help fight infection. They also act as phagocytes.

Type of white blood cells

MHC proteins found on the surface of cells that help the immune system recognize foreign substances

  • group of membrane bound proteins that present antigens for inspection of T cells

MHC1- antigens from within the cell
2- antigen presenting cells- macrophages, dendritic cells, and B cells

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29
Q

what originates from the dermis?

A
  • hair follicles
  • sweat glands
  • blood vessels
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30
Q

what does the hypodermis contain?

A
  • fat and connective tissues
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31
Q

what does a silent mutation do

A

no effect on protein

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32
Q

what does a missense mutation do?

A

results in the substitution of one amino acid for another

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33
Q

What does a nonsense mutation do

A

Sub in a stop codon for the amino acid

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34
Q

what is the recombination frequencies between tightly linked genes and weak linked genes?

A
  • tightly linked have RF of close to 0 percent
  • Weakly linked have fre of close to 50 percent
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35
Q

what produces glucagon?

A

alpha cells of the pancreas

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36
Q

what is the function of glucagon?

A
  • causes blood glucose concentration to increase by signalling cells to use fat and protein as an energy source
  • by breaking down glycogen into glucose (glycogenolysis)
    -synthesizing glucose and releasing it into the bloodstream (gluconeogenesis)
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37
Q

In the loop of Henle what is permeable in the ascending limb and the descending limb ?

A

The descending is permeable to water, yeilding more concentrated filtrate at the bottom of the loop

The ascending limb is permeable to solutes, resulting in more dilute filtrate at the top of the ascending limb

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38
Q

where does impulse initiation occur in the heart?

A
  • the SN node, which generates 60-100 signals per minute, without neural input
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39
Q

Describe heart contractions

A
  • Atrail systole, results in an increase in atrial pressure that forces a little more blood into ventricles.
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40
Q

What are C cells

A

C- cells are parafollicular cells

  • excrete calcitonin
  • the function of calcitonin is to decrease plasma calcium by increasing excretion from kidneys, decreasing calcium reabsorption from the gut. and increasing storage of calcium in the bone,
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40
Q

What are C cells

A

C- cells are parafollicular cells

  • excrete calcitonin
  • the function of calcitonin is to decrease plasma calcium by increasing excretion from kidneys, decreasing calcium reabsorption from the gut. and increasing storage of calcium in the bone,
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41
Q

what two types of leukocytes (white blood cells) that can function as phagocytes?

A
  • Neutrophils and monocytes
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42
Q

Describe the function of Eosinophils?

A
  • Release Histamine which helps drive the inflammatory response of the body.
  • Common response in parasitic infections
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43
Q

What do Natural Killer cells do?

A
  • Natural killer cells are involved in phagocytosis of virally-infected cells and would not induced inflammation
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44
Q

Basic unit of compact bone?

A

Osteon

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45
Q

what is ADH and where is it produced and released?

A

ADH= vasopressin

peptide hormone

synthesized in hypothalamus, released by posterior pituitary, in response to high blood osmolarity.

it alters permeability of the collecting duct, allowing more water to be reabsorbed by making the cell junctions of the duct leaky

increased concentration in the interstitium (hypertonic to the filtrate) will cause the reabsorption of water from the tubule.

ADH decreases urine output and increased urine concentration

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45
Q

what is ADH and where is it produced and released?

A

ADH= vasopressin

peptide hormone

synthesized in hypothalamus, released by posterior pituitary, in response to high blood osmolarity.

it alters permeability of the collecting duct, allowing more water to be reabsorbed by making the cell junctions of the duct leaky

increased concentration in the interstitium (hypertonic to the filtrate) will cause the reabsorption of water from the tubule.

ADH decreases urine output and increased urine concentration

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46
Q

what happens if you increased sympathetic nervous system activity? ( in regards to the heart)

A
  • Increased cardiac contractility
  • Increased Heart rate
  • Increased vascular resistance
47
Q

where is the ETC in prokaryotes?

A
  • Plasma membrane
  • used for ETC and generation of ATP
48
Q

what do afferent and efferent arterioles do?

