Human Anatomy & Physiology

18/08/2026

18/08/2026

Stomach parts

The stomach is divided anatomically into 4 main parts:
Cardia – the area where the esophagus enters the stomach.
Fundus – the dome-shaped upper part, above the level of the gastroesophageal junction.
Body (corpus) – the largest central portion of the stomach.
Pyloric part – the lower portion, consisting of:
Pyloric antrum
Pyloric canal
Pylorus, which opens into the duodenum through the pyloric sphincter.

03/08/2026

Stem cell anatomy

26/02/2026

Types of synovial joint

26/02/2026

Types of fibrous joint

26/02/2026

Types of Joint

21/12/2025

Bone cell types
1. Osteoblast
2.Osteocyte
3. Osteoclast
Bone cell function :
Bone cell–এর কাজ (Functions of bone cells):
1️⃣ Osteoblast
👉 হাড় তৈরি করার কোষ
কাজঃ
Bone matrix (osteoid) তৈরি করে
Collagen type-I নিঃসরণ করে
Calcium ও phosphate জমা করে হাড় শক্ত করে (mineralization)
Healing ও bone growth-এ গুরুত্বপূর্ণ
2️⃣ Osteocyte
👉 পরিণত হাড় কোষ (osteoblast থেকে তৈরি)
কাজঃ
হাড়ের ভেতরে বসে হাড়ের রক্ষণাবেক্ষণ করে
Nutrient exchange নিয়ন্ত্রণ করে
Mechanical stress বুঝে bone remodeling-এর সংকেত দেয়
হাড়কে জীবিত ও শক্ত রাখে
3️⃣ Osteoclast
👉 হাড় ক্ষয়কারী কোষ
কাজঃ
পুরোনো বা ক্ষতিগ্রস্ত হাড় ভেঙে ফেলে (bone resorption)
Calcium রক্তে ছাড়ে
Bone remodeling-এ osteoblast-এর সাথে balance রাখে
📌 অতিরিক্ত কাজ করলে → osteoporosis
📌 কম কাজ করলে → osteopetrosis
4️⃣ Bone lining cell
👉 Inactive osteoblast
কাজঃ
Bone surface ঢেকে রাখে
Calcium exchange নিয়ন্ত্রণ করে
Bone remodeling শুরু হলে আবার osteoblast এ রূপ নিতে পারে
🔑 সংক্ষেপে মনে রাখার কৌশল:
Osteoblast = Build
Osteoclast = Break
Osteocyte = Maintain

08/12/2025

The three types of muscles in the body are skeletal, smooth, and cardiac. Skeletal muscles are voluntary and attached to bones to enable movement, while cardiac and smooth muscles are involuntary. Cardiac muscle is found only in the heart and pumps blood, whereas smooth muscle is found in organs, blood vessels, and other internal structures.

Skeletal muscle
Function: Enables voluntary movement and posture.
Location: Attached to bones by tendons.
Appearance: Striated (striped).
Control: Voluntary, meaning it can be consciously controlled.

Smooth muscle
Function: Moves substances like food, waste, and blood through organs and vessels.
Location: Found in the walls of hollow organs like the intestines, stomach, and uterus, as well as in blood vessels and the respiratory system.
Appearance: Spindle-shaped and non-striated.
Control: Involuntary, meaning it operates without conscious thought.

Cardiac muscle
Function: Pumps blood throughout the body.
Location: Found only in the walls of the heart.
Appearance: Striated.
Control: Involuntary.

04/12/2025

Somatic Nervous System

03/12/2025

Autonomic Nervous System