Tagged Questions

The study of the internal structure of organisms.

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2
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1answer
18 views

Why is the vermis of the cerebellum associated with speech?

I've found multiple sources claiming that damage or impairment as a result of alcohol to the vermis of the cerebellum results in speech impairment. I find this a bit surprising, since the only areas I ...
1
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1answer
13 views

Lateral corticospinal tract and termination

I'm studying the motor pathways of the brain and I'm a bit confused about how the lateral corticospinal tract descends. From Neuroanatomy: Text and Atlas by ...
0
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0answers
30 views

Why are there no animals with a length greater than 30-40 meters or with a mass greater than 200 tonnes?

The biggest and heaviest aquatic animal is the blue whale: 30 meters long and a mass of 200 tonnes. The biggest and heaviest terrestrial animal was a Sauropod (plant-eating, long-necked dinosaur): 40 ...
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2answers
63 views

Why do small organisms make faster movements than big organisms?

I hesitated to ask this question because it seems so obvious and intuitive. However, I am not able to explain this tendency. Background It seems to me that small organisms make faster movements than ...
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0answers
38 views

Planes of the Body [closed]

I have a number of Orientation sections in an application that apply to classifying wounds on a human body. I'm looking to add relevant names for each section, but am a little stumped as to what the ...
4
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1answer
100 views

What are the atmospheric requirements for large dinosaurs?

What are the atmospheric requirements for large dinosaurs? and are the atmospheric constituents for supporting large dinosaurs any different from the atmosphere today?
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2answers
52 views

Periodic Muscular Growth in Humans

If a healthy human is at a certain muscle state and then experiences muscular atrophy solely due to disuse/lack of exercise, is it easier to gain that muscle back than if the human had never reached ...
5
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1answer
125 views

Why does the sacrum fuse together?

Everywhere I look describes how the 5 sacral vertebrae start fusing together during adolescence and are totally fused by the time you're 30 or so. But nobody seems to explain why this happens. It ...
-2
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1answer
32 views

What is the smallest known organism with a skeleton? [closed]

See question title. After doing some looking around on my own I haven't found much so I figured I'd ask some experts.
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2answers
321 views

Which organs do cats not eat on their prey?

My female cat is a very active hunter and brings me her prey daily. Except for shrews and birds, she always eats them entirely. This afternoon she brought me this: It was quite large (maybe ...
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1answer
116 views

Identifying structures from anterior end of dissected prawn

Note: This image might be disturbing. I want to know what the red and the black structures (directly posterior to the red structure) are. I guess it's the heart.
0
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1answer
231 views

Identifying internal structure of dissected prawn

Note: Some of the images might be disturbing. I have dissected prawn for the first time. Would like your help in identifying some structures . This is the dissection of the posterior part of the ...
3
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1answer
61 views

Identifying internal structures of dissected fish

Note : Images displayed below might be disturbing to some people. I have dissected a fish for the first time ! I have some idea of what some of the structures might be but I am not sure and so would ...
0
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1answer
24 views

Why rectus abdominis is not proximal muscle?

I am thinking this picture which shows proximal muscles. Why for instance pectoralis major, subclavius and rectus abdominalis are not included in proximal muscles?
1
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1answer
107 views

Raising two legs together while lying on bed

Let's do some exercise(duh!) Ok so lie on the bed. Lift your left leg. Put it down. Lift your right leg.Put it down. Easy? Now lift your left leg and without putting it down, lift your right leg. ...
0
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1answer
66 views

Stomach sagittal section

Can anyone please tell me where is exactly the stomach in this image? This is a sagittal section from the University of Michigan Visible Human Browsers. Thank you.
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5answers
1k views

Why do most mammals have long snouts?

It seems like most mammals, e.g. dogs, have long snouts. My pet dog's snout would seem to me like an evolutionary disadvantage, since her canine teeth are way out at the end of her jaw, which acts as ...
6
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1answer
200 views

evolutionary reason behind sharing the same path for food and air?

What is the evolutionary reason behind sharing the same path for food and air? For example, we have a nose and lungs, yet they are linked by the pharynx, which is shared with the mouth and ...
2
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0answers
62 views

Where are the gastralia (stomach ribs) attached?

Crocodiles and some dinosaurs have a second set of ribs between the sternum and pelvis called gastralia. Where are the gastralia attached to the rest of the skeleton?
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1answer
234 views

Why do rodents' teeth continue to grow?

Why do rodents' teeth continue to grow? Enamel formation and/or root formation continue throughout rodents' lives. What's the mechanism that causes this?
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1answer
603 views

What determines the size and shape of a cell

What determines the size and shape of a cell? They differ at different tissues / organs/ species
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1answer
60 views

Is there differences in components of saliva among species

Are there differences in the components of saliva among species? Also, do the functions of saliva differ between species?
0
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1answer
34 views

Can we remove impacted teeth by key hole surgery?