A

-afferent arterioles bring blood into the glomerulus, while efferent arterioles take it away

49
Q

so if pressure in the glomerulus increased due to effrerent side, what happend to the filtration rate and the afferent side

A

afferent side will continue to wokr, and thus cause an increase in pressure as the fluids builds up on teh afferent side, causing an increase in filtration, because capiillary pressure has increased as well

50
Q

what is senescence?

A
  • biological aging, and lack of further cell division
51
Q

what type of cells produce antibodies

A

B cells exclusively

52
Q

what is the purpose of self antigens?

A
  • help the immune system to distinguish self from foreign by signalling to ummune sells, that the cell is not a threat, and should not be attacekd
53
Q

what does ADH do to the body

A

– stimulates water reabsorption by increasing use of aquaporins into the kidney tubules

  • Decrease plasma osmolarity
  • increases osmolarity of the urine

-more adh the more water reabsorbed into the body, add water to the blood, and removing water from the filtrate

54
Q

what are glucocorticoids?

A
  • steroid hormones that regulate glucose levels

-can effect protein metabolism

  • EX: cortisol

Functions: raise blood glucose by increase gluconeogenesis and decreasing protein synthesis

55
Q

what is the function of cortisol?

A
  • decrease inflammation and immunologic response
  • increases Blood sugar
  • by gluconeogenesis
56
Q

what are the 2 functions of the pancreas?

A
  • suppresses insulin release

-stimulates glucagon release

57
Q

what is sympatheric vs parasympathetic

A

sympathetic- fight or flight

parasympathetic- rest and digest

58
Q

what does the pulmonary artery do ?

A
  • carrys CO2 rich, oxygen poor blood because it prior to the alveolus.
59
Q

what does the pulmonary vein do

A
  • carry carbon dioxide poor oxygen rich blood because it has been oxygenated
60
Q

the brain and spinal cord are derived from what germ layer

A
  • only from the ectoderm
61
Q

what is incomplete dominance

A
  • heterozygote has a mix of of the 2 phenotytpes of dominant and recessive
62
Q

what is codominance?

A
  • both of the alleles are dominnay in the heterozygote
63
Q

what is the function of Bile Salts?

A
  • Bile salts emulsify fats to help digestion by pancreatic lipase,

-but it has nothing to do with protecting intestine from damage or preventing activation of fatty acids

64
Q

what is the function of bicarbonate in the small intestine?

A
  • neutralize acidic chyme entering from the stomach
  • presence of bicarbonate mainintans the PH in the small intestine at the correct pH for optimum finction of the pancreatic enzymes
65
Q

where does digestion take place?

A

Duodenum

-DDDDDoudenum

66
Q

where does absorption take place?

A
  • Jejunum and Ileum
67
Q

what is the function of parathyroid hormones and calcitonin?

A

PTH= released via parathyroids

bone break down leads to calcium increase in blood

Calcitonin= tones it down, released by thyroid, use the Calcium in blood to rebuild bone

68
Q

Describe type 1 2a,2b muscle fibers

A

type 1= high oxidative capacity, utilize oxygen, resistant to fatigue

type 2a= need mitochondira to help utilize oxygen, but not as much as type 1, uses both anaerobic respiration adn oxidative phos

type 2b= most explosive, need most energy burns the most glycogen stores

69
Q

what stages make up the interphase?

A

G1, S, G2

logest part of the cell cycle, cell spends most of its time there

g0= cell is simply living and serving its function, without preparation for division

70
Q

what is the function of microglia ?

A
  • phagocytic cells that ingest and break down waste products and pathogens in the CNS
  • they are macrophages of the CNS
71
Q

what tissues derived from the mesoderm?

A
  • muscles
    -bones,
    -circulatory system
  • gonads
72
Q

what tissues are derived from the endoderm?

A
  • Internal lining of the digestive tract, which includes esophagus, is derived from the endoderm
73
Q

what does the ectoderm give rise too?

A
  • epidermis, eye, skin, mouth, nose
  • brain and cornea
  • Beauty stuff

Ectoderm is atractoderm= qualities that may attract you to someone

74
Q

Describe Steroid Hormones vs Peptide hormones

A

Steroid Hormone are non polar and small, thereform they pass through the membrane adn directly stimulate transcription. All steroid hormones influence cell behavior by modifying transcription

  • peptide hormones- cant pass through the membrnea, and not directly stimulate transcription. Peptide hormones bind to membrane bound receptors to initiate a signal cascade, using second messengers like cAMP
75
Q

Describe Inversion for gene alteration

A
  • Sequence intract, but reversed within the chormosome, it will change the order in which genes appear during sequencing, but no genes will appear msising
76
Q

what are the cell to cell communication? and define how they communicate

A

Autocrine- signal act on the same cell that secreted the signal in the first place

Paracrine- act on cells in the local area

Juxtacrine - signals do not usually involve diffusion, but rather cell stimulating a cell directly next to it. Autocrine is a example of juxtacrine

77
Q

what is the function of semineferous tubules and leydig cells

A

leydig cells- produce testosterone

seminiferous tubules- responsible for producing sperm, not testosterone

78
Q

what is expressivity?

A

-variability in phenotype for one genotype. If expressivity is constant, then all individuals with given genotype will have that phenotype.

but if its variable, i can have varying phenotypes even if i have identical genotypes.

79
Q

what do chymotrypsin and carboxypeptidase do?

A

chymotrypsin- cleaves the peptide bond at the N- terminal, helps digest proteins

carboxypeptidase- makes the peptide bond at the C- terminal. helps digest proteins

80
Q

what cells does the pancreas have

A

Beta cells- secrete and make insulin

alpha cells- make and secrete glucagon

acinar cells- exocrine, produce and release pancreatic enzymes like lipase, chymotrypsin, amylase.

80
Q

what cells does the pancreas have

A

Beta cells- secrete and make insulin

alpha cells- make and secrete glucagon

acinar cells- exocrine, produce and release pancreatic enzymes like lipase, chymotrypsin, amylase.

81
Q

what is the difference between yellow marrow and red marrow?

A

red marrow- production site of red blood cells or white blood cells

yellow marrow- stores fat as an energy source

82
Q

where are tropic hormones made and released and what is their function

A

made and released from pituitary tend to stimulate secretion of hormones, as well as growth of target endocrine tissues/glands.

they tend to be derived from amino acid precursors. they must also be able to bind to hypothalamus and pituitary to have negative feedback inhibition

examples- TSH, corticotropin, FSH and LH

83
Q

what is reduced penetrance?

A

Penetrace is the proportion of individuals in the population carrying the allele who actually expresses the phenotype.

Reduced penetrance would be having the genotype, but not having the phenotype

84
Q

What part of the brain controls the breathing rate/regulation rate

A

Medulla oblongata.

85
Q

What muscles are engaged during inhalation?

A
  • the diaphragm and external intercostal muscles

-

86
Q

what muscles are engaged during exhalation?

A
  • internal intercostal muscles
  • abdominal muscles are used to forced exhalation.
87
Q

what is the function of cholecystikinin ?

A
  • stimulate bile secretion to help digest fats after meal.
  • duodenum (made or released)?
  • inhibits gastric emptying
  • induced satiety
  • triggers release of pancreatic enzymes.
87
Q

what is the function of cholecystikinin ?

A
  • stimulate bile secretion to help digest fats after meal.
  • duodenum (made or released)?
  • inhibits gastric emptying
  • induced satiety
  • triggers release of pancreatic enzymes.
88
Q

Describe Innate Immunity

A
  • made of non specific defenses

such as interferons, macrophages, natural killer cells

89
Q

describe antibody-mediated immunity

A
  • does require interactions with T cells.
  • all cells are made in bone marrow
    b/t cells mature in diff locations
  • B cells mature differently and may make antibodies, even if T cell maturation is inhibited.
90
Q

describe adaptive immune system

A

2 lymphocytes
B cells + T cells

B cells govern humoral response
T cells create the cell mediated response

91
Q

What does LAB RAT have to with the heart

A

Left Atrium= Bicuspid

Right Atrium= Tricuspid

92
Q

what is the function of superior and inferior vena cava ?

A

Superior Vena Cava- returns blood from the portions of the body above the heart

inferior - returns blood from the portions below the heart

93
Q

what is required for B12 absorption?