Can we remove impacted teeth by key hole surgery, rather than an open technique, like lithotripsy?
3
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1answer
195 views

Is there a difference between pig and cow anatomy that makes religious slaughter of the latter less painful?

This question is not for the squeamish. I was told that non-Kosher animals like pigs have a different anatomy in their neck compared to kosher animals like cows such that the Shechita method of ...
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2answers
72 views

Plant anatomy, what are these stem like filaments growing under the flower

The picture below shows what I am talking about. Each flower has one and I am just wondering what they are?
7
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1answer
250 views

What is the name of the appendage that mantis shrimp use to rub their eyes?

In this short clip, you can see the mantis shrimp using some sort of feathery arm/claw to rub its eyes. Looking at a diagram here, it appears possibly that it's using maxillipeds. Someone with ...
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1answer
818 views

Structure of adenoids

I am not sure this question belongs in biology, but I can't find a more suitable stack exchange site, feel free to delete it if this doesn't fit here. Also, this question is going to be slightly ...
1
vote
1answer
66 views

Is stereo olfactory ability restricted to humans?

Most animals I see around seem to have two nostrils - humans, snakes, birds, fish .. and so on. From reading online I see that 2 nostrils provide a stereo olfactory effect. This stereo effect is ...
4
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1answer
129 views

What limits the size of fish compared to marine mammals?

The largest extant fish species is the whale shark (Rhincodon typus). With a length of 13 meters and a mass of about 20-30 metric tons, the whale shark is relatively small compared to the largest ...
3
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1answer
52 views

What accounts for size variation in breeds of dogs?

My assumption is that dogs vary so much in size because of artificial selection pressures coming from human breeders, but are there genetic loci that roughly determine approximate size? Do other ...
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2answers
1k views

Why Is Most Life Symmetrical Externally But Not Internally?

Mammals, reptiles, arachnids, insects, etc are all as far as I am aware symmetrical in appearance. Take a human for instance, make a line from the top of our head right down the middle. However, ...
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2answers
4k views

Do other male mammals except for humans have nipples?

When I grew rabbits, I had a pair, one male and one female. And while the female's nipples were quite prominent, especially after giving birth, I don't remember the male having any nipples at all. Do ...
12
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1answer
250 views

Evolution of long necks in giraffes

In this question, the OP uses giraffe necks as a supportive example of evolution. Is the mechanism described in this post accurate? At some point, I thought I remember hearing that giraffes did not ...
3
votes
1answer
75 views

Text/resource with information on all skeletal muscles and their motor units

Something analogous to an encyclopedia on baseball players with a list of all thier stats would be ideal. I'm not looking for just generic muscle names, locations and illustrations. Good answers ...
5
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2answers
497 views

Did dinosaurs have more than one brain? If so, why?

I once remember reading (15 years ago) that dinosaurs had two brains. One for their head and another one for their digestive functions. What is the current opinion on this theory? Has more evidence ...
7
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1answer
284 views

Skeletal muscle without antagonist

Is there any skeletal muscle that does not have an antagonist? Excluding circular muscles such as around eye and mouth. The reason why I am wondering is because in biology normally nothing is ever ...
13
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1answer
254 views

Do the majority of fish lack scales on their heads?

Based on pictures, it seems to me that a vast majority of fish species that have scales do NOT have scales on their heads. Is that fact true? To make this properly answerable: lets' define a ...
6
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1answer
1k views

What is the average Leg-to-Foot Length/Width Ratio?

I'm making a program that estimates a probable size (widest width and longest length) for a human's foot given the length and width of the leg to which it is attached. However, try as I might, I can't ...
10
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1answer
889 views

Is there a correlation between muscle fibers and body types?

I have been told the number of muscle fibers a particular muscle has varies from person to person. Unfortunately, the person who told me this did not know much more than this. Initial searching on the ...
8
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1answer
199 views

Do antigens protrude through the capsule/slime layer in prokaryotic organisms where these features are present?

In prokaryotic organisms that have a slime layer or capsule, do intrinsic/extrinsic proteins and other molecules that could be used as antigens protrude through the capsule? I assume that they ...
9
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1answer
584 views

Why are there nail growth differences between humans and other mammals?

When a cat is growing, his nails are growing with him to some extent. A grown cat has a fixed nail length that is not extending. By contrast, human finger nails just keep on growing, so we have to ...
13
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2answers
410 views

What is the morphological difference between Leydig cell in human and pig?

The pig is only an example, just an animal. Leydig cells have protein inclusions (Reinke crystals) that are mostly made of crystallised lipofuscin. They are secretory inclusions i.e. cells formed in ...