A

Intrinsic factor- a protein made by the parietal cell of the stomach.

B12 is water soluble vitamin absorbed in ileum of small intestine.

94
Q

What is tidal volume

A
  • volume of air inhaled or exhaled in a normal breath
95
Q

Describe the chest wall/rib cage and diaphragm during inhalation

A

Diaphragm contracted
Chest well/ribcage expanded

96
Q

Describe the chest wall/rib cage and diaphragm during exhalation

A
  • chest wall/ribcage contracted

-diaphragm relaxed

97
Q

what is the function of aldosterone?

A

increases salt reabsorption in the distal convoluted tube, increases BP

98
Q

where is aldosterone released from?

A
  • adrenal cortex is where aldosterone is made and secreted from
  • aldosterone is a steroid
99
Q

what does calcium do in muscle contraction

A

During muscle contraction, calcium binds to troponin molecules,

when troponin is bound to calcium, it changes the conformation of tropomyosi, exposing the myosin binding sites on the actin filaments

100
Q

what is the ANS made of

A

peripheral nerves that regulate involuntary bodily functions

  • smooth muscle contractions in blood vessels, secretion of certain endocrine hormones
101
Q

how are lipids digested in the small intestine

A
  • emulsification (mechanical digestion by bile salts)
  • hydrolysis (chemical digestion by pancreatic lipase)
102
Q

what is the small intestine broken down into

A

duodenum, jejunum, ileum

in which macromolecules are digested, and important things are digested.

absorption happens across the epithelial cell lining the materials

103
Q

Describe the endocrine and exocrine function of the pancreas

A

endocrine- islets of langerhan cells secrete hormones into blood vessels

exocrine- acinar cells secrete digestive enzymes into pancreatic ducts, they go into the small intestine to assist in digestive processes and to neutralize the acidity of chyme

these enzymes are delivered to the small intestine via the common bile ducts

104
Q

Compare the right and left ventricle

A

the right ventricle has thinner walls to pump blood at lower pressure to lungs

left ventricle has thicker walls ro pump blood at high pressure to all body tissues except lungs

105
Q

what two branches is the autonomic nervous system composed of ?

A

Sympathetic nervous system

parasympathetic nervous system

106
Q

what does the adrenal medulla secrete vs the adrenal cortex ?

A

Adrenal medulla secretes amino acids based hormones like NE and EPI (catecholamines)
- that increases HR
- increases BP
- increases metabolic rate
- glycogenolysis ( results in glucose release into blood stream)
- inhibition of glycogenesis

Adrenal cortex secretes steroid hormones
like glucocorticoids and mineralocorticoids
- long term responses
(cortisol)
- promote gluconeogenesis
-increased blood glucose level
-inhibition of immune system
- promote lipolysis

mineralocorticoids(aldosterone)

107
Q

what does aldosterone do ?

A

reabsorption of Na+ and H20 in the kidneys

increased blood volume
increased blood pressure

108
Q

where is ACTH released from?

A

its released from Anterior pituitary and acts on adrenal cortex to promote secretion of cortisol

109
Q

where is cortisol derived from?

A

it is a steroid hormone produced from cholesterol

it depends on the availability of cholesterol from transport into the cell and from production of SER proteins

110
Q

what are connective tissues and what are types of connective tissue

A

consist of specialized cells that secrete and maintain an extensive extracellular matrix and have several functions

serves to attach tissues and organs to one another and is essential for the protection and support of surrounding structures

Bones
Blood
Adipose tissue

111
Q

what is hemoglobin?

A

oxygen binding protein found in RBC.

Oxygen diffuses into the bloodstream via gas exchange in the lungs, binds hemoglobin, and is transported through the circulatory system

112
Q

where is RBC produced

A

Produced from stem cells in the bone marrow

113
Q

In the center of the spinal cord and the periphery, what is present?

A

Gray matter is composed of unmyelinated neuron cell bodies and dendrite

in the periphery of the spinal cord, white matter is composed of myelinated and unmyelinated axons taht allow for long distnace communicaiton between nuerons

114
Q

afferent axonal tracts do what?

A

take responses from body to brain

MCAT decks (6 decks)

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